Qualification: 
Ph.D, M.Tech, BE
Email: 
g_santhoshkumar@cb.amrita.edu

Dr. Santhoshkumar G. currently serves as Assistant Professor (Sr. Gr.) at the Department of Civil Engineering, School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore. He works in the area of computational and experimental geomechanics, soil dynamics and geotechnical earthquake engineering.

Education

  • 2015-2020: Ph. D.
    Geotechnical Engineering, IIT Kanpur, India.
  • 2010-2012: M.Tech
    Geotechnical Engineering, IIT Kanpur, India.
  • 2004-2008: B.E.
    Civil Engineering, Government College of Technology, Coimbatore

Experience

Year Affiliation
March 2021 – Present Assistant Professor (Sr. Gr.),
Amrita Vishwa Vidyapeetham, Coimbatore
July 2020 – March 2021 Senior Research Fellow,
Indian Institute of Technology Kanpur, India
June 2012 – December 2014 Assistant Professor,
Amrita Vishwa Vidyapeetham, Coimbatore
April 2010 – June 2010 Project Associate,
Indian Institute of Technology Madras, India
September 2008 – June 2009 Engineer (Civil),
Gammon India Limited, Mumbai

Research Interest

  • Numerical and analytical methods in geomechanics
  • Earth pressure on retaining walls
  • Interaction effect of footings and anchors
  • Effect of earthquake on geotechnical structures
  • Analysis of pile foundations

Awards & Recognition

  • Best paper presentation in Indian Geotechnical Conference 2020.
  • Recipient of Foundation Awards 2019, fromInternational Society for Soil Mechanics and Foundation Engineering (ISSMGE), London.
  • Finalist in Research Awards at IACMAG symposium 2019 at IIT Gandhinagar, India.

Publications

Publication Type: Journal Article

Year of Publication Title

2021

Dr. Santhoshkumar G. and Ghosh, P., “Closed-Form Solution for Seismic Earth Pressure on Bilinear Retaining Wall Using Method of Characteristics”, Journal of Earthquake Engineering, vol. 25, pp. 1171-1190, 2021.[Abstract]


This paper presents a simplified mathematical formulation for a set of closed-form solutions to compute static and seismic active and passive earth pressure on a retaining wall with bilinear backface. The concept of the method of stress characteristics in the framework of hyperbolic partial differential equations has been employed for the intended purpose. The advantage of varying the wall geometry for obtaining an economical design is briefly discussed. This mathematically robust but elementary procedure may be useful as a predecessor for obtaining an efficient and economical design of a retaining wall to palliate the earthquake damage.

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2021

S. Nandi, Dr. Santhoshkumar G., and Ghosh, P., “Determination of critical slope face in c-ϕ soil under seismic condition using method of stress characteristics”, International Journal of Geomechanics, vol. 21, p. 04021031, 2021.[Abstract]


This study proposes a plasticity-based approach to ensure the static and seismic stability of a finite soil slope supporting a uniformly distributed surcharge on the horizontal top surface. Most of the available investigations based on the limit equilibrium and the limit analysis method mainly rely on the assumed slip surface to determine the stability of a slope with a given geometry. The present analysis employs the method of stress characteristics coupled with the original pseudodynamic approach to trace the actual slip surface of a soil slope under the seismic condition. The results are presented in terms of the critical slope face (CSF) corresponding to a global factor of safety of 1.0. The obtained CSF can be used as a reference to determine the stability of slopes with different geometries. The current approach supersedes the available theories developed to analyze slopes by presenting a more general solution without assuming any predefined slip surface. The proposed idea is endorsed with a detailed parametric study that demonstrates the influence of various parameters such as cohesion and the angle of internal friction of soil, surcharge loading, and seismic wave properties on the stability of a finite slope. As a notable outcome, this investigation promotes a bilinear or concave slope face, which may be an efficient and economical alternative to the traditional linear slope face.

