NUMERICAL AND THEORETICAL RESEARCH ON MECHANICAL PERFORMANCE OF OUTRIGGER TRUSS-WALL JOINT IN SUPER HIGH-RISE BUILDINGS

Based on the experimental research on two kinds of outrigger truss-shear wall joints which are applicable to super high-rise buildings, further elaborate analysis using the finite element and theoretical methods are conducted for the seismic behavior and load transfer mechanism of the joint. According to the analysis results, design methods and proposals for the joints are given. Firstly the nonlinear numerical simulation of the joint is done by using finite element program MSC.MARC (2010). The finite element analysis results correlate well with the test results. Furthermore, the stress distribution of the outrigger truss, concealed ending column, outside (encased) steel plate and concrete wall are discussed and the simplified method to assess the bearing capacity of the joint is proposed. Finally a local model of the joint plate is established based on the whole model of joints and the load transfer mechanism of the plate is analyzed. The reasonableness of simplified design formula for this kind of joint plate is discussed. Analysis results indicate that the concrete wall between the upper and lower steel plates is under shear and a diagonal strut is thus formed; the assumption of plane section is not followed on the critical section of the plate due to the existence of shearing load and short plate. Conclusions drawn in this paper are helpful for the design and construction of the outrigger truss-wall joint in super high-rise buildings.