材料刚度匹配关系在地下结构减震原理中作用的研究

前期研究和工程实践证明，围岩、抗减震层和隧道衬砌等材料关于刚度、阻尼和密度之间的匹配关系，对隧道在地震过程中的动态响应有至关重要的影响。为更深入了解隧道动态响应与相关材料匹配关系之间的内在联系，利用动力学振动理论给出了关于地下结构位移传递系数的一个解析解，并首次提出关于地下结构综合位移传递系数的概念。对计算公式进行验证后表明：在隧道的抗减震设计中，当不考虑抗减震层的材料阻尼时，抗减震措施的材料刚度对地震波中的低频部分具有较好的减震效果，而对于地震波中的高频部分，抗减震层的减震效果不明显；无论是抗震层刚度的增加，还是减震层刚度的减小，均存在一个合理的刚度增大或减小的范围，当刚度位于该范围内时，才能使隧道的综合位移传递系数较小，并且在经济上不会产生浪费。

Study on Action of Material Stiffness Matching Relationship in Antiseismic Mechanism of Underground Structure

The matching relationship of material property （including stiffness, damp and density） of the surrounding rock, the antiseismic （or damping） structure and the tunnel liner has important influence on the tunnel＇s dynamic response in earthquake process, which has been proven by earlier researches and engineering practice. For intensive understanding of the inherent relationship between the tunnel＇s dynamic response and the matching relationship of material property, the analytical solution for the displacement transfer coefficient of underground structure is excogitated by utilizing the vibration theory of dynamics, and the definition of the composite transfer coefficient of displacement is gained for the first time. The computing formula is tested, and the result shows that： in design scheme on antiseismic （or damping） structure of tunnel, the material stiffess of the structure has visible damping effect on the low-frequency segment of seismic wave but not on the highfrequency segment of seismic wave when the material damp of the model was not taken into account. Whether to increase stiff- ness of the antiseismic structure or to diminish stiffess of the damping structure, there is a logical change range of the material stiffess. The composite transfer coefficient of displacement is small and there is no extravagancy when the material stiffess is within this range.