Faculty Publications
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Item Seismic Behaviour of Soil Nailed Wall(Springer Science and Business Media Deutschland GmbH, 2021) Amrita; Jayalekshmi, B.R.; Shivashankar, R.Soil nailing is a technique used to stabilise steep cut slopes and to retain excavations. The method consists of inserting nail bars into the ground either by drilling or by grouting. The present study evaluates the seismic behaviour of a soil nailed wall supporting a vertical cut of height 6 m. The finite element analysis has been carried out to study the stability and performance of the soil nailed wall using ANSYS software. The seismic resistance of the wall is analysed under the El-Centro ground motion. The seismic response variation for different parameters such as angle of inclination of nails and soil strength properties are studied. The maximum lateral displacements and acceleration response of soil nailed wall are evaluated under static as well as dynamic conditions. The results of the study indicate that soil nailed system imparts stability to the retaining system under dynamic conditions. © 2021, Springer Nature Singapore Pte Ltd.Item Dynamic Response of Soil Nailed Wall(Springer Science and Business Media Deutschland GmbH, 2021) Amrita; Jayalekshmi, B.R.; Shivashankar, R.Soil nailing is a technique used to stabilize steep cut slopes and to retain excavations. The method consists of inserting nail bars into the ground to stabilize the soil mass. The present study evaluates the dynamic response of a soil nailed wall supporting a vertical cut of height 6 m. The finite element analysis has been carried out to study the stability and performance of the soil nailed wall using PLAXIS 2D software. The seismic resistance and failure mechanism of the wall are analyzed under the El Centro ground motion. The seismic response variation for different parameters such as angle of inclination of nail and length of nail is studied. The results are observed in terms of maximum lateral displacement, development of maximum tensile force in nails and failure mechanism of soil nailed wall under static and dynamic conditions. The results of the study indicate that the soil nailed structure is an effective method which imparts stability to the retaining system under dynamic conditions. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Dynamic Soil–Structure Interaction Effects in Integrated Retaining Wall-Building System(Springer Science and Business Media Deutschland GmbH, 2022) Vinay, N.S.; Amrita; Jayalekshmi, B.R.; Shivashankar, R.As the area of land suitable for construction goes on reducing day by day, it is a challenge for civil engineers to utilise the space available in most efficient way possible. This study explores the feasibility of integrating buildings with retaining walls for utilising the maximum space available in commercial zones where the landscape is at different levels demanding the provision of retaining walls. A retaining wall of 6 m height and a multi-storey RC frame having 18 m height in the adjoining lower ground at a distance of 4 m are considered for the study. The effects of integrating the retaining wall to building frame by utilising the 4 m space available between them have been studied by providing a connection through the available space and by attaching the retaining wall as a shear wall to the building leaving no space in between them. The three-dimensional finite element model of the integrated retaining wall-building system has been analysed under dynamic loading. Parameters such as deflection and acceleration at top most storey, bending moments, and shear forces in building components are evaluated. Results are compared amongst different cases of retained soil types and different positions of building from retaining wall. The results show considerable reduction in the building deflection and acceleration when the two structures are connected through the space. Reduction in shear force and bending moment in building components are observed when the two structures are attached to each other without any space in between. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Investigation on Stability of Vertical Cuts Retained by Soil Nailing Using Finite Element Method(Springer Science and Business Media Deutschland GmbH, 2024) Amrita; Jayalekshmi, B.R.; Shivashankar, R.One of the methods that can be effectively used for stabilisation of vertical cuts, excavations and natural slopes is soil nailing. It comprises of insertion of nails into the soil mass to be retained and providing stability to it against failure. This study deals with numerical analysis of vertical cuts under static loading that have been stabilised using soil nailing by incorporating soil-structure interaction. Performance and characteristics of soil nailed vertical cuts of three different heights are evaluated. Finite element analysis of 6 m, 10 m and 14 m high soil nailed walls retaining three different types of soil masses are performed to evaluate the response of the structure under different parameters to obtain the more stable structure against overall failure. Stability of these structures expressed with respect to global factor of safety are evaluated using Ï•-c reduction analysis. Horizontal displacement of wall and mobilised axial nail forces are also determined. The effect of orientation of nail with horizontal and length of nail inserted into the soil mass on the response of nailed structures are evaluated. Studies conclude that the nail inclination of 15° results in maximum safety factor, minimum deformation and least axial nail forces. Increasing nail length results in structures with higher safety factors but a minimum length of 0.7 times the height of the wall is recommended. