scholarly journals Assessment of Stabilized Silt Clay Sand with Oil Palm Fibre Bunch (OPFB) Local Fibre for Slope Foundations: A Case of Coastal Soils of Mombasa, Kenya

2021 ◽  
pp. 20-38
Author(s):  
Jared Kambaga Makone ◽  
Ezra Wekesa
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Oil Palm ◽  
Reinforced Soil ◽  
Fibre Content ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Deviator Stress ◽  
Oil Palm Fibre ◽  
Palm Fibre

Improvement of shear strength parameters is essential for designing the OPFB fiber mix with silt clay sand for slope stability. The objective of this study was to assess the stabilized silt clay with oil palm fibre bunch (OPFB) local fibre for slope foundation. Series of laboratory tests were conducted on various materials under study and the results revealed that, OPFB mix can be used as an additive to cement for purpose of improving engineering properties of the Silt Clay sand to cut down costs without compromising the set standards. It was established that, the shear strength parameters of the soil-fibre mixture (φ and C) can be improved significantly up to an optimum and reach a certain point where it starts to decline. The shear stress–strain curves obtained from the CU triaxial tests for reinforced sands with 30 mm fibre length together with those for unreinforced silty sand were compared; the result indicated that, fibre-reinforced specimen showed higher deviator stress at 0.25% fibre and reduces at 0.5% fibre. The strain corresponding to the peak deviator stress was increased by fibre content. Patterns of stress–strain curves for all reinforcedsamples indicated improvement in the deviator stress for all compositions and fibre content. Deviator stress of fibre-reinforced soil showed a slight increase with increasing pore pressure. The increase of the fibre content caused an increase in pore water pressure due to inclination of specimens to decrease the volume. Changes in the shear strength of fibre-reinforced soil indicated that soil strength parameters (internal friction angle φ’ and cohesion C’) increase as the internal friction surface increases between fibre and soil at certain point.

Study on the Granular Shear Strength Parameters of Dumping Site

2012 ◽  
Vol 256-259 ◽  
pp. 358-361
Author(s):  
Xiang Yun Kong ◽  
Guang Jin Wang ◽  
Xiao Chao Zhou
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Shear Strength ◽  
Internal Friction ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Dumping Site ◽  
Size Grading

Apparent particle size grading is the important characteristic of super-high bench dumping site, and the critical factors with the impact of its stability and disaster prevention are the fragmentation distribution and shear strength parameters of granular. With the copper mine dumping site which had the feature of apparent particle size grading, the thesis carried out the study of on-site particle size investigation and indoor laboratory. The particle-size distribution law with the changing of dumping-site height was analyzed and quantitative relationship between the fragmentation distribution and shear strength parameters of granular was discussed. The research results indicated that coarse-grain contents and maximum grain size were increased significantly according to the decreasing of dumping-site height, which showed that the dumping-site had the feature of apparent particle size grading. The coarse particle content in the grain size composition and internal friction angle φ of shear strength parameters increased with the obvious increment of the distribution value B. The relationship between distribution value B and the internal friction angle φ could be expressed by exponential function curve.

scholarly journals Estimation of shear strength parameters of soil using Optimized Inference Intelligence System

2021 ◽  
Vol 43 (2) ◽  
Author(s):  
Binh Thai Pham ◽  
Mahdis Amiri ◽  
Manh Duc Nguyen ◽  
Trinh Quoc Ngo ◽  
Kien Trung Nguyen ◽  
...  
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Physical Parameters ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Inference System ◽  
Angle Of Internal Friction ◽  
Intelligence System ◽  
Statistical Measures ◽  
Model Study

