盐岩全过程蠕变试验及模型参数辨识

对国内拟建地下盐穴储库的岩心进行三轴蠕变试验，得到泥质盐岩全过程蠕变试验曲线。基于试验的非线性蠕变特点和损伤力学理论，借助伯格斯模型建立了可以反映盐岩加速蠕变阶段的本构模型，并给出参数辨识方法，同时与试验曲线进行了比较研究。结果表明：较高轴向力下进行分级蠕变试验能够加快第三蠕变阶段（加速蠕变阶段）破坏，轴向力越大，加速蠕变起始应变值及蠕变破坏时应变值越小；增大围压时，加速蠕变起始应变值及蠕变破坏时应变值会变大。该本构方程能够很好地反映盐岩蠕变全过程，表明所建模型的正确性及合理性。

The whole process experiment of salt rocks creep and identification of model parameters

Triaxial creep tests of cores from the proposed underground salt-cavern storage were carried out and experimental curves for the whole process of muddy salt rocks creep were obtained.Based on nonlinear creep characters of the test and the damage mechanical theory as well as assisted with the Burgers model,we built a constitutive model for describing the accelerated creep stage of salt rocks.Furthermore,a method to distinguish parameters of the model was given and comparisons were made between theoretical data and experimental curves.The research result showed that a higher axial force in graded creep tests can speed up the destruction of the third creep stage(the accelerated creep stage).Both the initial strain value of accelerated creep and the strain value at creep rupture are decreasing with the increase of axial force,therefore,their behaviors are just opposite as the confining pressure increases.This constitutive model can well describe the whole process of salt rocks creep,which means the model are valid and rational.