不同膨胀状态下膨胀岩剪切蠕变试验研究

Experimental research on shear creep properties of a swelling rock under different expansive states

对不同膨胀状态下的膨胀岩进行无膨胀作用的剪切蠕变试验、膨胀与蠕变完全耦合的剪切蠕变试验、膨胀与蠕变不完全耦合的剪切蠕变试验、膨胀与蠕变分开耦合的剪切蠕变试验。得出如下试验结果:膨胀与蠕变耦合的剪切蠕变曲线与无膨胀作用的剪切蠕变曲线有相似规律性。膨胀和蠕变耦合方式对膨胀岩长期强度影响显著,具体表现为膨胀作用下的膨胀岩长期强度远小于无膨胀作用下的膨胀岩长期强度,膨胀与蠕变完全耦合下的膨胀岩长期强度低于膨胀与蠕变分开耦合下的膨胀岩长期强度。对于膨胀与蠕变完全耦合作用下的膨胀岩,求出了法向应力与长期强度拟合关系式;对于膨胀与蠕变分开耦合作用下的膨胀岩,求出了预加法向应力与长期强度拟合关系式。

In order to study the effect of different expansive states on the shear creep characteristics of the swelling rock,the creep test without expansion,the expansion and creep completely coupled test,the expansion and creep incompletely coupled creep test,and the expansion and creep separately coupled test were carried out. The creep curves of all tests have similar regularities. The long-term strength under expansion is much smaller than that under no expansion,and the long-term strength under completely coupled expansion and creep is smaller than that under separately coupled and creep. In completely coupled expansion and creep situation,a function made by curve fitting is used to express the relationship between long-term strength and normal stress. In separately coupled expansion and creep situation,a function is used to express the relationship of the normal pre-stress and the long-term strength.