An efficient approach for assessing the seismic soil structure interaction effect for the asymmetrical pile group

Abstract

All of the civil engineering structures involve some type of structural element which is in direct contact with soil. To estimate the accurate response of the superstructure it is necessary to consider the response of the soil supporting structure, and is well explained in the soil structure interaction analysis. Many attempts have been made to model the SSI problem numerically; however the soil nonlinearity, foundation interfaces and boundary conditions make the problem more complex and computationally costlier. To overcome this problem the attempt has been made to optimize the computational efficiency by applying the equivalent pier method for the deep foundation system. In this research paper the L-shape 11 storey building supported by a pile foundation with homogeneous local soil condition is analyzed for dynamic loading including the SSI effect. The significance of the SSI effect has been studied by comparing the responses of the system for fixed base and flexible base condition. A new approach has been proposed to provide simplicity in SSI modeling and reduce the computational cost (both memory and time wise). The approach includes the applicability of the equivalent pier method for the asymmetrical pile groups system, including SSI effect of the pile foundation system. The approach is validated for group effect and found that equivalent pile method can successfully be adopted and helps to reduce the computational cost of SSI problem. To understand the applicability of EPM approach, the parametric study has been carried out for different input of earthquakes and soil types. In accordance with this the three distinct earthquakes, including 1995 Chamba (M = 4.9), 1999 Uttarkashi (M = 6.9) and 2001 Bhuj (M = 7.7) and soil types including cohesive, cohesionless and C-Phi soils have been considered for SSI analysis. The study observed that, earthquake magnitude and soil type shows the major impact on the response of the SSI system.

Dynamic Soil–Structure Interaction Effects in Buildings Founded on Vertical Reinforcement Elements

“…This method is able to simultaneously consider with accuracy the behavior of both the soil and the structure. Several researchers [11,12,16,17,22,[27][28][29] have studied the effect of the soil-pile-structure interaction on the behavior of buildings, adopting the direct method to get realistic analysis. In this study, the direct method is employed because of its adaptability to deal with complex geometries and material properties.…”

“…The results showed that the lateral displacements of the floating pile foundations are greater than the ones of the structure with a fixed-base condition, but are more reduced than the shallow foundation case due to the rocking components. Badry and Satyam [16] analyzed the dynamic response of a 3D nonlinear finite element system that consisted of an L-shape 11-storey building supported by a pile foundation with homogeneous soil conditions. The research included the applicability of the equivalent pier methods for the asymmetrical pile groups and the SSI effect of the system.…”

A review on soil–structure interaction analysis of laterally loaded piles

“…Seismic soil-structure interaction of a pile group was studied using equivalent pier method (EPM) by Badry et al [9]. The study was conducted on an axisymmetric multistoried building and the peak response of the building under fixed base condition and flexible base condition were studied.…”

“…8 Building pile system supported by the free-field ground through winkler type soil model [50] Fig. 9 Sketch of bending moment distribution in fixed head pile group [105] the difference in maximum bending moment and pile top deflection in comparison to the other's methods. Many researchers have performed the finite element analysis using the software PLAXIS 3D Foundation using embedded pile element and the analysis results are in good agreement with the pile load test conducted by various researchers.…”

Effect of soil-pile-structure interaction on seismic behaviour of nuclear power station via shaking table tests

“…For example, Mostafa and EI Naggar [14] proposed a method to analyse the dynamic lateral response of pile group under harmonic excitation. Basack and Nimbalkar [15] developed a numerical model based on a two-dimensional (2D) dynamic finite-element (FE) approach.. For cases when superstructures were considered, the seismic response of the pile-soil-structure interaction were studied experimental [16][17][18][19] and numerically [20][21][22][23][24][25]. As n-g centrifuge experiment, liquefication study and numerical simulation beyond the scope of this paper, so they are not discussed in this paper.…”