Journal articles on the topic 'Cohesive soils'
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1
Gao, Xiaojing, Qiusheng Wang, Chongbang Xu, and Ruilin Su. "Experimental Study on Critical Shear Stress of Cohesive Soils and Soil Mixtures." Transactions of the ASABE 64, no. 2 (2021): 587–600. http://dx.doi.org/10.13031/trans.14065.
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HighlightsErosion tests were performed to study the critical shear stress of cohesive soils and soil mixtures.Linear relationships were observed between critical shear stress and cohesion of cohesive soils.Mixture critical shear stress relates to noncohesive particle size and cohesive soil erodibility.A formula for calculating the critical shear stress of soil mixtures is proposed and verified.Abstract. The incipient motion of soil is an important engineering property that impacts reservoir sedimentation, stable channel design, river bed degradation, and dam breach. Due to numerous factors influencing the erodibility parameters, the study of critical shear stress (tc) of cohesive soils and soil mixtures is still far from mature. In this study, erosion experiments were conducted to investigate the influence of soil properties on the tc of remolded cohesive soils and cohesive and noncohesive soil mixtures with mud contents varying from 0% to 100% using an erosion function apparatus (EFA). For cohesive soils, direct linear relationships were observed between tc and cohesion (c). The critical shear stress for soil mixture (tcm) erosion increased monotonically with an increase in mud content (pm). The median diameter of noncohesive soil (Ds), the void ratio (e), and the organic content of cohesive soil also influenced tcm. A formula for calculating tcm considering the effect of pm and the tc of noncohesive soil and pure mud was developed. The proposed formula was validated using experimental data from the present and previous research, and it can reproduce the variation of tcm for reconstituted soil mixtures. To use the proposed formula to predict the tcm for artificial engineering problems, experimental erosion tests should be performed. Future research should further test the proposed formula based on additional experimental data. Keywords: Cohesive and noncohesive soil mixture, Critical shear stress, Erodibility, Mud content, Soil property.
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Khazratov, A. N., O. Sh Bazarov, A. R. Jumayev, F. F. Bobomurodov, and N. Z. Mamatov. "Influence of cohesion strength in cohesive soils onchannel bed erosion." E3S Web of Conferences 410 (2023): 05018. http://dx.doi.org/10.1051/e3sconf/202341005018.
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The results of experimental studies on the mechanical properties of cohesive soils associated with the use in the study of the erosion process are presented. The influence of the cohesion strength of cohesive soil on erosion is described. The relationship between the erosionflow velocities and cohesion strength has been obtained.
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Nnamani, Chidiebere Henry. "The Chemical and Mineralogical Composition and Their Effects on Strength Parameters of Cohesive Soil Developed over Enugu Shale." European Journal of Environment and Earth Sciences 3, no. 1 (January 29, 2022): 28–35. http://dx.doi.org/10.24018/ejgeo.2022.3.1.234.
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The results of chemical and mineralogical composition of cohesive soils developed over Enugu Shale, as well as the effects on the strength parameters are presented in this paper. The strength parameters were determined in the cohesive soil specimens in the study area, while the chemical and mineralogical tests were done on the representative soil types from the study area. Some correlations between chemical composition and strength parameters of cohesion and angle of internal friction as well as other physical parameters such as liquid limit, plastic limit, plasticity index and activity of soil were obtained. The effects of chemical and mineralogical composition on strength parameters, based on the correlation between chemical composition and strength parameters (cohesion and angle of internal friction) were examined. The results show that chemical and mineralogical compositions significantly affect the angle of internal friction and cohesion thereby impacting on the strength of cohesive soils developed over Enugu Shale.
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Estikhamah, Fithri, and Dian Purnamawati Solin. "Correlation Between Cone Resistance Values and Cohesion Values in Cohesive Soils (Case Study in Gunung Anyar District)." E3S Web of Conferences 328 (2021): 01005. http://dx.doi.org/10.1051/e3sconf/202132801005.
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The physical and mechanical properties of the soil can be determined based on laboratory tests by testing soil samples obtained from field drilling. At one point it can be done simultaneously between SPT testing and drilling. Therefore, it can be known simultaneously the value of N-SPT with the physical and mechanical properties of the soil. The purpose of this study was to obtain a relationship between the cone resistance value (qc) obtained in the field and the cohesion value for cohesive soil types. This study uses primary data, and secondary data. The results of the correlation between the cone resistance value (qc) obtained in the field and the cohesion value for cohesive soil types show a strong correlation. This is indicated by the regression value which reaches a value of 0.75, which is 0.7809. The regression equation obtained is y = 0.0138x – 0.0063. The coefficient of the cone resistance value is 0.0138, indicating that every 1 constant increase in the cone resistance value variable will increase the cohesive value in the cohesive soil by 0.0138. The positive regression coefficient indicates that the higher the cone resistance value (qc), the higher the value of cohesion (c) for cohesive soils.
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Mahabub, Md Shakil, and Mohammad Rafikul Islam. "The Subsoil Characterization of Matarbari Ultra Super Critical Coal-Fired Power Project, Bangladesh." Volume 5 - 2020, Issue 9 - September 5, no. 9 (October 4, 2020): 931–45. http://dx.doi.org/10.38124/ijisrt20sep699.
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In this research, the subsoil characteristics and geotechnical issues have been evaluated for ground improvement, land development and design facilitation of Matarbari Ultra Super Critical Coal-Fired Power Project, Bangladesh. The subsoil conditions and geotechnical issues are addressed by determining the geotechnical parameters of soil. The soil characteristics are obtained from soil investigation and executed under land development for the procurement of power plant facilities. The American Society for Testing and Materials (ASTM International) standard is used to estimate all the soil parameters in field and laboratory tests. The measured soil properties establish the area consists mainly of two types of soils, i.e., Cohesive Clayey and non-cohesive Sandy soils. The cohesive soils are mostly composed of gray to dark gray CLAY, CLAY with Sand, SILT with Sand, and Sandy CLAY with fine to mediumgrained Sand. The upper cohesive soil layer (Ac-1) is very soft to soft, normal to slightly consolidated with low undrained cohesion. This layer is expected to have a high potential for differential settlement because of the proposed design load. The lower cohesive soils (Ac-2 and Ac-3) are firm to very stiff and moderately over consolidated. These soils have moderate to high shear strengths with low compressibility relating to the expected range of the design loads. The non-cohesive Sandy soils consist of dark gray to gray SAND, SAND with Silt, Silty SAND, and Clayey SAND. The Sandy soils are poorly graded and loose to very loose at the upper part (As-1) and medium dense to dense in lower parts (As-2 & As-3) that expect less immediate settlement when a load placed on that. Geotechnical site conditions are challenging and deplorable. The soft soil layer Ac-1 (with As-1) complicates the design, especially in terms of foundation soil instability and settlement for certain structure types. Ground improvement techniques such as prefabricated vertical drain (PVD) and deep mixing method (DMM) can be applied to mitigate these challenges and for the improvement of the soft ground of the project area.
