Shear Strength of Soils

2015 ◽  
pp. 249-312
Keyword(s):  
Shear Strength ◽  
Bearing Capacity ◽  
Continuum Mechanics ◽  
Geotechnical Engineering ◽  
Soil Mass ◽  
Physico Chemical ◽  
Soil Deposits ◽  
Intrinsic Capacity ◽  
The Stability ◽  
Multi Phase

Shear strength is a very important property of soils. The concept is used by geotechnical engineers in estimating the bearing capacity of foundations and in assessing the stability of retaining walls, slopes, and embankments and the design and construction of highway and airfield pavements. The shear strength of a soil can be regarded as its intrinsic capacity to resist failure when forces act on the soil mass. The strength is a function of the type as well as the physico-chemical make-up of the soil. This chapter explores the strength theories that are used in geotechnical engineering and which derive essentially from the classical theories of elasticity and plasticity. Such theories are usually modified when used by soil engineers in recognition of the discrete and multi-phase nature of soil deposits. It is important therefore to understand some of the fundamental concepts or hypothesis of continuum mechanics to be able to appreciate the limitations and applicability of strength theories in geotechnical engineering.

The Relation between Moisture Content and Share Strength of Swelling Soft Rock in the North of Xianfeng Town Open-Cast Coal

2014 ◽  
Vol 971-973 ◽  
pp. 2168-2171
Author(s):  
Qing Shui Liu ◽  
Ying Hui Chen ◽  
Wen Lian Liu
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Soft Rock ◽  
Soil Mass ◽  
Soaking Time ◽  
The North ◽  
Disturbed Soil ◽  
Strength Tests ◽  
The Stability ◽  
Open Cast

We did sorts of shear strength tests in different moisture content conditions with amount of disturbed soil which was collected from the swelling soft rock in the north of xianfeng town open-cast coal. Furthermore, we analyzed the physical relationships between moisture content of the rock-soil mass and shear strength under different soaking time or different moisture content conditions. Finally, we find the shear strength of rock-soil mass drops along with the saturated degree of test specimen doubled and re-doubled. We get a conclusion that soaking of the rock-soil mass has a strong influence on the strength of rock-soil mass. The soaking of groundwater and surface water could soft the rock-soil mass, which plays an important role in controlling the stability of side slope, also in continuing slip deformation.

scholarly journals VARIATION IN BEARING CAPACITY OF SOIL DUE TO CHANGES IN WATER TABLE DEPTH IN DHAKA, BANGLADESH

2021 ◽  
Vol 33 (2) ◽  
Author(s):  
Ahanaf Tahmid ◽  
Siam Junaed ◽  
A S M Fahad Hossain
Keyword(s):  
Bearing Capacity ◽  
Water Table ◽  
Geotechnical Engineering ◽  
Water Table Depth ◽  
Soil Test ◽  
Foundation Engineering ◽  
Dhaka City ◽  
Sound Design ◽  
The Stability ◽  
Poor Soil

The bearing capacity of the soil is a significant topic in geotechnical engineering, especially in foundation engineering, as the stability of any foundation depends on it. A structure with a very sound design may collapse standing on poor soil with low bearing capacity. As the depth of the water table increases, the ultimate bearing capacity of soil increases. The effect of an increase in depth on safe bearing capacity is predominant due to an increase in surcharge weight. The higher the water table, the lesser is as far as possible and strength of the soil. In this research, soil test reports of different locations of Dhaka city were collected, and the bearing capacity of the soil was calculated by Terzaghi's method based on a fixed foundation depth with a variation of water table depth. Bearing capacity was compared with the depth of the water table in graphical format and it was seen that bearing capacity of soil increases with the increase of water table depth.

