Conference Papers
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Item Finite Element Modelling of Laboratory One-Dimensional Consolidation of Soft Clays(Springer Science and Business Media Deutschland GmbH, 2023) Kasyap Vasudevan, A.S.; Sridhar, S.Consolidation of soft clays is always a challenge in foundation engineering. Different material models have been developed to capture the compression and recompression properties of clays. However, the deformation behaviour of clay is captured relatively well by modified cam clay. Validation of the material models and software tools which uses numerical analysis is very crucial before one use them to analyse field problems. A successful validation can open the possibilities for wide range application of the model. This study attempts to validate numerical model of a one-dimensional consolidation of soft clay using the results of consolidation test already conducted in laboratory. The time settlement data for different compression loads is obtained by simulating the laboratory experimental setup in ABAQUS finite element software. The boundary conditions are defined to simulate the drainage conditions in the experimental setup. The results from both experimental and numerical analysis are compared. The time settlement behaviour from numerical analysis for different loads were found comparable with experimental results. The dissipation of pore pressure and development of effective stress is also presented. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Seepage Analysis of Resilient Rubble Mound Breakwater Under Tsunami Overflow: Numerical Analysis(Springer Science and Business Media Deutschland GmbH, 2023) Sajan, M.K.; Chaudhary, B.A breakwater is an offshore structure which is constructed to protect ports and harbours from the destructive effects of sea waves, currents, typhoons, and even tsunamis by reflecting and dissipating their wave energies. Among the various types of breakwaters, the rubble mound (RM) breakwater is the most common type constructed near the seacoasts of many countries across the globe. The most devastating natural hazard that a breakwater could possibly encounter during its design life is a tsunami wave. Several breakwaters were severely damaged or completely collapsed in several countries during past tsunamis. The coastal areas of India bore the brunt of the damage during the 2004 Indian Ocean tsunami. Therefore, it is utmost important to develop new techniques such as placing special gabions and rows of sheet piles as countermeasures for making RM breakwaters tsunami resilient. One of the longest breakwaters in India, the north breakwater at the Ennore Port (Chennai) has been chosen as prototype. The numerical modelling of the RM breakwater along with the seabed soil with two layers has been done in Plaxis 2D to observe the effectiveness of these countermeasures during tsunami-induced seepage through the breakwater and seabed soils. It was found that the provision of special gabions with impermeable layer and sheet piles beneath the mound can effectively prevent the seepage of water that occurs during tsunami overflow. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Numerical study on the behavior of RC beams by using GFRP bars as an alternate to steel bars(Elsevier Ltd, 2023) Kuttagola, I.; Prashanth, M.H.; Kumar, A.The numerical study of the behavior of reinforced concrete beams by using Glass fiber reinforced polymer (GFRP) bars as an alternate to steel bars has been explored in this research. The numerical modelling of the beams is done using Finite element analysis (FEA) software ABAQUS. In the present study the beam with Glass fiber reinforced polymer (GFRP) bars as both longitudinal & transverse reinforcement is compared with conventional reinforced concrete beam. The numerical simulation is performed for three-point bending for displacement control. The results of load, strain and deflection data has been obtained from the numerical modelling. Stress versus strain curves, load versus strain curves and load versus deflection curves are plotted using the output data. The displacement, strain developed in longitudinal bars and stirrups, load carrying capacity, energy absorbed are then calculated using the data and are compared. From the results, it is observed that the Glass fiber reinforced polymer (GFRP) reinforced concrete beams have load carrying capacity par with conventional reinforced concrete beam. Further, Glass fiber reinforced polymer (GFRP) reinforced concrete beams have higher yield strains and experienced more energy absorption over conventional reinforced concrete beam. © 2023 Elsevier Ltd. All rights reserved.Item Stability Analysis of Rubble Mound Breakwaters Under Tsunami Overflow(Springer Science and Business Media Deutschland GmbH, 2024) Sajan, M.K.; Chaudhary, B.; Akarsh, P.K.; Kumar, S.Rubble mound (RM) breakwaters are the most commonly constructed breakwaters across the globe. Even though the breakwaters are designed to withstand to dynamic wave loadings, a