论文部分内容阅读
动剪切模量和阻尼比是岩体重要的动力特性参数,其取值的合理性对场地地震响应分析的结果有重要影响.利用WDT-1500多功能材料试验机,对砂岩、砾岩和砂砾岩等软岩试样进行了循环荷载试验,研究了软岩的动剪切模量和阻尼参数对应力、应变幅值和应力水平的响应特性,得到了动剪切模量和阻尼参数随应力幅值、应力水平及含水率的变化规律,讨论了其变化机理.结果表明,在不同应力水平和不同应力幅值下阻尼参数随着应力幅值的增大而增大,与应力幅值成线性拟合关系.当应力幅值较小时,含水率对岩石动剪切模量的影响较小,而对阻尼比和阻尼系数的影响较大;当应力幅值较大时,恰好相反.含水率,应力水平和应力幅值都相同时,应力水平逐级增大的应力路径下测得的阻尼参数大于应力幅值逐级增大的应力路径下测得的阻尼参数.建立的不同应力水平和不同应力幅值条件下软岩的动剪切模量与阻尼比关系模型能够描述分级循环荷载过程中阻尼行为.研究成果对抗震工程的地震反应分析和场地安全性评价有着重要参考价值.
Dynamic shear modulus and damping ratio are important dynamic parameters of rock mass, and their rationality has an important influence on the result of site seismic response analysis.With the WDT-1500 multifunctional material testing machine, sandstone, conglomerate and Sandstone and other soft rock samples were subjected to cyclic loading tests. The response characteristics of dynamic shear modulus and damping parameters of soft rock to stress, strain amplitude and stress level were studied. The dynamic shear modulus and damping parameters The variation of stress amplitude, stress level and moisture content were discussed, and the variation mechanism was discussed.The results show that the damping parameters increase with the stress amplitude at different stress levels and different stress amplitudes, Linear relationship.When the stress amplitude is small, the influence of water content on the dynamic shear modulus of the rock is small, while the damping coefficient and damping coefficient are more affected. When the stress amplitude is larger, the opposite is true. When the water content, the stress level and the stress amplitude are the same, the damping parameters measured under the stress path with gradually increasing stress level are larger than the damping parameters measured under the stress path with gradually increasing stress amplitude. The established different stress Level and different should be Dynamic shear modulus and damping amplitude under conditions of soft rock than the relational model able to describe the process of cyclic loading classification damping behavior research on the seismic response of seismic engineering analysis and safety evaluation of the site has important reference value.