基于等代加速度的地下洞室抗震简化设计法

Discussion on a Simplified Analysis Method for Underground Rock Cavern Based on Equivalent Static Method

在基于性能的地震工程框架之下,地下洞室的地震稳定性评价方法可根据掌握难易程度、计算工作量、结果详尽程度划分为简化及精细两类方法。而当前对地下洞室的地震稳定性研究多针对动力数值方法,也即精细化分分析方法,而对简化设计方法设计较少。针对这一现状,引入拟静力形式的等代加速度法,对于等代加速度法应用于地下洞室群地震响应分析的一些问题进行了探讨。并在考虑洞室埋深和岩体性质的基础上,基于位移等效原则,通过数值试算,得到等代地震加速度修正系数的取值范围与回归公式。结果表明,当采用修正系数对利用等代地震加速度得到的结果进行修正后,与动力时程计算得到的结果吻合度较好。本文的研究内容为地下洞室地震稳定性的简化设计分析提供了一种新的思路。

On the basis of performance-based earthquake engineering, analysis methods for underground rock caverns may be categorized into a simplified method and a sophisticated method, based on respectively difficulty level, calculation burden, and level of detail for results. However, many efforts have been paid on the full dynamic method, i.e. sophisticated method, yet less attention has been given to the simplified method. An equivalent static method based simplified method was presented and verified. Correction coefficients for respectively index were given via numerical trail calculation in accordance with the equivalence displacement. It is found that the proper corrected results of simplified analysis method agree well with that of the full dynamic method. In this way, the proposed method may provide certain reference for other researches for this issue.