不同规范中地下结构地震反应分析的反应位移法对比研究

Comparative study of response deformation methods for seismic analysis of underground structures in different design codes

反应位移法是一种实用的地下结构抗震反应分析方法,该方法计算步骤相对简便,具有较好的分析精度,在地下结构抗震设计计算中得到广泛使用,已被包括《城市轨道交通结构抗震设计规范》(GB 50909—2014)和《建筑抗震设计规范》(GB 50011—2010)等多部规范所采用。但是由于该方法在理论推导上的不同,以及不同研究者理解上的不一致,导致现行不同规范的计算模型和荷载输入存在差别。文中给出反应位移法的推导过程,分析反应位移法中各项荷载的合理形式和意义,对现行不同规范中反应位移法的计算模型作出明确判断,通过与动力时程计算结果的对比分析表明:反应位移法中地震作用的输入通过结构周边自由场应力实现,忽略部分周边自由场应力的计算模型是不合理的。

The response deformation method is a practical calculation method for the seismic analysis of underground structures. This method is simple in calculation and possesses good analysis precision. Therefore, the method has been recommended in some Chinese codes, including《Code for seismic design of urban rail transit structures》 （ GB 50909-- 2014） and 《Code for seismic design of buildings》 （GB 50011--2010）. However, due to the differences in theoretical derivations of the method and its understanding by different researchers, the computational model and load input in different codes differ from each other. In this work, the derivation process of the response deformation method is given and the reasonable forms and meanings of different loads are analyzed. Compared with the results from the finite element dynamic analysis, the results calculated based on different codes show that the input of seismic action of response deformation method is realized by surrounding free field stress. Therefore, the computational model, in which surrounding free field stresses are partially neglected, is unreasonable.