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Gong, Mingze, Sivar Azadi, Adrien Gans, Philippe Gondret, and Alban Sauret. "Erosion of a cohesive granular material by an impinging turbulent jet." EPJ Web of Conferences 249 (2021): 08011. http://dx.doi.org/10.1051/epjconf/202124908011.
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The erosion of a cohesive soil by an impinging turbulent jet is observed, for instance, during the landing of a spacecraft or involved in the so-called jet erosion test. To provide a quantitative understanding of this situation for cohesive soils, we perform experiments using a model cohesion controlled granular material that allows us to finely tune the cohesion between particles while keeping the other properties constant. We investigate the response of this cohesive granular bed when subjected to an impinging normal turbulent jet. We characterize experimentally the effects of the cohesion on the erosion threshold and the development of the crater. We demonstrate that the results can be rationalized by introducing a cohesive Shields number that accounts for the inter-particles cohesion force. The results of our experiments highlight the crucial role of cohesion in erosion processes.
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Gosk, Wojciech. "The use of cohesive soils improved with lime as an example of circular economy in earthworks." Inżynieria Bezpieczeństwa Obiektów Antropogenicznych, no. 3 (September 30, 2022): 10–20. http://dx.doi.org/10.37105/iboa.146.
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A common practice in civil engineering during earthworks is the usual replacement of cohesive soils (fine soils), excavated during earthworks, with non-cohesive soils (coarse soils). Until recently, such a procedure was dictated primarily by economic and technical reasons. From an economic point of view, the ease of access and therefore low cost of using such soils instead of cohesive soils was crucial. The technical reason is, above all, the ease of compacting fine soils (as opposed to cohesive soils) and well-developed and well-known engineering methods for controlling their compaction.
The situation changed radically when the new environmental regulations came into force and enforcement by the inspection authorities began. Currently, soil removed from a construction site according to regulations should be classified as waste. This fact has completely changed the approach of participants in the construction process to the use of local soils, especially cohesive soils (e.g. clays). Their use "on site" has stopped being an expensive option and has become a necessity.
This paper presents aspects of the use of lime-improved cohesive soils that can be successfully used on site as excavation backfill. Problems related to the proper preparation of soil-lime composites are described, as well as the results of compaction tests. The paper presents the author's own methodology for selecting the content of quicklime in the soil-lime composite.
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Świdziński, Waldemar, Jacek Mierczyński, and Agata Mikos. "Response of Partially Saturated Non-cohesive Soils." Archives of Hydro-Engineering and Environmental Mechanics 64, no. 3-4 (December 1, 2017): 187–207. http://dx.doi.org/10.1515/heem-2017-0012.
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AbstractThis paper analyses and discusses experimental results of undrained triaxial tests. The tests were performed on non-cohesive partially saturated soil samples subjected to monotonic and cyclic loading. The tests were aimed at determining the influence of saturation degree on soil’s undrained response (shear strength, excess pore pressure generation). The saturation of samples was monitored by checking Skempton’s parameter B. Additionally, seismic P-wave velocity measurements were carried out on samples characterized by various degrees of saturation. The tests clearly showed that liquefaction may also take place in non-cohesive soils that are not fully saturated and that the liquefaction potential of such soils strongly depends on the B parameter.
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Eshev, Sobir, Mahmud Rahmatov, Alisher Khazratov, Nurbek Mamatov, Jasur Sagdiyev, and Mustafo Berdiev. "Critical flow velocities in cohesive saline soils." E3S Web of Conferences 264 (2021): 03071. http://dx.doi.org/10.1051/e3sconf/202126403071.
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The article discusses the issue of determining non-erosion velocities for cohesive saline soil at the bottom and slopes of canals. Based on the formulas of Ts.E. Mirtskhulava for the determination of non-eroding velocities of water flow in cohesive soils, equations for determining non-eroding velocities for cohesive saline soil are proposed. A brief technique for conducting laboratory experiments and modeling of saline soil is presented. Based on the obtained data of laboratory experiments, the dependences for determining the non-eroding velocities of the water flow in the channels of the cohesive saline soils are obtained.
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Zabielska-Adamska, Katarzyna. "Characteristics of Compacted Fly Ash as a Transitional Soil." Materials 13, no. 6 (March 19, 2020): 1387. http://dx.doi.org/10.3390/ma13061387.
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Cohesive and non-cohesive soils show a number of properties typical of a given category. Cohesive soils are characterized by cohesion, and the properties of compacted soils closely depend on moisture at compaction. However, many researchers have found the existence of so-called mixed or transitional soils. Compacted transitional soils, macroscopically recognized as non-cohesive, are characterized by mechanical properties and hydraulic conductivity which are strictly dependent on the moisture content at compaction. The aim of this work is to show the influence of the content of fine particles in fly ash on the variation of California Bearing Ratio (CBR) values as a parameter strictly dependent on initial compaction. The CBR values were interpreted in terms of moisture at compaction, void ratio and intergranular void ratio. Three different research samples were selected with fine contents of 45%, 55% and 70%; all samples corresponded in terms of grading with sandy silt. Fly ash containing only non-plastic fines behaved as cohesive soils despite the lack of plasticity. The CBR values decreased with increasing moisture at compaction or void ratio. The CBR values, plotted as a function of the intergranular void ratio, have lower penetration resistance together with fine content.
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Aliev, T. A. "Canals in cohesive soils." Hydrotechnical Construction 19, no. 6 (June 1985): 301–7. http://dx.doi.org/10.1007/bf02028562.
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Nieto Leal, Andres, and Victor N. Kaliakin. "General response observed in cyclically loaded cohesive soils." Ciencia e Ingeniería Neogranadina 26, no. 1 (April 30, 2016): 21. http://dx.doi.org/10.18359/rcin.1673.
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<p>The response of cohesive soils subjected to cyclic loading is affected by different factors; the most important are soil type, stress or consolidation history, and specific test conditions. To better understand the behavior of cohesive soils subjected to cyclic loading, beginning in early 1960’s, a rather substantial body of experimental work has been performed. This has involved different types of soils, tested at different values of overconsolidation ratio, and subjected to different cyclic loading histories. This paper compiles the most important findings of the aforementioned experimental work on cohesive soils. It summarizes the general behavioral trends observed for cyclically loaded cohesive soils. Besides, several key characteristics of cyclically loaded cohesive soils that any rational mathematical simulation must account for have been identified, thus offering the general trends that should be taken into account in the development of new constitutive models used in predicting the response of such soils.</p>
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Abdalla, Tavga Aram, and Nihad Bahaaldeen Salih. "Hydrated Lime Effects on Geotechnical Properties of Clayey Soil." Journal of Engineering 26, no. 11 (November 1, 2020): 150–69. http://dx.doi.org/10.31026/j.eng.2020.11.10.
