Theoretical model and finite element analysis for restoring moment at column foot during rocking

Abstract

Column usually rests directly on top of a stone base without any physical connection in traditional timber structures. When timber structure is subjected to horizontal loads, rotation around the edge of column foot may occur with or without slippage of column. Columns rock with cyclic lift and reset. Compression deformation occurs to column foot due to the heavy vertical load of the structure and it is an important factor to the loading bearing capacity of timber structure. Accordingly, the rotation behavior of column foot during rocking has to be taken into account when carrying out the structural analysis. For this purpose, rotation behaviors of column foot during rocking is studied, and theoretical model of restoring moment at column foot joint is proposed with consideration of the compression effect; finite element model is established to verify the proposed model and good agreement of the two models is found. Result shows that column foot has contributions to resist horizontal loads with rocking under lateral load.