Influence of Fine Fraction on Shear Parameters and Consolidation Behavior of Tropical Residual Soil (original) (raw)
Related papers
2012
This paper describes the physical and engineering properties of three different types of soil. One has been collected from NIT Agartala campus and other from River bank of Howrah from different locations of State of Tripura, India. A mixture of both the soils is also investigated. Laboratory tests have been conducted on grain size analysis, specific gravity, Atterberg’s limits, standard Proctor compaction, direct shear, and one-dimensional consolidation to find out various parameters. As clay content increases in the soil, the plasticity index (PI) increases and angle of internal friction (φ) decreases; with the increase of plasticity index, optimum moisture content (OMC) of the soil increases. As liquid limit (LL) increases, compression index (Cc) increases. With the increase of OMC, Cc also increases. Correlations have also been established; PI, OMC and Cc found out with the help of other parameters.
Effect of wetting on the collapsibility and shear strength of tropical residual soils
2008
Residual soils with extensive weathering of parent materials can yield collapsible soil deposits. In Malaysia, residual granite and sedimentary rock soils occur extensively, i.e. cover more than 80% of the country's land area. These types of soil have a high possibility to collapse when wetted. This paper described a study that had been carried out to examine the effect of wetting on the collapsibility and shear strength of the tropical residual soils. Odometer tests (single and double) and double shear box tests were carried out on selected soil samples. In addition Scanning Electron Microscopic (SEM) test and X-Ray Diffraction Analysis were also carried out. From the result obtained, both types of soils were found to collapse upon wetting (inundation). The finer granitic residual soil (MH) apparently showed a slightly higher collapse potential compared with the relatively coarser sedimentary residual soil (SM). The SEM analysis indicated that the soil structure became more compacted and voids between the structures became smaller upon collapse. The shear strength tests showed that the shear strength of both soil reduced significantly upon collapse, in particular the soil apparent cohesion, with the granitic residual soil showing more strength reduction compared with the sedimentary residual soil.
International Journal for Research & Development in Technology (IJRDT), 2021
Infrastructure constructions are flourishing in developing countries in current centuries. For these conditions, geotechnical engineering properties of soils are dynamic for design purposes. The laboratory equipment's and field instruments are not accessible in all extents to get these engineering properties of soil. In addition, it necessitates more effort, time, and money. Thus, Geotechnical engineers usually striving to distinguish engineering properties of soil for a definite area and soil variety, which is used particularly for analysis and design tenacities. In this study, Undrained Shear Strength & some of Index properties of Cohesive Soils found in Agaro Town was studied. Index properties and undrained shear strength behavior of these soils were performed in the geotechnical laboratory of Jimma University, Jimma Institute of Technology (JIT).In this work, undisturbed and disturbed soil samples from fifteen test pits at 1.5 m and 3.0 m depth were collected. Thirty representative samples were taken from test pits. For all test procedures, American Society for Testing & Material (ASTM) standard was used. To preset the intended results of a study, Microsoft word-2013 and Microsoft Excel-2013 software's were used. For the study area natural moisture content, field density and specific gravity value range .95 % and Liquidity index ranges from 0.01-0.35 or 1%-35%. The percentage of finer on sieve #200 (0.075mm) is more than 90%.This indicates that the soil of study area is classified as fine-grained soils. The soils in the study area grouped under MH (Highly Plastic Silt) while the rest are categorized CH (Highly Plastic clay) soil group based on Unified soil classification systems. Shear strength parameter like undrained shear strength values range from 47.01-77.08 kPa. Using obtained test results, it is expected to have a wide application in the design & construction of different infrastructure of the study area to minimize the cost, effort, and time for laboratory tests.
Effect of Wetting on Collapsibility and Shear Strength of Tropical Residual Soils
Electronic Journal of Geotechnical …, 2008
Residual soils with extensive weathering of parent materials can yield collapsible soil deposits. In Malaysia, residual granite and sedimentary rock soils occur extensively, i.e. cover more than 80% of the country's land area. These types of soil have a high possibility to collapse when wetted. This paper described a study that had been carried out to examine the effect of wetting on the collapsibility and shear strength of the tropical residual soils. Odometer tests (single and double) and double shear box tests were carried out on selected soil samples. In addition Scanning Electron Microscopic (SEM) test and X-Ray Diffraction Analysis were also carried out. From the result obtained, both types of soils were found to collapse upon wetting (inundation). The finer granitic residual soil (MH) apparently showed a slightly higher collapse potential compared with the relatively coarser sedimentary residual soil (SM). The SEM analysis indicated that the soil structure became more compacted and voids between the structures became smaller upon collapse. The shear strength tests showed that the shear strength of both soil reduced significantly upon collapse, in particular the soil apparent cohesion, with the granitic residual soil showing more strength reduction compared with the sedimentary residual soil.
