Готові списки джерел за темами / WEAK SOIL

Добірка наукової літератури з теми "WEAK SOIL"

Автор: Grafiati

Опубліковано: 11 вересня 2023

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Зміст

Статті в журналах
Дисертації
Книги
Частини книг
Тези доповідей конференцій
Звіти організацій

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "WEAK SOIL".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "WEAK SOIL"

Usmanov, Rustam, Ivan Mrdak, Nikolay Vatin, and Vera Murgul. "Reinforced Soil Beds on Weak Soils." Applied Mechanics and Materials 633-634 (September 2014): 932–35. http://dx.doi.org/10.4028/www.scientific.net/amm.633-634.932.

Повний текст джерела

Анотація:

Changing a layer of weak soil in deformed foundation with a compacted soil bed consisted of various strong materials (sand, gravel, pebble-gravel, production waste materials). Existing calculation methods and techniques to build compacted soil beds based on weak highly compressive soils do not meet up-to-date requirements. Calculation methods used the dimensions of compacted beds quite often appear to be overestimated, and this results in increase in costs and working hours needed to build artificial foundation. The paper presents the possibility of using reinforced soil beds as an efficient method to build artificial foundation based on weak soils.

Стилі APA, Harvard, Vancouver, ISO та ін.

Zaitsev, A. A., and V. G. Ofrikhter. "THE RESULTS OF FIELD TESTS OF WEAK SOILS." Construction and Geotechnics 10, no. 2 (December 15, 2019): 56–65. http://dx.doi.org/10.15593/2224-9826/2019.2.05.

Повний текст джерела

Анотація:

Organization of construction on sites built of weak soils is associated with certain problems, one of which is the construction of temporary roads and foundations for building mechanisms (pile drivers, cranes, etc.). Temporary roads necessary attributes of any construction, ensuring the availability of facilities and linear structures. One of the features of the temporary roads is their erection in accordance with the staged scheme of the organization of construction. Physico-mechanical characteristics of the soils are necessary for the design of such passages using which it is possible to perform calculations using approved soil models. During civil engineering processes on weak soils, it is also important to preserve geological diversity, which is possible with a comprehensive assessment of soil properties. Work on weak soils, even at the survey stage, is associated with accessibility problems due to their low bearing capacity. Usually travel by transport on such soils in warm season is impossible. Evaluation of the physico-mechanical properties of weak soils is possible using lightweight portable devices that can be delivered to the testing sites manually. This paper presents the results of the evaluation of the mechanical characteristics of weak soil using lightweight portable devices such as probe penetrometer, vane shear meter, and dynamic density meters. Soil properties obtained during field tests can be used as input parameters for design models, the use of which allows to perform immediate out calculations temporary road construction or the base for the construction mechanism. Works performed according to the proposed method are of low laboriousness, low cost and high efficiency, do not require the use of mechanisms and can be performed by one person.

Стилі APA, Harvard, Vancouver, ISO та ін.

Akulova, Yu N., I. I. Sakharov, and V. V. Lushnikov. "Strengthening of weak foundation soils with crushed stone piles." Вестник гражданских инженеров 17, no. 6 (2020): 126–31. http://dx.doi.org/10.23968/1999-5571-2020-17-6-126-131.

Повний текст джерела

Анотація:

The article presents an innovative technique of deep vibration compaction for soft saturated soils with crushed stone piles. The methods for calculating the strength and deformation characteristics of reinforced soil mass proposed by H. J. Priebe and A. Z. Ter-Martirosyan are presented. An example of the road embankment base in the Plaxis 3D software package is given, taking into account the improvement of the soil mass with crushed stone piles.

Стилі APA, Harvard, Vancouver, ISO та ін.

Alsharef, Jamal M. A., Mohd Raihan Taha, Ali Akbar Firoozi, and Panbarasi Govindasamy. "Potential of Using Nanocarbons to Stabilize Weak Soils." Applied and Environmental Soil Science 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/5060531.

Повний текст джерела

Анотація:

Soil stabilization, using a variety of stabilizers, is a common method used by engineers and designers to enhance the properties of soil. The use of nanomaterials for soil stabilization is one of the most active research areas that also encompass a number of disciplines, including civil engineering and construction materials. Soils improved by nanomaterials could provide a novel, smart, and eco- and environment-friendly construction material for sustainability. In this case, carbon nanomaterials (CNMs) have become candidates for numerous applications in civil engineering. The main objective of this paper is to explore improvements in the physical properties of UKM residual soil using small amounts (0.05, 0.075, 0.1, and 0.2%) of nanocarbons, that is, carbon nanotube (multiwall carbon nanotube (MWCNTs)) and carbon nanofibers (CNFs). The parameters investigated in this study include Atterberg’s limits, optimum water content, maximum dry density, specific gravity, pH, and hydraulic conductivity. Nanocarbons increased the pH values from 3.93 to 4.16. Furthermore, the hydraulic conductivity values of the stabilized fine-grained soil samples containing MWCNTs decreased from 2.16E-09 m/s to 9.46E-10 m/s and, in the reinforcement sample by CNFs, the hydraulic conductivity value decreased to 7.44E-10 m/s. Small amount of nanocarbons (MWCNTs and CNFs) decreased the optimum moisture content, increased maximum dry density, reduced the plasticity index, and also had a significant effect on its hydraulic conductivity.

Стилі APA, Harvard, Vancouver, ISO та ін.

Lawrence, David M., and Julia M. Slingo. "Weak Land–Atmosphere Coupling Strength in HadAM3: The Role of Soil Moisture Variability." Journal of Hydrometeorology 6, no. 5 (October 1, 2005): 670–80. http://dx.doi.org/10.1175/jhm445.1.

Повний текст джерела

Анотація:

Abstract A recent model intercomparison, the Global Land–Atmosphere Coupling Experiment (GLACE), showed that there is a wide range of land–atmosphere coupling strengths, or the degree that soil moisture affects the generation of precipitation, amongst current atmospheric general circulation models (AGCMs). Coupling strength in the Hadley Centre atmosphere model (HadAM3) is among the weakest of all AGCMs considered in GLACE. Reasons for the weak HadAM3 coupling strength are sought here. In particular, the impact of pervasive saturated soil conditions and low soil moisture variability on coupling strength is assessed. It is found that when the soil model is modified to reduce the occurrence of soil moisture saturation and to encourage soil moisture variability, the soil moisture–precipitation feedback remains weak, even though the relationship between soil moisture and evaporation is strengthened. Composites of the diurnal cycle, constructed relative to soil moisture, indicate that the model can simulate key differences in boundary layer development over wet versus dry soils. In particular, the influence of wet or dry soil on the diurnal cycles of Bowen ratio, boundary layer height, and total heat flux are largely consistent with the observed influence of soil moisture on these properties. However, despite what appears to be successful simulation of these key aspects of the indirect soil moisture–precipitation feedback, the model does not capture observed differences for wet and dry soils in the daily accumulation of boundary layer moist static energy, a crucial feature of the feedback mechanism.

Стилі APA, Harvard, Vancouver, ISO та ін.

Kopiika, Nadiia, and Yuriy Petrenko. "Analysis of the Weak Soil Behavior, Modified Through Cementation." Advanced Journal of Graduate Research 7, no. 1 (October 20, 2019): 27–36. http://dx.doi.org/10.21467/ajgr.7.1.27-36.