Slope Stability Analysis under the Condition of Seepage

2012 ◽  
Vol 204-208 ◽  
pp. 241-245
Author(s):  
Yang Jin
Keyword(s):  
Finite Element Method ◽  
Shear Strength ◽  
Slope Stability ◽  
Negative Impact ◽  
Strength Reduction ◽  
Soil Slope ◽  
Failure State ◽  
Calculation Results ◽  
The Stability ◽  
Shear Strength Reduction

The stability of soil slope under seepage is calculated and analyzed by using finite element method based on the technique of shear strength reduction. When the condition of seepage or not is considered respectively, the critical failure state of slopes and corresponding safety coefficients can be determined by the numerical analysis and calculation. Besides, through analyzing and comparing the calculation results, it shows that seepage has a negative impact on slope stability.

scholarly journals Mechanical Properties and Micro Mechanism of Nano-Clay-Modified Soil Cement Reinforced by Recycled Sand

2021 ◽  
Vol 13 (14) ◽  
pp. 7758
Author(s):  
Biao Qian ◽  
Wenjie Yu ◽  
Beifeng Lv ◽  
Haibo Kang ◽  
Longxin Shu ◽  
...  
Keyword(s):  
Shear Strength ◽  
Void Ratio ◽  
Soil Mass ◽  
Direct Shear ◽  
Test Results ◽  
The Sustainable Development ◽  
Direct Shear Tests ◽  
Soil Cement ◽  
Nano Clay ◽  
New Material

To observe the effect of recycled sand and nano-clay on the improvement of the early strength of soil-cement (7d), 0%, 10%, 15% and 20% recycled sand were added. While maintaining a fixed moisture content of 30%, the ratios of each material are specified in terms of soil mass percentage. The shear strength of CSR (recycled sand blended soil-cement) was investigated by direct shear test and four groups of specimens (CSR-1, CSR-2, CSR-3 and CSR-4) were obtained. In addition, 8% nano-clay was added to four CSR groups to obtain the four groups of CSRN-1, CSRN-2, CSRN-3 and CSRN-4 (soil-cement mixed with recycled sand and nano-clay), which were also subjected to direct shear tests. A detailed analysis of the modification mechanism of soil-cement by recycled sand and nano-clay was carried out in combination with scanning electron microscopy (SEM) and IPP (ImagePro-Plus) software. The test results showed that: (1) CSR-3 has the highest shear strength due to the “concrete-like” effect of the incorporation of recycled sand. With the addition of 8% nano-clay, the overall shear strength of the cement was improved, with CSRN-2 having the best shear strength, thanks to the filling effect of the nano-clay and its high volcanic ash content. (2) When recycled sand and nano-clay were added to soil-cement, the improvement in shear strength was manifested in a more reasonable macroscopic internal structure distribution of soil-cement. (3) SEM test results showed that the shear strength was negatively correlated with the void ratio of its microstructure. The smaller the void ratio, the greater the shear strength. This shows that the use of reclaimed sand can improve the sustainable development of the environment, and at the same time, the new material of nano-clay has potential application value.

scholarly journals Effect of Urease Enzyme on Shear Strength of Clay Shale

2018 ◽  
Vol 7 (4.36) ◽  
pp. 424 ◽  
Author(s):  
Maxwel Joseph Henri Nainggolan ◽  
Wiwik Rahayu ◽  
Puspita Lisdiyanti
Keyword(s):  
Shear Strength ◽  
Bearing Capacity ◽  
Triaxial Test ◽  
Clay Soil ◽  
Soil Strength ◽  
Clay Shale ◽  
Strength Performance ◽  
Enzyme Mixture ◽  
Urease Enzyme

In recent years, utilization of biotechnology in geotechnical field has rapidly grown. One of the biotechnologies being utilized is urease enzyme, a stabilization material by bio-cementation method studied in this research.  Urease enzyme is manually mixed with additional 10% of clay soil to clay shale. The objective of mixing it is to increase the bearing capacity of the clay shale. Consolidated undrained triaxial test was performed for testing the soil strength performance for samples that had undergone curing for 2, 4, and 6 weeks. The results indicated that the sample stiffens, proved by the increase of shear strength from consolidated undrained triaxial test. The shear strength value produced by the variation of the urease enzyme mixture + 10% the clay is higher than that of without the original clay shale.  

