Geotechnical Investigations of an Earth-Filled Site for Construction of a Building

There is a growing need of construction around the globe. This need tends to provide newer opportunities for construction of buildings over reclaimed lands or earth filled areas. Mostly, the earth is filled with soils as it is an easily available material. Soil is a complex materials, and its properties can vary due to several reasons. If not understood properly, it can damage undisturbed samples collected from earth-filled soils. The basic properties of soils, the stress-strain behavior and strength parameters are presented and discussed. Results show that soil exhibits strain hardening and normally consolidated behavior in direct shear and oedometer test respectively. It is observed that the compression index values are in the range of 0.157 to 0.182 which indicates that the material is silty soils with low plasticity. The allowable bearing capacity in our study was 305 kPa and allowable load on footing was 987 kN. The strength parameters, i.e., friction angle and cohesion are 37 degree and 2 kPa respectively.

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Stability Analysis of Dam Slope by Double Safety Factors of Dynamic Local Strength Reduction Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.744-746.593 ◽

2015 ◽

Vol 744-746 ◽

pp. 593-596

Author(s):

Yuan Meng

Keyword(s):

Internal Friction ◽

Reduction Method ◽

Failure Process ◽

Friction Angle ◽

Strength Reduction ◽

Internal Friction Angle ◽

Material Strength ◽

Strength Reduction Method ◽

Strength Parameters ◽

Local Strength

When calculating the dam slope failure process, traditional strength reduction method doesn't consider the difference of decay rate between cohesion and internal friction angle and discount the strength parameters for all elements. This paper uses two different reduction factors for material strength parameters, slope cohesion and internal friction angle. Based on the yield approach index criterion, we change the reduction region in time and put forward a double safety factor of dynamic local strength reduction method for engineering analysis of dam slope stability.

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Determination of Equivalent Mohr-Coulomb Criterion from Generalised Hoek-Brown Criterion

10.21203/rs.3.rs-1073021/v1 ◽

2021 ◽

Author(s):

Qingqing Yang ◽

Fei Cai

Keyword(s):

Principal Stress ◽

Least Squares Method ◽

Method Comparison ◽

Friction Angle ◽

Engineering Practice ◽

Shear Strength Parameters ◽

Strength Parameters ◽

Coulomb Criterion ◽

Minor Principal Stress

Abstract A new analytical solution is presented for determining equivalent Mohr-Coulomb (MC) shear strength parameters over an arbitrary interval of minor principal stress σ3 from the generalised Hoek-Brown (HB) criterion using least squares method. Comparison with several published examples demonstrates that the proposed solution had a capacity to accurately determine equivalent MC parameters over a given interval of σ3, as well as instantaneous MC parameters by using a very small interval of σ3. EMC parameters depended heavily on the interval of σ3, which highlighted the importance of intervals of σ3. A calculation case shows that the equivalent internal friction angle and cohesion over the interval of σ3 from tension cut-off σcut−off to maximum minor principal stress σ3max were approximately 12% smaller and 10.3% larger than those over an interval from tensile strength to σ3max, respectively. The proposed solution offers great flexibility for the application of the HB criterion with existing methods based on the MC criterion for rock engineering practice.

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Influence of the structure on the collapse potential and shear strength of a residual soil in the semiarid region of Northeast Brazil

MATEC Web of Conferences ◽

10.1051/matecconf/202133701003 ◽

2021 ◽

Vol 337 ◽

pp. 01003

Author(s):

Valteson da Silva Santos ◽

Allan B.Silva de Medeiros ◽

Romário S.Amaro da Silva ◽

Olava F. Santos ◽

Osvaldo de Freitas Neto ◽

...

Keyword(s):

Shear Strength ◽

Expansive Soils ◽

Friction Angle ◽

Semiarid Region ◽

Original Structure ◽

Residual Soil ◽

Residual Soils ◽

Strength Parameters ◽

Effective Measure ◽

Two Samples

In the last decades, several engineering works have been developed in the Northeast of Brazil, a region marked by the occurrence of collapsible and expansive soils. This work aimed to characterize and study the behavior of two samples of residual soils collected in the municipality of Salgueiro-PE regarding their collapse potentials and shear strength parameters, in natural and disturbed conditions, evaluating the influence of the applied vertical stresses and the structural arrangement in these properties. The results obtained showed that the two samples analyzed show collapsible behavior, however, the observed potential for collapse was lower after the original structure arrangement was undone. From the direct shear strength tests, the strength parameters of the two soils were obtained, which pointed effective friction angle close to 30° and cohesive intercept close to 0 kPa. The destructuring of the samples did not cause a considerable variation in these parameters. Thus, it was possible to conclude that for these samples the microstructure has a predominant influence on the occurrence of collapsibility, but does not have the same relevance on the shear strength, such that the material’s destructuring can be considered as an effective measure to reduce the potential collapse.

