The Experimental Study of the Influence of the Matric Suction on the Unsaturated Soil Strength

2014 ◽  
Vol 580-583 ◽  
pp. 514-517 ◽  
Author(s):  
Cui Ran Liu
Keyword(s):  
Experimental Study ◽  
Shear Strength ◽  
Moisture Content ◽  
Unsaturated Soil ◽  
Matric Suction ◽  
Saturated Soil ◽  
Triaxial Apparatus ◽  
Soil Shear Strength ◽  
Soil Triaxial Apparatus ◽  
Water Contents

With modified unsaturated soil triaxial apparatus, unsaturated soil shear strength of the tests under the condition of different water contents are done. Experimental results show that the matric suction exist in unsaturated soil and increases with the decrease of moisture content. And the shear strength of unsaturated soil is higher than that of saturated soil. Shear strength of unsaturated soil varies as the matric suction and water content. The shear strength increases when the matric suction increases. when soil tend to be saturated, the matric suction will tend to be zero. And the shear strength of unsaturated soil values gradually close to the strength of the saturated soil.

Shear Strength Monitoring System Based on Measurement of Shear Wave Velocity and Moisture Content

2014 ◽  
Vol 635-637 ◽  
pp. 750-754
Author(s):  
Peng Hu ◽  
Qing Li ◽  
Yi Wei Xu ◽  
Nan Ying Shentu ◽  
Quan Yuan Peng
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Shear Wave ◽  
Monitoring System ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Bender Elements ◽  
Strength Measurement ◽  
Soil Shear Strength ◽  
The Relationship

Expound the importance of soil shear strength measurement at mudslide hidden point to release the loss caused by the disaster, explain the relationship between shear wave velocity, moisture content and shear strength, design the shear strength monitoring system combining the shear wave velocity measured by Piezoelectric bender elements and moisture content.

scholarly journals Prediction of Shear Strength of Soil Using Direct Shear Test and Support Vector Machine Model

2020 ◽  
Vol 14 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Hai-Bang Ly ◽  
Binh Thai Pham
Keyword(s):  
Support Vector Machine ◽  
Shear Strength ◽  
Moisture Content ◽  
Mean Squared Error ◽  
Learning Algorithm ◽  
Liquid Limit ◽  
Support Vector ◽  
Plastic Limit ◽  
Svm Model ◽  
Soil Shear Strength

Background: Shear strength of soil, the magnitude of shear stress that a soil can maintain, is an important factor in geotechnical engineering. Objective: The main objective of this study is dedicated to the development of a machine learning algorithm, namely Support Vector Machine (SVM) to predict the shear strength of soil based on 6 input variables such as clay content, moisture content, specific gravity, void ratio, liquid limit and plastic limit. Methods: An important number of experimental measurements, including more than 500 samples was gathered from the Long Phu 1 power plant project’s technical reports. The accuracy of the proposed SVM was evaluated using statistical indicators such as the coefficient of correlation (R), Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) over a number of 200 simulations taking into account the random sampling effect. Finally, the most accurate SVM model was used to interpret the prediction results due to Partial Dependence Plots (PDP). Results: Validation results showed that SVM model performed well for prediction of soil shear strength (R = 0.9 to 0.95), and the moisture content, liquid limit and plastic limit were found as the three most affecting features to the prediction of soil shear strength. Conclusion: This study might help in quick and accurate prediction of soil shear strength for practical purposes in civil engineering.

scholarly journals Study on Water Characteristic Curve and Shear Characteristics of Typical Unsaturated Silty Clay in Shaoxing

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ruiqian Wu ◽  
Youzhi Tang ◽  
Shaohe Li ◽  
Wei Wang ◽  
Ping Jiang ◽  
...  
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Unsaturated Soil ◽  
Direct Shear Test ◽  
Shear Test ◽  
Characteristic Curve ◽  
Friction Angle ◽  
Matric Suction ◽  
Silty Clay ◽  
Direct Shear

In order to probe into one simplified method to predict the shear strength of Shaoxing unsaturated silty clay, the test method combining unsaturated soil consolidation instrument and conventional direct shear instrument is used to study the shear strength, and the method is compared and verified with the results of equal suction direct shear test. The research results show that the soil water characteristic curve fitted by the measured data points and VG model has obvious stage characteristics in the range of 0~38 kPa, 38~910 kPa, and 910~10000 kPa. The shear strength of unsaturated soil measured by consolidation meter combined with conventional direct shear test is in good agreement with that measured by equal suction direct shear test in the range of 0~500 kPa. The results show that the shear strength, total cohesion, and effective internal friction angle of soil increase slightly with the increase of matric suction in the range of 0~38 kPa. When the matric suction increases from 38 kPa to 500 kPa, the shear strength and total cohesion force of the soil have similar stage characteristics with the SWCC, which first increases and then tends to be stable, while the effective internal friction angle changes slightly. Finally, taking the air-entry value as the demarcation point, an improved model of unsaturated shear strength is proposed by analyzing the error value. Compared with the measured value, the absolute value of relative error is basically kept in the range of 5%~10%, which is close to the measured value.

scholarly journals Role of hydromechanical properties of plant roots in unsaturated soil shear strength

