弹性半空间中含粘性滑移界面圆形衬砌洞室对平面SH波的散射

Scattering of plane SH waves by a circular lining cavity with viscous-slip interface in elastic half space

为揭示粘性滑移界面对衬砌洞室地震响应规律的影响,采用一种高精度的间接边界积分方程法,基于粘性滑移界面模型,求解了弹性半空间中浅埋圆形衬砌洞室对入射平面SH波的散射。结果表明:中低频波入射时,随着界面滑移刚度系数的增加,衬砌洞室上方地表位移幅值减小,而界面粘性系数对地表位移反应不明显;衬砌内壁应力幅值随界面滑移刚度系数的增加而增大。高频波入射下,较小的界面粘性系数对地表位移放大效应更为显著;当界面滑移刚度系数较小时,部分频段由于体系共振效应会造成显著的应力集中;高频特别是共振频率段,粘性系数对应力幅值有明显的降幅效应。研究结论可为实际地下工程结构的抗震设计提供部分理论依据。

In order to reveal the effects of viscous-slip interface on the seismic response of lining cavity,this paper presents an indirect boundary integration equation method(IBIEM)of high precision for solving the scattering of plane SH waves by a shallow two-dimensional circular lining cavity with a viscous-slip interface model in elastic half-space.The results show that when the frequency of incident waves is low and medium,the surface displacement above the lining cavity decreases with increasing stiffness parameter of visco-elastic interface,on the contrast,the viscosity coefficient of visco-elastic interface has a light effects on the surfacedisplacement;the stress amplitude of internal surface of lining increases with increasing stiffness parameter of visco-elastic interface.When the frequency of incident waves is high,the small viscosity coefficient of visco-elastic interface has obvious effect on the surface displacement amplification;in the case of small stiffness parameter of visco-elastic interface,some frequency bands have significant stress concentration effects due to the system resonance effect;at high frequency,especially in resonant frequency band,the viscosity coefficient of visco-elastic interface has obvious decrease effect on the stress amplitude.The conclusions provide some theoretical basis for seismic design of underground engineering structures.