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Cohesive soils present difficulties in construction projects because it usually contains expansive clay minerals. However, the engineering properties of cohesive soils can be stabilized by using various techniques. The research aims to elaborate on the influences of using hydrated lime on the consistency, compaction, and shear strength properties of clayey soil samples from Sulaimnai city, northern Iraq. The proportions of added hydrated lime are 0%, 2.5%, 5%, 7.5% and 10% to the natural soil sample. The results yielded considerable effects of hydrated lime on the engineering properties of the treated soil sample and enhancement its strength. The soil's liquid limit, plasticity index, and optimum moisture content were decreased with the increase of hydrated lime percent. The soil's other geotechnical properties such as plastic limit, maximum dry density, and unconfined compressive strength were increased with the hydrated lime content increase. The oedometer test results produced a notable decrease in the compressibility characteristics of the lime-treated soil sample. Hence, hydrated lime is successfully contributed and can be considered as an effective material to improve the strength, compressibility, and consistency properties of the cohesive soils in Sulaimani city.
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Khassaf, Saleh Issa. "Effect of Cohesive and Non-Cohesive Soils on Equilibrium Scour Depth." Tikrit Journal of Engineering Sciences 14, no. 2 (June 30, 2007): 73–85. http://dx.doi.org/10.25130/tjes.14.2.04.
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In this research ,the effect of cohesive soils ( clay ) and non –cohesive soils sand on equilibrium scour depth was studied .Experiments were carried out on two types of clay and two types of sand as a bed material using an obstruction ( pier ) to create a local scour. The effect of flow velocity and Froude number on scour depth and the occurrence time of equilibrium scour depth were studied . The results show that for the same conditions, the rate of scour in the clayey soils is less than in sandy soils. Also the time required for occurrence of the maximum scour depth ( equilibrium depth ) in clayey soils is more than in sandy soils. Two formulas were found to predict the equilibrium scour depth in terms of Froude number ,the first is for clayey soils and the second for sandy soils .
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KHAN, Muhammad Imran, Muhammad IRFAN, Mubashir AZIZ, and Ammad Hassan KHAN. "GEOTECHNICAL CHARACTERISTICS OF EFFLUENT CONTAMINATED COHESIVE SOILS." Journal of Environmental Engineering and Landscape Management 25, no. 1 (November 28, 2016): 75–82. http://dx.doi.org/10.3846/16486897.2016.1210155.
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In developing countries like Pakistan, raw industrial effluents are usually disposed-off directly into open lands or in water bodies resulting in soil contamination. Leachate formation due to rainfalls in openly dumped solid waste also adds to soil contamination. In this study, engineering behavior of soils contaminated by two industrial effluents, one from paper industry (acidic) and another from textile industry (basic), has been investigated. Laboratory testing revealed significant effects of effluent contamination on engineering behavior of tested soils. Liquid limit, plasticity index, optimum moisture content and compression index of tested soils were found to increase with effluent contaminant, indicating a deterioration in the engineering behavior of soils. Whereas maximum dry density, undrained shear strength and coefficient of consolidation of the contaminated soils showed a decreasing trend. The dilapidation in engineering characteristics of soils due to the addition of industrial effluents could pose serious threats to existing and future foundations in terms of loss of bearing capacity and increase in settlement. Keywords: soil contamination, industrial waste, engineering behavior, effluent waste, leachate.
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Javankhoshdel, Sina, and Richard J. Bathurst. "Simplified probabilistic slope stability design charts for cohesive and cohesive-frictional (c-ϕ) soils." Canadian Geotechnical Journal 51, no. 9 (September 2014): 1033–45. http://dx.doi.org/10.1139/cgj-2013-0385.
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Design charts to estimate the factor of safety for simple slopes with cohesive-frictional (c-[Formula: see text]) soils are now available in the literature; however, the factor of safety is an imperfect measure for quantifying the margin of safety of a slope because nominal identical slopes with the same factor of safety can have different probabilities of failure due to variability in soil properties. In this study, simple circular slip slope stability charts for [Formula: see text] = 0 soils by Taylor in 1937 and c-[Formula: see text] soils published by Steward et al. in 2011 are extended to match estimates of factors of safety to corresponding probabilities of failure. A series of new charts are provided that consider a practical range of coefficient of variation for cohesive and frictional strength parameters of the soil. The data to generate the new charts were produced using conventional probabilistic concepts together with closed-form solutions for cohesive soil cases, and Monte Carlo simulation in combination with conventional limit equilibrium-based circular slip analyses using the SVSlope program for c-[Formula: see text] soil cases. The charts are a useful tool for geotechnical engineers when making a preliminary estimate of the probability of failure of a simple slope without running Monte Carlo simulations.
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Izzo, Michael Z., and Marta Miletić. "Sustainable Improvement of the Crack Resistance of Cohesive Soils." Sustainability 11, no. 20 (October 19, 2019): 5806. http://dx.doi.org/10.3390/su11205806.
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Desiccation cracking of cohesive soils is the development of cracks on the soil surface as a result of a reduction in the soil moisture content. The decrease in soil surface area owing to the desiccation of cohesive soils has an undesirable impact on the mechanical, hydrological, thermal, and physico-chemical properties. Many efforts have been made to improve the desiccation crack resistance of cohesive soils, but the current solutions raise a number of environmental issues, increasing the demand for sustainable soil improvement alternatives. Therefore, the main objective of this study is to investigate novel eco-friendly soil improvement techniques, such as recycled carpet fibers and a gelatin-based bioplastic, and their effect on desiccation cracking in cohesive soils. The improvement of soil crack resistance was studied by conducting desiccation cracking tests on plain and improved soils. In addition, image processing was conducted to quantitatively describe the effect of soil improvement type on the geometrical characteristics of crack patterns. Each soil improvement technique enhanced the soil strength and reduced cracking at room temperature, at an elevated temperature, and when subjecting to cyclic wetting and drying. The addition of bioplastics proved to be the most effective solution, thus demonstrating a viable option to advance future sustainable engineering practices.
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Harrop-Williams, Kingsley, and Samuel Ejezie. "Stochastic description of undrained soil strength." Canadian Geotechnical Journal 22, no. 4 (November 1, 1985): 437–42. http://dx.doi.org/10.1139/t85-063.
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The probabilistic description of the undrained strength of cohesive soils is important in the reliability analysis of short-term slope stability. In this paper the undrained strength is derived to be identically beta-distributed with depth. The approach is through consideration of particle-to-particle effects in the soil and the overall contribution of both cohesion and friction to the undrained strength. The final result confirms experimental investigation in these soils.
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Yang, Shu-Rong, Wei-Hsing Huang, and Yu-Tsung Tai. "Variation of Resilient Modulus with Soil Suction for Compacted Subgrade Soils." Transportation Research Record: Journal of the Transportation Research Board 1913, no. 1 (January 2005): 99–106. http://dx.doi.org/10.1177/0361198105191300110.
