Analysis of planar reinforced concrete frames with weak storey subjected to earthquakes considering soil-structure interaction

Abstract

Structures with weak storey are quite common in practice because the first storey is usually designed without partition walls to use as a car park or a hall. Meanwhile, partition walls are used to divide upper storeys into apartments or offices. As a result, the first storey is weaker than other storeys and it thus becomes vulnerable to earthquakes. Besides, soil-structure interaction (SSI) should be considered when structures are subjected to earthquakes. This paper presents the analytical results of reinforced concrete frames with weak storey subjected to earthquakes considering SSI. A three-storey reinforced concrete frame with soft first storey representing for low-rise structures was selected for analysis. The results show that patition walls redistribute the storey drifts when the structure is subjected to earthquakes. When the partition walls are not considered, the storey drift of the second storey is larger than that of the first storey. When the partition walls are considered, the drift of the first storey is largest. The storey drift of the first storey increases by nearly 50% and it is 3.4 times larger than that of the upper storeys. At the same time, the drifts of storeys with partition walls decreases sharply because the partition walls increase the stiffness of these storeys. SSI slightly increases the storey drifts by 3.2% compared with those in the case without considering SSI.