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Daniel, Christopher Ryan. "Energy transfer and grain size effects during the Standard Penetration Test (SPT) and Large Penetration Test (LPT)." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/775.
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The Standard Penetration Test (SPT) is the most widely used in-situ soil test in the world. "Large Penetration Test" (LPT) is a term used to describe any scaled up version of the SPT. Several types of LPT have been developed around the world for the purpose of characterizing gravel deposits, as SPT blow counts are less reliable in gravels than in sands. Both tests suffer from the lack of a reliable means of determining transferred energy. Further, the use of LPT blow counts is generally limited to calculation of equivalent SPT blow counts using correlation factors measured in sands. Variation of LPT blow counts with grain size is assumed to be negligible.
This research shows that safety hammer energies can be reliably estimated from measurements of hammer impact velocity for both SPT and LPT. This approach to determining transferred energy is relatively simple, and avoids the primary limitation of existing methods, which is the inability to calibrate the instrumentation.
Transferred energies and hammer impact velocities are collected from various sources. These data are used to determine the ratio between the hammer kinetic energy and the transferred energy (energy transfer ratio, ETR), which is found to follow a roughly Normal distribution for the various hammers represented. An assessment of uncertainty is used to demonstrate that an ETR based approach could be superior to existing energy measurement methods.
SPT grain size effects have primarily been characterized as the variation of an empirical relative density correlation factor, (CD)SPT, with mean grain size. In this thesis, equivalent (CD)LPT data are back-calculated from measured SPT-LPT correlation factors (CS/L). Results of a numerical study suggest that SPT and LPT grain size effects should be similar and related to the ratio of the sample size to the mean grain size. Based on this observation, trend-lines with the same shape as the (CD)SPT trend-line are established for the back-calculated (CD)LPT data. A method for generating the grain size effect trend-line for LPT is then proposed. These trend lines provide a rational approach to direct interpretation of LPT data, or to improved prediction of equivalent SPT blow counts.
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Butlanska, Joanna. "Cone penetration test in a virtual calibration chamber." Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/279364.
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Cone penetration test (CPT) is a fast and reliable site investigation tool for exploring soils and soft ground. While the interpretation of the test results in clay has advanced considerably from a theoretical and numerical viewpoint that of tests in sands still relies largely on empirical correlations. A major source of such correlations comes from tests done in calibration chambers (CC), where soil state and properties might be tightly controlled. Calibration chambers are relatively large pieces of equipment, and calibration chamber testing is expensive and time consuming. Moreover, CC tests are performed on freshly reconstituted sands whose fabric may vary from that of natural sand deposits. Hence, correlations developed for one type of sand might not be suitable for another sand deposit. Numerical DEM-based calibration chambers might offer an interesting alternative to the more cumbersome physical tests. This study is the first attempt to perform a three-dimensional DEM-based simulation of cone penetration test. The three-dimensional commercial DEM code (PFC3D) is used to develop Virtual Calibration Chamber CPT (VCC CPT) model. To achieve that objective, several steps were necessary. First, calibration of an analogue discrete material to represent Ticino sand was performed using single-element tests. Afterwards, the mechanical response of the discrete material was further validated by performing additional triaxial tests with different initial conditions. The VCC CPT model was then constructed. Comprehensive dimensional analysis showed that the best option to balance computational efficiency and realism was to fill the chamber with a scaled-up calibrated discrete material. An original filtering technique was proposed to extract steady state cone resistances. A basic series of simulations was performed to explore the effect of initial stress and relative density in cone resistance. The results obtained from the simulations did fit closely the trends that had been previously established using physical chambers. That result was taken as a general validation of the proposed simulation approach. From the micromechanical point of view, the granular material is highly discontinuous and inhomogeneous. Obtaining a homogeneous initial state (especially in the zone of the penetrating cone) is crucial to obtain easily interpretable results. Specific procedures to assess initial state inhomogeneities were developed. DEM-based models can provide results at various level of resolution i.e. the microscale, the meso-scale and the macro-scale. A large series of VCC CPT has been performed. Simulations were performed for models with different horizontal servo-control walls, various sizes of chamber, cone and particles and two boundary conditions. The results were analyzed, focusing on aspects such as chamber size, particle size and boundary condition effects on steady state cone resistance values. A smaller number of tests have also been examined from the point of view of shaft resistance. Most trends and results obtained are shown to be in agreement with previous physical tests. When disagreements appear, the causes are identified: the most severe disagreements result from initial inhomogeneities in the discrete model. The work described in this thesis showed ease the burden of future CPT calibrations in granular materials.<br>Los ensayos de penetración estática de cono (CPT) son una de las herramientas más importantes en el reconocimiento geotécnico. La interpretación de los resultados de ensayo en arcilla ha avanzado considerablemente desde un punto de vista teórico y numérico. Sin embargo la interpretación de los resultados en los materiales granulares por ejemplo arena) todavía está basada en correlaciones empíricas provenientes de las pruebas realizadas en cámaras de calibración (CC), donde el estado del suelo y sus propiedades pueden ser controlados. Las cámaras de calibración son equipos relativamente grandes, y los ensayos en ellas son bastante costosos en tiempo y recursos. Por otra parte, las pruebas se realizan en muestras de arenas reconstituidas cuyas propiedades varían respecto de los depósitos naturales de donde provienen. Por lo tanto, las correlaciones desarrolladas en un tipo de arena podrían no ser adecuadas para otro depósito distinto. Cámaras de calibración numéricas (virtuales) basadas en el método de elementos discretos (DEM) podrían ofrecer una alternativa interesante a los ensayos físicos. Este estudio es el primer intento de realizar una simulación basadas en el método de los elementos discretos tridimensionales de ensayos de penetración de cono. El código comercial tridimensional (PFC3D) ha sido usado para desarrollar el modelo de CPT de Cámara de Calibración Virtual (CPT VCC). Para alcanzar este objetivo fueron necesarios varios pasos. En primer lugar, se llevó acabo la calibración de un material discreto análogo a arena de Ticino mediante ensayos elementales. A continuación se construyó el modelo CPT VCC. Un análisis dimensional exhaustivo mostró que la mejor opción para crear un modelo eficiente y real era llenar la cámara con un material con el tamaño de grano 50 veces mayor que el de la arena de Ticino. Se propuso una técnica original de filtrado para extraer la resistencia de punta estacionaria. Se realizó una serie básica de simulaciones para explorar el efecto de la tensión inicial y la densidad relativa sobre la resistencia de cono. Los resultados obtenidos de las simulaciones se ajustan estrechamente a las tendencias establecidas previamente en cámaras físicas. Este resultado fue tomado como una validación general del programa de simulación propuesto. Desde el punto de vista de la micro-mecánica, el material granular es muy discontinuo y no homogéneo. La obtención de un estado inicial homogéneo (especialmente en la zona de penetración del cono) es crucial para obtener resultados fácilmente interpretables. Por lo tanto se han desarrollado procedimientos específicos para evaluar heterogeneidades del estado inicial. Los resultados manifestaron el papel clave del contorno de modelo (paredes rígidas), tanto pasivo como activo (servo-controlados), durante la formación del modelo. Los modelos basados en el DEM puede proporcionar resultados a varios niveles de la resolución, es decir del micro-, meso- y macro escala. Se ha realizado una gran serie de VCC CPT. Las simulaciones se realizaron para modelos con diferentes posiciones en las paredes horizontales de servo-control, varios tamaños de cámara, varios tamaños del cono y de las partículas y dos condiciones de contorno. Los resultados se analizaron centrándose en varios aspectos como el tamaño de la cámara, el tamaño de las partículas y los efectos de condiciones de contorno sobre el valor de la resistencia de punta. Un número limitado de los CPT fue examinado desde el punto de vista de la resistencia del fuste del cono. Se observó que la mayoría de las tendencias y los resultados obtenidos estaban de acuerdo con resultados previos obtenidos en ensayos físicos. El trabajo presentado en esta tesis debería facilitar futuras calibraciones CPT en materiales granulados.