Повний текст джерела

Анотація:

The purpose of the study is to conduct thorough theoretical research and literature overview regarding possible ways of soil stabilization on the basis of this practice increasing demand. In particular an emphasis is made on the chemical technique for weak soils strengthening, due to its prevalence and various practical and economic advantages. Great amount of promiscuous data was analyzed and organized; in addition on its basis an attempt is made to provide convincing calculation technique for further usage in engineering soils` stabilization practice. Besides, various factors which could influence on the results` accuracy are identified with corresponding recommendations for further possible research on this issue.

Стилі APA, Harvard, Vancouver, ISO та ін.

Eisa, M. S., M. E. Basiouny, A. Mohamady, and M. Mira. "Improving Weak Subgrade Soil Using Different Additives." Materials 15, no. 13 (June 24, 2022): 4462. http://dx.doi.org/10.3390/ma15134462.

Повний текст джерела

Анотація:

Weak subgrade is the main problem facing most highway projects. Therefore, this study focuses on trying to improve the properties and increase the strength of weak, clayey, swelling soil for use as a subgrade for pavement structural sections. This trial was developed using a mix of granular and chemical stabilization for the soil. Granular stabilization was applied firstly by mixing natural sand at different percentages of 20%, 35%, and 50% of the total weight of clayey, swelling soil samples to find the minimum percentage that could be added to improve it to sandy, clayey soil, which is acceptable as a subgrade according to the Egyptian highway specification code. Secondly, chemical stabilization was applied to enhanced sandy, clayey soil to increase its strength properties. This was performed by adding chemical additives (lime, cement kiln dust (CKD), fiberglass, Addicrete 11, and gypsum) at different ratios of 2%, 4%, and 6% of the total weight of the samples of enhanced sandy, clayey soil. An experimental program was conducted consisting of characteristics and consistency tests, the California bearing ratio (CBR) test, a proctor test, and a consolidated-drained (C-D) tri-axial shear test. The results showed that 50% sand was the minimum percentage that could be mixed with swelling, clayey soil for granular stabilization to be enhanced and become sandy, clayey soil, which is accepted as a subgrade layer according to the Egyptian highway specification code. In addition, using a mix of granular and chemical stabilization increased the compressive strength of this enhanced subgrade by adding 6% lime or cement kiln dust (CKD) of the total sample weight. They enhanced the strength of the soil and reduced its plasticity. Adding 6% fiberglass and polymers could slightly enhance the desired properties; however, it is not recommended to use them due to their slight effect and economic cost. In addition, it is not recommended to use gypsum at more than 4% due to its negative effect on CBR.

Стилі APA, Harvard, Vancouver, ISO та ін.

Jayasree, Parameswaran K., and Musthafakunju Ansar. "Use of novel materials for reinforced soil walls on weak soils." Proceedings of the Institution of Civil Engineers - Construction Materials 165, no. 6 (December 2012): 345–53. http://dx.doi.org/10.1680/coma.10.00038.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Yadav, B. Manoj. "Improvement of weak soil by DSM method." International Journal of Civil Engineering 4, no. 6 (June 25, 2017): 42. http://dx.doi.org/10.14445/23488352/ijce-v4i6p107.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Lin, Chunxiu, Chang Xia, Zhen Liu, and Cuiying Zhou. "A Comprehensive Correlation Study of Structured Soils in Coastal Area of South China about Structural Characteristics." Journal of Marine Science and Engineering 10, no. 4 (April 6, 2022): 508. http://dx.doi.org/10.3390/jmse10040508.

Повний текст джерела

Анотація:

Granite residual soil is a common engineering material, and its mechanical properties are of great importance to engineering safety. This kind of soil presents obvious structural characteristics, and many researchers have emphasized the significance of its structural features. According to previous experiments, from a macroscopic perspective, many researchers have investigated the structural relationship between undisturbed and remolded soils, but few studies have considered it in the mesoscopic aspect. Adopting DEM (a mesomechanical simulation method), we can study how the structure affects the mechanical process between undisturbed and remolded soil. Therefore, this paper combines DEM with laboratory tests to study the structural characteristic correlation between undisturbed and remolded soil. The results indicate that a weak cohesion effect exists in undisturbed soil, and the damage of weak cohesion elements accompanies the failure process. Weak cohesion elements in undisturbed soil cause inhomogeneities in deformation, stress state, and damage accumulation, which ultimately causes differences in strength curves. This paper explains the mechanism of the structural effect on mechanical evolution from a mesomechanical perspective. The DEM simulation method proposed in this paper can be applied to structured soils and better guide engineering practice.

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Дисертації з теми "WEAK SOIL"

Shi, Liangyu. "Influence of artificial weak cementation on loose silty sand behavior /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20SHI.

Повний текст джерела

Анотація:

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.
Includes bibliographical references (leaves 163-170). Also available in electronic version. Access restricted to campus users.

Стилі APA, Harvard, Vancouver, ISO та ін.

A, Rashid Ahmad Safuan. "Behaviour of weak soils reinforced with soil columns formed by the deep mixing method." Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548631.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

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.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

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.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Ley, George J. "A study of hard-setting behaviour of structurally weak tropical soils." Thesis, University of Aberdeen, 1988. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU010493.

Повний текст джерела

Анотація:

Some soils set to a hard structureless mass on drying and this behaviour may limit crop productivity. The purpose of this study was to assess the extent to which soil management and soil properties influence hard-setting behaviour in order to identify those soil properties which are most appropriate to characterise the limitations to management and crop growth imposed by hard-setting. Five sites from four vegetation zones of Nigeria were investigated. Within each site soils were sampled from no-till or forested plots and these were contrasted with cleared (deforested) amd ploughed plots. Hard-setting behaviour was determined by measuring the unconfined compressive and tensile strengths of small undisturbed cores (minicores) which had been equilibrated at a range of matric potentials. Rooting potential was assessed both by measuring needle penetrometer resistance or cores equilibrated at potentials of -6 and -100 kPa; and also by measuring penetrometer resistance in the field at a range of moisture contents. Soil bulk density, organic matter concentration, soil friability, aggregate stability and amounts of water suspendable solids were also measured to assess soil properties that are likely to be diagnostic of hard-setting behaviour. The limitations imposed by hard-setting behaviour on rooting and yields of maize and cowpea were assessed at IITA. The minicore strengths increased as the moisture content decreased but the increase was much more marked for mechanized cleared or tilled soils than for the less disturbed treatments of forestry and a no-till system. For all soils the most pronounced effects of moisture content deplection on soil strength occurred at potentials of < -100 kPa. Theoretical considerations indicated that the effective stress accounted for over half of the strength of minicores at -100 kPa and more than accounted for the strength of minicores at -1 MPa. The greater strength in tilled soils was attributed to a decrease in organic matter content, wet aggregate stability and friability and to an increase in bulk density. Needle and field penetrometer resistance results indicated that rooting potential was reduced on hard-setting soils and actual root measurements supported this view. Consequently maize and cowpea yields were reduced.

Стилі APA, Harvard, Vancouver, ISO та ін.

Shorten, David. "The quantification and improvement of vehicle support capacity in a weak soil." Thesis, Cranfield University, 2004. http://dspace.lib.cranfield.ac.uk/handle/1826/11193.