In recent years, machine learning techniques have been developed and used to build intelligent information systems for solving problems in various fields. In this study, we have used Optimized Inference Intelligence System namely ANFIS-PSO which is a combination of Adaptive Neural-Fuzzy Inference System (ANFIS) and Particle Swarm Optimization (PSO) for the estimation of shear strength parameters of the soils (Cohesion “C” and angle of internal friction “φ”). These parameters are required for designing the foundation of civil engineering structures. Normally, shear parameters of soil are determined either in the field or in the laboratory which require time, expertise and equipments. Therefore, in this study, we have applied a hybrid model ANFIS-PSO for quick and cost-effective estimation of shear parameters of soil based on the other six physical parameters namely clay content, natural water content, specific gravity, void ratio, liquid limit and plastic limit. In the model study, we have used data of 1252 soft soil samples collected from the different highway project sites of Vietnam. The data was randomly divided into 70:30 ratios for the model training and testing, respectively. Standard statistical measures: Root Mean Square Error (RMSE), Mean Absolute Error (MAE) and Correlation Coefficient (R) were used for the performance evaluation of the model. Results of the model study indicated that performance of the ANFIS-PSO model is very good in predicting shear parameters of the soil: cohesion (RMSE = 0.075, MAE = 0.041, and R = 0.831) and angle of internal friction (RMSE = 0.08, MAE = 0.058, and R = 0.952).

Reliability of Shear-Box Tests Upon Soaking Process on the Sand Soil in Al-Najaf City

2020 ◽  
Vol 857 ◽  
pp. 212-220
Author(s):  
Mohammed Sh. Mahmood ◽  
Waseem H. Al-Baghdadi ◽  
Asaad M. Rabee ◽  
Suhad H. Almahbobi
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Sandy Soil ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Engineering Structures ◽  
Angle Of Internal Friction ◽  
Shear Box ◽  
Testing Condition ◽  
Direct Shear Apparatus

Accurate prediction of the soil shear strength parameters is essential in the reliable geotechnical design of civil engineering structures. This recent paper investigates the effect of the dry testing condition on the shear strength parameters of the sandy soil using the direct shear apparatus and compared with the saturated condition tests in previous researches on the same soil. The dry soil, usually above the water table, is the principal condition of the Al-Najaf city soil in Iraq. Samples are selected from the site of the University of Kufa, which represents the sandy soil of the city. For reliability purposes, the soil is exposed to different pre-soaking durations (one, two, and four weeks) then air-dried for shear tests. The main results revealed that the angle of internal friction (Φ) tested as a dry sample decreases about -6% up to two-weeks soaking then recovered upon four-week soaking about +6%. Compared to the saturated testing, there are increases in F between 6%-17% from saturated tests. Finally, it is recommended to aware in the selection of testing conditions for calculations of the angle of internal friction.

scholarly journals The Influence of Compaction and Water Conditions on Shear Strength and Friction Resistance between Geotextiles and Ash-Slag Mixture

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1086
Author(s):  
Andrzej Gruchot ◽  
Tymoteusz Zydroń ◽  
Agata Michalska
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Water Saturation ◽  
Friction Angle ◽  
Interaction Coefficient ◽  
Interfacial Friction ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Angle Of Internal Friction ◽  
Friction Resistance

The paper presents the results of tests of the shear strength of the ash–slag mixture taken from the landfill located in Kraków (Poland) and the interfacial friction resistance at the contact between the ash–slag mixture and woven or nonwoven geotextiles. The tests were carried out in a direct shear apparatus on samples with and without water saturation. The samples for testing were formed in the apparatus box at the optimum moisture by compacting them to IS = 0.90 and 1.00. The test results reveal that the shear strength parameters of the ash-slag mixture were large. It was stated the significant influence of the compaction, the growth of which has resulted in an increase in the angle of internal friction (from 7% to 9%) and cohesion (from 60% to 97%). Whereas the saturation of the samples reduced the shear strength parameters (from 4% to 6%, of the internal friction angle and 30% to 43% of cohesion). The values of the interfacial friction resistance at the contact between the ash–slag mixture and the geotextiles were large as well, but slightly smaller than the values of the shear strength parameters of the mixture itself. The compaction caused an increase in the angle of interfacial friction (from 1% to 5%) and adhesion (from 31% to 127%). The water-saturation of the samples caused a change in the angle of interfacial friction (from −6% to 3%) and decline in the adhesion (from 22% to 69%). Values of the interaction coefficient were about 0.8–1.0 and they tended to rise with increasing the normal stress. Higher values of this parameter were obtained in tests with water saturation and for non-woven geotextiles.

scholarly journals Estimation of shear strength parameters of soil using Optimized Inference Intelligence System