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Regional Geotechnical Mapping Employing Kriging on Electronic Geodatabase

Applied Sciences ◽

10.3390/app10217625 ◽

2020 ◽

Vol 10 (21) ◽

pp. 7625

Author(s):

Muhammad Usman Arshid ◽

M. A. Kamal

Keyword(s):

Bearing Capacity ◽

Soil Classification ◽

Geostatistical Analysis ◽

Kriging Interpolation ◽

Geospatial Information ◽

State Highway ◽

Capacity Evaluation ◽

Geotechnical Investigations ◽

Allowable Bearing Capacity ◽

Spatial Analyst

A regional geotechnical map was developed by employing kriging using spatial and s geostatistical analysis tools. Many studies have been carried out in the field of topography, digital elevation modeling, agriculture, geological, crop, and precipitation mapping. However, no significant contribution to the development of geotechnical mapping has been made. For the appraisal of a geotechnical map, extensive field explorations were carried out throughout the geotechnically diversified plateau spread over an area of approximately 23,000 km2. In total, 450 soil samples were collected from 75 data stations to determine requisite index properties and soil classification for the subsequent allowable bearing capacity evaluation. The formatted test results, along with associated geospatial information, were uploaded to ArcMap, which created an initial input electronic database. The kriging technique of geostatistical analysis was determined to be more feasible for generating a geotechnical map. The developed map represents the distribution of soil in the region as per the engineering classification system, allowable bearing capacity, and American Association of State Highway and Transportation Officials (AASHTO) subgrade rating for 1.5-, 3.0-, and 4.5-m depths. The accuracy of the maps generated using kriging interpolation technique under spatial analyst tools was verified by comparing the values in the generated surface with the actual values measured at randomly selected validation points. The database was primarily created for the appraisal of geotechnical maps and can also be used for preliminary geotechnical investigations, which saves the cost of soil investigations. In addition, this approach allows establishing useful correlations among the geotechnical properties of soil.

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Study on the Granular Shear Strength Parameters of Dumping Site

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.256-259.358 ◽

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.

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A Study on the Effects of Water Content on Strength Parameters of Landslide Soil

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.170-173.785 ◽

2012 ◽

Vol 170-173 ◽

pp. 785-788

Author(s):

Jian Feng Qi ◽

Xue Lin Song ◽

Ji Chao Liu

Keyword(s):

Internal Friction ◽

Water Content ◽

Yunnan Province ◽

Turning Point ◽

Friction Angle ◽

Soil Samples ◽

Plastic Limit ◽

Strength Parameters ◽

Geotechnical Tests ◽

Slide Zone

Soil samples of slide body and slide zone are obtained to study the strength parameters from a landslide in Yunnan Province, China. Firstly, the basic physical properties of the two soil samples are measured. Then geotechnical tests are performed to study the variation law of strength parameters under different water content by using the automatic KTG triaxial shear apparatus. The results show that the cohesion of soils rapidly reduces with water content increasing, and slowly reduces when plastic limit attains, and it seems that a turning point appears at the location of plastic limit.The relation of cohesion with water content approximately conforms to the exponential function, and the relation of internal friction angle  with water content approximately conforms to the linear relation.

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Improving Shear Strength Parameters of Sandy Soil using Enzyme-Mediated Calcite Precipitation Technique

Civil Engineering Dimension ◽

10.9744/ced.20.2.91-95 ◽

2018 ◽

Vol 20 (2) ◽

pp. 91 ◽

Cited By ~ 4

Author(s):

Heriansyah Putra ◽

Hideaki Yasuhara ◽

Naoki Kinoshita ◽

Erizal . ◽

Tri Sudibyo

Keyword(s):

Shear Strength ◽

Sandy Soil ◽

Friction Angle ◽

Soil Improvement ◽

Soil Mass ◽

Shear Strength Parameters ◽

Calcite Precipitation ◽

Strength Parameters ◽

Direct Shear Tests ◽

Potential Applications

Several methods have been established for their various potential applications as soil improvement technique, and recently the application of grouting technique using biological process have been proposed. This study discussed the applicability of enzyme-mediated calcite precipitation (EMCP) in improving the shear strength parameters of sandy soil. In this study, soil specimens were prepared and treated with the grouting solutions composed of urea, calcium chloride, magnesium sulfate and enzyme of urease. Evolutions in the cohesion and internal friction angle of the improved soil were examined through the direct shear tests. The presence of the precipitated materials, comprising 4.1 percent of the soil mass of the treated sand, generated a cohesion of 53 kPa. However, contrary to the improvement of cohesion, the friction angle is relatively constant. It indicated that the application of the EMCP technique has no significant impact on the friction angle

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Experimental Study on Shear Strength Parameters of Soil Mixed with Glass Fiber

European Journal of Engineering Research and Science ◽

10.24018/ejers.2019.4.6.1381 ◽

2019 ◽

Vol 4 (6) ◽

pp. 124-128

Author(s):

Mohamad Farouk Abd-elmagied

Keyword(s):

Shear Strength ◽

Strength Properties ◽

Vital Role ◽

Peak Shear Strength ◽

Shear Strength Parameters ◽

Fiber Glass ◽

Strength Parameters ◽

Sample Weight ◽

Strain Behavior ◽

Shear Box

Determining the shear strength properties of the soil is a vital step in investigation its stress-strain behavior. Moreover, suction plays a vital role in the shear strength of the unsaturated soil. This paper investigates the influence of the fiber glass on the shear strength parameters of (c-ɸ) soil with different ratios. To achieve this purpose, the samples of (c- ɸ) soil from El-Fardos gardens housing compound, Benha city, Egypt, were prepared at their maximum dry densities with corresponding optimum moisture content. Direct shear box test of 60 x 60 mm under a relentless rate of 1 mm/min was employed with the proposed range of ASTM D 3080. Different fiber glass ratios of 0.1, 0.50 and 1.00 % of soil sample weight were used. The results confirmed that the peak shear strength parameters increased with increasing the fiber ratio.