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Zhang, Ningning. "A micromechanical study of the Standard Penetration Test." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/668841.
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This thesis explores the potential of models based on the discrete element method (DEM) to study dynamic probing of granular materials, considering realistic particle-scale properties.
The virtual calibration chamber technique, based on the discrete element method, is applied to study the standard penetration test (SPT). A macro-element approach is used to represent a rod driven with an impact like those applied to perform SPT. The rod is driven into a chamber filled with a scaled discrete analogue of a quartz sand. The contact properties of the discrete analogue are calibrated simulating two low-pressure triaxial tests. The rod is driven changing input energy and controlling initial density and confinement stress. Energy-based blowcount normalization is shown to be effective. Results obtained are in good quantitative agreement with well-accepted experimentally-based relations between blowcount, density and overburden.
A comprehensive energetic balance of the virtual calibration chamber is conducted. Energy balance is applied separately to the driven rod and the chamber system, giving a detailed account of all the different energy terms. The characterization of the evolution and distribution of each energy component is investigated. It appears that the SPT test input energy is mainly dissipated in friction. The energy-based interpretation of SPT dynamic response proposed by Schnaid et al. (2017) is then validated in comparisons between static and dynamic penetration results. Moreover, microscale investigation provides important information on energy dissipation mechanisms.
A well-established DEM crushing contact model and a rough Hertzian contact model are combined to incorporate both effects in a single contact model. The efficient user defined contact model (UDCM) technique is used for the contact model implementation. Parametric studies explore the effect of particle roughness on single particle crushing event. The model is then used to recalibrate the contact properties of the quartz sand, being able to use realistic contact properties and then correctly capture both load-unload behaviour and particle size distribution evolution.
The calibration chamber results are exploited to investigate the relation between static and dynamic penetration test. This is done first for unbreakable materials and later for crushable and rough-crushable ones. It is shown that the tip resistance measured under impact dynamic penetration conditions is very close to that under constant velocity conditions, hence supporting recent proposals to relate CPT and SPT results. It is also shown that penetration resistance reduces if particles are allowed to break, particularly when roughness is also considered.<br>Esta tesis explora el potencial de los modelos basados en el método de elementos discretos (DEM) para estudiar el sondeo dinámico de materiales granulares, considerando propiedades realistas a escala de partículas. La técnica de cámara de calibración virtual, basada en el método de elemento discreto, se aplica para estudiar la prueba de penetración estándar (SPT). Se utiliza un enfoque de macroelemento para representar una barra impulsada con un impacto como los aplicados para realizar SPT. La varilla se introduce en una cámara llena de un análogo discreto escalado de arena de cuarzo. Las propiedades de contacto del análogo discreto se calibran simulando dos pruebas triaxiales de baja presión. La varilla se acciona cambiando la energía de entrada y controlando la densidad inicial y el estrés de confinamiento. La normalización del recuento de golpes basado en energía se muestra efectiva. Los resultados obtenidos están en buen acuerdo cuantitativo con relaciones basadas en experimentos bien aceptadas entre recuento de golpes, densidad y sobrecarga. Se realiza un balance energético integral de la cámara de calibración virtual. El balance de energía se aplica por separado a la varilla impulsada y al sistema de cámara, dando una descripción detallada de todos los diferentes términos de energía. Se investiga la caracterización de la evolución y distribución de cada componente energético. Parece que la energía de entrada de prueba SPT se disipa principalmente en fricción. La interpretación basada en la energía de la respuesta dinámica SPT propuesta por Schnaid et al. (2017) luego se valida en comparaciones entre los resultados de penetración estática y dinámica. Además, la investigación en microescala proporciona información importante sobre los mecanismos de disipación de energía. Un modelo de contacto de trituración DEM bien establecido y un modelo de contacto hertziano aproximado se combinan para incorporar ambos efectos en un modelo de contacto único. La técnica eficiente de modelo de contacto definido por el usuario (UDCM) se utiliza para la implementación del modelo de contacto. Los estudios paramétricos exploran el efecto de la rugosidad de las partículas en el evento de trituración de partículas individuales. El modelo se usa para recalibrar las propiedades de contacto de la arena de cuarzo, pudiendo usar propiedades de contacto realistas y luego capturar correctamente el comportamiento de carga y descarga y la evolución de la distribución del tamaño de partícula. Los resultados de la cámara de calibración se explotan para investigar la relación entre la prueba de penetración estática y dinámica. Esto se hace primero para materiales irrompibles y luego para materiales triturables y desmenuzables. Se muestra que la resistencia de la punta medida en condiciones de penetración dinámica de impacto es muy cercana a la de condiciones de velocidad constante, por lo tanto, respalda propuestas recientes para relacionar los resultados de CPT y SPT. También se muestra que la resistencia a la penetración se reduce si se permite que las partículas se rompan, particularmente cuando también se considera la aspereza.
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Teh, Cee-Ing. "An analytical study of the cone penetration test." Thesis, University of Oxford, 1987. http://ora.ox.ac.uk/objects/uuid:e339b846-021c-4d25-9f56-0f969c77ead2.
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The quasi-static penetration of a cone penetrometer into clay can be formulated as a steady state problem by considering a steady flow of soil past a stationary cone. The soil velocities are estimated from the flow field of an inviscid fluid, and the incompressibility condition is achieved by adopting a stream function formulation. Emphasis is placed on obtaining an accurate velocity estimate and this is accomplished by a solution of the Navier-Stokes equations. The strain rates are evaluated from the flow field using a finite difference scheme. The clay is modelled as a homogeneous incompressible elastic-perfectly plastic material and the soil stresses are computed by integrating along streamlines from some initial stress state in the upstream region. These stresses do not in general obey the equilibrium equations, although one of the two equations can be satisfied by an appropriate choice of the mean stress. Several attempts have been made to use the remaining equilibrium equation to obtain an improved velocity estimate and three plausible iterative methods are detailed in this thesis. In a second study, a series of finite element calculations on the cone penetration problem is performed. In modelling the penetration process, the cone is introduced in a pre-formed hole and some initial stresses assumed in the soil, incremental displacements are then applied to the cone until a failure condition is reached. Although the equilibrium condition is satisfied very closely in the finite element calculations, it is extremely difficult to achieve a steady state solution. In a third series of computations, the stresses evaluated by the strain path method are used as the starting condition for the finite element analysis. This is believed to give the most realistic solution of the cone penetration problem because both the steady state and equilibrium conditions are approximately satisfied. Numerically derived cone factors are presented and these are found to depend on the rigidity index of the soil and the in situ stresses. The pore pressure distribution in the soil around the penetrometer is estimated using Henkel's empirical equation. The dissipation analysis is based on Terzaghi's uncoupled consolidation theory. The governing equation is formulated in the Alternating-Direction-Implicit finite difference scheme. This formulation is unconditionally stable and variable time steps are used to optimise the solution procedure. The dissipation curves are found to be significantly affected by the rigidity index of the soil and a dimensionless time factor is proposed to account for this effect.
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Pohorila, Victoriia, and Вікторія Миколаївна Погоріла. "Application penetration test and its necessity in 2021." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/51509.
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1. PENTESTS OF SITES AND WEB-APPLICATIONS [Electronic resource]. – Electronic magazine. Access mode: https://amonitoring.ru/service/pentest/web/
2. Randy Lindberg. Types of Penetration Testing for 2021 [Electronic resource]. – Electronic magazine. – November 10, 2020 – Access mode: https://www.rivialsecurity.com/blog/types-of-penetration-testing
3. Cryptoperty. What is pentest? [Electronic resource]. – Electronic magazine. – May 04, 2020 – Access mode: https://itsecforu.ru/2020/05/04/chto-takoe-pentest/ 4. 10Guards. Pentest: what is hidden under the white hood?. [Electronic resource]. – Electronic magazine. – December 18, 2019 – Access mode: https://10guards.com/ru/articles/pentest-under-the-white-hood/<br>A modern site is a system with a complex architecture, containing on average 20 vulnerabilities that can be exploited by attackers. 62% of sites are subject to medium to high risk vulnerabilities. On the corporate website or on the website of the state department, it is necessary to ensure protection against distortion, destruction of publicly available information or blocking access to it.<br>Сучасний сайт - це система зі складною архітектурою, що містить в середньому 20 вразливих місць, якими можуть скористатися зловмисники. 62% сайтів зазнають вразливостей від середнього до високого ризику. На корпоративному веб-сайті або на веб-сайті державного департаменту необхідно забезпечити захист від спотворення, знищення загальнодоступної інформації або блокування доступу до неї.
