Study on Overturning Resistant Property of slope with unequal altitude supports under Earthquake Action

The building structure with unequal number of stories due to sloped ground, or the structure on slope, is a typical structural form in mountainous areas and has been widely constructed in mountainous cities. This type of buildings in a community located in Dujiangyan suffered serious damages during the 5-12 Wenchuan Earthquake in 2008. The characteristics of such structure have not been extensively studied. For instance, its mechanical properties and seismic performances are different from those of the regular structure constructed on flat ground due to the different restraining conditions of their supports. The seismic overturning resistant behavior is significant for ensuring structural seismic safety. This paper focuses on the seismic overturning resistant behavior of this type of buildings. Considering the structure and soil interaction, overall finite element models including soil and structure were established using ANSYS. Through the simulations by the finite element models, the rule of base shear distribution under horizontal earthquake action was obtained. The influences of story number and bay number on the overturning resistant behavior were investigated. Analyses of structures constructed on flat ground were also conducted for comparison. Based on the analyses results, suggestions are made for the check of seismic overturning resistant capacity of the structures with unequal number of stories due to sloped ground.