Повний текст джерела

Анотація:

The aim of this study was to improve the characteristics of surfacing methods/materials for the temporary support of military vehicles travelling over weak soils. Both off road travel and poor existing road networks provide problems for vehicle mobility in military operations under these conditions. Conventional road construction materials are often in short supply and engineered solutions such as Class 30 & 70 Trackway are expensive and form a significant logistical burden on the military supply chain. In this situation the use of locally available alternative materials in the construction of temporary roads can reduce the time taken to get routes operational, allowing the tempo of operations to be maintained. The work reported focussed on two main areas of work, namely: i) The development of a technique for assessing the soil support capacity in the form of a flat plate (45 x 30 mm) penetrometer to aid the decision/ planning process when faced with poor soil support, and ii) the evaluation of the relative performance of a range of alternative materials/ techniques in laboratory conditions at 1/5'*’ scale and full size. The results of load-sinkage tests of a family of plate sizes indicate that by normalising the data with respect to plate width a common relationship existed for all plate sizes in each of the soil conditions investigated. From this, a technique was developed to estimate the load support of a plate with dimensions equivalent to the contact patch of a tyre using load-sinkage data from a small plate penetrometer, allowing estimates of: i) sinkage or rut depth expected from a vehicle load, and ii) the load at a sinkage equivalent to the tyre contact patch width, a point at which the vehicles were assumed to be immobilised. Comparison between the rut depth of a single pass of a towed wheel and the sinkage from plate tests (45 x 30 mm) were within 20% in a sandy loam soil of bulk unit weight 12.2 and 13.4 kN/m^. Load sinkage predictions of a 450 x 300 mm plate from a small plate penetrometer were within 35% in a sandy loam soil with bulk unit weights of 11.7 and 13.4 kN/m^. Load sinkage predictions for a very weak sandy loam (11.3 kN/m^) and loose sand (15.1 - 16.1 kN/m^) soils tended to be significantly underestimated especially at large plate sizes, mainly due to scaling effects in these David Shorten, 2004 Cranfield University, Silsoe 11 situations as well as the significant re-arranging occurring in weak soil subjected to loaded plates. Improvements in accuracy to 25-35% could be made in these conditions by increasing the size of the plate penetrometer to 90 x 60 mm and utilising a similitude scaling technique. Materials/techniques for improving soil support have been classified into 4 categories, namely: sheet materials, rigid members, aggregate materials and stabilisation techniques. The use of sheet materials, in this case a Hessian geotextile, proved effective in improving the in situ soil support; it was possible to optimise the width and placement depth to increase load support by a factor of 1.8. A folded confinement technique encapsulating a soil fill was developed further, resulting in a 3-fold improvement in the load support. Tied corduroy techniques performed best with a 5- fold improvement in load support. Factors such as the rope tension between members were found to be important to produce a stable road surface. The performance of aggregates increased with larger aggregate sizes. Increasing the thickness of the aggregate layer enhanced load support in stone aggregate, while in wood and rubber aggregate performance is affected by the initial compressibility of the material. Aggregate mixed with a sand filler proved effective at reducing the compressibility of the alternative aggregate materials, thus enhancing performance. The use of alternative materials in military operations has been identified as very scenario dependent. Alternative materials have been shown to increase the load support capability of weak soils. Although alternative materials are unlikely to be used as a substitute in conventional road construction, their use on short sections of roadway is feasible. Situations where conventional aggregate materials are limited and an alternative aggregate can be obtained locally would offer a solution enabling military operations to continue. Significant quantities of materials are required to construct even small sections of roadway in weak soil conditions; success is very much dependent on the amount of material locally available, for example a 100 m section may require 180 m^ of timber aggregate approximately equal to 0.25 ha of a 45 yr Sitka Spruce plantation. This information will be of use to aid decisions made by the Combat Engineer and has been recommended by the MOD for inclusion in the Military Engineering Volume.

Стилі APA, Harvard, Vancouver, ISO та ін.

Bowers, Keith Henry. "An appraisal of the New Austrian Tunnelling Method in soil and weak rock." Thesis, University of Leeds, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.580652.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Althoff, Sebastian. "Nutzung gering tragfähiger Böden für geokunststoffbewehrten Erdbau." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2015. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-162385.

Повний текст джерела

Анотація:

Geokunststoffe sind beständige Produkte aus Polymeren, die in Boden eingelegt werden um geotechnische Probleme zu lösen. Eine Kategorie der Geokunststoffe sind Geogitter, bei denen die Längs- und Querelemente eine offene, gitterförmige Struktur bilden und die meist zur Bodenbewehrung eingesetzt werden. Ihre Verwendung zur Bewehrung von gering tragfähigen Böden für kunststoffbewehrte Erd- und Stützbauwerke kann enorme ökologische und ökonomische Vorteile bieten. Trotz der Tatsache, dass die Verwendung von Geogittern in den letzten Jahren stark zugenommen hat, sind die Grundlagen zum Bau und zur Bemessung limitiert. Besonders die Schlüsselfrage, wie Geogitter und verschiedene Lockergesteine in unterschiedlichen Belastungssituationen interagieren, ist ingenieursmäßig nur lückenhaft untersucht worden. Im Rahmen dieser Dissertation wurde deshalb in über 250 großmaßstäblichen Scher-, Herauszieh- und Reibungsversuchen das Verbundverhalten Geokunststoff/Locker¬gestein eingehend untersucht. Dazu wurden 14 handelsübliche Geogitter, die teilweise auch modifiziert wurden, in dem Interaktionsprüfgerät des Institutes für Geotechnik der TU Bergakademie Freiberg mit verschiedenen Böden systematisch getestet. Die vielen Versuchsanordnungen und die aus ihnen abgeleiteten Überlegungen und gewonnenen Erkenntnisse belegten, dass die wichtigsten Parameter interagieren, und zwar in verschiedenen Abhängigkeiten wie weitere Variationen der Bodenparameter (Kornverteilung, Wassergehalte, Verdichtung, Bindemittelzusatz etc.), der unterschiedlichen Geogitterparameter (Oberflächenbeschaffenheit, Struktur, etc.) und der Belastung gezeigt haben. Darüber hinaus wurde das Interaktionsprüfgerät für zukünftige Versuche weiterentwickelt (Entkopplung des Versuchseinbaus vom Versuchsgerät usw.). Der Fokus der Forschungsarbeit lag dabei in der Schaffung von Grundlagenkenntnissen für den gemeinsamen Einsatz von bindigen Lockergesteinen und Geokunststoffen. Bei rolligen Böden zeigte sich, dass die Rautiefe sich stärker (positiv) auf die Widerstände auswirkt als bei den bindigen Böden. Hingegen waren bei bindigen Böden die Auswirkungen durch eine Erhöhung der Querelemente deutlicher. Darüber hinaus konnte gezeigt werden, dass dreidimensionale Querelemente das Verbundverhalten verbessern und Tests an Geogittern mit einem größeren Verhältnis von Öffnungsweite zu Maschenweite zeigten höhere Adhäsionswerte. Die Reibungsversuche hatten einen gleichmäßigeren Verlauf und geringere Streuungen zwischen den unterschiedlichen Geogittern, weshalb aufgrund der deutlicheren Unterschiede zwischen den Produkten bei den Herausziehversuchen detaillierte Schlussfolgerungen gezogen werden konnten. Die vorliegende Arbeit leistet einen Beitrag zur Verbesserung der Bemessungsgrundlagen und ermöglicht ein detaillierteres Verständnis des Verbundverhaltens. Des Weiteren werden Vorschläge ausgearbeitet die im Labor erzielten Ergebnisse auf die Baupraxis zu übertragen, wie zum Beispiel durch das Vermeiden von Trennflächen zwischen Geogitter und Boden bei der Verdichtung
Geosynthetics are durable polymeric products placed in soil to help solve civil engi-neering problems; one category of these is geogrids. Geogrids are polymers formed into an open, grid-like configuration and function primarily as soil reinforcement. Their use to reinforce soil with weak bearing capacity could have big ecological and economical advantages. Although geogrid use has grown in recent years, there is still limited design information available due to the wide variety of design configurations and soil variability. One of the key factors lacking for more widespread engineering implementation is a greater understanding of the interaction between various geogrids and soil combinations when exposed to different load effects. In more than 250 shear, pull-out, and friction tests, this interaction behavior was examined in detail. Fourteen general geogrids (sometimes additionally modified) using dif-ferent soil types were systematically tested in the Interaction Testing Device at the Geotechnical Institute of the TU Bergakademie Freiberg. Combining the huge quantity of test results with a theoretical analysis, the main parameters which affect soil behavior could be defined. Furthermore the Interaction Testing Device could be improved for test in future. Our analysis showed us that the roughness of the geogrid has more of a beneficial impact on the strength of frictional soils than it does for silty soils. Silty soils however, were more affected by the height of cross elements in the geogrid than other types. It was also observed that 3D elements in the cross machine direction improve the interaction behavior. Tests with geogrids which have a bigger ratio of opening size to mesh size showed higher adhesion values. The friction test results were more regular, had a uniform progress and had smaller differences between geogrid configurations. Therefore, conclusions with higher certainty could be drawn from the pull-out tests with the differential results. The present research contributes to the limited design information to help provide a better understanding of the interaction behavior. Furthermore, suggestions are given to use the laboratory detected results in real-world applications, one of which is the way of compaction to minimize the potential for creating a slip-surface between the geogrid and soil