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2020

V. Srinivasan, Ghosh, P., and Dr. Santhoshkumar G., “Experimental and Numerical Analysis of Interacting Circular Plate Anchors Embedded in Homogeneous and Layered Cohesionless Soil”, International Journal of Civil Engineering, vol. 18, pp. 231-244, 2020.[Abstract]


In this paper, the interaction phenomenon of two closely spaced symmetrical circular plate anchors buried at shallow depth in homogenous and layered sand strata was carefully observed from a series of large-scale model tests. A numerical model is further proposed by validating the experimental data. The motivation for the present investigation actually arrived from the fact that the uplift capacity of anchors is often analyzed as a single entity, whereas the anchors are actually placed in group. The present experimental observations revealed that the interacting anchors experience higher displacement along with the significant reduction in the uplift capacity at the closer spacing. Similar to the single anchors, the uplift capacity of interacting anchors increases with the embedment depth. The size effect of the anchor plate is found to be a significant parameter in pronouncing the interaction effect. However, the rate of reduction in the uplift capacity mainly depends on the embedment depth and the relative density of soil. Unlike the homogenous sand bed, the shear mobilization is not uniform in a layered sand bed although the rupture surface is progressive from the edge of the anchor plate to the ground surface in both the cases. The proposed numerical model performs well in capturing the interaction of circular plate anchors in homogenous and layered sand bed as well. The quality of the results is assured by comparing with the similar works available in the literature.

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2020

Dr. Santhoshkumar G. and Ghosh, P., “Ultimate bearing capacity of skirted foundation on cohesionless soil using slip line theory”, Computers and Geotechnics, vol. 123, p. 103573, 2020.[Abstract]


A plasticity-based model is developed under the framework of the slip line theory to estimate the ultimate bearing capacity of a skirted strip foundation resting on cohesionless soil under both static and seismic conditions. The analysis is performed considering a both-side failure mechanism beneath the foundation. The bearing capacity is eventually derived by satisfying the force equilibrium of the soil wedge trapped between the skirts. A pseudo-static analysis is performed to encompass the effect of an earthquake in the present analysis. The enhancement in the bearing capacity of a skirted foundation compared to a conventional surface foundation is demonstrated with a comprehensive parametric study. The obtained results are found to be lesser than that obtained through the upper bound solution reported in the literature but closer to the available experimental studies. Reduction in the bearing capacity of a skirted foundation during any seismic event is found to be lesser due to the presence of the skirts.

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2020

Dr. Santhoshkumar G. and Ghosh, P., “Seismic Stability of a Broken-Back Retaining Wall Using Adaptive Collapse Mechanism”, International Journal of Geomechanics, vol. 20, p. 04020154, 2020.[Abstract]


In this study, the pertinence of a broken-back retaining wall with bilinear backface in mitigating the effect of earthquake is demonstrated using the method of stress characteristics coupled with the pseudodynamic approach. Unlike the available studies reported in the literature considering the limit equilibrium or the limit analysis method, a priori failure mechanism is not assumed in this analysis, and the failure mechanism automatically gets evolved from the solution of stress characteristic equations. The versatility of the solution procedure is explored with the available seismic methods such as pseudostatic, original pseudodynamic, and modified pseudodynamic approaches. The effect of various parameters such as inclination and roughness of the wall, angle of internal friction of the backfill soil, damping of the soil, and phase difference of seismic waves on the active thrust is determined in the analysis. The stability analysis of the wall is performed using the classical Newmark's sliding block approach. The present results are compared with the available data reported in the literature. The seismic stability factors are found to be critical while considering the dynamic properties of the soil and the wall. The efficacy of employing the broken-back geometry over the conventional vertical retaining wall is presented for different wall configurations.

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2020

Dr. Santhoshkumar G. and Ghosh, P., “Seismic stability analysis of a hunchbacked retaining wall under passive state using method of stress characteristics”, Acta Geotechnica, vol. 15, 2020.[Abstract]


he potential use of a hunchbacked retaining wall over a conventional retaining wall under the seismic passive state is emphasised in this study employing the method of stress characteristics coupled with the modified pseudo-dynamic approach. Unlike the available studies established with the limit equilibrium or the limit analysis method where a predefined failure mechanism is assumed prior to the analysis, the failure surface is continuously traced in due course of the present analysis. The seismic stability of a hunchbacked retaining wall under the passive condition is found to be affected greatly while considering the effect of damping of the soil-wall and the phase difference of the seismic waves. A detailed parametric study is conducted considering the influence of different soil and wall parameters such as soil-wall inertia, soil friction angle, wall inclination and roughness. The present results are obtained from a rigorous computational effort without assuming a failure mechanism and found to be in good agreement with the previous studies available in the literature.

