地下结构地震破坏静-动力耦合模拟研究

Research on underground structure seismic damage using static-dynamic coupling simulation method

地下结构地震破坏过程模拟是研究地下结构抗震性能的有效手段,通过人工边界条件设置将围岩土体的自重应力作为动力响应模拟的初始状态,实现了地下结构地震响应静-动力耦合数值模拟。基于有限元分析软件ABAQUS,将极限剪应变作为破坏标准,采用生死单元法模拟了地下结构的地震破坏过程,通过结构埋深考虑了初始地应力对地下结构抗震性能的影响。模拟结果表明,地下结构的抗震性能存在一个最不利埋深,即最容易地震破坏的埋深,当结构的埋深超过最不利埋深时,结构的极限抗震能力增强,若结构产生地震破坏,则结构埋深越深即初始地应力越高其破坏程度也越强。

Underground structure seismic damage process simulation is an effective means to study the underground structure aseismic performance.Through setting artificial boundary condition,taking dead weight stress of rock and soil mass as an initial state of dynamic response simulation,the static-dynamic coupling numerical simulation of earthquake response of the underground structures is realized.Based on finite element analysis software ABAQUS,taking ultimate shear strain as a failure criterion,the seismic damage process of underground structures is simulated by the birth-death element method.Considering structure depth,the influence of initial geostress on aseismic performance of underground structure is analyzed.The results show that the aseismic performance of underground structures has a most unfavorable depth,namely the most easily damaged depth in earthquake.When the depth exceeds the most easily damaged depth,the ultimate aseismic capacity of structures enhances.If the earthquake damage occurs,the damage degree of structures will be greater with the increasing of depth.