某砖石古塔-地基相互作用系统地震反应分析

SEISMIC RESPONSE ANALYSIS OF INTERACTION SYSTEM OF MASONRY PAGODA AND SUBSOIL

为了研究在考虑土与结构作用时砖石古塔的地震反应规律,为砖石古塔的抗震加固提供参考,以西安兴教寺玄奘塔为研究对象,通过附加人工边界,建立玄奘塔与地基相互作用系统的数值计算模型,同时输入三向地震波,对相互作用系统进行时程分析。计算结构的位移和应力反应,并与不考虑相互作用时的计算结果进行比较。结果表明,结构的水平剪应力、竖向剪应力及竖向正应力在塔体中部最大,层间位移值在塔体中部及顶部均较大,且最大值分布于中间楼层。由计算结果可知,中间楼层和顶层均为砖石古塔的抗震危险截面。

In order to study the characters of seismic response of masonry pagoda under the interaction of soil and structure, to refer to seismic reinforcement to masonry pagoda, artifical boundary conditions ware set up, and the calculation model which included interaction system of soil and structure of Xuanzhuang Pagoda in Xingjiao Temple in Xi＇an, Shaanxi Province was established. Under three dimension earthquake waves, the seismic response analysis was done by time history analysis method. The follows were indicated by calculation results that the maximum value of horizontal stress, the vertical stress and the axial stress of the tower were located in the mid of the structure. And the story drift in the mid and top of the structure was larger than the other and the maximum value was in the mid. Therefore, the mid story and top story were critical seismic sections of masonry pagoda.