店埠河特大桥工程场地地震安全性评价研究

Study on seismic safety evaluation of Dianbu river bridge project site

安徽省合肥地区地处郯庐地震带末端,与华北平原、长江下游-黄海两个地震带接壤,为分析多个地震带交接区域地震安全性,以合肥包公大道店埠河特大桥工程场地为研究对象,从该工程场地的地形地貌、近场地震活动特性入手,研究确定场地的地震动特征参数与衰减关系,通过计算分析地震动加速度峰值和反应谱特征,并在此基础上就确定地震动持时参数,采取人工合成的方法拟合地震动时程曲线。研究表明:该场地地震极限值M uz为8.5,参与计算最低震级M 0为4.0级;场地所在郯庐地震带b值为0.85和ν4为4.0;在不同超越概率下场地基岩水平峰值加速度分别为22gal、78gal、151gal和34gal、107gal、188gal。研究结果能为该区域相似桥梁工程以及相关工程抗震设计提供参考。

Hefei area of Anhui province is located at the end of the Tanlu seismic zone,bordering on the North China Plain and the lower reaches of the Yangtze river Yellow sea.In order to analyze the seismic safety of the junction area of multiple seismic zones,this paper taks the Dianbu river bridge project site of Baogong Avenue in Hefei as the research object,starting from the landform and Near-Field Seismic activity characteristics of the project site,the seismic characteristic parameters and attenuation relationship of the site are studied and determined.Based on the calculation and analysis of the characteristics of ground motion acceleration peak and response spectrum,the seismic duration parameters are determined,and the artificial synthesis method is adopted to fit the ground motion time history curve.The research shows that the seismic limit value of the site is M UZ=8.5,and the lowest magnitude involved in the calculation is M 0=4.0;Tanlu seismic zone where the site is located b=0.85 andν4=4.0;Under different exceedance probabilities,the horizontal peak acceleration of bedrock in the field is 22gal,78gal,151gal and 34gal,107gal and 188gal respectively.The research results can provide reference for the seismic design of similar bridge projects and related projects in this area.