【摘要】 地震作用是影响大型地下洞室群长期安全运行的主要外界因素。采用时程分析法模拟地震灾变中洞室围岩地震响应过程,是研究地下洞室抗震的一种有效方法。为此,开发地下洞室地震灾变三维动力有限元数值模拟系统。该系统采用显式中心差分法求解。为加快求解速度,对程序进行并行化处理并在积分方法上提出多高斯点分区混合积分法;考虑高应变率下材料的强化特性和循环荷载作用下围岩损伤特性,提出适用于地下洞室抗震分析的岩体动力本构模型;人工边界采用黏弹性边界;考虑地震波入射的方向性、多面性和非一致性,提出适用于地下洞室抗震分析的地震波空间斜入射法。通过计算通用数值分析软件的验证算例,表明该系统程序求解的正确性。同时,通过对鲁基场窑洞式地下厂房地震灾变时程模拟,表明系统程序在实际工程问题分析中的可靠性和实用性。更多还原

【Abstract】 The earthquake impact is a major external factor influencing the long term stability of underground caverns.Time-history analysis method is able to simulate the earthquake response of surrounding rock in underground caverns during earthquake disaster process.It has been proved to be an effective method to analyze the aseismic issue of underground caverns.The numerical simulation system using three-dimensional dynamic finite element method is developed to study the earthquake disaster in underground caverns.Central difference method is employed in this system to solve the problem.To enhance the solving speed,parallel procedures and hybrid Gauss point integration method are proposed in programming.Strengthening features of materials under high strain rate and damage features of surrounding rock under cyclic loading are considered.The dynamic constitutive model for rock masses is presented.It is suitable for the aseismic analysis of underground caverns.Visco-elastic boundary is adopted in artificial boundary.The spatial oblique incident method which is suitable for the aseismic analysis of underground caverns is proposed.It is able to reflect the specific incident direction,the multi-incident surfaces and the inconsistency of seismic wave.An example is given to verify the correctness of the developed system by comparing its calculation results with common software’s calculation results.A case study is then conducted to simulate the earthquake disaster process of the cave-typed underground caverns at Lujichang hydropower plant.The results derived from time-history analysis indicate the reliability and practicability of the developed system.更多还原