Browsing by Author "Kumar, Kamalesh"

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An Approach to Estimate the Atterberg Limits of Pilani Soil Using Ultrasonics
(BP International, 2020) Kumar, Kamalesh
Basics Of Environmental Resource Management
(New Age International, 2017) Kumar, Kamalesh
Correlation Between Safe Bearing Capacity and Angle of Internal Friction of Pilani Soil
(International Journal of Technology Innovations and Research, 2015-07) Kumar, Kamalesh
Safe bearing capacity of soils is used in foundation design. Shallow foundations in the form of continuous strips are widely used. Standard equations are available to estimate the safe bearing capacity of soil supporting strip shallow foundations. It appears from these equations that there is a stro ng dependence of bearing capacity on angle of internal friction. An attempt has been made in the present study to get simplified correlation between safe bearing capacity of soil and angle of internal friction using the principle of least squares. Correlat ion has been developed by analyzing 20 different soil samples and verified for 19 other soil samples. Analytical equations in the form of linear as well as quadratic polynomial have been developed. Correlation coefficient between actual and estimated value of safe bearing capacity for linear and quadratic polynomial was found to be 0.869319 & 0.942516.
Direct Shear Testing of Coal Dust Mixed Pilani Soil at Three Different Water Contents
(International Association of Scientific Innovation and Research, 2016) Kumar, Kamalesh
Shear strength of soil is an important geotechnical design consideration. It depends on its cohesion & angle of internal friction value. Coal dust is available as waste material with domestic cooking coal suppliers at very small price in India. Shear strength parameters (cohesion and angle of internal friction) of soil are altered when coal dust is mixed in soil. They are conveniently determined from direct shear testing for freely draining soils like Pilani soil. In the present experimental study, four different percentages of coal dust was added in local Pilani soil. In these soil-coal dust mixtures, three different water contents were added (0%, in-situ & in-situ saturation). Direct shear testing on these samples was conducted to find out cohesion and angle of internal friction variation. Results of the experiments were analyzed. Practical significance of the obtained experimental results was also discussed.
Interrelation between Safe Bearing Capacity and Angle of Internal Friction of Pilani Soil
(BP International, 2020-10) Kumar, Kamalesh
Liquefaction Potential of Pilani Soil
(IOSR Journal of Mechanical and Civil Engineering, 2019) Kumar, Kamalesh
Liquefaction takes place when seismic shear waves pass through a saturated granular soil layer. These shear waves distort its granular structure, and cause some of its pore spaces to collapse. This collapse increases pore water pressure and decreases soil's shear strength. If pore space water pressure increases to the point where the soil's shear strength can no longer support the weight of the overlying soil, liquefaction results. In simplified procedure, cyclic stress ratio and cyclic resistance ratio at required depth is determined. These are used to find out factor of safety against liquefaction. It has been suggested that this factor should be more than 2 to ensure safety with respect to liquefaction, excess pore pressure development and ground settlement. Pilani soil is sand till substantial depth below ground surface. Normally water table is at substantial depth. Only during rainfall, soil from ground surface momentarily gets saturated and is below water table. Although this condition of saturation from ground surface with soil below water table is not very likely during earthquake, factor of safety against liquefaction for Pilani soil has been determined for these conditions using simplified procedure. Results have been analyzed and its practical significance has been explained.
Moisture Content Effect on Sliding Shear Test Parameters in Woven Geotextile Reinforced Pilani Soil
(International Journal of Engineering Science Invention, 2013-08) Kumar, Kamalesh
Woven geotextile is widely used as reinforcing material in soil. Adhesion and interface friction are the primary parameters affecting reinforced soil performance under these conditions. They are determined using sliding shear test in the laboratory. Soil gradation, plasticity, in-situ dry density, moisture content and surface characteristics of the geotextile are important parameters affecting them. In the present experimental study, effect of moisture content on adhesion and on interface friction has been studied for local soil reinforced with woven geotextile. Trend of variation has been explained. Practical significance of the study has also been discussed.
Nondestructive evaluation and study of various parameters affecting the strength of soil
(BITS Pilani, 2001-12-20) Kumar, Kamalesh
Pore fluid effect on shear strength of Pilani soil
(Journal of the Institution of Engineers, 2001) Kumar, Kamalesh
Soil strength and its accurate determination are always important issues to a soil engineer. Pore fluid and its characteristics are found to have significant effect in modifying shear strength parameters. Present study focuses on effect of pore fluid quantity and its electrolyte concentration on shear strength parameters of soil samples collected locally. Soil samples of specific particle size were subjected to direct shear testing when pore water content and its electrolyte concentration was changed. Variation of cohesion and angle of internal friction with above parameters was thus studied. Cohesion and angle of internal friction can be determined conveniently and accurately and provide valuable information about shear strength status of soil samples when pore water content and electrolyte concentration of pore water of the soil system changes. Thus optimum level of pore water quantity and electrolyte concentration in it has been determined to obtain optimum shear strength of soil mix tested.
