Investigation on Steel Staggered-Truss System RC Slab

Abstract

For steel staggered-truss (SST) system, RC slabs are the main structure members to make the whole building work together beside to take the vertical load. There are openings in the RC slabs due to requirement of staircases、lift wells and other services, these openings will reduce the stiffness of RC slab and make stress concentration. Usually, the RC slab is designed under vertical load only, this will lead to the design defect and building calapse for SST structure. There are few research for SST RC slab are presented untill now. In the paper, based on two different 3D models considering or ignoring the stiffness of infilled walls (SIW), a numerical investigation is presented on the structural behaviors of the SST system utilizing the soft ware ETABS. As a finite element analysis method, the shell element is adopted for RC slab & infilled wall, the beam element is adopted for beam、colum and truss members. The structure is asymmetrical due to the SIW, it causes the torsional forces in the building and the extra stresses in the RC slabs, the additional reinforcement need to be provided to strengthen the high stress areas. Comparing with the results of response spectrum analysis under the combination with earth quake load, we make some conclusions, including the capacity of anti-seismic and the effect of the SIW for SST system RC slab，that could be a reference for SST structure design.