scholarly journals Stability of Fe-oxide nanoparticles coated with natural organic matter under relevant environmental conditions

2014 ◽  
Vol 70 (12) ◽  
pp. 2040-2046 ◽  
Author(s):  
L. Chekli ◽  
S. Phuntsho ◽  
L. D. Tijing ◽  
J. L. Zhou ◽  
J.-H. Kim ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Environmental Conditions ◽  
Divalent Cations ◽  
Oxide Nanoparticles ◽  
Fe Oxide ◽  
Coated Nanoparticles ◽  
Aggregation Behaviour ◽  
Physico Chemical ◽  
The Stability

Manufactured nanoparticles (MNPs) are increasingly released into the environment and thus research on their fate and behaviour in complex environmental samples is urgently needed. The fate of MNPs in the aquatic environment will mainly depend on the physico-chemical characteristics of the medium. The presence and concentration of natural organic matter (NOM) will play a significant role on the stability of MNPs by either decreasing or exacerbating the aggregation phenomenon. In this study, we firstly investigated the effect of NOM concentration on the aggregation behaviour of manufactured Fe-oxide nanoparticles. Then, the stability of the coated nanoparticles was assessed under relevant environmental conditions. Flow field-flow fractionation, an emerging method which is gaining popularity in the field of nanotechnology, has been employed and results have been compared to another size-measurement technique to provide increased confidence in the outcomes. Results showed enhanced stability when the nanoparticles are coated with NOM, which was due to electrosteric stabilisation. However, the presence of divalent cations, even at low concentration (i.e. less than 1 mM) was found to induce aggregation of NOM-coated nanoparticles via bridging mechanisms between NOM and Ca2+.

scholarly journals Thermal effects on the stability of circular graphene sheets via nonlocal continuum mechanics

2014 ◽  
Vol 11 (4) ◽  
pp. 704-724 ◽  
Author(s):  
Saeid Reza Asemi ◽  
Ali Farajpour ◽  
Mehdi Borghei ◽  
Amir Hessam Hassani
Keyword(s):  
Continuum Mechanics ◽  
Thermal Effects ◽  
Graphene Sheets ◽  
Nonlocal Continuum ◽  
The Stability

Application of the Taguchi Method to Enhance Bearing Capacity in Geotechnical Engineering: Case Studies

2021 ◽  
Vol 21 (9) ◽  
pp. 04021167
Author(s):  
Hamid Mortazavi Bak ◽  
Makan Noorbakhsh ◽  
Amir M. Halabian ◽  
Mohammadali Rowshanzamir ◽  
Hamid Hashemolhosseini
Keyword(s):  
Taguchi Method ◽  
Bearing Capacity ◽  
Case Studies ◽  
Geotechnical Engineering

An analytical model for predicting the shear strength of unsaturated soils

2022 ◽  
pp. 1-57
Author(s):  
Tuan A. Pham ◽  
Melis Sutman
Keyword(s):  
Shear Strength ◽  
Analytical Model ◽  
Unsaturated Soils ◽  
High Performance ◽  
Micromechanical Model ◽  
Experimental Studies ◽  
Stress Equilibrium ◽  
Proposed Model ◽  
New Equation ◽  
Multi Phase

The prediction of shear strength for unsaturated soils remains to be a significant challenge due to their complex multi-phase nature. In this paper, a review of prior experimental studies is firstly carried out to present important pieces of evidence, limitations, and some design considerations. Next, an overview of the existing shear strength equations is summarized with a brief discussion. Then, a micromechanical model with stress equilibrium conditions and multi-phase interaction considerations is presented to provide a new equation for predicting the shear strength of unsaturated soils. The validity of the proposed model is examined for several published shear strength data of different soil types. It is observed that the shear strength predicted by the analytical model is in good agreement with the experimental data, and get high performance compared to the existing models. The evaluation of the outcomes with two criteria, using average relative error and the normalized sum of squared error, proved the effectiveness and validity of the proposed equation. Using the proposed equation, the nonlinear relationship between shear strength, saturation degree, volumetric water content, and matric suction are observed.

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