Shear and P-Wave Velocity Interrelation of Pilani Region Soil
(IJNIET, 2024) Kumar, Kamalesh
According to elastic rebound theory, earth’s crust behaves like an elastic medium. Due to earthquake, aerial bombardment or bomb-blast ground motion occurs resulting in stress waves. Shear wave as well as P-wave are two different type of stress waves. They are also called body waves because they travel through the earth. The propagation velocities of shear waves as well as P-waves are determined by the modulus of elasticity of the propagation medium like soil. Shear waves are quite damaging to geotechnical construction. Standard field based and lab based methods are available for shear wave velocity determination as well as estimation. All of them require complicated experimental setup. Laboratory based P-wave through soil determination is very simple on the other hand. In the present study, interrelation between shear wave velocity and P-wave velocity based on laboratory set-up has been studied for Pilani region. Exponential curve of best fit equation to obtain estimated value of shear wave velocity has been obtained knowing the P-wave velocity. Study is for Pilani region soil. Similar study can be undertaken at similar other regions also
Shear Strength Characteristics of Coal Dust Mixed Pilani Soil
(International Journal of Innovative Science, Engineering & Technology, 2016) Kumar, Kamalesh
Cooking coal dust has the potential to replace traditional admixtures used to improve soil properties. The low cost of this coal dust is an added benefit as it can be used either alone or in combination with regular admixtures in the construction of foundations, embankments, retaining walls etc. The aim of this paper is to determine the shearing strength parameters of Pilani soil mixed with varying coal dust amount. The experimental values will give us a better understanding of the range of coal dust usage in construction. Disposal of the huge amount of produced coal dust poses a potentially serious environmental threat due to paucity of land for disposal. Therefore, using coal dust in construction can, in addition to reducing expenditures, will also solve the headache of its safe disposal and help in preventing environmental degradation. Direct shear testing was conducted at in-situ water content & at OMC conditions.
Shear wave velocity estimation of pilani soil using ultrasonics
(Revolution Code Blue, 2025) Kumar, Kamalesh
In order to evaluate dynamic response of soils, shear wave velocity of soils is widely used. This is small-strain parameter. These dynamic responses are seismic site response, machine foundation vibration and liquefaction potential of soil at site. Geologic aging of soil, its stress history, density, in-situ void ratio and effective confining stress are important parameters affecting shear wave velocity. Its correlation with SPT N value is available in literature. Involved technique of obtaining shear wave velocity of soil is complicated. There should be simple alternative of estimating it. In present study, ultrasonic P wave propagation at five different silty clay contents for Pilani region soil has been used for this purpose. SPTNvalue for these silty contents have been determined based on correlation equations available in literature. Based on these SPT N values, shear wave velocity for same silty clay contents have been determined for Pilani region soil. Variation of P wave velocity and shear wave velocity with silty clay content can be used as calibration curve. P wave velocity through 300micron sieved soil of same region can be determined. Its estimated value of shear wave velocity can be obtained from the calibration curve. For some sites in the region, additional sieving through 150micron sieve will also be required. This technique of estimating shear wave velocity is much simple for a specific region soil.
Sliding Shear Testing of Nonwoven Geotextile Reinforced Pilani Soil
(International Journal of New Innovations in Engineering and Technology, 2021) Kumar, Kamalesh
Geotextiles and related products support many civil engineering applications. Geotextile is permeable textile material. Geotextile is made up of natural as well as of synthetic fibers which could be woven or nonwoven. Woven geotextiles consist of fibers or yarns of a polymer that are oriented in two perpendicular directions, one over the other. There are four main fiber types which are used to manufacture woven geotextiles: monofilament, multifilament, slit-film and fibrillated fibers. Nonwoven geotextiles consist of discrete fibers which may be oriented or randomly distributed. There are also different fiber types used to manufacture nonwoven geotextiles: continuous filaments; and staple fibers. Nonwoven geotextile made up of synthetic fiber and used as reinforcing agent in local soil has been used in present study. Sliding shear testing of nonwoven geotextile reinforced experimental soil was conducted at four different water contents to investigate the effect of water content on adhesion and on interface friction angle under these conditions. Testing was done under fully drained conditions.
Soil Bearing Capacity Determination using Ultrasonics
(Journal of Pure and Applied Ultrasonics, 2000) Kumar, Kamalesh
Water Content Effect on Shear Strength Parameters in Coir Fiber Reinforced Pilani Soil
(BASHA RESEARCH CENTRE, 2014-10) Kumar, Kamalesh
Recently, much work has been done on strength deformation behaviour of fiber reinforced soil and it has been established beyond doubt that addition of fiber in soil improves the overall engineering performance of soil. Fiber reinforced soil is effective in all types of soils (i.e. sand, silt and clay). Use of natural fibers in civil engineering construction practice is often advantageous as they are cheap, locally available, biodegradable, and ecofriendly. Among the available natural fibers (jute, coir, bamboo, etc.), coir is produced in large quantities in South Asian countries, such as India, Ceylon, Indonesia, Philippines, etc. and has better mechanical properties, such as tensile strength. In this paper, results on the cohesion and angle of internal friction behavior (obtained from direct shear testing) of local soil reinforced with coir fibers are presented at varied water contents. Soil sample reinforced with randomly distributed coir fibers of 2.5cm length and 2.85mm to 0.64mm average diameter range (measured using screw gauge) were made for direct shear testing at 0.5% fiber content. Testing was done at four different water contents. The results show that cohesion increased and angle of internal friction decreased with increase in water content. Unreinforced in-situ local soil has negligible cohesion and angle of internal friction around 280 under similar direct shear testing conditions. Practical significance of the study has also been discussed.