Seismic soil structure interaction analysis for asymmetrical buildings supported on piled raft for the 2015 Nepal earthquake

• Published in: Journal of Asian earth sciences Vol. 133; pp. 102 - 113
• Main Authors: Badry, Pallavi, Satyam, Neelima
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2017
• Subjects: Asymmetrical building; Asymmetrical pile groups; DSSI; Nepal earthquake; Soil pile interaction; Asymmetrical building; Soil pile interaction; DSSI; Asymmetrical pile groups; Nepal earthquake
• ISSN: 1367-9120; 1878-5786
• DOI: 10.1016/j.jseaes.2016.03.014

•Numerical implementation of seismic soil pile structure interaction by including contact and sliding behavior between soil and pile, earthquake and absorbing boundary conditions for semi infinite soil domain, soil nonlinearity under small loading condition, integrated superstructure and foundation system has been considered.•Effect of 2015 Nepal earthquake on asymmetrical buildings of different configuration like L, T and C shape including interaction effect.•Study the effect of peak ground acceleration of the earthquake and asymmetry of the buildings on its response to understand the risk criterion under seismic event.•Comparative analysis of 3 different earthquakes with Nepal earthquake in context of asymmetrical buildings. Seismic damage surveys and analyses conducted on modes of failure of structures during past earthquakes observed that the asymmetrical buildings show the most vulnerable effect throughout the course of failures (Wegner et al., 2009). Thus, all asymmetrical buildings significantly fails during the shaking events and it is really needed to focus on the accurate analysis of the building, including all possible accuracy in the analysis. Apart from superstructure geometry, the soil behavior during earthquake shaking plays a pivotal role in the building collapse (Chopra, 2012). Fixed base analysis where the soil is considered to be infinitely rigid cannot simulate the actual scenario of wave propagation during earthquakes and wave transfer mechanism in the superstructure (Wolf, 1985). This can be well explained in the soil structure interaction analysis, where the ground movement and structural movement can be considered with the equal rigor. In the present study the object oriented program has been developed in C++ to model the SSI system using the finite element methodology. In this attempt the seismic soil structure interaction analysis has been carried out for T, L and C types piled raft supported buildings in the recent 25th April 2015 Nepal earthquake (M=7.8). The soil properties have been considered with the appropriate soil data from the Katmandu valley region. The effect of asymmetry of the building on the responses of the superstructure is compared with the author’s research work. It has been studied/observed that the shape or geometry of the superstructure governs the response of the superstructure subjected to the same earthquake load.