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The variations of resilient modulus with the postconstruction moisture content and soil suction for cohesive subgrade soils were evaluated. In particular, the effects of relative compaction of the subgrade on the suction and resilient modulus were investigated. To simulate subgrade soils at in-service conditions, soil specimens were compacted at various relative compactions and optimum moisture content and then saturated to equilibrium moisture content to test for resilient modulus and soil suction. The filter paper method was used to measure the total and matric suctions of two cohesive soils. Test findings demonstrated that resilient modulus correlated better with the matric suction than with total suction. Matric suction was found to be a key parameter for predicting the resilient modulus of cohesive subgrade soils. A prediction model incorporating deviator stress and matric suction for subgrade soil resilient modulus was established.
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Al-Neami, Mohammed A., Falah H. Rahil, and Yaseen H. Al-Ani. "Behavior of Cohesive Soil Reinforced by Polypropylene Fiber." Engineering and Technology Journal 38, no. 6A (June 25, 2020): 801–12. http://dx.doi.org/10.30684/etj.v38i6a.109.
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For any land-based structure, the foundation is very important and has to be strong to support the entire structure. In order for the foundation to be strong, the soil underneath it plays a very critical role. Some projects where the soil compacted by modifying energy is insufficient to achieve the required results, so the additives as a kind of installation and reinforcement are used to achieve the required improvement. This study introduces an attempt to improve cohesive soil by using Polypropylene Fiber instead of conventional kinds used in soil stabilization. Three different percentages (0.25%, 0.5%, and 0.75% by dry weight of soil) and lengths (6, 12, and 18) mm of fiber are mixed with cohesive as a trial to enhance some properties of clay. The results of soil samples prepared at a dry density at three different water conditions (optimum water content, dry side, and wet side) showed that the increase of the percentage and length of polypropylene fiber causes a reduction in the maximum dry density of soils. Soil cohesion increases with the increase of PPF up to 0.5% then decreased. The length of Polypropylene fiber has a great effect on the cohesion of soil and adding 0.5% Polypropylene fibers with a length of 18mm to the soils consider the optimum mix for design purposes to improve the soil. Finally, the soil reinforced by PPF exhibits a reduction in the values of the compression ratio (CR) and accelerates the consolidation of the soil.
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Kamphuis, J. W., P. N. Gaskin, and E. Hoogendoorn. "Erosion tests on four intact Ontario clays." Canadian Geotechnical Journal 27, no. 5 (October 1, 1990): 692–96. http://dx.doi.org/10.1139/t90-082.
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Erosion tests were carried out on four natural intact cohesive soils from Ontario using laboratory flume tests with both clear water and water with sand in suspension. It was found that erosion was initiated at discontinuities. The critical shear stresses were low and were not related to the geotechnical properties of the soils. Higher rates of erosion occurred with the sand suspension, and erosion appeared to be controlled by the movement of the sand particles. It is suggested that where the eroding water contains particles in suspension, such as in river beds and along shorelines of cohesive soil, erosion may be controlled by the size of the particles rather than the properties of the cohesive soil or the eroding water. Key words: erosion, cohesive soil, flume test.
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SALAHELDIN MOSTAFA, TAREK. "Erosion resistance of cohesive soils." Journal of Hydraulic Research 46, no. 6 (2008): 777. http://dx.doi.org/10.3826/jhr.2008.2794.
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Mori, Akira, and Masahito Tamura. "Hydrofracturing Pressure of Cohesive Soils." Soils and Foundations 27, no. 1 (March 1987): 14–22. http://dx.doi.org/10.3208/sandf1972.27.14.
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Doherty, Paul, and Kenneth Gavin. "Pile Aging in Cohesive Soils." Journal of Geotechnical and Geoenvironmental Engineering 139, no. 9 (September 2013): 1620–24. http://dx.doi.org/10.1061/(asce)gt.1943-5606.0000884.
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Mostafa, Tarek Salaheldin, Jasim Imran, M. Hanif Chaudhry, and Irwin B. Kahn. "Erosion resistance of cohesive soils." Journal of Hydraulic Research 46, no. 6 (November 2008): 777–87. http://dx.doi.org/10.1080/00221686.2008.9521922.
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Lee, Woojin, N. C. Bohra, A. G. Altschaeffl, and T. D. White. "Resilient Modulus of Cohesive Soils." Journal of Geotechnical and Geoenvironmental Engineering 123, no. 2 (February 1997): 131–36. http://dx.doi.org/10.1061/(asce)1090-0241(1997)123:2(131).
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Geniev, G. A. "Dynamic strength of cohesive soils." Soil Mechanics and Foundation Engineering 34, no. 4 (July 1997): 101–3. http://dx.doi.org/10.1007/bf02465940.
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Fener, Mustafa, Sair Kahraman, Yakup Bay, and Osman Gunaydin. "Correlations between P-wave velocity and Atterberg limits of cohesive soils." Canadian Geotechnical Journal 42, no. 2 (April 1, 2005): 673–77. http://dx.doi.org/10.1139/t04-102.
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Undisturbed and disturbed samples of cohesive soils were collected from eight different locations to investigate the possibility of estimating the Atterberg limits of cohesive soils from P-wave velocity measurements. Each soil type was classified according to the Unified Soil Classification System, and then Atterberg limits of soils were determined and P-wave velocity measurements carried out on the undisturbed samples of each soil type. P-wave velocity values were correlated with the corresponding values of Atterberg limits. It was found that liquid limit, plastic limit, and plasticity index exhibit good correlations with P-wave velocity. The relations follow a logarithmic function. Liquid limit, plastic limit, and plasticity index decrease with an increase in P-wave velocity. In addition, liquid limit, plastic limit, and plasticity index exhibit very good correlations with the ratio of P-wave velocity to water content. Liquid limit, plastic limit, and plasticity index decrease logarithmically with an increase in the ratio of P-wave velocity to water content. It can be concluded that the Atterberg limits of cohesive soils can be predicted from P-wave velocity measurements for preliminary investigations. The developed equations have some limitations and further study is required in this area.Key words: Atterberg limits, cohesive soils, P-wave velocity, regression analysis.
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Zhang, Junhui, Junhui Peng, Yejuan Chen, Jue Li, and Feng Li. "Estimation of Soil-Water Characteristic Curve for Cohesive Soils with Methylene Blue Value." Advances in Civil Engineering 2018 (July 5, 2018): 1–7. http://dx.doi.org/10.1155/2018/9213674.
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This study described a new methylene blue test to measure the methylene blue value (MBV) for 15 cohesive soils and established the relationship between MBV and plasticity index (PI) and between MBV and percent passing No. 200 sieve (P200), respectively. Thereafter, the soil-water characteristic curves (SWCCs) for 15 cohesive soils based on Fredlund and Xing’s model were generated by the pressure plate test. Then, regression equations for determining the four fitting parameters in a previously developed SWCC equation by using the measured MBV were utilized to generate the SWCC for the cohesive soils. At the same time, the slope parameter, bf, in the SWCC equations was found to be associated with the moisture susceptibility of cohesive soils. A higher bf value indicates that the material is more moisture susceptible. In addition, a lower MBV/PI/P200 shows a lower suction at the same degree of saturation; on the other hand, a higher MBV/PI/P200 presents a higher suction. Therefore, the moisture-holding capacity of cohesive soils increases with increasing MBV, PI, and P200. Finally, the proposed estimation method was validated by a comparison between the four determined fitting parameters from MBV and the pressure plate test.