Стилі APA, Harvard, Vancouver, ISO та ін.

Бережанська, С., та І. В. Маєвська. "Аналіз сучасних конструктивних рішень фундаментів малоповерхових будівель". Thesis, ВНТУ, 2018. http://ir.lib.vntu.edu.ua//handle/123456789/20979.

Повний текст джерела

Анотація:

Розглянуто основні конструктивні схеми фундаментів для малоповерхового будівництва при великій товщі глинистого ґрунту. Виконано розрахунок і проектування обраних конкурентоспроможних варіантів фундаментів, техніко-економічне порівнянні конструктивних рішень і вибір найбільш оптимального з них.
The basic constructive schemes of foundations for low-rise construction with a large thickness of clay soil are considered. The сalculation and design of selected competitive options, technical and economic comparison of constructive solutions and the choice of the most optimal ones are performed.

Стилі APA, Harvard, Vancouver, ISO та ін.

Quirke, SJ. "Abrasive wear testing of steels in soil." Master's thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/21798.

Повний текст джерела

Анотація:

Bibliography: pages 133-136.
A survey has been made of the quality and type of materials used for tillage tools in South Africa. Conclusions have been drawn regarding the inadequacy of the manufacturing processes used and the resultant quality of the tool material. A rig has been designed for the abrasion testing of materials in soil. The reproducibility of the method has been shown to be high and an evaluation has been made of the relative wear resistance of a series of ·heat treated steels. A medium carbon boron steel has been shown to have great promise as a tillage tool material because of its high wear resistance and toughness. The deformed surface layers and the mechanisms of wear of steels subjected to field and laboratory abrasive testing has been examined. The removal of material through predominantly ploughing or cutting mechanisms has been shown to be dependent on the heat treatment and composition of the steels together with the nature of the abrasive. White surface layers have been observed to form on medium and high carbon steels subjected to soil abrasion. Suggestions have been advanced for their formation. Attempts have been made to assess the transferability of data between field and laboratory testing.

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Книги з теми "WEAK SOIL"

Sorokina, G. V. Engineering properties of weak soils at foundations of buildings. Rotterdam: A.A. Balkema, 1995.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Conference, Geological Society of London Engineering Group. The engineering geology of weak rock. Rotterdam: A.A. Balkema, 1993.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

European conference on soil mechanics and geotechnical engineering (15 2011 Athènes). Proceedings of the 15th European conference on soil mechanics and geotechnical engineering: Geotechnics of hard soils-weak rocks = la géotechnique des sols indurés-roches tendres. Amsterdam: IOS press, 2011.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Brown, D. A. (Dan A.), National Research Council (U.S.). Transportation Research Board, National Cooperative Highway Research Program, American Association of State Highway and Transportation Officials, and United States. Federal Highway Administration, eds. Design guidelines for increasing the lateral resistance of highway-bridge pile foundations by improving weak soils. Washington, D.C: Transportation Research Board, 2011.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Kristin, Carroccino, and Kilmer Ricci, eds. A journey into wholeness: Soul travel from Lent to Easter. Seattle, Wa: MSA Pub., 2014.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Andrus, Crystal. Simply-- woman!: The 12-week body-mind-soul total transformation program. Carlsbad, Calif: Hay House, 2008.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Was im Gedächtnis bleiben soll: Das literarische Werk von Karin Gündisch. Hermannstadt: Schiller Verlag, 2014.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Andrus, Crystal. Simply-- woman!: The 12-week body-mind-soul total transformation program. Carlsbad, Calif: Hay House, 2008.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Andrus, Crystal. Simply-- woman!: The 12-week body-mind-soul total transformation program. Carlsbad, Calif: Hay House, 2008.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Brown, Dan, and Kyle Rollins. Design Guidelines for Increasing the Lateral Resistance of Highway-Bridge Pile Foundations by Improving Weak Soils. Washington, D.C.: National Academies Press, 2011. http://dx.doi.org/10.17226/14574.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Частини книг з теми "WEAK SOIL"

O’Donnell, B., A. Swarup, A. Sidiq, D. Robert, and S. Setunge. "Guidelines for Enzymatic Soil Stabilization." In Lecture Notes in Civil Engineering, 373–98. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3330-3_40.

Повний текст джерела

Анотація:

AbstractThere are numerous manuals to guide practitioners in utilizing traditional additives in the construction of road, rail and dam construction but they fall short of specific guidance for non-standard additive-based ecofriendly and cost-effective soil stabilization. Increased attention has recently been on the use of non-standard additives for stabilizing weak soils due to environmental and cost concerns associated with traditional additives. We summarize the specific guidelines of using environmental-friendly enzymes to treat weak soils. We elaborate on the requirements and specifications for the Eko-Soil multi-enzyme product that is manufactured from water and proteins extracted from fermented exudes of plants. Specific tests (laboratory and field) and conditions required for soil stabilization using Eko-Soil enzyme are elaborated using the experience of past construction projects. The guide also elaborates enhancing the efficiency of enzymatic soil stabilization by correctly incorporating the required mixing proportions and pre-requisite condition tests. Professionals and practitioners will benefit from using novel eco-friendly sustainable stabilization techniques in the treatment of weak soils covering many applications including roads, foundations, water containment areas, landfills, working platforms and slope erosion control.