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Payoongwong, Chatchawahn. "Field and laboratory studies of the behavior of spread footing for highway bridge construction (HAM-32-0.14)." Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1177085999.
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Xiong, Pulei. "A Model-driven Penetration Test Framework for Web Applications." Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20552.
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Penetration testing is widely used in industry as a test method for web application security assessment. However, penetration testing is often performed late in a software development life cycle as an isolated task and usually requires specialized security experts. There is no well-defined test framework providing guidance and support to general testers who usually do not have in-depth security expertise to perform a systematic and cost-efficient penetration test campaign throughout a security-oriented software development life cycle.
In this thesis, we propose a model-driven penetration test framework for web applications that consists of a penetration test methodology, a grey-box test architecture, a web security knowledge base, a test campaign model, and a knowledge-based PenTest workbench. The test framework enables general testers to perform a penetration test campaign in a model-driven approach that is fully integrated into a security-oriented software development life cycle. Security experts are still required to build up and maintain a web security knowledgebase for test campaigns, but the general testers are capable of developing and executing penetration test campaigns with reduced complexity and increased reusability in a systematic and cost-efficient approach.
A prototype of the framework has been implemented and applied to three web applications: the benchmark WebGoat web application, a hospital adverse event management system (AEMS), and a palliative pain and symptom management system (PAL-IS). An evaluation of the test framework prototype based on the case studies indicates the potential of the proposed test framework to improve how penetration test campaigns are performed and integrated into a security-oriented software development life cycle.
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Eslami, Abolfazl. "Bearing capacity of piles from cone penetration test data." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq21000.pdf.
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Walker, James. "Adaptive finite element analysis of the cone penetration test." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438553.
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Lee, Wai-ming. "Correlation of PCPT and SPT data from a shallow marine site investigation /." View the Table of Contents & Abstract, 2004. http://sunzi.lib.hku.hk/hkuto/record/B30110385.
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Lee, Wai-ming, and 李慧明. "Correlation of PCPT and SPT data from a shallow marine site investigation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B44570077.
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Wong, Kan-hok Ken. "Review of Menard pressuremeter test in weak rocks." Click to view the E-thesis via HKUTO, 2003. http://sunzi.lib.hku.hk/hkuto/record/B4257724X.
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Finke, Kimberly Ann. "Piezocone penetration testing in Piedmont residual soils." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/21452.
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Wong, Kan-hok Ken, and 王勤學. "Review of Menard pressuremeter test in weak rocks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B4257724X.
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Fan, Tailin. "Multi-plate penetration tests to determine soil stiffness moduli." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63172.
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Yang, Wenwei. "Development and application of automatic monitoring system for standard penetration test in site investigation." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36811919.
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Greig, James William. "Estimating undrained shear strength of clay from cone penetration tests." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25076.
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This paper discusses several proposed methods for estimating undrained shear strength from cone penetration tests. This correlation has been studied in the past, however, most have focussed only on the cone bearing. In addition to discussing these traditional methods, this paper evaluates recently proposed methods of estimating Su from CPT pore pressure data.
The results of field vane and cone penetration tests from five lower mainland sites are presented in relation to the different proposed correlation techniques. The results show that there is no unique cone factor for estimating Su from CPT for all clays, however, a reasonable estimate of Su can be made by comparing the predictions from several of the proposed methods. With local correlations these techniques can be quite reliable. The results also show that the estimation of Su from CPT is influenced by various factors relating to: the choice of a reference Su, cone design, CPT test procedures and the soil characteristics. In particular, the estimation of Su from CPT is strongly influenced by such soil parameters as stress history, sensitivity and stiffness. Increases in OCR and sensitivity were reflected by increases in the traditional cone factors Nc and Nk.
The use of pore pressure data appears to be a promising means of estimating. Su from CPT. Expressions have been developed that predict excess pore pressures based on cavity expansion theory and attempt to include the effects of sensitivity, stress history and stiffness. In addition, comparisons between friction sleeve measurements and Su and a method for estimating sensitivity from friction ratios are presented. Lastly, recommended procedures for estimating Su from CPT are given.<br>Applied Science, Faculty of<br>Civil Engineering, Department of<br>Graduate
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Brown, Douglas Neil. "The prediction of clay soil properties using the piezocone penetration test." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/20969.
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Cargill, Patrick Ethan. "The influence of friction sleeve roughness on cone penetration test measurements." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/23002.
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Eid, Walid Khaled. "Scaling effect in cone penetration testing in sand." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/49849.
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The Cone Penetration Test (CPT) was developed originally in Holland in the 1930’s as a device which provides a small scale model of a pile foundation. Early versions were simple cone points for which the only measurement was the thrust required to push the point through the ground. Over the past 20 years, the cone was standardized to a tip area of 10 cm², and an electrical version was produced, which allows for continuous measurement of the cone tip resistance and sleeve friction along with a computer-based data acquisition system. The electrical cone represents a significant step forward for the CPT, since it provides a continuous profile of information that can be used to identify soil type and define important engineering parameters. More recently, the CPT has shown considerable potential for calculation of settlements of footings on sand, determination of pile capacity, assessment of ground pressures, and evaluation of liquefaction potential for cohesionless soils.
Along with the widening application of the CPT, new varieties of cone penetrometers have appeared, with different sizes than the standard. Smaller cones are used for instances where relatively small depths of soil need to be penetrated, and larger cones have been developed for penetrating dense and gravelly soils. With the introduction of the new cones, there has been a tendency to assume that the methods for reducing CPT data for the standard sized cone can be extrapolated to the other sizes of cones. That is, it is assumed that there are no scale effects in cones of different sizes. While this may be true, to date, little direct evidence has been produced to support this view, and the issue is an important one from two points of view:
1. The present data analysis technology is based on that primarily from testing with a standard cone. lt is important to know if any changes are needed in this approach, or if the existing methods can be used with confidence for any size cone.
2. If it can be shown that no scale factor exists, then this will allow the use of new, smaller cones in experimentation in modem calibration chambers with the knowledge that the test results are applicable for the cones that a.re more widely used in practice. The smaller cones offer several advantages in this type of work in that they facilitate the research considerably by reducing the effort involved in sample preparation, and they are less likely to produce results influenced by boundary conditions in the chamber.
One of the major objectives of this research is to develop an insight into the issue of the scale factor caused by the use of different sizes of cones. This is accomplished through an experimental program conducted in a new large scale calibration chamber recently constructed at Virginia Tech.
Many of the latest developments in cone penetration testing have been forthcoming from testing done in calibration chambers where a soil mass can be placed to a controlled density under known stress conditions. To conduct the experimentation of this work, it was necessary to design, fabricate, and bring to an operational stage a calibration chamber. The Virginia Tech chamber is one of the largest in the world. A significant portion of the effort involved in this thesis research was devoted to this task. In particular, attention was devoted to the development of a system for placement of a homogeneous soil mass in the chamber, and the implementation of a microcomputer-based data acquisition unit to record and process the test results.
The scale effects investigation was performed using three different sizes of cone penetrometers in a test program conducted in the calibration chamber. Of the three cones, one is smaller than the standard with a tip area of 4.23 cm², one was a standard cone with a tip area of 10 cm², and one was larger than the standard cone with a tip area of 15 cm². A total of 47 tests were carried in the chamber using two different levels of confining stress and two different sand densities. The test results show that while a scale factor might exist, the degree of its influence on interpreted soil parameters for a practical problem does not appear significant.<br>Ph. D.<br>incomplete_metadata
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Gustafson, Ellen, and Emelie Strömgren. "Cone Penetration Test - a comparative study of the equipment and the performance." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-121130.