natural disaster such as tsunami could impart additional loadings beyond the designed limits and thereby reduce the stability of the structure. Unfortunately, several RM breakwaters were severely damaged or even collapsed under the impact of past tsunamis such as the 2004 Indian Ocean tsunami and 2011 Great East Japan tsunami. The failure of these breakwaters would lead to the inundation of tsunami waves to the coastal areas causing devastating damages to life and property. Therefore, it is relevant to make the RM breakwaters resilient against tsunami impacts, so that the breakwater can either completely prevent or at least reduce the impact height of tsunami waves. In order to design a RM breakwater resilient against tsunami, the failure mechanisms under tsunami overflow conditions have to be properly understood. The present study thus aims to numerically evaluate the stability of RM breakwaters under tsunami overflow conditions. The cross-section details of the North breakwater at the Ennore Port, Chennai, India have been modelled at full scale in the finite element software Plaxis. The model was then subjected to a tsunami overflow condition. The corresponding deformations and stability of the RM breakwater were estimated. It was observed that the stability of the breakwater was considerably reduced under tsunami overflow conditions. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Finite Element Modelling of Foundation on Soft Clay Improved by Geocell and Boulder-Sand Layer: A Comparative Study(Springer Science and Business Media Deutschland GmbH, 2025) Rao, M.S.; Sridhar, G.Rapid infrastructure development urges for sufficient competent ground, which is currently scarce. Thus, the major focus of geotechnical engineers is the development of techniques for improving poor soil. A variety of strategies are used to reduce post-construction settlement, increase the shear strength of the soil, enhance the bearing capacity of the soil system, and improve the stability of superstructures. Among these, soil replacement is the simplest and most widely used method, while geocell reinforcement has been found to be an effective methodology. The three-dimensional structure of geocell provides better lateral confinement to the infill soil, improving its ability to support loads. However, because of its intricate honeycomb structure, numerical modelling of geocell has always proven difficult. Thus, an attempt has been made to generate a three-dimensional model of geocell using PLAXIS 3D. Finite element model was validated using laboratory model test results. A numerical analysis of footing resting over unimproved soft soil and soft soil improved by boulder-sand replacement and geocell reinforcement has been carried out. It was found that by replacement and reinforcement techniques, the performance of the footing can be doubled. The influence of width and depth of the boulder-sand layer and depth of the first geocell layer on bearing capacity improvement has been studied. The effect of the depth of boulder-sand bed on the influence factor was found to be higher compared to the effect of width. Maximum improvement by the inclusion of geocell was observed when it was placed in the middle of the sand layer with an improvement factor of 2.25. Further, using soil investigation data from in situ and laboratory tests, the concept has been extended to a field problem. © Deep Foundations Institute 2025.Item Critical Review and Finite Element Analysis of Smear Zone in Soft Clay Improved by Prefabricated Vertical Drains(Springer Science and Business Media Deutschland GmbH, 2025) Mahesh, D.; Sridhar, G.Structures built on soft soils are often affected by settlement problems. Over the past decades, one of the best methods to accelerate the consolidation process is preloading technique with pre-fabricated vertical drains. However, while installing these drains the soil around the drain gets disturbed, which in turn reduces the permeability of soil in radial direction. This disturbance is known to be smear effect and the region of this disturbed soil is the smear zone. This paper presents a state-art-of-the review on analytical, laboratory, field and numerical studies on the smear zone behaviour. Pore pressure variation, water content and permeability in the smear and undisturbed zone are compared. Finite element modeling carried out for better understanding of consolidation behaviour of soft clay improved with PVD is also presented in this paper. The effect of smear is considered in the finite element model and the results from the finite element model are compared with laboratory test results. The soil behaviour is modelled using the modified cam-clay model and the ABAQUS finite element application is used for numerical modelling. Based on the results, the time-settlement data and pore pressure dissipation predicted by the numerical model were comparable with the laboratory results reported in the literature with a variation of upto 10%. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.