Стилі APA, Harvard, Vancouver, ISO та ін.

Ye, Wei-Min, Ya-Wei Zhang, Bao Chen, and Shi-Fang Zhang. "Characteristics of Shear Strength of Unsaturated Weak Expansive Soil." In Advances in Environmental Geotechnics, 505–10. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-04460-1_45.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Koskinen, William C., Alegria Cabrera, Kurt A. Spokas, Lucia Cox, Jennifer L. Rittenhouse, and Pamela J. Rice. "Effect of Carbonaceous Soil Amendments on Potential Mobility of Weak Acid Herbicides in Soil." In Functions of Natural Organic Matter in Changing Environment, 497–500. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-5634-2_90.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Liu, Chun, Qingyi Lin, and Hang Zhang. "The application of PDA on weak soil in Fujian China." In Application of Stress-Wave Theory to Piles, 279–83. London: Routledge, 2022. http://dx.doi.org/10.1201/9781315137544-39.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Kim, You-Seong, and Myoung-Soo Won. "Deformation Behaviors of Geosynthetic Reinforced Soil Walls on Shallow Weak Ground." In Soil Stress-Strain Behavior: Measurement, Modeling and Analysis, 819–30. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6146-2_61.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Furukawa, Makoto, Shuichiro Yoshida, and Naoto Nihei. "Evaluation of the Absorption of Different Forms of Cesium from Soil." In Agricultural Implications of Fukushima Nuclear Accident (IV), 55–61. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-9361-9_7.

Повний текст джерела

Анотація:

AbstractCesium in soil exists in two forms. The soil in Fukushima Prefecture contaminated with radioactive cesium was classified into two fractions: the fraction of cesium with weak adsorption to soil (F1), and the fraction of cesium with strong adsorption to soil (F2). We evaluated the absorption of Cs by different crops (rice, soybean, and buckwheat) in different soil fractions by measuring the 133Cs and 137Cs concentrations in the soil and crops. We also evaluated the effect of potassium fertilization on cesium suppression in different soil fractions.Without K fertilization, 137Cs was absorbed mostly from the F1 fraction by all three crops; 133Cs was absorbed mostly from the F2 and F1 fractions by soybean and buckwheat, respectively, and from both F1 and F2 fractions by rice. Potassium fertilization decreased the percentages of both 137Cs and 133Cs absorbed from the F2 fraction by soybean. In contrast, buckwheat presented reduced absorption from the F1 fraction. In rice, the uptake of cesium by fraction did not change with or without potassium fertilization, indicating that different crops absorb cesium from different soil fractions.

Стилі APA, Harvard, Vancouver, ISO та ін.

Rosolem, Ciro A., Antonio P. Mallarino, and Thiago A. R. Nogueira. "Considerations for Unharvested Plant Potassium." In Improving Potassium Recommendations for Agricultural Crops, 147–62. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-59197-7_6.

Повний текст джерела

Анотація:

AbstractPotassium (K) is found in plants as a free ion or in weak complexes. It is easily released from living or decomposing tissues, and it should be considered in fertilization programs. Several factors affect K cycling in agroecosystems, including soil and fertilizer K contributions, plant K content and exports, mineralization rates from residues, soil chemical reactions, rainfall, and time. Soil K+ ions can be leached, remain as exchangeable K, or migrate to non-exchangeable forms. Crop rotations that include vigorous, deep-rooted cover crops capable of exploring non-exchangeable K in soil are an effective strategy for recycling K and can prevent leaching below the rooting zone in light-textured soils. The amount of K released by cover crops depends on biomass production. Potassium recycled with non-harvested components of crops also varies greatly. Research with maize, soybean, and wheat has shown that 50–60% of K accumulated in vegetative tissues is released within 40–45 days. A better understanding of K cycling would greatly improve the efficacy of K management for crop production. When studying K cycling in agricultural systems, it is important to consider: (1) K addition from fertilizers and organic amendments; (2) K left in residues; (3) K partitioning differences among species; (4) soil texture; (5) soil pools that act as temporary sources or sinks for K. In this chapter, the role of cash and cover crops and organic residues on K cycling are explored to better understand how these factors could be integrated into making K fertilizer recommendations.

Стилі APA, Harvard, Vancouver, ISO та ін.

Badry, Pallavi, and Ravi Shankar Badry. "Seismic Soil Structure Interaction Analysis of Rigid Piled Isolated Footing for Mid Rise Building in a Weak Soil." In Dynamic Soil-Structure Interaction for Sustainable Infrastructures, 27–39. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01920-4_3.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Yin, Jianliang, Zhikui Liu, Zhanfei Gu, Yan Yan, Yong Xiong Xie, and Bingyan Huang. "Effect of Dry-Wet Cycling on Shear Strength of Phyllite-Weathered Soil in Longsheng, Guilin." In Lecture Notes in Civil Engineering, 479–94. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1748-8_42.

Повний текст джерела

Анотація:

AbstractThe phyllite-weathered soil is a regional speciality. It is essential to study the changes in shear strength of phyllite-weathered soil under dry-wet cycles to understand the changes in mechanical properties of phyllite-weathered soil in the process of dry-wet climate and to manage the slope of phyllite-weathered soil. This paper simulated 12 dry-wet cycles on the specimens of remodelled phyllite-weathered soil. Direct shear and SEM tests were conducted on the specimens in the 0th, 3rd, 6th, 9th, and 12th drying paths. The effects of moisture content and the number of dry-wet cycles on the shear strength of phyllite-weathered soil were analysed macroscopically and microscopically. The following conclusions were obtained: (1) The cohesion of the weathered soil of phyllite will be reduced by increasing the number of cycles, and the more the number of dry-wet cycles, the more pronounced the reduction; the internal friction angle of the weathered soil of phyllite will be reduced by increasing the number of cycles, but the pattern of the decrease in the internal friction angle is not obvious. (2) The increase in the number of dry-wet cycles will increase the stiffness and brittleness of the phyllite-weathered soil specimen, and it will change from the weak hardening type of plastic damage to the solid softening type of brittle damage after a certain number of cycles. (3) The SEM test found that phyllite-weathered soil particles in Longsheng, Guilin are large, and most of the particles are in face-to-face and angle-to-face contact, which is easy to form a hollow structure, and the dry density value of the soil in the natural state is small. At the same time, the soil is reddish-brown in colour because of the leaching of Fe2 O3. The shear strength index of the cemented phyllite-weathered soil with Fe2 O3 is more significant than that of phyllite-weathered soil in other areas. The soil has a good shear strength index and a small dry density.

Стилі APA, Harvard, Vancouver, ISO та ін.

Mangushev, Rashid, Evgeny Rybnov, Askar Zhussupbekov, and Abdulla Omarov. "Investigation of the Work of the Lakhta Center in Weak Soil Foundations of St. Petersburg." In XV International Scientific Conference “INTERAGROMASH 2022”, 2428–38. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-21432-5_265.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "WEAK SOIL"

Vynnykov, Yuriy, and Roman Razdui. "Comparison of Settlements of Buildings on Soil-Cement Soil Bases Determined Analytically and by Long-Term Geodetic Observations." In International Scientific Applied Conference "Problems of Emergency Situations". Switzerland: Trans Tech Publications Ltd, 2023. http://dx.doi.org/10.4028/p-x7fhpi.