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2019

Dr. Santhoshkumar G., Ghosh, P., and Murakami, A., “Seismic Active Resistance of a Tilted Cantilever Retaining Wall considering Adaptive Failure Mechanism”, International Journal of Geomechanics, vol. 19, p. 04019086, 2019.[Abstract]


In this paper, the seismic active resistance of a slanted cantilever retaining wall holding a cohesionless backfill is computed using the method of stress characteristics in association with the pseudodynamic approach. Dissimilar to the past investigations reported in literature adopting the limit analysis or the limit equilibrium method, a preordained failure mechanism is not assumed in this analysis. Various parameters such as inclination and roughness of the wall, angle of internal friction of the backfill soil, and phase difference of the seismic waves are considered in this study. The present results are compared with the results reported in literature. The present values of seismic active earth pressure coefficients are found to be higher than the values obtained from the pseudodynamic analysis, assuming the linear failure surface, but are found to be lower than the magnitudes derived from the pseudostatic analysis where constant ground acceleration is considered throughout the influence domain.

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2018

Dr. Santhoshkumar G. and Ghosh, P., “Seismic passive earth pressure on an inclined cantilever retaining wall using method of stress characteristics – A new approach”, Soil Dynamics and Earthquake Engineering, vol. 107, pp. 77-82, 2018.[Abstract]


This paper depicts the computation of passive earth pressure on an inclined retaining wall supporting a cohesionless backfill subjected to earthquake loading condition. The method of characteristics in association with the pseudo-dynamic approach has been adopted for the intended purpose. Unlike the previous studies considering the limit equilibrium or limit analysis method, a priori failure mechanism is not assumed in this analysis. The effect of various parameters such as angle of internal friction of the backfill soil, inclination and roughness of the wall, and phase difference of the seismic waves is discussed in detail. While comparing with the available literature, the present values of seismic passive earth pressure coefficient are mostly found to be lesser than the values reported by earlier pseudo-dynamic analyses assuming the linear failure surface.

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2016

P. Ghosh and Dr. Santhoshkumar G., “Vertical Uplift Capacity of Two Nearby Horizontal Strip Anchors Using the Method of Stress Characteristics”, International Journal of Geomechanics, vol. 16, p. 04015015, 2016.[Abstract]


The present study addresses the effect of interference on the uplift capacity of two closely spaced horizontal strip anchors embedded in cohesionless soil. The analysis has been performed using the method of stress characteristics coupled with the limit equilibrium approach. The method consumes fewer assumptions and provides a zone in which the force equilibrium and plastic yield conditions are simultaneously satisfied for given boundary stresses. The effects of surcharge and unit weight of soil on the pullout resistance of anchors have been determined in terms of uplift capacity factors (Fq and Fγ) and are presented as functions of embedment ratio (λ) and angle of internal friction of soil (ϕ). Similarly, the interaction phenomenon of two closely placed anchors has been expressed in terms of efficiency factors (ξq and ξγ). A detailed parametric study has been carried out by varying the clear spacing (S) between two anchors, embedment ratio, and soil friction angle. The results of the numerical analysis are compared with the available theoretical and experimental data reported in the literature.

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Publication Type: Conference Paper

Year of Publication Title

2020

M. D, Dr. Santhoshkumar G., and P., G., “Ultimate bearing capacity of strip footing on reinforced embankment using upper bound limit analysis”, in Proceedings of Indian Geotechnical Conference, Andhra University, Visakhapatnam, 2020.

2019

Dr. Santhoshkumar G. and Ghosh, P., “Seismic Passive Resistance of Cantilever Retaining Wall with an Efficient Adaptive Failure Mechanism”, in 16th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering (16ARC), Taipei, Taiwan, 2019.

2015

P. Ghosh and Dr. Santhoshkumar G., “Vertical Uplift Capacity of Two Nearby Horizontal Strip Anchors Using the Method of Stress Characteristics”, in International Journal of Geomechanics, 2015, vol. 16, p. 04015015.[Abstract]


The present study addresses the effect of interference on the uplift capacity of two closely spaced horizontal strip anchors embedded in cohesionless soil. The analysis has been performed using the method of stress characteristics coupled with the limit equilibrium approach. The method consumes fewer assumptions and provides a zone in which the force equilibrium and plastic yield conditions are simultaneously satisfied for given boundary stresses. The effects of surcharge and unit weight of soil on the pullout resistance of anchors have been determined in terms of uplift capacity factors (Fq and Fγ) and are presented as functions of embedment ratio (λ) and angle of internal friction of soil (φ). Similarly, the interaction phenomenon of two closely placed anchors has been expressed in terms of efficiency factors (ξq and ξγ). A detailed parametric study has been carried out by varying the clear spacing (S) between two anchors, embedment ratio, and soil friction angle. The results of the numerical analysis are compared with the available theoretical and experimental data reported in the literature.

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