节理面非线性变形对SV波透反射性能影响  

EFFECT OF NONLINEAR DEFORMATION AT JOINT INTERFACE ON TRANSMISSION AND REFLECTION

作　　者：石崇[1] 徐卫亚[1] 周家文[1] 张金龙[1] 

机构地区：[1]河海大学岩土工程研究所,江苏南京210098

出　　处：《岩石力学与工程学报》2008年第S1期2661-2668,共8页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展规划(973)项目(2002CB412707);国家自然科学基金重点项目(50539110)

摘　　要：平面SV波穿越节理面是一个复杂的问题,节理面刚度、入射角、法向非线性位移、切向非线性位移、入射波频率等都是影响节理透反射性能的重要因素。采用射线理论推导SV波穿越线性变形节理的透反射解析解,利用Lemaitre等效应变假设原理,分别采用Goodman和Duncan模型描述节理面非线性变形,考察节理面透反射性能受法向与切向非线性位移的影响。研究结果发现:SV波垂直入射节理面,只产生反射SV波和透射SV波,由于节理面刚度参数的影响,刚度越大则反射系数降低、透射系数增加,非线性位移越大其变化随刚度变化越快;节理面呈现出低通滤波器功能,频率越高越容易被反射,越低则越容易透射;法向与切向位移对不同波场的影响程度不同,正是非线性位移的大小决定节理面法向与切向的有效刚度,最终决定弹性波在节理面上的透反射性能。Propagation through joint interface of SV wave is a complicated problem,and the stiffness incident angel,nonlinear normal displacement,nonlinear tangential displacement,frequency of incident wave are factors affecting the transmission and reflection coefficient. According to ray theoretical method,the transmission and reflection analytic solution of SV wave propagating through linear deformation joint are attained. Then based on the Lemaitre hypothesis of equivalent effective strain,the Goodman and Duncan models are adopted to study transmission and reflection of wave at joint interface affected by nonlinear normal deformation and nonlinear tangential displacement. The results indicate,if the SV wave is normal incident,only refection SV wave and transmission wave SV are produced;due to the effect of stiffness,the reflection coefficient will decrease and transmission coefficient will increase with the increasing of stiffness;the higher the nonlinear displacement ratio is,the faster the trendy is. The joint interface is like a low filter,the higher frequency will be easily reflected,and the lower frequency will be easily transmitted. If the incident angel of SV wave is under superior limit,the joint stiffness is related with the normal and tangential nonlinear displacements,but the influencing degree of the normal and tangential displacement is much different to every wave field,it is the nonlinear displacement that determines the effective stiffness of joint interface,and eventually determines the transmission and the reflection characterises.

关 键 词：岩石力学 SV波 透射系数 反射系数 非线性法向位移 非线性切向位移 

分 类 号：TU452[建筑科学—岩土工程]