Повний текст джерела

Анотація:

Comparative results of settlements of soil-cement soil bases of multi-story residential buildings determined by the methods of linear soil mechanics, finite element modeling in a planar (2D) and spatial (3D) setting using an elastic-plastic soil model, as well as long-term (over ten years) data of geodetic observations of natural objects are given. The object of this work was to evaluate the reliability of various methods of predicting the settlements of soil-cement soil bases of buildings on strip foundations in the presence of weak soils within the compressible soil thickness and reinforcement of the massif to a depth smaller than the width of the foundations. It was established that in the presence of layers of weak soils within the compressible soil thickness under strip foundations and reinforcement of the massif to a depth less than their width the actual settlements of such soil base exceeds the values allowed by the norms. The scientific novelty of the work is it was determined in the first time that under these conditions the methods of linear soil mechanics underestimate the calculated settlements by more than two times compared to their actual values. On the other hand, the high reliability of the use of mathematical modeling methods using the elastic-plastic soil model has been proven.

Стилі APA, Harvard, Vancouver, ISO та ін.

Nishimura, S., T. Shibata, T. Shuku, and K. Imaide. "Geostatistical Analysis for Identifying Weak Soil Layers in Dikes." In Geo-Risk 2017. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784480724.048.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Shivashankar, R., and J. Jayamohan. "Behaviour of Prestressed Reinforced Foundation Beds Overlying Weak Soil." In Geo-Shanghai 2014. Reston, VA: American Society of Civil Engineers, 2014. http://dx.doi.org/10.1061/9780784413401.039.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Turner, E. L., J. Chevallier, and V. Rapoport. "Placement of Mat-Supported Jackup Rig on Very Weak Soil." In Offshore Technology Conference. Offshore Technology Conference, 1987. http://dx.doi.org/10.4043/5358-ms.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Zaytsev, Andrey, Andrei Petriaev, and Laura Černiauskaite. "Track structure reconstruction practice for the subgrade on weak foundation soil." In Fifth International Conference on Road and Rail Infrastructure. University of Zagreb Faculty of Civil Engineering, 2018. http://dx.doi.org/10.5592/co/cetra.2018.972.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Vijay, Roshni, and K. Ramya. "Application of Sisal Fibre for the Improvement of Weak Subgrade Soil." In International Conference on Emerging Trends in Engineering & Technology (ICETET-2015). Singapore: Research Publishing Services, 2015. http://dx.doi.org/10.3850/978-981-09-5346-1_ce-509.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Sarač, Dino, Zhendong Li, Harkaman Gurung, and Alwalid Alekrish. "FINITE ELEMENT ANALYSIS OF WEAK ROCK UNDERCUT REINFORCED WITH SOIL NAILS." In GEO-EXPO. Društvo za geotehniku u Bosni i Hercegovini, 2018. http://dx.doi.org/10.35123/geo-expo_2018_19.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Al-Mansob, Ramez A., Lim Yi Jia, Jamal M. A. Alsharef, Taha M. Jassam, Jing Lin Ng, Shaban Ismael Albrka Ali, and Salihah Binti Surol. "Effects of carbon-nanotube and lime on the weak soil stability." In INTERNATIONAL CONFERENCE ON FOOD SCIENCE AND BIOTECHNOLOGY (FSAB 2021). AIP Publishing, 2021. http://dx.doi.org/10.1063/5.0073028.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Syed, Z. I., N. I. Alkhatib, and Md Arifuzzaman. "Structural behavior of non-uniform mat foundation on weak sandy soil." In 4th Smart Cities Symposium (SCS 2021). Institution of Engineering and Technology, 2021. http://dx.doi.org/10.1049/icp.2022.0375.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Cramer, Chris H. "Comparing Weak- and Strong-Motion Spectral Ratios at the Turkey Flat Site Effects Test Area, Parkfield, California: Possible Nonlinear Soil Behavior." In Geotechnical Earthquake Engineering and Soil Dynamics Congress IV. Reston, VA: American Society of Civil Engineers, 2008. http://dx.doi.org/10.1061/40975(318)11.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "WEAK SOIL"

Bishop, Megan, Jay Clausen, Samuel Beal, and Patrick Sims. Comparison of the quantitation of heavy metals in soil using handheld LIBS, XRFS, and ICP-OES. Engineer Research and Development Center (U.S.), June 2023. http://dx.doi.org/10.21079/11681/47182.

Повний текст джерела

Анотація:

Handheld laser-induced breakdown spectroscopy (LIBS) is an emerging analytical technique that shows the potential to replace X-ray fluorescence spectroscopy (XRFS) in the field characterization of soils containing heavy metals. This study explored the accuracy and precision of handheld LIBS for analyzing soils containing copper and zinc to support LIBS as a re-placement for XRFS technology in situ. Success was defined by handheld LIBS results that could be replicated across field analyzers and verified by inductively coupled plasma–optical emission spectrometry (ICP-OES). A total of 108 soil samples from eight military installations were pressed into 13 mm pellets and then analyzed by XRFS and LIBS. Handheld LIBS has a spot-size area 100-fold smaller than that of XRFS, and though it provided accurate measurements for NIST-certified reference materials, it was not able to measure unknown soils of varying soil texture with high particle size variability, regardless of sample size. Thus, soil sample particle size heterogeneity hindered the ability to provide accurate results and replicate quantitation results across LIBS and XRFS. Increasing the number of particles encountered by each shot through particle size reduction improved both field-analyzer correlation and the correlation between handheld LIBS and ICP-OES from weak (<15%) to strong (>80%).

Стилі APA, Harvard, Vancouver, ISO та ін.

Honegger. L51990 Extended Model for Pipe Soil Interaction. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), August 2003. http://dx.doi.org/10.55274/r0010152.

Повний текст джерела

Анотація:

This program contributes to maintaining and improving the integrity and safety of existing pipelines with regard to ground movement hazards, and reducing the capital costs of new pipeline systems. The research program focused on the axial, lateral and complex loading of pipeline due to soil movements. It includes (1) a literature review: it presents significant issues related to modeling pipe-soil interaction with a focus to recent development since ASCE (1984); (2) axial loading: it includes a summary of the methods to estimate the axial soil forces on pipeline and recent field measurements on decommissioned pipe sections in weak to desiccated, cohesive to sandy silts in California; (3) lateral loading of buried pipeline: it covers the effects of cover depth, soil strength, loading rate, trench geometry and backfill strength on pipe-soil interaction; (4) complex loading of buried pipeline: the interaction between the lateral and axial soil forces on pipeline are studied; and (5) quantification of mitigative methods: a physical testing program including a total of 20 laterally loaded pipelines are used to identify and quantify the effects of various mitigative methods on reducing lateral loads transferred to a buried pipeline.

Стилі APA, Harvard, Vancouver, ISO та ін.

Christoforidou, Eirini, Antonio Bobet, Tommy Nantung, and Philippe L. Bourdeau. Use of Geosynthetics on Subgrade and on Low and Variable Fill Foundations. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317437.