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Dynamic stability evaluation of nail stabilised vertical cuts in various site classes(Techno-Press, 2024) Amrita; Jayalekshmi, B.R.; Shivashankar, R.The soil nailing method entails the utilisation of nails to reinforce and stabilise a zone of soil mass. This is widely used for various applications due to its effective performance under various loading conditions. The seismic response of 6m high vertical soil-nailed cut in various site classes under dynamic excitations has been investigated in this study considering various lengths and inclinations of nails. The influence of frequency content of dynamic excitation on the response of structure has been assessed through finite element analysis using time history data of three different earthquakes. The seismic stability of the nailed cut in retaining soil in various sites under El Centro, Kobe and Trinidad earthquake ground motion is evaluated based on maximum acceleration response, maximum horizontal deformation, earth pressure distribution on the wall and maximum axial force mobilised in nails. The optimum nail inclination is identified as 15° and a minimum nail length ratio of 0.7 is essential for a stable vertical cut under dynamic excitations. © 2024 Techno-Press, Ltd.Item Integrating soil-nailed walls with RC building for seismic stability in space-constrained sites(Springer Science and Business Media Deutschland GmbH, 2024) Amrita; Jayalekshmi, B.R.; Shivashankar, R.In urban environments, space constraints necessitate innovative construction methods. Due to rising demand for infrastructures and scarcity of plane ground, structures are built on sloping or irregular ground. To make use of available land, vertical cuts or excavations are made in the natural soil stratum which can be effectively retained using the soil nailing technique. However, if the area adjacent to the nailed vertical cut is utilised for constructing a multi-storeyed building, the behaviour of the nailed structure may vary. This study examines the impact of the presence of multi-storeyed RC buildings on the response of soil-nailed structures in their proximity during earthquake ground motion. The seismic response of a soil-nailed structure is evaluated in the presence of various heights of medium-rise multi-storeyed buildings. Three-dimensional multi-storeyed buildings and soil-nailed structures are analysed with various arrangements and connectivities between them, taking into account different soil profiles at the site. Dynamic finite element analyses of integrated soil-nailed wall-building systems have been performed using time history data of ground motion. The findings suggest that the integration between the two structures enhances the seismic stability of both the structures under dynamic load as evident in the reduced deformation and acceleration of the structures. It restricts the lateral movement of the nailed wall and reduces its displacement by about 40%. This integration can be implemented in space-constrained sites for optimum utilisation of available space. © The Author(s) 2024.Item Dynamic response assessment of RC buildings featuring basement storeys integrated with soil-nailed structures(Elsevier Ltd, 2025) Amrita; Jayalekshmi, B.R.; Shivashankar, R.The rising demand for high-rise buildings and infrastructure has led to construction on hilly and sloping terrains, necessitating their stabilisation. The area adjacent to a vertical cut, stabilised through the soil nailing technique, presents opportunities for constructing multi-storey buildings. Incorporating basement levels in buildings is also a common practice to maximise the utility of space. This study evaluates the seismic performance of integrated soil-nailed wall-building systems, where the multi-storey building is connected to the soil-nailed structure through a shear wall, termed the Shear wall (SW) system. The effect of providing two basement levels on the seismic response of the integrated SW system is analysed in soft soil conditions, denoted as the SWB system (Shear wall system with basement floors). Finite element analysis of three-dimensional models of these integrated systems is conducted in PLAXIS software. The influence of the frequency content of dynamic excitations on the responses of these structures is assessed using time history data of three different earthquakes, considering various heights of the building. Results indicate that the SWB system provides substantial benefits, including a 35.17 % reduction in seismic building deformation, a 19.23 % reduction in soil-nailed wall acceleration, an 81.66 % reduction in axial nail force and a 54.77 % reduction in inter-storey drift. However, these improvements come with increased lateral earth pressure on the soil-nailed wall, necessitating careful design to ensure optimal seismic performance. These integrated configurations are recommended as suitable for optimum space utilisation in space-constrained urban sites while ensuring structural stability under seismic loading. © 2025 Elsevier LtdItem Numerical study on reinforced vertical cuts integrated with RC buildings under the effects of ground motion(Institute of Engineering Mechanics (IEM), 2025) Amrita; Jayalekshmi, B.R.; Shivashankar, R.Soil nailing is an effective method used for stabilizing excavations and natural ground slopes. In situations with space constraints due to rapid urbanization, the available space near the soil-nailed vertical cuts can be utilized to construct multi-storied buildings. However, the presence of a building in proximity to the retained soil mass may alter the seismic response of a nailed structure. The building can be either constructed at a distance, connected or attached to the soil-nailed structure depending on the space availability. This study evaluates the behavior of such an integrated soil-nailed, wall-building system under seismic excitations by employing finite element analysis. The seismic response of a nailed wall supporting a vertical cut of a height of 6m under different connectivity conditions with an adjacent multi-story RC building is analyzed. Parametric studies are conducted with various heights of a building and under different frequency content of seismic excitations. The performance of the integrated system is evaluated regarding displacement and the acceleration response of the soil-nailed wall, as well as tensile force mobilized in nails. The innovative concept of integration between the two structures yields better seismic stability of the nailed structure, as well as for optimum use of land in space-constrained grounds with vertical cuts. © Institute of Engineering Mechanics, China Earthquake Administration 2025.