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Nunes, Vinicius de Jesus, Elton da Silva Leite, José Maria de Lima, Ronny Sobreira Barbosa, Davi Ney Santos, Fabiane Pereira Machado Dias, and Júlio César Azevedo Nóbrega. "Soil preparation systems and type of fertilization as affecting physical attributes of cohesive soil under eucalyptus in Northeastern Brazil." Acta Scientiarum. Agronomy 45 (November 22, 2022): e58010. http://dx.doi.org/10.4025/actasciagron.v45i1.58010.
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Cohesive Oxisols are widely used for cultivating eucalyptus in the Coastal Tablelands of the northeastern region of Brazil. However, mechanization and plant cultivation in these soils are difficult because of their cohesive layers. Therefore, the objective of this study was to identify better combinations between tillage systems and types of fertilization to improve the physical attributes of cohesive soil, with the aim of improving eucalyptus growth. The experimental design was completely randomized in a 4 × 2 factorial scheme (soil preparation × fertilization). The tillage systems tested were: i) conventional tillage (CT) - one plowing combined with two harrowings, ii) minimum tillage (MT) - subsoiling down until 0.57 m depths in the planting line, iii) no-tillage type 1 (NT1) - planting in 0.3 m-deep pits, and iv) no-tillage type 2 (NT2) - planting in 0.6 m-deep pits. The types of fertilization tested were mineral (MF) and organic fertilization (OF). The diameter of the soil aggregates was reduced after being subjected to any combination of cohesive soils. Furthermore, OF provided the best levels of plant-available water, attenuating the adverse conditions of the cohesive layer. MT, NT1, and NT2 improved the soil physical attributes when compared to CT. Therefore, the combination of either NT1 or NT2 with OF, followed by the combination of either NT1 or NT2 with MF, was determined to be the best way to cultivate eucalyptus on cohesive soils.
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Mazurek, Kerry A., and Tanvir Hossain. "Scour by jets in cohesionless and cohesive soils." Canadian Journal of Civil Engineering 34, no. 6 (June 1, 2007): 744–51. http://dx.doi.org/10.1139/l07-005.
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A technique is developed in this paper to unify the methods of analyzing scour by turbulent water jets in cohesionless and cohesive soils. Data from previous studies using circular turbulent impinging jets and circular turbulent wall jets are used to compare the scour in low void ratio cohesive soils to that in uniform sands and gravels. Scour by these jets is related to the dimensionless excess stress on the soil bed. It is seen that this parameter will likely work well for developing a method to predict scour for circular wall jets that is applicable to both materials. However, a circular impinging jet appears to vary appreciably in its interaction with the bed between the two types of soil, which makes developing a unified method to predict scour by impinging jets more difficult. Key words: erosion, scour, water jets, cohesionless sediments, cohesive sediments, fine-grained soils, coarse-grained soils.
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Viveka, Tudumu, Namburu Sandeep Kumar, and K. Shyam Chamberlin. "Stabilization of Slopes of Sandy Soils by Using Geosynthetics." IOP Conference Series: Materials Science and Engineering 1197, no. 1 (November 1, 2021): 012081. http://dx.doi.org/10.1088/1757-899x/1197/1/012081.
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Abstract This paper intended on the interactive performance of geo-synthetics in slope stabilization of non-cohesive soils. Presently, geo-synthetics are performing crucial role in geo-technical uses for reinforcing of soils for slope of stabilization, soil reinforcement for foundations, R E walls for highway and flyover construction etc. Usually, cohesion less soil is ideal for backfills of the embankments as of its exceptional drainage properties, at a low-level hydrostatic pressure built-up on slopes and excessive internal resistance owing to friction and interlocking. To research this property of geo-synthetics, relative density and shear box tests are done on the soil by varying geosynthetics for assessment of the shear parameters of sample. The mosquito reinforcement net as reinforcement on cohesionless soils, improvement in the angle of internal friction of the soil was observed by twenty-two percentage that the shear strength to be improved by 26.5%. So, the soil’s lateral load resistance or load transfer capacity improved to prevent the slope failure thereby saves the entire structure.
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Melo, Diego Vandeval Maranhão de, Brivaldo Gomes de Almeida, Edivan Rodrigues de Souza, Laércio Santos Silva, and Paulo Klinger Tito Jacomine. "Structural quality of polyacrylamide-treated cohesive soils in the coastal tablelands of Pernambuco." Revista Brasileira de Ciência do Solo 38, no. 2 (April 2014): 476–85. http://dx.doi.org/10.1590/s0100-06832014000200012.
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Water-soluble polymers are characterized as effective flocculating agents due to their molecular features. Their application to soils with horizons with structural problems, e.g, a cohesive character, contributes to improvements in the physical quality and thus to the agricultural suitability of such soils. The purpose of this study was to evaluate the structural quality of soils with cohesive horizons of coastal tablelands in the State of Pernambuco treated with polyacrylamide (PAM) as chemical soil conditioner. To this end, three horizons (one cohesive and two non-cohesive) of a Yellow Argisol (Ultisol) were evaluated and to compare cohesive horizons, the horizon of a Yellow Latosol (Oxisol) was selected. The treatments consisted of aqueous PAM solutions (12.5; 50.0; 100.0 mg kg-1) and distilled water (control). The structural aspects of the horizons were evaluated by the stability (soil mass retained in five diameter classes), aggregate distribution per size class (mean weight diameter- MWD, geometric mean diameter - GMD) and the magnitude of the changes introduced by PAM by measuring the sensitivity index (Si). Aqueous PAM solutions increased aggregate stability in the largest evaluated diameter class of the cohesive and non-cohesive horizons, resulting in higher MWD and GMD, with highest efficiency of the 100 mg kg-1 solution. The cohesive horizon Bt1 in the Ultisol was most sensitive to the action of PAM, where highest Si values were found, but the structural quality of the BA horizon of the Oxisol was better in terms of stability and aggregate size distribution.
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Gnanapragasam, Nirmala. "Active earth pressure in cohesive soils with an inclined ground surface." Canadian Geotechnical Journal 37, no. 1 (February 1, 2000): 171–77. http://dx.doi.org/10.1139/t99-091.
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An analytical solution is developed to determine the active lateral earth pressure distribution on a retaining structure when it consists of a cohesive backfill (internal friction angle ϕ > 0, cohesion c > 0) with an inclined ground surface. The solution derived encompasses both Bell's equation (for cohesive or cohesionless backfill with a horizontal ground surface) and Rankine's solution (for cohesionless backfill with an inclined ground surface). The orientation of the failure surface is also determined. Results indicate that, unlike the soil-wall scenarios of Bell and Rankine where the failure planes are parallel with a fixed orientation independent of the overburden pressure, for sloping cohesive backfill (ϕ > 0, c > 0) the slope of the failure surface is a function of the overburden pressure and becomes shallower with depth, thus forming a curvilinear failure surface. The solution developed can also be used to check the sustainability of a slope. The analytical solution can be programmed conveniently in a computer.Key words: retaining structure, active earth pressure, cohesive backfill.