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Inom geotekniken behövs ofta jordlagerföljden och jordens egenskaper bedömmas. För att göra detta används ofta sonderingsmetoden Cone Penetration Test (CPT), som används främst till att ge en preliminär bedömning av jordlagerföljden och en uppskattning av geotekniska egenskaper. CPT-sondering är en avancerad metod som ställer högre krav på både fältgeotekniker och handläggande geotekniker jämfört med andra metoder och är en metod där många faktorer påverkar resultatet. Detta examensarbete undersöker vilka faktorer som påverkar CPT-sondering med fokus på utrustning och handhavandet hos teknikkonsultföretaget WSP i Östergötland. Syftet med arbetet är att jämföra och utvärdera metod och resultat hos WSP för att se om det finns några skillnader i handhavandet och mellan de tre olika sonderna som är använda i studien. I studien utfördes 12 stycken CPT-sonderingar i samma område och dessa utfördes av samma fältgeotekniker, där häften av sonderingarna var utförda med förborrning och vattenfyllt sonderingshål och den andra hälften utförda med endast förborrning. Dessutom utfördes en skruvprovtagning i området. När sonderingarna var gjorda utvärderades resultaten i programvaran Conrad. Sonderingarna utfördes i ett område mellan Vånga och Göten, väster om Norrköping och området består främst av silt med lager av sand. Resultatet av studien visar att sond A har de jämnaste resultaten och orsaken till detta är troligtvis att denna sond är den som senast har kalibrerats. Efter sondering 2-C upptäcktes en skada på friktionshylsan för sond C, friktionshylsan byttes ut och trots detta ser resultatet för denna sond bra ut. Den första sonderingen gjord efter byte av friktionshylsan avviker dock i resultatet jämfört med de andra sonderingarna gjorda med sond C. Resultatet från sond B visar att denna sond uppnår lägre värde jämfört med de andra sonderna. En orsak till detta anses vara att denna sond är den sond som är kalibrerad med det tidigaste datumet. Slutsatsen i studien är att de faktorer som påverkar resultatet mest är kalibrering, att sonden är vätskemättad och att kontroller har utförts av sonden innan och efter sonderingen.
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Rahardjo, Paulus P. "Evaluation of liquefaction potential of silty sand based on Cone Penetration Test." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/53844.
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Liquefaction ls a phenomenon where a saturated soil can temporarily lose its shear strength during an earthquake as a result of the development of excess pore pressures. For the past 25 years since Iiquefaction phenomenon was first explained, it was thought to be mainly a problem with clean sand, and most of the research has focused on these soils. However, as case history information has come to light, it has become apparent that silty sands are commonly involved, and in some cases even silts. This has generated a need for knowledge about the response of silty sands and silts under seismic loading. Related to this issue is the question of how best to determine the Iiquefaction resistance of these soils in a practical setting.
This research has the objectives of providing an understanding of the behavior of saturated silty sands under seismic loading, and developing a rational basis for the use of the Cone Penetration Test (CPT) to predict Iiquefaction resistance in these materials. The study is primarily experimental, relying on laboratory and field testing and the use of a unique, large scale calibration chamber. The calibration chamber allows the field environment to be duplicated in the laboratory where conditions can be closely controlled and accurately defined.
One of the first problems to be overcome in the research was to determine how to prepare specimens of silty sands that would reasonably duplicate field conditions in both the small scale of the conventional laboratory tests, and the large scale of the calibration chamber. Out of four different methods explored, consolidation from a slurry proved to be best. Two silty sands were located which had the desired characteristics for the study. Field work, involving both the Standard Penetration Test (SPT) and CPT was done as part of this investigation. The behavior of the silty sands were determined in the laboratory from monotonic and cyclic loading tests.
The test results show that the effect of fines is to reduce the cone penetration resistance, but not to affect the liquefaction resistance. The steady state shear strength of the soils seems to be correlated to the cone tip resistance, however, this correlation shows a higher steady state shear strength than those back figured from case history data. The results were also used to define state parameters for both of the soils tested. The state parameter was found to be a reliable index to the liquefaction potential and further study in this area is recommended.<br>Ph. D.
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Ozan, Cem. "Estimation Of Grain Characteristics Of Soils By Using Cone Penetration Test (cpt) Data." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1088988/index.pdf.
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Due to lack of soil sampling during a conventional cone penetration testing (CPT), it is necessary to classify soils based on recorded tip and sleeve friction and pore pressure (if available) values. However, currently available soil classification models are based on deterministic and judgemental determination of soil classification boundaries which do not address the uncertainties intristic to the problem. Moreover, size and quality of databases used in the development of these soil classification models are undocumented and thus questionable. Similar limitations do also exist in the development of SPT-CPT correlations which are widely used in SPT dominated design such as soil liquefaction triggering. To eliminate these discussed limitations, within the confines of this study it is attempted to present (1) a new probabilistic CPT- based soil classification methodology, and (2) new SPT-CPT correlations which address the uncertainties intrinsic to the problems. For these purposes, a database composed of 400 CPT/SPT boring data pairs was compiled. It is intended to develop probabilistic models, which will correlate CPT tip and sleeve friction values to actual soil classification and CPT tip resistance to SPT blow count N. The new set of correlations, model parameters of which estimated by implementing maximum likelihood methodology, presented herein are judged to represent a robust and defensible basis for (1) prediction of soil type based on CPT data and, (2) estimation of SPT-N value for given CPT data.
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Teeter, Russell Daniel. "Two dimensional mesoscale simulations of projectile instability during penetration of dry sand." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Fall2007/r_teeter_121107.pdf.
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Stevens, John Boyet. "Finite Element Analysis of Adiabatic Shear Bands in Impact and Penetration Problems." Thesis, Virginia Tech, 1996. http://hdl.handle.net/10919/36650.
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We study axisymmetric deformations of depleted uranium (DU) and tungsten heavy alloy (WHA) rods impacting at normal incidence both a rigid, planar target and a thick, deformable steel target. Each deformable material is modeled as elastic thermoviscoplastic; the flow stress increases with an increase in the effective plastic strain and effective plastic strain-rate but decreases with a rise in the temperature. An objective of this work is to ascertain when and where a shear band, defined as a narrow region of rapid, intense plastic deformation, forms in each material subject to impact loading. The Taylor impact simulations show that shear bands form earlier in WHA than in DU for the material parameters used. In the penetration simulations, shear bands form continuously in the ejecta of the DU penetrator while only one shear band occurs in the WHA ejecta followed by more uniform deformations.
Note: In order to view the computer animations referenced in this thesis, one must have a QuickTime movie player and download the files named Ujce.mov Uz2e.mov Uz3e.mov Wjce.mov Wz2e.mov and Wz3e.mov from the same directory the "pdf" file resides in.<br>Master of Science
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Fazi, Giovanni. "Serverless Computing: Penetration Testing e Metodi per la sicurezza." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20524/.
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Il modello di elaborazione Serverless fa parte delle ultime tecnologie per la progettazione e distribuzione di applicazioni. I grandi nomi di questa industria sono Amazon AWS, Google Cloud, Microsoft Azure e IBM. Sebbene questo nuovo paradigma risolve alcuni problemi dal punto di vista della sicurezza informatica, dall'altro ne vengono introdotti di nuovi. In questo elaborato viene quindi presentato uno studio di sicurezza delle piattaforme di serverless computing, analizzando sia dal punto teorico i problemi di tali piattaforme e delle applicazioni realizzate con esse, sia dal punto pratico mostrando un caso reale di penetration test della piattaforma Apache OpenWhisk.
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Lu, Dandan, and 卢丹丹. "Effects of static pile penetration on an adjacent earth retaining structure." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47054670.
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Yang, Wenwei, and 楊文衛. "Development and application of automatic monitoring system for standard penetration test in site investigation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B36811919.