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Shear Strength and Pull-Out Response of Tire Shred-Sand Mixture Reinforced with Deformed Steel Bars

Advances in Civil Engineering ◽

10.1155/2020/5185093 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Beenish Jehan Khan ◽

Irshad Ahmad ◽

Hassan Nasir ◽

Abdullah Abdullah ◽

Qazi Khawar Gohar

Keyword(s):

Shear Strength ◽

Large Scale ◽

Friction Angle ◽

Sand Mixture ◽

Strain Behavior ◽

Backfill Material ◽

Pull Out ◽

Tire Shreds ◽

Steel Bars ◽

Different Diameters

The use of scrap tires in various engineering applications has been extensively explored. The present study has the following aim: to evaluate the suitability of tire-sand mixtures as backfill material based on its shear strength. To achieve this objective, modified Proctor compaction tests were performed on tire shred-sand mixture with mixing proportions by weight of tire shreds and sand (0/100, 20/80, 30/70, and 40/60) using different sizes of tire shreds (50 mm, 75 mm, and 100 mm). Based on the results of the modified Proctor compaction test, the two mixing proportions, i.e., tire shred/sand, 20/80 and 30/70, respectively, were selected. Large-scale direct shear test indicated higher internal friction angle and cohesion values for tire shred-sand mixtures (30/70) with 100 mm tire size (38.5° and 19 kPa) as compared with sand-only backfill material (30.9° and 0 kPa). Based on stress-strain behavior plots, it was indicated that the inclusion of tire shreds imparts ductility to backfill mixtures. To achieve the second objective, the pull-out tests were performed with deformed steel bars of two different diameters (12.7 mm and 15.8 mm) embedded in various backfill mixtures prepared with tire shreds of three different sizes (50, 75, and 100 mm). The pull-out test result indicated that the deformed steel bars exhibit higher pull-out resistance in tire shred-sand mixtures (9.9 kN/m) compared with sand-only backfill material (4.1 kN/m).

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UNDRAINED SHEAR STRENGTH PARAMETERS OF SAPROCK FROM A WEATHERING PROFILE OVER PORPHYRITIC BIOTITE GRANITE AT KM 31 OF THE KUALA LUMPUR - KARAK HIGHWAY, PENINSULAR MALAYSIA

Malaysian Journal of Civil Engineering ◽

10.11113/mjce.v33.16400 ◽

2021 ◽

Vol 33 (2) ◽

Author(s):

John Kuna Raj

Keyword(s):

Shear Strength ◽

Friction Angle ◽

Undrained Shear Strength ◽

Triaxial Tests ◽

Regression Analyses ◽

Shear Strength Parameters ◽

Weathering Profile ◽

Strength Parameters ◽

Zone Ii ◽

Undrained Shear

Three broad zones can be differentiated at the weathering profile; an upper, 9.4 m thick, pedological soil (zone I), an intermediate, 31.7 m thick, saprock (zone II) and the bottom bedrock (zone III). The saprock (zone II) comprises gravelly silty sands that distinctly preserve the minerals, textures and structures of the original granite and can be separated into sub-zones II A, II B, II C, and II D, based on differences in preservation of relict structures and content of litho-relicts (core-boulders). To characterize the undrained strength of saprock, samples were collected from sub-zones II A, II B, II C and II D and their physical and soil index properties determined before unconsolidated undrained triaxial tests were carried out on remolded samples. Three to four individual samples from each sub-zone were compressed under confining pressures of 138 kPa, 207 kPa, 276 kPa and/or 345 kPa. Plots of pf = [(σ1 + σ3)/2] versus qf = [(σ1 - σ3)/2] were then used to calculate apparent cohesions of 41.9 kPa, 100.3 kPa, 76.1 kPa and 73.9 kPa, and friction angles of 32.2o, 28.1o, 26.6o and 27.8o, for the samples from sub-zones II A, II B, II C, and II D, respectively. Regression analyses show apparent cohesions to decrease with increasing clay contents, and degrees of saturation; features indicating the influence of negative pore water (or suction) pressures. Regression analyses also show apparent friction angle to increase with increasing sand contents; a feature attributed to greater inter-locking and resistance to displacement of these particles. It is concluded that the undrained shear strength parameters of saprock are characterized by an average apparent cohesion of 54.6 kPa, and friction angle of 30.5o; the parameters influenced by the degree of saturation as well as clay and sand contents.

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