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Wrzesiński, Grzegorz. "Permeability coefficient tests in non-cohesive soils." Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 29, no. 1 (April 4, 2020): 72–80. http://dx.doi.org/10.22630/pniks.2020.29.1.7.
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The paper aims to comparison the permeability coefficient in non-cohesive soils by the method of test pumping and based on tests in a consolidometer. The tests were carried out on 18 types of non-cohesive soils with different fraction. Pumping tests were carried out according to the standard method i.e. by making one well with a diameter of 400 mm and installing two piezometers at different distances from the well. The water table change was measured in piezometers during water pumping from the well. Tests in the consolidometer were carried out on soil samples that were first compacted to the same density index as in the test site. The tests were carried out with a continuous inflow of water from below with constant gradients of 0.50. The tests presented in the paper allow to verify and compare the values of the permeability coefficient in non-cohesive soils determined in the field and laboratory tests.
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Kired, Fawzia, Miloš Šešlija, Tiana Milović, Anka Starčev-Ćurčin, Vesna Bulatović, and Nebojša Radović. "Stabilization of Different Soil Types Using a Hydraulic Binder." Buildings 13, no. 8 (August 10, 2023): 2040. http://dx.doi.org/10.3390/buildings13082040.
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This paper presents an analysis of the stabilization of different soil types using a hydraulic binder. A study was carried out on soils that can be classified into two groups: cohesive and non-cohesive soils. Clay soils of medium and low plasticity according to the USCS classification were used as cohesive materials, while the sandy material containing dust was considered as non-cohesive material. Samples were taken from fifteen locations in Vojvodina province, Serbia. A hydraulic binder was used as a binder based on cement and lime. The amounts of the binder were estimated at 3, 5, 7, and 9%. In order to determine the basic physical and mechanical characteristics of the specimens, the following tests were performed: unconfined compressive strength after 7 and 28 days, indirect tensile strength after 7 and 28 days, as well as the California Bearing Ratio. Based on the obtained results, it can be concluded that increasing the amount of binder results in an increase in the subgrade load-bearing capacity. However, it should be emphasized that the subgrade containing non-cohesive material had a lower growth in the load-bearing capacity than those with the cohesive material.
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Abbas, Jawdat K., and Ayad S. Sabbar. "Finite Element Analysis for Bearing Capacity of Rectangular Footing Resting Near Sloped Cohesive Soil." Tikrit Journal of Engineering Sciences 18, no. 3 (September 30, 2011): 33–41. http://dx.doi.org/10.25130/tjes.18.3.04.
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Finite element method is used to investigate the ultimate bearing capacity of rectangular footing resting on cohesive soil near slope. The effect of footing aspect ratio (L/B), distance ratio (b/B), and slope angle (β) on the bearing capacity are calculated. A new reduction factor (Rs) is proposed to compute the ultimate bearing capacity for rectangular footing adjacent to slope of cohesive soil from ultimate bearing capacity for similar rectangular footing resting on ground level of cohesive soils. This study shows that the ultimate bearing capacity for rectangular footing adjacent to slope of cohesive soils decreases when slope angle (β) and aspect ratio (L/B) increases. Also the ultimate bearing capacity increases when the distance ratio (b/B) increases. Finally, the effect of slope diminishes as the distance ratio (b/B) equal, or exceeds 0.75
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Bagriacik, Baki, Bahadir Ok, and Mustafa Tahseen Mohamed Ali Kahiyah. "An experimental study on improvement of cohesive soil with eco-friendly guar gum." Soils and Rocks 44, no. 2 (June 18, 2021): 1–9. http://dx.doi.org/10.28927/sr.2021.060020.
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Recently, the demand for environmentally friendly products has been increasing worldwide. In this study, the improvement of cohesive soil with a biopolymer material (Guar Gum), which is a type of additive and organic, environmentally friendly, is investigated. For this purpose, various laboratory tests have been conducted on the biopolymer-added soils, including the compaction test, the Atterberg limits test, and the unconfined compressive strength test. The samples for tests have been prepared that the biopolymer has been mixed with the soil in three different proportions to determine the optimum mixing ratio. Also, in the biopolymer-added soils, some samples have been cured at varying times to determine the effect of curing periods on their strength. For comparison, the tests performed on improved soils have been also carried out on the untreated cohesive soil. For a comprehensive evaluation, scanning electron microscopy analyses (SEM analyses) was carried out on some samples. On the other hand, X-ray fluorescence analysis (XRF analysis) was performed to have an idea about the composition of the cohesive soil. Consequently, the biopolymer additive material has improved the geotechnical properties of the cohesive soil in all mixing ratios and curing times. Moreover, the optimum mixing ratio has been obtained at 1% according to the results of tests.
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Wilk, Krzysztof. "The meaning of effective soil parameters for determining of the bearing capacity of cohesive soils." Budownictwo i Architektura 13, no. 2 (June 11, 2014): 057–64. http://dx.doi.org/10.35784/bud-arch.1878.
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The paper presents the analysis of the bearing capacity of cohesive soils, which was calculated based on the PN-EN-1997-1 methodology. This computations take into account the effect of pore water pressure on the soil strength parameters. The parameters for calculating the strength of the soil can be determined by direct tests (triaxial apparatus) or by indirect methods. Used in the previous norm PN-81/B-03020 correlations of physical parameters and strength parameters relate to the total stress. They do not include, what part of the stress is carried by an increase the pore water pressure, and what part acts on the soil skeleton. The problem of dispersion efficiency of excessive the pore water pressure during load relates in particular the soils with the fine particle sizes - cohesive soils. There is no defined dependencies, which can be used in indirect determining the bearing capacity of cohesive substrate according to PN-EN-1997-1.
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Basheer, I. A. "Empirical modeling of the compaction curve of cohesive soils." Canadian Geotechnical Journal 38, no. 1 (February 1, 2001): 29–45. http://dx.doi.org/10.1139/t00-068.
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Compaction curves (or densitymoisture relationships) of cohesive soils are essential components for establishing practical and reliable criteria for effective control of field compaction. In this paper, modules built from empirical models for simulating the compaction curves of cohesive soils based on easily measured basic soil properties and compaction energy were developed using both statistical regression and artificial neural networks (ANNs) techniques. A large number of compaction curves pertaining to a wide variety of fine-grained soils were collected and used in modeling. The developed modules were able to predict compaction curves of soils with good accuracy, with the ANN-based module outperforming the statistical-based analog. The compaction modules were utilized to inquire about the compactibility behavior of fine-grained soils in relation to their properties and the compaction energy used. Besides their use as independent compaction curve predictors, the compaction modules can be used as supplementary units in numerical models for solving geotechnical engineering problems and as tools useful in preliminary design phases and feasibility studies.Key words: cohesive soils, compaction curve, modeling, neural networks, regression.
