交叉换乘地铁车站地震特性及其设计方法

Seismic characteristics and design method for cross transfer subway stations

为了研究交叉换乘地铁车站结构的地震特性提出一种适用于该类型地铁车站的抗震设计方法.利用动力有限元数值模拟对比三维交叉换乘地铁车站及相对应的二维标准车站结构内力给出交叉换乘地铁车站中交叉部分的影响范围.与此同时基于薄板弯曲理论提出探讨交叉换乘地铁车站中交叉部分影响范围的简化理论模型通过将交叉部分影响范围问题转换为双向板短边约束影响范围问题并求解 2 类双向板理论解析解验证数值模型中交叉部分影响范围.并在此基础上提出了分步抗震设计方法即对影响范围外的结构沿用传统设计、影响范围内的结构采用改进方法进行设计.结果表明:在常规中硬场地中单层交叉换乘地铁车站的交叉部分存在影响范围阈值且影响范围为3倍结构层间高度或1.5倍结构宽度.该结论证明了所提交叉换乘地铁车站结构抗震分步设计方法的可行性.

To study the seismic characteristics of the cross transfer subway station a new design method for such structural type was put forward. Based on the dynamic finite element numerical sim ulation the influence range of the intersection part of the cross transfer subway station was given by comparing the internal forces of the 3D cross transfer subway station and the corresponding 2D stand ard station. At the same time based on the theory of thin plate bending simplified theoretical mod els were proposed to discuss the influence range of the intersection part of the cross transfer subway station. By converting the influence range problem of the intersection part into that of the short side constraint of the two way plate and solving the theory solutions of two two way plates the influence range of the intersection part in numerical models was verified. Meanwhile a new seismic stepwise design method was proposed. The structure outside the influence area was designed with the tradi tional method and the structure inside the influence area was designed with the improved method. The results show that the influence range threshold exists in the intersection part of single storey cross transfer subway station and the influence range is 3 times inter layer height of the structure and 1. 5 times width of the structure in middle hard soil sites. The conclusion proves the feasibilities of the seismic stepwise design method for the cross transfer subway station.