地下结构抗震分析中地震动输入方法研究

Research on method of seismic motion input in aseismic analysis for underground structure

在考虑不同节点处地震波相位差及自由表面处地震反射波影响的基础上,基于波场分离技术与黏弹性人工边界条件推导了适用于地下结构的节点力地震动输入方法。这种地震动输入方法能够有效保证边界应力及位移与原场一致且能考虑地震波传播的相位差。将这种地震动输入方法在通用有限元计算软件ABAQUS中实现,实例验证结果与解析结果对比表明,这种方法具有良好的精度。最后将这种地震动输入方法运用于某越江盾构隧道进行动力分析,得到了管片与地层之间的摩擦系数对管片节点相对位移及管片内力的影响。

Considering the phase difference and reflection of seismic wave,method of seismic motion input for undergroud structure was presented on the basis of viscoelastic artificial boundary conditions and wave field separation technique.The method can guarantee that the stress and displacement at boundary nodes are consistent with actual value.Besides,it can effectively take the phase difference of seismic wave into account.Compared with analytical result,the result of the method has high precision in FEM software ABAQUS.Finally,this method was used to dynamic analysis of a cross-river shield tunnel,and achieved the influence of the friction coefficient between segment and soil on the relative displacement of nodes and internal force.