整体式反应位移法的理论推导及一致性证明

Theorectical derivation and consistency proof of the integral response deformation method

整体式反应位移法是近几年提出的用于地下结构抗震分析的实用计算方法,目前适用于复杂断面形式地下结构抗震分析的整体式反应位移法已被《地下结构抗震设计标准》(GB/T 51336-2018)采用。该方法通过建立地层-结构整体模型来反映岩土介质与结构之间的相互作用、采用自由场地层模型计算等效输入地震荷载,避免了经典反应位移法中由地基弹簧的确定和使用带来的计算量和计算误差,同时弥补了经典反应位移法只适用于规则断面形状地下结构抗震分析的局限性。文章基于有限元离散模型,给出地下结构地震反应分析的整体式反应位移法的理论推导,并证明地下结构抗震设计标准中采用的整体式反应位移法与理论推导给出的整体式反应位移法的一致性,有助于对整体式反应位移法的理解和正确使用。

Integral response deformation method, as a kind of practical calculation method proposed recently, has been applied to seismic analysis of underground structures. The method, which is applied to seismic analysis of underground structures with complex cross-sections, has already been adopted by National Standard "Code for seismic design of underground structures"(GB/T 51336 - 2018). In the proposed method, an integral stratum-and-structure model is established to reflect the interaction of stratum and structure, and the equivalent seismic loads are calculated by adopting stratigraphic free-field model. As a result, the calculation errors due to ground springs used in the classical response deformation method can be obviated, and the limitation that the classical method is only applicable to seismic analysis of underground structures with regular cross-sections can be removed. In this paper, the integral response deformation method is theoretically derived based on the finite element analysis model. Besides, the consistency in principle of the integral response deformation method in the national code and the theoretically derived one is also proved, which is beneficial to understanding and properly impelementing the integral response deformation method.