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Ofrikhter, Vadim Grigor’evich, and Yan Vadimovich Ofrikhter. "RESULTS OF COMPRESSION TESTING ON PSEUDO-COHESIVE SOIL." Vestnik MGSU, no. 9 (September 2015): 61–72. http://dx.doi.org/10.22227/1997-0935.2015.9.61-72.
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Natural non-treated sand reinforced with randomly oriented short polypropylene fibers of 12 mm in length was tested to determine creep characteristics. This study is a part of the research aimed at encouraging fibrosand (FRS) application in subsoils, embankments and retaining wall constructions. Fiber content was accounted for 0.93 %. Twin specimens were put to creep tests (1-D compression) using the two curve method. The test results were analyzed and checked with the use of ageing, hardening and hereditary creep theories. On the basis of approximation of the test results the creep deformation equation at constant stress for tested fibrosand was obtained. The assessment of fibrosand secondary compression was carried out by the FORE method. As a result, the value of the void ratio by the end of the secondary compression had been eu=0.7041. For determination of the beginning of the secondary compression the rate equation was superimposed on the empirical curve. The point of the graph divergence is the beginning of the secondary compression process. The secondary compression had begun by the time moment being equal to 9360 min. The void ratio by the beginning of the secondary compression had amounted to 0.70574. Fibrosand is a specific type of improved soil relating to so-called pseudo-cohesive soil. This type of soil is characterized by cohesion like cohesive soils, but, at the same time, by the filtration coefficient of about 1 m per day like non-cohesive soils. Pseudo-cohesive soil testing helps to understand the distinctive features of the stress-strain state of this kind of materials. Municipal solid waste also relates to them.
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Виноградов, А. Ю., О. В. Зубова, and Е. А. Парфенов. "Calculation of erosion scour of cohesive soil." Известия СПбЛТА, no. 235 (June 1, 2021): 187–95. http://dx.doi.org/10.21266/2079-4304.2021.235.187-195.
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Проведен анализ существующих способов оценки размыва грунтов в гидротехнических и водопропускных сооружениях, показывающий, что определение глубины и скорости размыва проводится без учета физических свойств связных грунтов. Таким образом, данные параметры оцениваются по эмпирическим зависимостям и с существенными погрешностями. Опытные данные по размыву связных грунтов доказывают, что большая удельная поверхность и гидрофильность глинистых частиц приводят к разуплотнению и выносу микроагрегатов грунта в поток. Предложена математическая модель расчета глубины размыва связных грунтов в зависимости от касательного напряжения в грунте. Учет показателей сцепления и угла внутреннего трения в данной модели позволит избежать погрешностей в расчетах. The analysis of existing methods for assessing soil erosion in hydraulic engineering and culverts, showing that the determination of the depth and rate of erosion is carried out without taking into account the physical properties of cohesive soils. Thus, these parameters are estimated using empirical relationships and with significant errors. Experimental data on erosion of cohesive soils prove that the large specific surface area and hydrophilicity of clay particles lead to decompaction and the removal of soil microaggregates into the flow. A mathematical model is proposed for calculating the depth of erosion of cohesive soils depending on the shear stress in the soil. Taking into account the adhesion indicators and the angle of internal friction in this model will avoid errors in the calculations.
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Meguid, Mohamed A., and Joe Mattar. "Investigation of Tunnel-Soil-Pile Interaction in Cohesive Soils." Journal of Geotechnical and Geoenvironmental Engineering 135, no. 7 (July 2009): 973–79. http://dx.doi.org/10.1061/(asce)gt.1943-5606.0000004.
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Vishweshwaran, Muralidaran, and Evangelin Ramani Sujatha. "Geotechnical Investigation of Gelatin Biopolymer on Cohesive Soils." Sustainability 15, no. 3 (January 20, 2023): 2041. http://dx.doi.org/10.3390/su15032041.
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Gelatin, a biopolymer derived from animal proteins, has been selected to stabilize three fine-grained soils by determining select index and engineering properties. Specimens for California Bearing Ratio (CBR) were tested using three different curing methods, i.e., thermally cured at 60 °C, unsoaked, and 7 days air-cured submerged specimens. The amount of gelatin added to the soil ranged from 0.5% to 2% by soil weight. The sequence of the interaction between gelatin and the clays is as follows: (A) The biopolymer solution is adsorbed and agglomerated onto the surface of the clay. (B) The presence of Al3+, Si4+, and K+ ions on the clay promotes the blending of connective linkages with negatively charged gelatin. (C) The connection reinforcements harden with the curing period and subsequent drying of the stabilized soils. (D) Drying of the gelatin–clay complex also establishes alternative bonding modes such as van der Waals interactions and ligand exchange. The biopolymer formed dry, rigid films after 72 h which were responsible for coating and reinforcing the soil particles. Thermal curing by 1% addition of gelatin yielded the maximum CBR of 91.42%, 141.1%, and 122.3% for high compressible clay, low compressible clay, and low compressible silt, respectively, and a maximum Unconfined Compressive Strength (UCS) of 3968 kN/m2 for the low compressible clay. The UCS results revealed that brittle failure was predominant for the gelatin-amended soils after 28 days of curing while shear failure was observed for the treated soils tested 2 h after sample preparation. Tests on pH revealed that the gelatin-stabilized soils displayed marginal variations after 28 days. Spectroscopic analysis revealed the various types of bonds between gelatin and the clays. A reduction in mass of 9% was observed for the alternate wetting and drying of the high compressible clay after a period of 12 cycles. The adsorption of the clay–gelatin complex was indicated by variation in average particle diameter and specific surface. Savings in 450 m3 and 93.75 m3 of coarse aggregates and dense bituminous macadam, respectively, were observed for a 1 km pavement for the stabilized low compressible clay.
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Krylov, Artem A., Dmitry A. Alekseev, Sergey A. Kovachev, Elena A. Radiuk, and Mikhail A. Novikov. "Numerical Modeling of Nonlinear Response of Seafloor Porous Saturated Soil Deposits to SH-Wave Propagation." Applied Sciences 11, no. 4 (February 19, 2021): 1854. http://dx.doi.org/10.3390/app11041854.
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Numerical modeling of seismic response of soil deposits is usually conducted as part of seismic hazard assessment, preceding facility construction in any tectonically active regions, including offshore sites. A significant feature of subsea soils is their porous and water-saturated structure. Thus, the purpose of the present study is to introduce a procedure for modeling nonlinear behavior of porous, moist soils during SH-wave propagation, to verify it and compare response for synthetic soil profiles with porous medium parameters specific for low moisture onshore and high moisture offshore sites with cohesive and non-cohesive soils. The well-known and approved NERA code was used as a basis and improved to incorporate the Biot and Gassman equations for elastic waves propagation in a fluid-saturated porous solid. The applicability of the presented approach was substantiated for integration into other well-known algorithms. Obtained results showed good agreement between the simulated by different methods and observed spectra. The modeling also showed that the response of cohesive and non-cohesive soils with moisture specific both for onshore and offshore sites is explained by effects of resonances and effect of seismic amplitude saturation, which, in turn, depend on the corresponding value of the layer thickness and S-wave impedance for porous saturated soil layer. The proposed scheme could have significant practical usage for studying the effect of porous medium parameters on the seismic response of the moist soil deposits.