2019 ◽  
Vol 7 (2) ◽  
pp. 133-138
Author(s):  
Anthony K. Leung ◽  
David Boldrin ◽  
Ali A. Karimzadeh ◽  
Anthony G. Bengough
Keyword(s):  
Shear Strength ◽  
Unsaturated Soil ◽  
Plant Roots ◽  
Soil Shear Strength

scholarly journals Relationship between the matric suction and the shear strength in unsaturated soil

2020 ◽  
Vol 13 ◽  
pp. e00441
Author(s):  
Idris A. Abd ◽  
Mohammed Y. Fattah ◽  
Haidar Mekkiyah
Keyword(s):  
Shear Strength ◽  
Unsaturated Soil ◽  
Matric Suction

Shear strength of unsaturated soil interfaces

2009 ◽  
Vol 46 (5) ◽  
pp. 595-606 ◽  
Author(s):  
Tariq B. Hamid ◽  
Gerald A. Miller
Keyword(s):  
Shear Strength ◽  
Unsaturated Soil ◽  
Characteristic Curve ◽  
Matric Suction ◽  
Direct Shear ◽  
Direct Shear Tests ◽  
Strength Failure ◽  
Suction Control ◽  
Failure Envelopes ◽  
Fine Grained Soil

Unsaturated soil interfaces exist where unsaturated soil is in contact with structures such as foundations, retaining walls, and buried pipes. The unsaturated soil interface can be defined as a layer of unsaturated soil through which stresses are transferred from soil to structure and vice versa. In this paper, the shearing behavior of unsaturated soil interfaces is examined using results of interface direct shear tests conducted on a low-plasticity fine-grained soil. A conventional direct shear test device was modified to conduct direct shear interface tests using matric suction control. Further, the results were used to define failure envelopes for unsaturated soil interfaces having smooth and rough counterfaces. Results of this study indicate that matric suction contributes to the peak shear strength of unsaturated interfaces; however, postpeak shear strength did not appear to vary with changes in matric suction. Variations in net normal stress affected both peak and postpeak shear strength. Failure envelopes developed using the soil-water characteristic curve (SWCC) appeared to capture the nonlinear influence of matric suction on shear strength of soil and interfaces.

Rate of strength increase of unsaturated lateritic soil

2008 ◽  
Vol 45 (9) ◽  
pp. 1335-1343 ◽  
Author(s):  
Meen-Wah Gui ◽  
Chun-Ming Yu
Keyword(s):  
Shear Strength ◽  
Failure Criterion ◽  
Matric Suction ◽  
Slope Instability ◽  
Lateritic Soil ◽  
Strength Increase ◽  
Residual Soil ◽  
Strength Tests ◽  
Soil Shear Strength ◽  
Intact Soil

Lateritic soil is a kind of residual soil that is widely distributed in Asia. The water table of the soil is normally very deep so the upper part of the soil is often unsaturated. The largest lateritic soil area in Taiwan is the Linkou terrace. Because the soil here is loosely cohered and consolidated, the problem of slope instability and landslides has always been a major concern. To evaluate the triggering mechanism of landslides, it is necessary to obtain the failure criterion that represents both the saturated and unsaturated conditions of the soil before any analysis is carried out. The parameter required to define such a failure criterion is the rate of shear strength increase, tan φb, which can be obtained via a series of laboratory strength tests in a modified triaxial system under various matric suction levels. Both the intact and remolded lateritic soils taken from Linkou terrace have been tested for this purpose. The results confirm that matric suction in the lateritic soil contributes significantly to the soil shear strength and that intact soil has a higher strength than remolded soil.

Experimental Study of Static Disintegration on Unsaturated Soil

2014 ◽  
Vol 580-583 ◽  
pp. 68-72 ◽  
Author(s):  
Nian Qin Wang ◽  
Qing Tao Wang ◽  
Qian Xue ◽  
Xiao Ling Liu
Keyword(s):  
Experimental Study ◽  
Moisture Content ◽  
Unsaturated Soil ◽  
Initial Moisture Content ◽  
Effective Porosity ◽  
Disintegration Rate ◽  
Porosity Ratio ◽  
Water Rate ◽  
Critical Moisture ◽  
Relationship Of

In order to explore the disintegration characteristics of compacted loess, through the unsaturated soil disintegration instrument by independently developed,conduct the soaking disintegration experimental study on remolded soil unsaturated samples,obtained a series of experimental results:①The curves can be divided into the slow disintegration, rapid disintegration and stabilization of disintegration in three stages，the degree of compaction and water rate impact on rapidly disintegrating stage;②When the degree of compaction is certain,the disintegration rate decreased with the water contented increasing,the decreased amplitude is increasing with the moisture content increased to18%,the disintegration characteristics disappeared with the moisture content increased to 22%;③When the initial moisture content is certain, the disintegration rate decreased with the degree of compaction increasing, The time significantly prolonged when the disintegration completed. the decreased amplitude is increasing with the degree of compaction increased to 95%,the disintegration characteristics basically disappeared. Based on the relationship of degree of compaction and the moisture content to void ratio, the thesis establishes the model between the disintegration rate and the effective porosity ratio,the formula can be used to calculate the disintegration rate of compacted loess.The specific conclusions are:①When the critical moisture content increased to 22%,the disintegration characteristics disappeared;②When the critical degree of compaction increased to95%，the disintegration characteristics also disappeared.

Sign in / Sign up

Export Citation Format

Share Document