地下结构抗震减震措施与研究方法探讨

由于地下结构一直被认为有较好的抗震性能,所以对其抗震减震的理论研究较少,实际工程中采取的抗震减震措施仅仅停留在经验阶段。通过对地下结构抗震减震措施及其分析方法进行研究,对目前地下结构的震害特点、抗震减震措施和理论分析方法进行了归纳总结。分析表明,地下结构的破坏过程主要受地震位移场的控制,与加速度场的关系不明显,所以应尽快修订《铁路抗震设计规范》中有关隧道抗震部分的条文;高烈度地震区的隧道抗震减震措施的耦合技术、减震机理与随机响应分析及动力可靠度的关系、洞口结构抗减震技术以及不同地震烈度下的设防长度、基础处理技术和减震层参数之间的联系等方面需加强研究。这些成果将为高烈度地震区进行的隧道设计和施工提供理论依据。

Discussion on a-seismic and seismic-relieving measures and corresponding research methods for underground structures

Theoretic researches on anti-seismic and seismic-relieving measures for underground structures are carried out not so often as compared with those for surface structures,and the anti-seismic and seismic-relieving measures for underground structures are now conducted only in the experiential stage since they are usually considered to be of good anti-seismicity.Based on the analysis of the anti-seismic and seismic-relieving measures and research methods of underground structures,the paper summarized several aspects including the characteristics of earthquake disasters,the anti-seismic and seismic-relieving measures and analytical methods.The analyses indicated that the Code of Anti-seismic Design of Railways should be revised for the articles concerning anti-seismic design of tunnels as soon as possible,since the control factor in the earthquake destroying process of underground structures is displacement field instead of acceleration field.In the area of high earthquake intensity,the following aspects of theoretical study need to be strengthened: the coupling of anti-seismic measures and seismic-relieving measures for tunnels;the relationship among seismic-relieving mechanism,stochastic response analyses and dynamical reliability;the anti-seismic and seismic-relieving measures for tunnel entrances;the relationship among the strengthened length of tunnels,the technology of foundation reinforcement and the parameters of seismic-relieving layer.The results of analyses will provide a theoretic basis for the design and construction of tunnels in the area with high earthquake intensity.