断层泥动剪切模量和阻尼比影响因素试验研究

EXPERIMENTAL STUDY ON INFLUENCING FACTORS OF DYNAMIC SHEAR MODULE AND DAMPING RATIO OF FAULT GOUGE

利用GDS共振柱试验系统对不同干密度、不同含水率的断层泥试样进行了动剪切模量和阻尼比试验研究。结果表明,使用Hardin-Drnevich双曲线模型能够较好地描述断层泥的动剪切模量随剪应变的变化趋势;随干密度增加,动剪切模量和阻尼比均增大;而随含水率增加,动剪切模量和阻尼比均减小;归一化动剪切模量试验点主要位于Seed和Idriss提出的砂土G/G_(max)~γ曲线变动范围内,且与Sun和Seed推荐黏性土曲线变化趋势一致;在半对数坐标系中,阻尼比与动剪应变呈良好的线性关系,并给出了拟合关系式。

Dynamic shear modulus and damping ratio test of fault gouge with different dry density values or water contents are performed using GDS resonant column system. The results show that the relationship between dynamic shear modulus and dynamic shear strain can be well fitted by Hardin-Drnevich hyperbolic model. The dynamic shear modulus and the damping ratio both increase with the dry density,while decrease with water content. Experimental points of normalized dynamic shear modulus are mainly located in the range of the G / Gmax- γ curve of sand which is proposed by Seed and Idriss,and in accordance with the trend of cohesive soil which is proposed by Sun and Seed.The damping ratio changes linearly with the dynamic shear strain under semilog coordination. The fitting formula is suggested.