Effect of Sand Gradation on the Shear Parameters in the Soil Sample a Case Study in Kadapa District
IJIRSET, 2016
Shearing strength of a soil is the most difficult to comprehend in view of the multitude of factors known to affect it. A lot of maturity and skill may be required on the part of the engineer in interpreting the results of the laboratory tests for application to the conditions it the field. The shear strength of soils is an important aspect in many foundation engineering problems such as the bearing capacity of shallow foundations and piles, the stability of the slopes of dams and embankments, and lateral earth pressure on retaining walls. A soil have been mixed with different gradations of sand to form a different soil-sand mixtures. The main purpose is to observe the effects of different soil-sand mixture on behavior of shear strength. The direct shear test is conducted with shear boxes without performing initial consolidation in large boxes. The test procedure is conducted about 50% soil-50% sand mixtures seems to be threshold composition and changes are found by increasing the gradations of sand content in drained shear test Mainly Direct Shear test is conducted to find out the soil-sand mixture which tends to maximum shear strength is 1.58 kg/cm 2 , Maximum cohesion and Minimum angle of internal friction will be 1.16 kg/cm 2 and 15˚48', and decreases the seepage through the sand.
4. Effect of Fine Materials on Shear Strength Behavior of Granular Soil.pdf
The shear strength of soils is an important aspect in many foundation engineering problems such as the bearing capacity of shallow foundations, the stability of the slopes of dams and embankments and lateral earth pressure on retaining walls. The purpose this study is to observe the shear strength behavior of granular soil with fine materials up to 20%. A series of direct shear test were conducted on two types of dry sandy soils (taken from Rangpur and Rajshahi areas of Bangladesh) with varying percentage of fine materials. In all, 5 specimens of each type of soils were considered for direct shear test with dry condition. The specimens were prepared by static compaction with different percentage of fine materials from 0% to 20%. Experimental results show that, the angle of internal friction decrease and cohesion increase with increase in percentage of fine materials for both samples. The combined effect of angle of internal friction and cohesion show that, the shear strength decrease with increase of fine materials. In this study it is also observed that, the bearing capacity of foundation, factor of safety against slope are decreases and earth pressure on retaining wall increases with increase in percentage of fine materials.
Laterites are used extensively as construction materials in Nigeria. Particle size distribution of the laterites from the sedimentary basin of Southern Nigeria show that laterites are composed of sands and clays. The dependence of the shear strength and compressibility on their clay content is investigated using field samples of sand and clay mixtures. The results show that the soils cohesion, plasticity index and compressibility index are directly proportional to the clay content, while the friction angle and initial void ratio are inversely proportional to the clay content at the same moisture content. Copyright © IJEATR, all rights reserved. Keywords: Clay content; sand and clay mixtures; soils cohesion; plasticity index; compressibility index; friction angle; initial void ratio
Nigerian Journal of Technology, 2021
Soil behaviour may be hinged on the relative composition and nature of arrangement of the various component fractions embedded in the soil. Whether the component proportions of the fines (silt/clay) are interwoven within the voids of coarse (sand) grains, or that the coarse grains are dispersed within the fines mass would determine sandy or clayey soils characteristics. Density and voids ratio assessments of tropical residual soils were conducted in this study on compacted reconstituted binary blends of fines and coarse soils which were also subjected to cycles of sustained compression loads. The soil was separated into fines and coarse fractions by sieving through a 75μm sieve. Reconstituted soil samples were prepared from these two fractions in varying percentages ranging from zero fines content (0:100) to 100 percent fines fraction (100:0) in 10 percent increment. The results indicate that the moisture contents and changes in density due to moisture movements were insignificant f...
International Journal of GEOMATE, 2021
Residual shear strength plays a very significant role in geotechnical engineering. This concept has contributed extensively to diverse studies on soil behaviors under the influence of shear failure, both in drained and saturated conditions. In terms of landslides, the assessment of the residual shear strength after an occurrence and the progressive failure risk of slope stability has been very useful. However, information on this shear property in laterite soil appears relatively minimal. This soil type is the most frequently applied embankment for road construction in every Kalimantan region. Therefore, the purpose of this research is to determine the behavior of residual shear strength in laterite soil and the effects of adding coarse sand and clay fractions, using direct shear analysis. Subsequently, the specimens were prepared by compaction tests to obtain the optimum moisture content and uniform density, using coarse sand of varying proportions, termed 5, 10, 15, 20 and 25%, while, the shear strength treatment with wetting and drying cycle conditions was conducted under 2, 4, 6, 8 and 10 days, respectively. The results showed that the addition of the coarse sand and clay (CL) portions was able to increase the residual shear strength parameters (cohesion and internal friction angle) by 4-6%, compared to the pure state. Therefore, the introduction of clay (CL) materials ranging from 20-25% appears suitable in enhancing the residual shear strength of laterite soil. However, the extensive wetting-drying cycle tends to reduce the peak and residual shear strength.