近断层强震作用下跨断层水工隧洞地震动强度参数优选研究

Optimization of Ground Motion Intensity Parameters for Cross Fault Hydraulic Tunnels under Near Fault Strong Earthquakes

为了选择合适的地震动强度参数来预测和评估跨断层水工隧洞在近断层地震动作用下的响应情况,对17个地震动强度参数与隧洞地震响应的相关性进行了研究。以某跨断层水工隧洞为例,从PEER NGA-West2中选取60条实测地震动分别作为输入,对模型进行非线性动力时程分析;选取断层处6个特征点间的最大相对位移表征衬砌的结构响应情况,分析各地震动强度参数与隧洞衬砌结构响应的相关性。结果表明,近断层地震动作用下,跨断层水工隧洞的地震响应与速度型地震动强度参数的相关性明显高于加速度型和位移型地震动强度参数。因此,在水工隧洞抗震性能研究时,应优先选用速度型地震动强度参数。

In order to select appropriate ground motion intensity parameters to predict and evaluate the response of cross fault hydraulic tunnels under near fault ground motion,this paper studied the correlation between 17 ground motion intensity parameters and tunnel seismic response.Taking a cross fault hydraulic tunnel as an example,60 measured ground motions were selected from PEER NGA-West2 as inputs for nonlinear dynamic time history analysis of the model.It selects the maximum relative displacement between the six characteristic points at the fault to characterize the structural response of the lining,and analyzes the correlation between the vibration intensity parameters of each location and the structural response of the tunnel lining.The results indicate that under the action of near fault seismic motion,the correlation between the seismic response of cross fault hydraulic tunnels and the velocity type seismic intensity parameters is significantly higher than that of the acceleration type and displacement type seismic intensity parameters.Therefore,when studying the seismic performance of hydraulic tunnels,priority should be given to selecting velocity based seismic strength parameters.