Повний текст джерела

Анотація:

There are significant problems during construction to establish an adequate foundation for fills and/or subgrade for pavements when the natural ground has low-bearing soils. Geosynthetics such as geogrids, geotextiles, and/or geocells could provide a less time-consuming, costly alternative for establishing an adequate foundation for the fill and/or subgrade. There is extensive evidence in the literature and on DOTs practices about the suitability of using geotextiles in pavements as separators. Previous studies have also shown that the use of geogrids in flexible pavements as a reinforcing mechanism could decrease the thickness of the base layer and/or increase the life of the pavement. In this study, analyses of selected pavement designs using Pavement ME—while considering geogrid-enhanced base or subgrade resilient modulus values—showed that geogrid-reinforcement, when placed at the interface between subgrade and base, did not produce significant benefits and only a modest increase in pavement life was predicted. In addition, parametric finite element analyses were carried out to investigate the potential benefits of placing a geogrid at the base of a fill over a localized weak foundation zone. The analyses showed that the use of geogrids is beneficial only when: (a) the stiffness of the weak foundation soil is about an order of magnitude smaller than the rest of the foundation soil; and (b) the horizontal extent of the weak foundation soil is at least 30% of the base of the embankment foundation. The largest decrease in differential settlements at the surface of the fill, resulting from geogrid-reinforcement, was less than 20% and, therefore, it is unlikely that the sole use of geogrids would be sufficient to mitigate differential settlements. Based on previous studies, a geocell mattress, which is a three-dimensional geosynthetic filled with different types of materials, could act as a stiff platform at the base of an embankment and bridge over weak zones in the foundation. However, given the limited experience in Indiana on the use of geocells, further research is required to demonstrate that geocells can be effectively used in place of other reinforcement methods.

Стилі APA, Harvard, Vancouver, ISO та ін.

Wang, Yao, Jeehee Lim, Rodrigo Salgado, Monica Prezzi, and Jeremy Hunter. Pile Stability Analysis in Soft or Loose Soils: Guidance on Foundation Design Assumptions with Respect to Loose or Soft Soil Effects on Pile Lateral Capacity and Stability. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317387.

Повний текст джерела

Анотація:

The design of laterally loaded piles is often done in practice using the p-y method with API p-y curves representing the behavior of soil at discretized points along the pile length. To account for pile-soil-pile interaction in pile groups, AASHTO (2020) proposes the use of p-multipliers to modify the p-y curves. In this research, we explored, in depth, the design of lateral loaded piles and pile groups using both the Finite Element (FE) method and the p-y method to determine under what conditions pile stability problems were likely to occur. The analyses considered a wide range of design scenarios, including pile diameters ranging from 0.36 m (14.17 inches) to 1.0 m (39.37 inches), pile lengths ranging from 10 m (32.81 ft) to 20 m (65.62 ft), uniform and multilayered soil profiles containing weak soil layers of loose sand or normally consolidated (NC) clay, lateral load eccentricity ranging from 0 m to 10 m (32.81 ft), combined axial and lateral loads, three different pile group configurations (1×5, 2×5, and 3×5), pile spacings ranging from 3 to 5 times the pile diameter, two different load directions (“strong” direction and “weak” direction), and two different pile cap types (free-standing and soil-supported pile caps). Based on the FEA results, we proposed new p-y curve equations for clay and sand. We also examined the behavior of the individual piles in the pile groups and found that the moment applied to the pile cap is partly transferred to the individual piles as moments, which is contrary to the assumption often made that moments are fully absorbed by axial loads on the group piles. This weakens the response of the piles to lateral loading because a smaller lateral pressure is required to produce a given deflection when moments are transferred to the head of the piles as moments. When the p-y method is used without consideration of the transferred moments, unconservative designs result. Based on the FEA results, we proposed both a new set of p-multipliers and a new method to use when moment distribution between piles is not known, using pile efficiency instead to calculate the total capacity of pile groups.

Стилі APA, Harvard, Vancouver, ISO та ін.

Litaor, Iggy, James Ippolito, Iris Zohar, and Michael Massey. Phosphorus capture recycling and utilization for sustainable agriculture using Al/organic composite water treatment residuals. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600037.bard.

Повний текст джерела

Анотація:

Objectives: 1) develop a thorough understanding of the sorption mechanisms of Pi and Po onto the Al/O- WTR; 2) determine the breakthrough range of the composite Al/O-WTR during P capturing from agro- wastewaters; and 3) critically evaluate the performance of the composite Al/O-WTR as a fertilizer using selected plants grown in lysimeters and test-field studies. Instead of lysimeters we used pots (Israel) and one- liter cone-tainers (USA). We conducted one field study but in spite of major pretreatments the soils still exhibited high enough P from previous experiments so no differences between control and P additions were noticeable. Due to time constrains the field study was discontinued. Background: Phosphorous, a non-renewable resource, has been applied extensively in fields to increase crop yield, yet consequently has increased the potential of waterway eutrophication. Our proposal impetus is the need to develop an innovative method of P capturing, recycling and reuse that will sustain agricultural productivity while concurrently reducing the level of P discharge from and to agricultural settings. Major Conclusions & Achievements: An innovative approach was developed for P removal from soil leachate, dairy wastewater (Israel), and swine effluents (USA) using Al-based water treatment residuals (Al- WTR) to create an organic-Al-WTR composite (Al/O-WTR), potentially capable of serving as a P fertilizer source. The Al-WTR removed 95% inorganic-P, 80% to 99.9% organic P, and over 60% dissolved organic carbon from the agro-industrial waste streams. Organic C accumulation on particles surfaces possibly enhanced weak P bonding and facilitated P desorption. Analysis by scanning electron microscope (SEM- EDS), indicated that P was sparsely sorbed on both calcic and Al (hydr)oxide surfaces. Sorption of P onto WW-Al/O-WTR was reversible due to weak Ca-P and Al-P bonds induced by the slight alkaline nature and in the presence of organic moieties. Synchrotron-based microfocused X-ray fluorescence (micro-XRF) spectrometry, bulk P K-edge X-ray absorption near edge structure spectroscopy (XANES), and P K-edge micro-XANES spectroscopy indicated that adsorption was the primary P retention mechanism in the Al- WTR materials. However, distinct apatite- or octocalciumphosphatelike P grains were also observed. Synchrotron micro-XRF mapping further suggested that exposure of the aggregate exteriors to wastewater caused P to diffuse into the porous Al-WTR aggregates. Organic P species were not explicitly identified via P K-edge XANES despite high organic matter content, suggesting that organic P may have been predominantly associated with mineral surfaces. In screen houses experiments (Israel) we showed that the highest additions of Al/O-WTR (5 and 7 g kg⁻¹) produced the highest lettuce (Lactuca sativa L. var. longifolial) yield. Lettuce yield and P concentration were similar across treatments, indicating that Al/O- WTR can provide sufficient P to perform similarly to common fertilizers. A greenhouse study (USA) was utilized to compare increasing rates of swine wastewater derived Al/O-WTR and inorganic P fertilizer (both applied at 33.6, 67.3, and 134.5 kg P₂O₅ ha⁻¹) to supply plant-available P to spring wheat (TriticumaestivumL.) in either sandy loam or sandy clay loam soil. Spring wheat straw and grain P uptake were comparable across all treatments in the sandy loam, while Al/O-WTR application to the sandy clay loam reduced straw and grain P uptake. The Al/O-WTR did not affect soil organic P concentrations, but did increase phosphatase activity in both soils; this suggests that Al/O-WTR application stimulated microorganisms and enhance the extent to which microbial communities can mineralize Al/O-WTR-bound organic P. Implications: Overall, results suggest that creating a new P fertilizer from Al-WTR and agro-industrial waste sources may be a feasible alternative to mining inorganic P fertilizer sources, while protecting the environment from unnecessary waste disposal.

