大理岩单轴蠕变模型参数

采用分级加载方式进行单轴压缩蠕变试验,获得大理岩的单轴压缩蠕变曲线。对比发现五元件Kelvin模型能较好的拟合蠕变试验曲线,取其作为大理岩蠕变模型。对同一应力水平下的蠕变曲线,取10 h、20 h、40 h和50 h四个蠕变时间段,用五元件Kelvin模型进行拟合,分别获得蠕变模型参数。拟合结果表明,蠕变模型参数在不同的应力水平下和不同的加载时间下都是变化的。当应力水平足够大(58 MPa),E2随加载时间的变化规律和E1刚好相反;当加载时间足够长(20 h)时,E2随应力水平的变化规律和E1刚好相同。当应力水平足够大(58 MPa),蠕变模型参数η1和η2始终随着加载时间的增加而增加。当加载时间足够长(=50 h),蠕变模型参数η1和η2始终随着应力水平的增加而增加。

Uniaxial creep model parameters of marble

Carrying out uniaxial compression creep test by step loading method,the uniaxial compression creep curve on marble is obtained.It is found that five component Kelvin model has a good agreement to the creep test curve.Thus,it is adopted as the creep model of marble.For the creep curve at the same stress level,taken four creep time scales at 10 h,20 h,40 h and 50 h,the creep model parameters of every time scale are obtained by using five component Kelvin model.The fitting results show that the creep model parameters are changable in both stress level and loading time.While the stress level is big enough （＞ 58 MPa）,the changing law of E2 with loading time is just opposite to that of E1.While the loading time is long enough （＞ 20 h）,the changing law of E2 with stress level is just the same with that of E1.While the stress level is big enough （＞58 MPa）,η1and η2always increase with the loading time.While the loading time is long enough （=50 h）,η1 and η2 always increase with the stress level.