【摘要】 验证了显示有限差分方法进行地震波衍射分析的可行性,并基于此方法分别建立了二维(2D)及三维(3D)数值模型,对溪洛渡地下洞室群的地震安全性进行了分析与讨论。研究表明,在唐山余震天津医院地震波作用下洞室群处于安全状态。对比2D及3D数值计算结果可以发现,2D数值模型计算效率远远高于3D数值计算模型;对于建造于完整性较好、强度较高的岩体介质中地下洞室群而言,可以采用2D数值模型粗略估算洞身部分的地震响应,而洞室端面的动力响应则必须通过建立3D模型来进行分析。更多还原

【Abstract】 Feasibility of explicit finite difference method(EFDM) to analyze the diffraction of seismic waves has been investigated. Based on EFDM, numerical models in 2D and 3D of Xiluodu underground cavern groups are generated; and detailed discussion of seismic response of underground cavern groups is carried out. Research shows that underground cavern groups are stable after the excavation; and the underground openings are safe under Tianjin hospital seismic waves arising from Tangshan aftershock. Comparison of numerical results between 2D and 3D of seismic response indicates that (1) 2D model is much more efficient than 3D one; (2) for underground caverns located in relatively intact and hard rock mass, 2D model can be used to predict the mechanical response of sections in the middle of caverns approximately; and 3D model has to be used to analyze the response of the sections near cavern portals.更多还原