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Svenhard, Petter, and Amir Radaslic. "A penetration test of an Internet service provider : Computer Forensics and Information Security." Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-18169.
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Computer security is of ever increasing importance in the modern corporate world due to the risk of disclosing sensitive assets. In a world where technology can be found in most organizations and businesses the importance of ensuring secure assets is not only a good habit but a necessity.This study concerned an Internet service provider in south western Sweden who saw an interest in ensuring the security of their computer systems. The Internet service provider wished to remain anonymous to protect its name and interests in casesensitive information were to be disclosed.The approach to test the service provider’s security was to perform an extensive penetration test of the ISP's relevant network and computer infrastructure. The aims of the penetration test were to map vulnerabilities and assess the risk that a possible flaw would pose if exploited.The results indicated that the systems of the ISP included several critical flaws that could lead to a denial of service condition and a complete compromise of the service provider’s office intranet. Furthermore the results indicated the possibility that the Internet service provider had in fact already been hacked by an unknown perpetrator.Finally the study was beneficial for the Internet service provider since they were provided with a deeper understanding of the security flaws in their computer system infrastructure. Moreover they were alerted to the presence of a possible crime scene on their property.
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Deshpande, Kedar M. "A Cone Penetration Test (CPT) based assessment of explosive compaction in mine tailings." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/8660.
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Failure of tailings dams can occur due to liquefaction of saturated and loosely deposited silt and sand sized tailings under both seismic and static conditions. The consequences in terms of loss of lives and property are severe. As tailings possess soil-like structure and grain size distribution, it is possible to use ground improvement measures typically used for soils to improve the stability of these dams. It is also possible to use densification techniques to reduce the volume of the in-place tailings to provide greater storage space.
This thesis reviews the assessment of ground densification at a tailings facility in Northern Ontario at which a section of tailings dam was densified by explosive compaction (EC). The EC was complemented by surface compaction using Dynamic Compaction and Rapid Impact Compaction. Due to the nature of tailings deposition, the grain size distribution and density of materials in the dam varied considerably both laterally and with depth. This complicated the assessment of the improvement obtained.
Piezometer cone penetration test data obtained before and at various times after ground treatment were reviewed to assess the range of tailings types encountered in the dam and the level of tip resistance achieved by the ground treatment. Settlement and piezometer data were also reviewed but were of insufficient quality or quantity to be useful as indicators of the degree of improvement obtained.
Cone data were normalized for stress level and were sorted according to a unified soil behaviour type classification scheme previously used in soils and tailings. The soil behaviour type index, Ic, was found to be a useful indicator of tailings type. Despite the extreme variability of the deposits, it proved possible to identify the level of tip resistance achieved by the ground treatment in various material types at the site.
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Mo, Pin-Qiang. "Centrifuge modelling and analytical solutions for the cone penetration test in layered soils." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/14319/.
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The interpretation of measurements from the cone penetration test is still predominately based on empirical correlations, which can be attributed to the lack of understanding of penetration mechanisms, that involve severe stress-strain and shear dilatancy close to the probe. Even so, it remains one of the most widely used in-situ tools for site characterisation, and several methods for displacement pile design have been developed using CPT data. This research investigates the response of penetrometers and the behaviour of layered soils during installation of probes using geotechnical centrifuge modelling and cavity expansion analysis. Two series of centrifuge tests were performed in stratum configurations of silica sand in a half-cylindrical axisymmetric model, allowing the observation of the induced soil deformation through a Perspex window. The variations of penetration resistance and soil deformation with penetration depth, soil density, stress level and soil layering are examined from the results of the centrifuge tests. The quantified soil displacements and the resulting strains in the axisymmetric model have provided an effective approach for investigation of penetration mechanisms with soil element trajectories, strain paths and rotations of principal strain rate. The effects of layering on both resistance and soil deformation are shown with dependence of the relative soil properties and profiles. The results presented also serve as a base for applications of cavity expansion solutions, back analyses and further studies. Analytical solutions for cavity expansion in two concentrically arranged regions of soil are developed using a non-associated Mohr-Coulomb yield criterion for large strain analysis of both spherical and cylindrical cavities. The solutions are validated against finite element simulations and a detailed parametric study of the layered effects on the pressure-expansion curves is performed. To apply the proposed solutions to penetration problems, a simplified combination approach is suggested to eliminate the discrepancy between concentric layering and horizontal layering. The analytical study of penetration in two-layered and multi-layered soils is therefore achieved, with comparisons to elastic solutions and numerical simulations provided. The back analyses based on the resistance and soil deformation emphasise the influences of small-strain stiffness, soil-probe interface friction angle, and relative density/state parameter. The correlation between the cone tip resistance and the pile bearing capacity is also discussed, and the scale effects are examined through the ground surface effect and the layering effect by the developed cavity expansion solutions. The penetration mechanisms are summarised from the aspects of soil stress-strain history, particle breakage, soil patterns, and penetration in layered soils. The layered effects emphasised in this research indicate that the penetration resistance is strongly dependent on the soil properties within the influence zones above and below the probe tip, and also related to the in-situ stress gradient along the penetration path. It is also suggested that correlations from calibration chamber tests using uniform soil and a constant stress field may not be suitable for direct interpretation of CPT data. Finally, the averaging technique for pile design is suggested based on the transition curve of tip resistance in layered soils with consideration of the scale effects.
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Ballew, Wesley D. "Taylor Impact Test and Penetration of Reinforced Concrete Targets by Cylindrical Composite Rods." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/34098.
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We use the three-dimensional finite element code DYNA3D to analyze two problems: (a) the normal impact of a cylindrical monolithic or composite rod against a smooth flat rigid target, (commonly known as the Taylor impact test), and (b) the penetration of composite and monolithic steel cylindrical rods into reinforced concrete targets. The composite rod is made of either a steel or copper shell enclosing a ceramic. The ceramic and the steel are assumed to fail at a critical value of the effective plastic strain, whereas no failure is considered in the copper. The thermoviscoplastic response of steel and copper is modeled by the Johnson-Cook relation and the ceramic and concrete are assumed to be elastic-plastic. Values of material parameters in the constitutive relation for the reinforced concrete (RC) are derived by the rule of mixtures. Failure of a material is simulated by the element erosion technique for ceramic and steel, and element erosion along with stiffness reduction for the RC. The effect of the angle of obliquity of impact on the damage induced in the target is ascertained.
<p>
For the solid cylindrical copper rod impacting a smooth flat rigid target, the time history of the deformed length and the axial variation of the final diameter are found to match well with the experimental findings. For the composite rod, the diameter of the deformed impacted surface, the shape and size of the mushroomed region and the volume fraction of the failed ceramic material strongly depend upon the impact speed, the shell wall thickness and the thickness of the solid copper rod at the front end.
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Some composite cylindrical rods impacting at normal incidence RC targets were found to buckle during the penetration process in the sense that their outer diameter at a cross-section close to the impacted end increased by at least 20%. For steel penetrators, the damage experienced increased as the nose shape got blunter and the angle of obliquity became larger whereas the damage induced to the target only increased with penetrator bluntness.<br>Master of Science
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Zhuang, Peizhi. "Cavity expansion analysis with applications to cone penetration test and root-soil interaction." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/42772/.
