循环荷载的频率和幅值对砂岩动力特性的影响

发布时间：2018-05-10 17:08

本文选题：循环荷载 + 频率　；参考：《岩土力学》2017年12期

【摘要】：岩体动力参数的取值关系到岩体结构工程动力计算结果是否符合工程实际。鉴于实际动力荷载的频率和幅值都可能在一定范围内变化,设计了综合考虑频率和幅值变化的循环加、卸载试验方案,分析这两种因素对砂岩动应力-应变滞回曲线、动弹性模量、阻尼比和阻尼系数等动力参数的影响。研究结果表明:(1)应力-应变滞回圈的形态与加卸载的频率和幅值有关,频率越大则越饱满,幅值越大则越狭长;(2)循环荷载频率从0.02 Hz增至1.00 Hz,砂岩的阻尼系数逐渐减小,而阻尼比和动弹性模量逐渐增大,比较而言,阻尼比和阻尼系数变化幅度较大,动弹性模量的变化幅度较小;(3)循环荷载应力幅从10 MPa增至35 MPa时,砂岩的阻尼比逐渐减小,阻尼系数变化不大,而动弹模逐渐增大,比较而言,应力幅对动弹性模量的影响较大。研究成果可为岩石动力参数的合理选取提供较好的参考。
[Abstract]:The value of dynamic parameters of rock mass is related to whether the dynamic calculation results of rock mass structure accord with the engineering practice. In view of the fact that the frequency and amplitude of the actual dynamic load may vary within a certain range, a cyclic loading and unloading test scheme considering the variation of frequency and amplitude is designed, and the hysteretic curves of dynamic stress-strain between these two factors are analyzed. The influence of dynamic elastic modulus, damping ratio and damping coefficient. The results show that the shape of stress-strain hysteresis loop is related to the frequency and amplitude of loading and unloading. The larger the frequency is, the fuller the amplitude is, and the longer the amplitude is, the longer the cyclic load frequency increases from 0.02 Hz to 1.00 Hz. The damping coefficient of sandstone decreases gradually. However, the damping ratio and dynamic elastic modulus of sandstone gradually increase, and the damping ratio and damping coefficient of sandstone decrease gradually when the amplitude of cyclic load stress increases from 10 MPa to 35 MPa, and the amplitude of dynamic modulus of elasticity is smaller than that of dynamic modulus of elasticity, and the damping ratio of sandstone decreases gradually when the amplitude of cyclic load stress increases from 10 MPa to 35 MPa. The damping coefficient does not change much, but the dynamic elastic modulus increases gradually. In comparison, the amplitude of stress has a great effect on the dynamic elastic modulus. The research results can provide a good reference for the reasonable selection of rock dynamic parameters.
【作者单位】：三峡大学三峡库区地质灾害教育部重点实验室;
【基金】：国家自然科学基金资助项目(No.51439003,No.51679127) 水利部公益性科研专项经费项目(No.201401029) 湖北省自然科学基金重点项目(No.2015CFA140) 三峡大学研究生科研创新基金(No.2015CX)~~
【分类号】：TU45

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