土质山地地形对抗震设计反应谱的影响

The Influence of Soil Mountainous Terrain on Seismic Design Response Spectrum

研究目的:研究山地地形效应,为山地建筑结构抗震提供合理的设计参数是山地建筑结构发展的首要任务;为确定土质山地建筑设计水平地震动放大系数,采用有限元数值分析方法建立相关的局部场地模型,输入近30条基岩地震波对场地模型进行动力时程分析;提取不同坡高、不同坡降H/L对应模型在斜坡段以及平台段的地震响应时程并转换成反应谱,通过对比斜坡段以及平台段的地表反应谱与平地地表反应谱,对区域放大系数进行调整。研究结论:(1)给出了土质山地地形对场地反应谱的主要影响规律;(2)给出了土质山地地形对场地反应谱谱比的主要影响规律;(3)给出了土质山地建筑结构设计水平地震动放大系数的建议值;(4)本研究成果可为山地建筑结构的地震动输入提供参考依据。

Research purposes: It is the necessary for the development of mountain building structures to study the effect of mountain terrain and provide reasonable design parameters for earthquake resistance of mountain building structures. In order to determine the horizontal ground motion magnification coefficient of earthen mountain building design, the finite element numerical analysis method was used to establish the relevant local site model, and nearly 30 seismic waves were input to carry out dynamic time-history analysis on the site model. Seismic response time history of H/L corresponding models with different slope heights and different slopes in slope section and platform section was extracted and converted into response spectrum. Regional magnification coefficient was adjusted by comparing the surface response spectrum of slope section and platform section with the response spectrum of flat surface.Research conclusions:(1)The main influence law of soil mountainous terrain on site response spectrum was offered.(2)The main influence law of soil mountainous terrain on site response spectrum ratio was presented.(3)The recommended value of the magnification coefficient under the horizontal seismic ground motion was put out.(4)The research results can be used as the reference for the seismic input of the mountainous building structures.