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As one of the most versatile and reliable in-situ devices, cone penetrometers have been extensively used in soil exploration (e.g. soil classification, soil profiling, back-calculation of soil properties etc.) both experimentally and theoretically over the past 80 years. To improve its site accessibility, reduce the required sample size with minimal boundary effects, or model soil penetration by plant roots or earthworms, cone penetrometers with various sizes are often employed both in the field and laboratory. Consequently, size-dependent performance may appear, and this is one of the subjects of this research. A series of cone penetration tests with three sized cone penetrometer (12mm, 6mm, 3mm) on the Leighton Buzzard sand with two fractions (E and C) was performed at the 1g condition. Evident size effects were observed both in the cone tip resistance and shaft friction. To account for the observed size-dependent behaviour, theoretical methods based on the cavity expansion theory were developed in addition to the available experimental findings. Firstly, a size-dependent quasi-static cavity expansion solution was developed by improving the conventional cavity expansion theory incorporating with a strain gradient theory of plasticity. A stiffer response is modelled for a smaller cylindrical/ spherical cavity with this solution. Based on the analogy of cone penetration and quasi-static cavity expansion, the developed size-dependent expansion solution for spherical cavities was employed to quantify the size effect in the cone tip resistance, and fair good agreements were achieved between the theoretical prediction and experimental results. Subsequently, the scale effect observed in shaft friction resistance was explained in terms of the interface frictional strength and mobilised lateral soil stress. The size-dependent interface frictional strength was discussed based on the available experimental data of other researchers, and an improved solution based on the elastic cylindrical cavity expansion solution was derived to quantify the size dependency of the mobilised lateral stress on the shaft. In the light of above discussions, dominating factors influencing the size-dependent behaviours in the cone penetration test are summarised. The other objective of the present research was to model the mechanical interaction between a growing root tip and the surrounding soil. Two elastic solutions for computing the stress and displacement fields around a displacement-controlled ellipse were developed based on the complex variable theory of elasticity and Fourier series method. By assuming the axial cross section of a root tip as a half-ellipse, the two-dimensional soil response to a short-term growing root tip was discussed with the derived elastic solutions. Benefits of radial swelling of the root tip to its axial penetration were summarised, and an approximate analytical method to estimate the soil resistance mobilised by a short-term root growth was suggested and employed in the present root tip-soil interaction analyses. In addition, influences of the additional shear stress in the process of static and quasi-static cavity expansion were analysed with an elastic-perfectly-plastic model. For Tresca materials, a non-equal initial stress field was considered in the static stress solution, and a quasi-static expansion solution was then derived for a cavity deforming in a hydrostatic stress field considering the material compressibility. The static stress solution is capable of calculating the stress redistribution around a circular rotating probe, and the large-strain quasi-static solution may be useful in theoretical predictions of the tip resistance of a rotating penetrometer (or pile) which has been often utilised in needle cone penetration tests for modelling the root tip elongation. Then the introduced methods in above solutions were applied to the static stress analysis of a circular cavity surrounded by the Mohr-Coulomb material under a non-equal stress field. Based on the conformal mapping function proposed by Detournay and Fairhurst (1987), both a loading and unloading analysis were carried out with the derived analytical solution. It can provide a simple method to predict the plastic failure zone and calculate the stress redistribution around a circular excavation (e.g. tunnel, pipeline) either under loading or unloading.
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Talbot, Michael H. "Dynamic Cone Penetration Tests for Liquefaction Evaluation of Gravelly Soils." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7542.
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Dynamic Cone Penetration Tests for LiquefactionEvaluation of Gravelly SoilsMichael H. TalbotDepartment of Civil and Environmental Engineering, BYUDoctor of PhilosophyIn North American practice, the Becker Penetration Test (BPT) has become the primary field test used to measure penetration resistance of gravelly soils. However, this test is expensive and uncertainties exist regarding correlations and corrections for rod friction. As an alternative, the dynamic penetration test (DPT) developed in China has recently been correlated with liquefaction resistance in gravelly soils. The DPT equipment consists of a 74 mm diameter cone tip driven by a 120 kg hammer with a free fall height of 100 cm using 60 mm drill rod to reduce friction. The DPT is a very rugged, economical device, capable of penetrating dense gravel layers. During DPT field investigations following the 2008 Wenchuan earthquake in China, liquefaction resistance was correlated with DPT blow count.Dynamic Cone Penetration tests (DPT) tests were also performed adjacent to Becker Penetration test (BPT) sites at Pence Ranch, Whiskey Springs, and Larter Ranch in Idaho where gravel liquefaction was observed during the 1983 Mw6.9 Borah Peak earthquake. Companion DPT tests were performed using an automatic hammer at two energy levels, namely the energy specified in the original Chinese standard and the energy typical of SPT testing which would be easier to use in practice. Companion testing was undertaken to determine if the cone could be driven in gravelly soil with more standard drilling equipment available to geo-professionals. The second energy level also offers the potential to provide more resolution on the soil layering. PDA measurements were made to determine the energy transferred to the cone rods and the statistical variation in the energy transferred.Additionally, companion DPT tests were undertaken at the downstream toe of Millsite Dam near Ferron, Utah, where gravelly soils are predicted to liquefy in an earthquake. Two energy levels were used, one using an automatic hammer and the other a manual donut hammer. The blow counts from the BPT and DPT correlated reasonably well for gravels using the automatic hammer, but poor correlation was obtained with the donut hammer. Liquefaction resistance for the BPT and DPT soundings were also in reasonable agreement for gravel layers suggesting that the DPT can provide liquefaction hazard evaluations more economically than the BPT using direct correlations with field performance.Correlations suggest that the standard energy corrections developed for the SPT can be used for the DPT. In general, the liquefaction resistance from the BPT and DPT correlated reasonably well when using the 30% probability of liquefaction resistance curve developed for the DPT.Keywords: Michael H Talbot, liquefaction, Chinese dynamic penetration test, gravelly soils.
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Sun, Tek-kei, and 孫廸麒. "Numerical modeling of skin friction and penetration problems in geotechnical engineering." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/195991.
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Numerical modeling using finite element method (FEM) is well-recognized as a powerful method for both engineers and researchers to solve boundary value problems. In the modeling of geotechnical problems, the analyses are often limited to simple static problems with either steady-state effective or total stress approach while the transient response (development and dissipation of excess pore water pressure, uex) is seldom considered. Besides, infinitesimal small soil deformation is usually assumed. The simulation is further complicated when the soil-structure interaction problems involve significant soil displacements; like a pile subject to negative skin friction (NSF) and a cone/pile penetration. However, conventional FEM analysis prematurely terminates due primarily to excessive mesh distortion. One could see that simulating a transient problem with large deformation and distortion remains a great challenge. In this study, advanced FE simulations are performed to give new insights into the problems of (1) a pile subject to NSF; and (2) a cone penetration. The transient response of the NSF problem is modeled with the fluid-coupled consolidation technique and geometric nonlinearity. The fluid-coupled cone penetration problem is modeled with a newly developed adaptive approach.
The NSF and cone penetration simulations involve complex soil-structure interface modeling. Two types of modified interface responses are developed and verified which consider fluid coupling. The developed algorithm is applied to back analyze a case history of a pile subject to NSF induced by surcharge loading. Promising results were shown. Development of dragload and neutral plane (NP) with time is studied. NP locates at 75% of the pile embedded length (D) in long-term. Next, a parametric study is performed to investigate the influences of pile geometries, ground compressibility and loading conditions towards the pile responses. The long-term NP locates at around 0.55D to 0.65D in the studied engineering scenarios. The maximum downdrag can be up to 10% of the pile diameter. NP shifts upward when the head load increases. A simple design chart is proposed which helps engineers to estimate the long-term axial load distribution. An illustrative example is given to demonstrate the application and performance of the chart.
The study is extended to investigate the cone penetration problem. An advanced adaptive method is developed and implemented into the FE package ABAQUS to resolve the problems of numerical instability, excessive mesh distortion and premature termination. The proposed method is verified by modeling a ground consolidation problem. Next, total stress back analysis of cone penetration is conducted with the proposed method. The development of cone factor predicted by the proposed method gives a better match with the laboratory result when comparing with the built-in ALE method. Next, the development and dissipation of uex during cone advancing with the proposed method and fluid-coupled technique is investigated. uex develops dramatically around the cone tip. The soil permeability is back calculated from the dissipation test and agrees well with the input value. It is believed that the construction effects of a press-in pile and the subsequence NSF on that pile can be modeled by utilizing the finding of this study.<br>published_or_final_version<br>Civil Engineering<br>Doctoral<br>Doctor of Philosophy
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Fransson, Johan. "A study of the correlation between soil-rock sounding and column penetration test data." Thesis, KTH, Jord- och bergmekanik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-40853.