2021 ◽  
Vol 43 (2) ◽  
pp. 189-198
Author(s):  
Binh Thai Pham ◽  
Mahdis Amiri ◽  
Manh Duc Nguyen ◽  
Trinh Quoc Ngo ◽  
Kien Trung Nguyen ◽  
...  
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Physical Parameters ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Inference System ◽  
Angle Of Internal Friction ◽  
Intelligence System ◽  
Statistical Measures ◽  
Model Study

In recent years, machine learning techniques have been developed and used to build intelligent information systems for solving problems in various fields. In this study, we have used Optimized Inference Intelligence System namely ANFIS-PSO which is a combination of Adaptive Neural-Fuzzy Inference System (ANFIS) and Particle Swarm Optimization (PSO) for the estimation of shear strength parameters of the soils (Cohesion “C” and angle of internal friction “φ”). These parameters are required for designing the foundation of civil engineering structures. Normally, shear parameters of soil are determined either in the field or in the laboratory which require time, expertise and equipments. Therefore, in this study, we have applied a hybrid model ANFIS-PSO for quick and cost-effective estimation of shear parameters of soil based on the other six physical parameters namely clay content, natural water content, specific gravity, void ratio, liquid limit and plastic limit. In the model study, we have used data of 1252 soft soil samples collected from the different highway project sites of Vietnam. The data was randomly divided into 70:30 ratios for the model training and testing, respectively. Standard statistical measures: Root Mean Square Error (RMSE), Mean Absolute Error (MAE) and Correlation Coefficient (R) were used for the performance evaluation of the model. Results of the model study indicated that performance of the ANFIS-PSO model is very good in predicting shear parameters of the soil: cohesion (RMSE = 0.075, MAE = 0.041, and R = 0.831) and angle of internal friction (RMSE = 0.08, MAE = 0.058, and R = 0.952).

scholarly journals Influence of lime stabilization on shear strength parameters of silty clay soil

2018 ◽  
pp. 143-156
Author(s):  
Marko Spasic ◽  
Nikola Zivanovic ◽  
Grozdana Gajic
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Clay Soil ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Silty Clay ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Lime Stabilization ◽  
Silty Clay Soil

Lime soil stabilization is a well-known and often used method. One of the methods of landslide stability improvement is changing soil with materials that have better physical and mechanical characteristics. In most of the methods for determining slope stability, the main input data are internal friction angle and cohesion. The main objective of this paper was to find out if the sampled silty clay soil was suitable for lime stabilization, and to get the values of shear strength parameters from soil samples with and without added lime. The results showed that by increasing lime content, internal friction angle rises, while cohesion values decrease, as well as deformations, all the way to 15% of lime by mass. The changes in internal friction angle, cohesion and deformations were most noticeable between 0 and 5% of added lime. Samples that endured the largest pressures were those containing 10% of lime.

Study on Shear Strength Experiments Base on the Modified Direct Shear Apparatus for Unsaturated Soils

2013 ◽  
Vol 438-439 ◽  
pp. 1176-1180 ◽  
Author(s):  
Gao Feng Chen ◽  
Ying Fa Lv ◽  
Zhi Huai Huang ◽  
Yan Chang
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Friction Angle ◽  
Soil Samples ◽  
Direct Shear ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
General Internal ◽  
Direct Shear Apparatus

The unconsolidated-undrained fast shear tests of saturated-unsaturated remolded soil samples under different moisture content which is 1.1%, 10.1%, 14.9%, 19.9%, 24.2%, 29.9%, 37.7% respectively, and normal stress which is 50kPa, 100kPa, 200kPa, 300kPa, 400kPa respectively, were studied by the modified SDJ-1-type strain direct shear apparatus and U.S. Lab VIEW data acquisition system. The shear strength parameters of unsaturated soil samples, i.e. general cohesion and general internal friction angle were obtained based on Mohr-Coulomb strength theory. The test results showed that the general cohesion firstly increased and then reduced with the moisture content increasing, and the general internal friction angle increased with the moisture content decreasing. The function between the general shear strength parameters and the moisture content was studied. The concept of general shear strength parameters was proposed in the paper, and would provide a simple and practical method to obtain the strength parameters for engineering practice.

scholarly journals Effect of Soaking and Non-soaking Condition on Shear Strength Parameters of Sandy Soil Treated with Additives

