大跨隔震结构多点地震计算模型的几点注记

Notes about calculation models for seismic analysis of long-span isolated structure under multi-point earthquake excitations

摘要:

为避免震害损失,大跨度结构的各支座常采用隔震支座,而隔震工况下的多点地震计算模型可能存在一定误差,本文意在阐明其误差根源并加以解决．首先给出了可用于大跨隔震结构多点地震响应分析的主要计算模型,采用严格理论推导探讨了各模型计算机理的异同和特色,并着重强调了位移模型的理论缺陷和误差,指出位移模型在大跨隔震结构中的盲目应用会导致严重错误,进而提出了实用有效的修正方法和理论依据．最后,以多自由度简化模型和机场维修机库大跨网架实际结构为例,对本文所提观点和建议进行了数值验证,证明了SAP2000内置位移模型在多点地震响应计算中的有效性．

Abstract:

There may be some obvious error in long-span isolated structures' seismic responses calculated by multi-point earthquake calculation models. In this paper error reason and corresponding solution methods are given. Firstly, several main calculation models for seismic analysis of long-span isolated structures under multi-point earthquake excitations are described, and their mechanisms and features are also explained by rigorous theoretical derivation. Then, theoretical defects and error of displacement model are especially pointed out, which would lead to wrong results if arbitrarily utilized in long-span isolated structures. Furthermore, some modification and theoretical basis are given. Finally, a multiple degrees of freedom simple model and a real long-span space truss structure of hangar are given as numerical example, and viewpoints and suggestions in this paper are verified. The displacement mode inherent in SAP2000 software is applicable in seismic response calculation of structure under multi-point earthquake excitations.