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Kucharczyk, Krystian, Andrzej Głuchowski, Maciej Miturski, and Wojciech Sas. "Influence of Load Frequency on Cohesive Soil Respond." Geosciences 8, no. 12 (December 10, 2018): 468. http://dx.doi.org/10.3390/geosciences8120468.
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The mechanism of cohesive soils response to cycling loading is less investigated compared to cohesionless soils. Multiple load-unload cycles cause significant changes in the structure of cohesive soils, which result in complex behaviour under the given load. The aim of the paper was to investigate and study the influence of load frequency on cohesive soil reaction. In order to obtain results, tests were conducted using the cyclic triaxial apparatus. Three cyclic tests were carried out, each for different frequency −0.5 Hz, 1.0 Hz, 2.0 Hz and one static triaxial test. The maximal value of deviator stress qmax, used in the cyclic tests, was set to 40 kPa. Afterwards samples were unloaded to qmin = 30 kPa. Cyclic loading triaxial tests were performed in a consolidated-undrained (CU) one-way loading manner, a sinusoidal waves were used. After the cycling loading was completed, a static triaxial shear test was conducted. Changes in the cohesive soil responses depending on cycling load frequency were presented in the paper. Differences in the accumulation of plastic strains were noticed, as well as changes of degradation index values, resilient degradation index values and differences in the excess pore water pressure development.
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Glade, Rachel C., Michael M. Fratkin, Mehdi Pouragha, Ali Seiphoori, and Joel C. Rowland. "Arctic soil patterns analogous to fluid instabilities." Proceedings of the National Academy of Sciences 118, no. 21 (May 21, 2021): e2101255118. http://dx.doi.org/10.1073/pnas.2101255118.
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Slow-moving arctic soils commonly organize into striking large-scale spatial patterns called solifluction terraces and lobes. Although these features impact hillslope stability, carbon storage and release, and landscape response to climate change, no mechanistic explanation exists for their formation. Everyday fluids—such as paint dripping down walls—produce markedly similar fingering patterns resulting from competition between viscous and cohesive forces. Here we use a scaling analysis to show that soil cohesion and hydrostatic effects can lead to similar large-scale patterns in arctic soils. A large dataset of high-resolution solifluction lobe spacing and morphology across Norway supports theoretical predictions and indicates a newly observed climatic control on solifluction dynamics and patterns. Our findings provide a quantitative explanation of a common pattern on Earth and other planets, illuminating the importance of cohesive forces in landscape dynamics. These patterns operate at length and time scales previously unrecognized, with implications toward understanding fluid–solid dynamics in particulate systems with complex rheology.
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Saye, Steven R., Bryan P. Kumm, and Alan J. Lutenegger. "Estimating overconsolidation ratio (OCR) in structured and unstructured cohesive soil with field vane tests referencing soil index properties." Canadian Geotechnical Journal 58, no. 1 (January 2021): 125–41. http://dx.doi.org/10.1139/cgj-2019-0414.
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Estimation of the preconsolidation stress and overconsolidation ratio (OCR) in uniform cohesive soils using a field vane is variably impacted by the combined effects of soil type and plasticity, geologic history, structured vs. unstructured behavior, and the presence of sand or organic matter. Published empirical correlations for cohesive soils consider the effects of soil type and plasticity, but significant variability can occur with changes in soil structure and organic matter content for specific instances. The adaption of the “stress history and normalized soil engineering properties” (SHANSEP) format improves the characterization of overconsolidated soils using field vane tests by applying a proposed empirical approach to identify structured soils from unstructured soils and updating the SHANSEP-based approach to separately evaluate structured and unstructured soils. Validation of the correlation coefficients for individual projects will be needed as the approach is applied to new geologic materials and with potentially different field vane equipment and laboratory testing procedures used to characterize the soils. This additional testing provides an opportunity to improve the correlations for specific conditions and reduce the variability in the OCR assessments.
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Rahimnejad, Reza, and Phillip S. K. Ooi. "Model for the Erosion Rate Curve of Cohesive Soils." Transportation Research Record: Journal of the Transportation Research Board 2657, no. 1 (January 2017): 19–28. http://dx.doi.org/10.3141/2657-03.
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The scour rate found by the cohesive soil-erosion function apparatus (SRICOS-EFA) method provides more accurate and realistic scour predictions than the Richardson and Davis equation, which tends to overpredict scour, especially in cohesive soils. Scour of cohesive soil occurs more slowly than scour of cohesionless soils. The time-dependent nature of scour of cohesive soils can be understood by considering both the variation of flood intensity over time and the scour characteristics of the soil, with an erosion rate curve obtained with an erosion function apparatus (EFA). One drawback of the SRICOS-EFA method is that the EFA requires a significant cost outlay. A model for the erosion rate curve is proposed on the basis of EFA tests conducted on 31 undisturbed fine-grained soils from five water channels on the island of Oahu, Hawaii. A hyperbolic regression model was developed with four explanatory variables: water content, liquid limit, plasticity index, and activity, which are easily measured in the laboratory. Parameter estimates for the model were then obtained using nonlinear ordinary least squares. A key element of the model is that the parameter estimates logically affect the sign and magnitude of critical shear stress, in accord with observed soil behavior—that is, it was found that the model captured the effects of water content and plasticity index on the critical shear stress quite effectively. Also, the model provided reasonable estimates of the 31 erosion rate curves. Use of this model in the SRICOS-EFA method to estimate scour depth can result in less scour and can result in significant bridge cost savings.
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Chi, Chao-Ming, and Zheng-Shan Lin. "The Bearing Capacity Evaluations of a Spread Footing on Single Thick Stratum or Two-Layered Cohesive Soils." Journal of Marine Science and Engineering 8, no. 11 (October 29, 2020): 853. http://dx.doi.org/10.3390/jmse8110853.
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Nowadays many countries plan to increase the percentages of renewable energies by developing offshore wind power. Due to the large sizes of offshore foundations, such as spudcan footings of jack-up barges or pile anchors of wind turbines, the affected soil depth range caused by the foundation under loading can be relatively deep, so the affected range may include a single thick layer or stratified soils. This paper utilizes limit analysis and FLAC numerical simulation to investigate the bearing capacity of a footing on single thick stratum or two-layered cohesive soils. Under nature deposition condition, the undrained shear strength of most cohesive soil approximately increases linearly as the depth increases. The closed-form upper bound solutions of fully rough or fully smooth footings on thick cohesive soils are provided, for the purpose of fast evaluations in practical engineering, and the outcomes are within the results from the FLAC simulation and slip circle method. The problems of punch-through shear failure or soil squeezing could be critical for two-layered soils under some conditions, and the associated bearing factors and the failure mechanisms from different methods are demonstrated and discussed in the article.