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Lime-cement columns have been used in Sweden to improve poor soil conditions since the 1970’s. The method is inexpensive and flexible, but is difficult to test since the columns are manufactured in-situ. Many test-methods have been developed for testing the column strength during the years. Most of them need to be evaluated using an empirical correction-factor known as the cone factor. The column penetration test, KPS, is the most commonly used method in Sweden, it is considered to be reliable since a large part of the column cross-section is tested. The problem is that the probe easily deviates out of the column to the softer surrounding soil. Today a pre-drilled guiding-hole, a soil-rock sounding, helps the probe to stay vertical. Although the soil-rock sounding is commonly not used for evaluation of column strength, the penetration resistance is recorded. A visual comparison between the plotted penetration resistances from the two methods shows similarities in both hard and soft areas of the columns. The relation can be measured using statistics, such as the correlation coefficient. A strong correlation was also found, suggesting that a similar equation used to evaluate the undrained shear strength from the column penetration tests can be applied with the data from the soilrock soundings. The statically pushed column penetration test probe and the rotated soil-rock sounding bit bore are likely to cause different failure modes in the column. This means that different empirical cone factors are needed when the undrained shear strength is evaluated. By evaluating the ratio between the cone factors of the column penetration test and the data from the soil-rock soundings from three sites, E-road E18 north of Stockholm, E-road E45 outside Gothenburg and at a construction site at Lidingö, the following aspects of the ratio was investigated: if the ratio was site-specific; the sensitivity to the binder content; the sleeve friction and; the sensitivity to rotational speed and rate of penetration. Average columns formed from the penetration resistance at depth from each site were used during the evaluations. The Swedish geotechnical society has standardised two methodologies that can be used for pre-drilling. The soil-rock sounding methodology which has no fixed rate of penetration or rotational speed, and the total sounding methodology, based on the Norwegian total sounding methodology which has fixed rate of penetration and rotational speed. The latter is to prefer when comparing results between sites. To remove the sleeve friction, the data from the soil-rock soundings needed to be de-trended. The amount of de-trending needed to find a constant cone factor varied at the sites between 0.5 kN/m and 1.0 kN/m. This however caused high interference, partly from scaling the variation. The cone factor for the total sounding methodology was found to be between 0.30- 0.45 times the cone factor for the column penetration test.
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Gillespie, Donald G. (Donald Gardner). "Evaluating shear wave velocity and pore pressure data from the seismic cone penetration test." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30573.
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Recent developments in cone penetration testing have resulted in the addition of both pore pressure measurements and seismometers. The seismometers allow shear wave velocity testing to be performed at designated intervals. Both of these additions were researched to improve their application and interpretation.
The significant factors effecting the pore pressure generated during cone penetration tests are discussed. The importance of various factors is especially dependent upon permeability, strength, and stiffness. For all sands tested, pore pressures lower than static were recorded behind the tip and higher than static were recorded on the face of the cone. It is believed that the large compressive stresses on the cone face result in positive pore pressures. As the cone tip passes a soil element unloading and continued shearing generate pore pressures lower than static in all sands. The sign of this pore pressure (higher or lower than static) was therefore considered primarily a function of the test equipment.
Pore pressure response and the rate of dissipation of excess pore pressures were found useful in distinguishing fine granular soils and explaining soil stratigraphy. In cohesive soils the details of pore pressure measurement were found to be important only in stiff soils. Pore pressures at all measurement locations were found to increase with soil strength in soft to firm clays but may be negative of static in very stiff clays. Pore pressures behind the cone tip were often negative of static in stiff clays.
Measurement techniques were refined to improve the accuracy of downhole shear wave velocity measurements. Comparisons of downhole and crosshole measurements were made at three well documented sites validating the technique. At several sites it was found useful to consider the Gmax values determined from shear wave velocity and density to distinguish soil type. Gmax to cone resistance ratios were shown to vary systematically with cone resistance values in sands. A wide range in Gmax to cone resistance was observed in clays. The dependence of both cone penetration resistance and Gmax to increased stress level or overburden stress is discussed.<br>Applied Science, Faculty of<br>Civil Engineering, Department of<br>Graduate
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Arndt, Alex Michael. "Performance-Based Liquefaction Triggering Analyses with Two Liquefaction Models Using the Cone Penetration Test." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6945.
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This study examines the use of performance-based engineering in earthquake liquefaction hazard analysis with Cone Penetration Test data (CPT). This work builds upon previous research involving performance-based liquefaction analysis with the Standard Penetration Test (SPT). Two new performance-based liquefaction triggering models are presented herein. The two models used in this liquefaction analysis are modified from the case-history based probabilistic models proposed by Ku et al. (2012) and Boulanger and Idriss (2014). Using these models, a comparison is made between the performance-based method and the conventional pseudo-probabilistic method. This comparison uses the 2014 USGS probabilistic seismic hazard models for both methods. The comparison reveals that, although in most cases both methods predict similar liquefaction hazard using a factor of safety against liquefaction, by comparing the probability of liquefaction, the performance-based method on average will predict a smaller liquefaction hazard.
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Taskinen, Timo I. "On the steady-state flow of an elastic-plastic material past cones and wedges." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302330.
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Chu, Lap-man Raymond. "Material identification and subsurface stratigraphy of Penny's Bay reclamation site : by the method of subsurface exploration : piezocone penetration test and drilling /." Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42576660.
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Corob, Alexander Edward. "Analysis of Applied Modifications to a Cone Penetration Test-based Lateral Spread Displacement Prediction Model." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/9065.
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This study set out to examine the effectiveness and reliability of six modifications to the Zhang et al. (2004) CPT-based lateral spread model. A regression analysis, distribution charts, and a discriminant analysis are performed to determine how effective the modifications are on the model. From the comparisons and statistical analysis performed in this study, application of these modifications reduces over-predictions from strain-based prediction methods. Unfortunately, the tendency to under-predict displacements on average is also increased.
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Žaržojus, Gintaras. "Analysis of the results and it influence factors of dynamic probing test and interrelation with cone penetration test data in Lithuanian soils." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101230_093807-41798.
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The object of the thesis is soils that occur within the territory of Lithuania and may be used as basis for building foundations. The thesis studies the interpretation of the results of Dynamic Penetration Test (DPT) and Cone Penetration Test (CPT) of soils, reliability of direct (number of blows (Nx)) and de-rivative (dynamic point resistance (qd)) DPT parameters, analyses the result influencing factors and interrelation between DPT and CPT parameters. The data analysis has been performed by means of mathematical methods of statistics, also using analytical and empirical solutions. Having examined calculation data it was determined that the indirect parameter of Dy-namic Penetration Test – dynamic point resistance (qd) should not be used due to calculation de-faults and replaced with the direct parameter – number of blows (Nx). The analysis of DPT re-sults influencing factors shows that the lateral overburden pressure together with friction of rods are those with the greatest impact on penetration data. Within the scope of the work, it has re-vealed that the number of blows (Nx) and static cone resistance (qc) are closely correlated and it depends on the grain size distribution of soil, geotechnical properties and depth of occurrence.<br>Disertacijos objektas yra Lietuvos teritorijoje slūgsantys gruntai, kurie gali būti statinių pamatų pagrindu. Disertacijoje nagrinėjama grunto tyrimo dinaminiu (DPT) ir statiniu (CPT) zondavimu rezultatų interpretacija, tiesioginio (smūgių skaičiaus (Nx)) ir išvestinio (dinaminės kūgio smigos (qd)) DPT rodiklių patikimumas, analizuojami rezultatus įtakojantys veiksniai ir sąsajos tarp DPT bei CPT zondavimo rodiklių. Duomenų analizė atlikta matematiniais statistiniais metodais, taip pat panaudojant analitinius ir empirinius sprendinius. Išnagrinėjus skaičiavimo duomenis buvo nustatyta, kad netiesioginis dinaminio zonda-vimo rodiklis – dinaminė kūgio smiga (qd) dėl skaičiavimo trukumų yra nenaudotinas ir keisti-nas į tiesioginį rodiklį – smūgių skaičių (Nx). DPT rezultatus įtakojančių veiksnių analizė paro-dė, kad zondavimo duomenims didžiausią įtaką turi gruntų šoninis geostatinis slėgis ir kartu zondavimo štangų trintis į gruntą. Darbo metu buvo gauta, kad egzistuoja tamprus koreliacinis ryšys tarp smūgių skaičiaus (Nx) ir statinės kūgio spraudos (qc), kuris priklauso nuo grunto gra-nuliometrinės sudėties, mechaninių savybių ir slūgsojimo gylio.
