深埋地下洞室群动力时程分析中人工边界的设置

针对深埋地下洞室群动力时程分析中建模范围和人工边界设置问题,基于地下洞室群地震波动场的分布特征,提出一种动力时程分析中洞室群模型人工边界的设置方法。该方法允许模型不建至地表,而采用解析法求解地表反射波动场,并通过人工边界入射至模型。基于波场分离原理,使模型四周边界仅透射外行散射波,保障模型四周边界的计算精度。理论试验和实际工程计算表明,该方法计算精度较高,能满足地下洞室群动力时程计算对人工边界的精度要求,同时有效减少模型单元量,缩短动力时程的求解耗时。

Method for Setting Artificial Boundary Used in Time History Analysis of Underground Caverns at Great Depth

A novel method of artificial boundary setup for dynamic time-history analysis of deep buried underground caverns is proposed based on the distribution of seismic wave field. Using this method, an analytical method is employed to solve wave field reflected by ground surface and thus finite element model is not necessary to established to ground. Based on wave field decomposition principle, only scattered wave is allowed to pass through the surrounding boundary to ensure calculation precise. Theoretical experiment and practical engineering simulation are conducted and it is shown that, presented method has high calculation precise of artificial boundary to satisfy the dynamic time-history analysis of deep buried underground caverns and the finite elements can be effectively reduced to shorten the calculation time-consuming.