2019 ◽  
Vol 5 (5) ◽  
pp. 1147-1161
Author(s):  
Roaa M. Fadhil ◽  
Haifaa A. Ali
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Sandy Soil ◽  
Dry Weight ◽  
Natural State ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Angle Of Internal Friction ◽  
Direct Shear Tests ◽  
Before And After

The present paper aims to improve shear strength parameters: cohesion (c), and angle of internal friction (∅) for sandy soil treated by additives before and after soaking. The samples of sandy soil were obtained from Karbala city and then classified as poorly graded sand (SP) with relative density Dr (30%) according to the system of (USCS). The experiment has three stages. In the first stage ,the soil was treated with three different  percentages of cement (3 ,5 and 7%) of dry weight for the soil with three different percentages of water content (2, 4 and 8%) in each above percentage of cement, while the second stage includes (2%) of lime  from  soil weight  mixed with each different percentage of cement . In the third stage, (50%) of polymer of cement weight was mixed with each different percentage of cement. An analysis of behavior sandy soils treated by additives was carried out with the Direct Shear Tests. All the samples were cured (3) days before and after soaking. The results of the experiment showed that increase in shear strength parameters of sandy soil; especially the angle of internal friction with the rate value (16.6 %) of cement only, (21.88 %) of cement with lime , (20.3%) of cement with the polymer before soaked condition. After soaking condition, it was increased with the rate value (14.3%) with cement only, (23.57%) of cement with lime, and (15.38%) of cement with the polymer as compared with soil in the natural state.

scholarly journals Statistical evaluation of shear strength parameters of fine grained tills

2021 ◽  
Author(s):  
Chandra Prakash Poudyal
Keyword(s):  
Shear Strength ◽  
Stress Ratio ◽  
Maximum Stress ◽  
Shear Failure ◽  
Triaxial Tests ◽  
Ratio Method ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Fine Grained ◽  
Deviator Stress

A statistical analysis is conducted in this study on the shear strength parameters of fine-grained tills from a series of consolidated undrained triaxial tests performed for a light rail transit project in the City of Toronto. Three different failure criteria are applied: the maximum stress ratio, the maximum deviator stress, and the residual stress. Three methods generate only minimal difference in the shear failure angle and a slight difference in cohesion. The friction angle calculated using the maximum stress ratio method ranges from 18.6 to 35.26 degrees compared with values ranging from 18.5 to 34.26 degrees by the maximum deviator stress method. The undrained shear modulus calculated from one-third and two-third peak deviator stress points generate a wide variation from 2 MPa to 167 MPa with an average value of 34 MPa.

scholarly journals The Dependence Between Shear Strength Parameters and Microstructure of Subgrade Soil in Seasonal Permafrost Area

2020 ◽  
Vol 12 (3) ◽  
pp. 1264 ◽  
Author(s):  
Hanbing Liu ◽  
Xiang Lyu ◽  
Jing Wang ◽  
Xin He ◽  
Yunlong Zhang
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Shear Failure ◽  
Plasticity Index ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Angle Of Internal Friction ◽  
Subgrade Soils ◽  
Subgrade Soil ◽  
Microstructure Parameters

Permafrost and seasonal permafrost are widely distributed in China and all over the world. The failure of soil is mainly shear failure, and the strength of soil mainly refers to the shear strength. The two most important parameters of shear strength are cohesion and angle of internal friction. In order to ensure the sustainability of road construction in seasonal permafrost area, the microstructure of subgrade soil was observed and analyzed. First, three subgrade soils with different plasticity indices were prepared for triaxial test and scanning electron microscope (SEM). Then, these specimens underwent freezing–thawing (FT) cycles and were obtained shear strength parameters by triaxial shear test. Next, the microstructure images of soil were obtained by SEM, and the microstructure parameters of soil were extracted by image processing software. Finally, the correlation method was used to analyze the dependence between the shear strength parameters and the microstructure parameters. Results revealed that subgrade soils with a higher plasticity index had higher cohesion and lower angle of internal friction. In addition, with the increase of the number of FT cycles, the diameter and number of soil particles and pores tend to increase, while the roundness, fractal dimension and directional probabilistic entropy of particles decreased. With the increase of the plasticity index, the particle and pore diameter decreased, but the particle and pore number increased. Besides, particle roundness had the greatest influence on the cohesion and angle of internal friction of shear strength parameters.

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