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Liao, Tianfei. "Post processing of cone penetration data for assessing seismic ground hazards, with application to the New Madrid seismic zone." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-05042005-133640/.
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Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2006.<br>Mayne, Paul W., Committee Chair ; Goldsman, David, Committee Member ; Lai, James, Committee Member ; Rix, Glenn J., Committee Member ; Santamarina, J. Carlos, Committee Member.
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Monahan, Patrick Alistair. "The application of cone penetration test data to facies analysis of the Fraser River Delta, British Columbia." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ37354.pdf.
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Lu, Yan-Ming, and 盧艷銘. "Penetration test on Android." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/04056412128671598757.
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碩士<br>國立交通大學<br>資訊科學與工程研究所<br>100<br>In recent years smart phone has been more and more popularization in handset market, especially the Android system. Regardless of being receives and sends the email, playing the game, listening to music, watching the movie…and so on, which can work on the smart phones completely. Android is an open-source software stack for mobile devices, enables each people to develop the application. For this reason, hackers can spread the malicious software, like steals the user personal privacy material, and uses the payment service. Android Market has no the strict examination mechanism for the applications on the market, in addition Android applications can be acquired from any third party alternatives to "official" market. These could let the user easily download the malicious software without consciously. Therefore, how to safeguard on the Android handset's security, is essential target which we study. Our penetration test system collects each kind of Android system's exploits, and provides the examination with the corresponding suggestion.
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Sy, Alexander. "Energy measurements and correlations of the standard penetration test (SPT) and the becker penetration test (BPT)." Thesis, 1993. http://hdl.handle.net/2429/8848.
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The Standard penetration test (SPT) and the Becker penetration test (BPT) are two of the
most widely used in-situ tests in North America. The SPT is most commonly used in sands
and silty sands, while the BPT, being a large-scale penetration test, is more useful in
gravelly soils. Both tests involve hammer impact on penetration rods, and the resulting
penetration resistance or blow count is strongly influenced by the amount of hammer energy
actually transferred into the drill rods. To make use of the large world-wide foundation
performance data base currently available for the SPT, the BPT blow counts are commonly
correlated to the SPT blow counts. Most of the existing correlations, however, have limited
applications since they do not take into account the inherently variable output of the diesel
hammer used in the Becker system and they ignore the soil friction acting on the Becker
casing during driving.
This research shows that the existing methods of SPT and BPT energy calibrations
have serious shortcomings, and that a more fundamental approach of determining the
transferred energy, based on force and acceleration measurements, should be adopted for
both tests. The proposed approach provides a unified method of measuring transferred
energy in the SPT and BPT, similar in principle to that currently used in dynamic testing of
piles.
At four research sites in Greater Vancouver, SPTs, BPTs and electric cone
penetration tests were conducted. Dynamic measurements were also carried out which
included force and acceleration near the top of the drill rods or pipes in the SPT and BPT, as well as bounce-chamber and combustion-chamber pressures in the double-acting diesel
hammer during the BPT.
An energy approach for correcting the measured BPT blow count to a reference
energy level, similar in concept to that used for the SPT, is proposed. Factors affecting the
BPT blow counts are investigated including hammer combustion conditions, different drill
rigs, and different pipe sizes. The test results confirm that the measured transferred energy
is a fundamental and useful parameter for normalizing the BPT blow counts to account for
the variable energy output of the diesel hammer.
The effect of casing friction in the BPT is investigated by field measurements and
numerical analyses. New BPT-SPT correlations are proposed which consider the energy
transfer in both tests and which, for the first time, account for casing friction in the BPT.
It is shown that the proposed BPT-SPT correlations provide a rational framework for
determining equivalent SPTN60 values from measured BPT blow counts, and can be applied
with some confidence to gravel sites for which the BPT has proven to be a most practical
and economical testing technique.
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Bo-An, Chen, and 陳柏安. "A Study of Penetration Test Methodology." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/13255486755437790630.
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碩士<br>中國文化大學<br>資訊安全產業碩士專班<br>102<br>This thesis proposes on a new methodology of penetration test, There are three processes in this methodology of the penetration test of this thesis are web, system and network. First, web process focus on using the web development framework or the know vulnerabilities of the module version to do the attack test, and using the Google hacker’s search technology to find the site of the injection point. Second system process is focus on the know vulnerabilities of the system service version and using the vulnerability scan to attack the server’s vulnerability. Third network process is focus on using the port scan tools to check the port status of the service, and using the send and get network package technology to analysis the firewall and router to do the attack test. Then attack using elevated privileges that after using those find vulnerabilities information to success attack, and prepare the penetration test report after finish all of the test process to tested party to do the fix the vulnerabilities. The final process is to do the re-test after tested party finish to fix the vulnerabilities.
The process of this thesis can be separate or combination that by different type of project that meet a variety of business needs, and improve the operating efficiency of penetration testing.
For the result of methodology of this thesis, we invited five experts of penetration test to evaluate it, considers that the framework can improve operational efficiency, penetration testing integrity, and is very helpful to do the penetration testing today.
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Chuang, Chwan-Yeh, and 莊傳業. "Application of Acoustic on Cone Penetration Test." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/40349832623836388132.
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碩士<br>國立中央大學<br>土木工程學系<br>84<br>This research described the properties of the acoustic
emission signal gen-erated on the static cone penetration tests.
As a penetrometer is penetrating into the soils, the acoustic
emissions are generated by soil grains sliding and rolling
over the penetrometer, sliding and rolling over one another and
being rushed. The major purpose of this paper is to improve the
technique of site investigation.This research includes the
development of measuring system of the acoustic emission,
understanding of the noise vibration control, ensur-ing of the
acoustic emission of rocks, application of the calibration
chamber,selection variables of tested soils, preparation method
of soils specimens, design of the acoustic penetrometer and
establishment the analytic models of measuring data.
The research establishes the relationship between the
engineering behavior and property of tested soils and the
amplitude of the spectral analysis which is treated by root-
mean-square operation and fast Fourier transform. In order to
understand the relationship between the amplitude of the
acoustic signal and soil variables which included grain size,
relative density, stress state and state of saturation. The
frequency of the acoustic signal indicates the constitution of
predominant frequency of soils.
Once acoustic data have been fully analyzed and the soil profile
establish-ed, it should be possible to determine the accuracy
with which the acoustic data indicated layering and other soil
characteristics.
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Chang, Jyh-Haur, and 張致豪. "Evaluation of Liquefaction Potential by Cone Penetration Test." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/65894703357733503437.
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Luo, Kuo-Yu, and 羅國育. "Evaluation of Strata Characteristics by Portable Penetration Test." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/77857869501102562055.
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碩士<br>國立臺灣大學<br>森林學研究所<br>87<br>It is necessary to have a complete strata characteristics survey before an engineering construction is built. The interpretation of strata characteristics is usually based on few sampling points of geological boring and standard penetration test. However, it is not enough to represent the strata characteristics of the whole area based on few points. The purpose of this study is to evaluate the strata characteristics applying portable penetration test, due to its economic, easy, and convenient, on the large area of slope-lands. The result shown that portable penetration test was well corresponding to the results of geological boring and electrical exploration. According to the convenience and economics, the portable penetration test could be an useful approach to estimate slope stability.
The results indicated that penetration resistance (Nc value) correlated with soil physics factors, cohesion, angle of friction, and void ration. Finally, the field test data of portable penetration test was used to compare with the data of laboratory soil physics experiment.