Study On The Seismic Performance Of Step-Terrace Structure

Step-terrace structure is a ground structure. It means the structure that the bottom interface is on different venues-surface elevation, and sets floor by storey height at the highest place of the following. The structural form is irregular at transverse and vertical level, distinct from that of ordinary structural system. However, Chinese code didn't prescribe seismic design of the structural form amply at present. Therefore it is worth researching the influence law of Step-terrace structure against earthquake.In this paper, step-terrace structure for study, analyzing seismic performance of Step-terrace structure with different ways of access ramp in SAP2000. We create a corresponding simplified calculation model depending on the way of access ramp. The paper researches into the law of seismic performance of step-terrace structure through a number of examples on different inter-out and different layers. It compares the seismic performance between step-terrace structure and ordinary frame structure in state of elastic-plastic, and also the differences of mechanical performance of the model taking into consideration soil-structure interaction in horizontal earthquake to not taking into consideration soil simplified calculation.Below are the conclusions:1. In horizontal earthquake,it differs in mechanical performance the step-terrace structure varied accessed ramp. The difference mainly comes from Step-terrace and first floor above the scarp.2. When the structure of the same height: for the structure with the retaining wall separated from main structure, the performance degrades with the increase of Step-terrace scarp and its cross region. When the height of scarp is about seventy percent of the total structure, the mechanical performance reaches its highest vulnerability. In comparison, the mechanical performance with the retaining wall adjoins to main structure stays much better.3. The weak storey of step-terrace structure is higher than the ordinary framework structure. With the increase of the layers below the scarp, the position of the weak layer shift upward. The weak storey of step-terrace structure is usually on the first floor above the scarp.4. Step-terrace structure will have a greater torsion effect for plane and facade of irregularness. 5. Comparing to the results considering soil-structure interaction, it is un-safer for the results of the model that don't consider soil-structure interaction, and the influence differs with the nature of soil.