Стилі APA, Harvard, Vancouver, ISO та ін.

VanderGheynst, Jean, Michael Raviv, Jim Stapleton, and Dror Minz. Effect of Combined Solarization and in Solum Compost Decomposition on Soil Health. United States Department of Agriculture, October 2013. http://dx.doi.org/10.32747/2013.7594388.bard.

Повний текст джерела

Анотація:

In soil solarization, moist soil is covered with a transparent plastic film, resulting in passive solar heating which inactivates soil-borne pathogen/weed propagules. Although solarization is an effective alternative to soil fumigation and chemical pesticide application, it is not widely used due to its long duration, which coincides with the growing season of some crops, thereby causing a loss of income. The basis of this project was that solarization of amended soil would be utilized more widely if growers could adopt the practice without losing production. In this research we examined three factors expected to contribute to greater utilization of solarization: 1) investigation of techniques that increase soil temperature, thereby reducing the time required for solarization; 2) development and validation of predictive soil heating models to enable informed decisions regarding soil and solarization management that accommodate the crop production cycle, and 3) elucidation of the contributions of microbial activity and microbial community structure to soil heating during solarization. Laboratory studies and a field trial were performed to determine heat generation in soil amended with compost during solarization. Respiration was measured in amended soil samples prior to and following solarization as a function of soil depth. Additionally, phytotoxicity was estimated through measurement of germination and early growth of lettuce seedlings in greenhouse assays, and samples were subjected to 16S ribosomal RNA gene sequencing to characterize microbial communities. Amendment of soil with 10% (g/g) compost containing 16.9 mg CO2/g dry weight organic carbon resulted in soil temperatures that were 2oC to 4oC higher than soil alone. Approximately 85% of total organic carbon within the amended soil was exhausted during 22 days of solarization. There was no significant difference in residual respiration with soil depth down to 17.4 cm. Although freshly amended soil proved highly inhibitory to lettuce seed germination and seedling growth, phytotoxicity was not detected in solarized amended soil after 22 days of field solarization. The sequencing data obtained from field samples revealed similar microbial species richness and evenness in both solarized amended and non-amended soil. However, amendment led to enrichment of a community different from that of non-amended soil after solarization. Moreover, community structure varied by soil depth in solarized soil. Coupled with temperature data from soil during solarization, community data highlighted how thermal gradients in soil influence community structure and indicated microorganisms that may contribute to increased soil heating during solarization. Reliable predictive tools are necessary to characterize the solarization process and to minimize the opportunity cost incurred by farmers due to growing season abbreviation, however, current models do not accurately predict temperatures for soils with internal heat generation associated with the microbial breakdown of the soil amendment. To address the need for a more robust model, a first-order source term was developed to model the internal heat source during amended soil solarization. This source term was then incorporated into an existing “soil only” model and validated against data collected from amended soil field trials. The expanded model outperformed both the existing stable-soil model and a constant source term model, predicting daily peak temperatures to within 0.1°C during the critical first week of solarization. Overall the results suggest that amendment of soil with compost prior to solarization may be of value in agricultural soil disinfestations operations, however additional work is needed to determine the effects of soil type and organic matter source on efficacy. Furthermore, models can be developed to predict soil temperature during solarization, however, additional work is needed to couple heat transfer models with pathogen and weed inactivation models to better estimate solarization duration necessary for disinfestation.

Стилі APA, Harvard, Vancouver, ISO та ін.

Clausen, Jay, Michael Musty, Anna Wagner, Susan Frankenstein, and Jason Dorvee. Modeling of a multi-month thermal IR study. Engineer Research and Development Center (U.S.), July 2021. http://dx.doi.org/10.21079/11681/41060.

Повний текст джерела

Анотація:

Inconsistent and unacceptable probability of detection (PD) and false alarm rates (FAR) due to varying environmental conditions hamper buried object detection. A 4-month study evaluated the environmental parameters impacting standoff thermal infra-red(IR) detection of buried objects. Field observations were integrated into a model depicting the temporal and spatial thermal changes through a 1-week period utilizing a 15-minute time-step interval. The model illustrates the surface thermal observations obtained with a thermal IR camera contemporaneously with a 3-d presentation of subsurface soil temperatures obtained with 156 buried thermocouples. Precipitation events and subsequent soil moisture responses synchronized to the temperature data are also included in the model simulation. The simulation shows the temperature response of buried objects due to changes in incoming solar radiation, air/surface soil temperature changes, latent heat exchange between the objects and surrounding soil, and impacts due to precipitation/changes in soil moisture. Differences are noted between the thermal response of plastic and metal objects as well as depth of burial below the ground surface. Nearly identical environmental conditions on different days did not always elicit the same spatial thermal response.

Стилі APA, Harvard, Vancouver, ISO та ін.

Edwards, Lulu, Charles Weiss, J. Newman, Fred Nichols, L. Coffing, and Quint Mason. Corrosion and performance of dust palliatives : laboratory and field studies. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/42125.

Повний текст джерела

Анотація:

This report details laboratory and field experiments on BioPreferred® dust suppressants to assess performance and corrosion characteristics. Numerous bio-based dust suppressant products are marketed, but little data are available to assess performance for dust abatement and corrosion of common metals. A laboratory study used an air impingement device and the Portable In-Situ Wind ERosion Laboratory (PI-SWERL) to simulate wind speeds similar to those in field conditions for rotary wing aircraft. Laboratory corrosion studies used metal coupons imbedded in soil treated with dust palliative. Field trials were conducted using ground vehicle traffic to minimize cost and lower safety concerns while increasing surface wear from repetitive traffic. These studies clearly show that bio-based products demonstrate low corrosion potential with similar dust abatement performance to synthetic-based agents.

Стилі APA, Harvard, Vancouver, ISO та ін.

Garcia, Lyan, James Rowland, and Jeb Tingle. Evaluation of geocell-reinforced backfill for airfield pavement repair. Engineer Research and Development Center (U.S.), December 2021. http://dx.doi.org/10.21079/11681/42550.

Повний текст джерела

Анотація:

After an airfield has been attacked, temporary airfield pavement repairs should be accomplished quickly to restore flight operations. Often, the repairs are made with inadequate materials and insufficient manpower due to limited available resources. Legacy airfield damage repair (ADR) methods for repairing bomb damage consist of using bomb damage debris to fill the crater, followed by placement of crushed stone or rapid-setting flowable fill backfill with a foreign object debris (FOD) cover. While these backfill methods have provided successful results, they are heavily dependent on specific material and equipment resources that are not always readily available. Under emergency conditions, it is desirable to reduce the logistical burden while providing a suitable repair, especially in areas with weak subgrades. Geocells are cellular confinement systems of interconnected cells that can be used to reinforce geotechnical materials. The primary benefit of geocells is that lower quality backfill materials can be used instead of crushed stone to provide a temporary repair. This report summarizes a series of laboratory and field experiments performed to evaluate different geocell materials and geometries in combinations with a variety of soils to verify their effectiveness at supporting heavy aircraft loads. Results provide specific recommendations for using geocell technology for backfill reinforcement for emergency airfield repairs.

Стилі APA, Harvard, Vancouver, ISO та ін.

Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!