大理岩阻尼参数与动弹性参数的动三轴试验研究

 首次利用MTS815 Flex Test GT岩石力学试验系统，在不同围压下对大理岩进行阻尼参数及动弹性参数的动三轴测试研究。波形为正弦波，频率3 Hz，振动循环30次，动应力上限与下限分别为相应围压下试样抗压强度的0.6倍和5.09 MPa。试验结果表明，大理岩阻尼比、阻尼系数随循环周次的增加而减小，随围压的增大而增大；动弹性模量随循环周次的增加而增大，随围压的增大而减小；各围压下动弹性模量均大于静弹性模量，动泊松比均小于静泊松比，且围压越大，二者差值越大；大理岩在30循环周次以内动荷载作用下，其力学性质会逐渐强化。

DYNAMIC TRIAXIAL EXPERIMENTAL RESEARCH ON DAMPING PARAMETERS AND DYNAMIC ELASTIC PARAMETERS FOR MARBLE

The dynamic triaxial tests for marble under different confining pressure are conducted on MTS815 Flex Test GT rock mechanics test system for the first time. Damping parameters and dynamic elastic parameters of marble are tested. The sine wave is adopted in cyclic loading tests at the frequency of 3 Hz，and the cyclic number is 30. The upper limit of dynamic stress is 0.6 times of the compressive strength of specimen under corresponding confining pressure，while the lower limit of dynamic stress is 5.09 MPa. The research results are shown as follows：damping ratios，damping coefficients and dynamic Poisson?s ratios of marble decrease with the increasing cyclic loading number，while they increase with the increasing confining pressure. Dynamic elastic moduli increase with the increasing cyclic loading number，while they decrease with the increasing confining pressure. Dynamic elastic moduli are always greater than static elastic moduli，while dynamic Poisson?s ratios are always smaller than static Poisson?s ratios under different confining pressures；and the higher the confining pressure is，the greater the difference value is. Mechanical properties of marble are gradually reinforced within 30 dynamic loading cycles.