Numerical simulation of seismic response of Slope–Foundation–Structure interaction for mid–rise RC buildings at various locations

Abstract

This study is intended to evaluate the seismic response of the Slope–Foundation–Structure interaction of the mid–rise building at various locations with varying slope angles for linear and nonlinear homogenous soil strata using finite element modelling. The dynamic implicit method is used for the time domain analysis, and the Kelvin element boundary is applied at the truncated soil domain to absorb the reflecting waves. The nonlinearity of soil is incorporated using the hyperbolic stress-strain model by developing the user-defined material (UMAT). The model is validated with published literature, and found the result in good agreement. Further, slope stability is evaluated using FLAC3D and found the factor of safety >1. The results are shown in terms of vertical displacement, horizontal displacement, drift ratio, peak horizontal floor acceleration (PHFA), the rocking of the foundation and base shear. The effects are calculated for the different locations of the building, nonlinearity and slope angle. Nonlinear soil behaviour shows the permanent vertical deformation of the foundation. The lateral displacement of the buildings constructed at the top of the slope and the bottom of the slope are more affected compared to the building constructed on the slope for all slope angles. The nonlinearity of soil is more likely to affect the lateral seismic response of the buildings located at the top and on the slope as compared to the building located at the bottom of the slope. The PHFA is reduced by incorporating the nonlinearity of soil for all slope angles. All buildings are experiencing a high interstorey drift ratio for slope angle 20. The base shear seems to increase with the decrease in slope angle for all buildings in case of linear and nonlinear soil behaviour. The building located on the slope is more vulnerable to rocking failure compared to buildings located at the top and bottom of the slope. With the increase in slope angle, the rocking of the foundation is also increasing.