应力-水流-化学耦合下岩石破裂全过程的细观力学试验

自行研制了应力–水流–化学耦合下岩石破裂全过程的细观力学试验系统,可以进行应力–水流–化学耦合下的多项岩石力学细观试验,实现了应力–水流–化学耦合下岩石破裂全过程的显微与宏观实时监测、控制、记录与分析的岩石力学试验。对不同化学溶液腐蚀的多裂纹灰岩试件,应用该系统进行了应力–水流–化学耦合下单轴压缩破坏全过程的试验。试验过程中试件一直浸泡在流速为513 mm/s 的相应的化学溶液中,对NaCl 溶液(0.01 mol/L,pH = 7)作用下裂纹的起裂、发展及贯通破坏过程进行了分析研究。与未受化学溶液腐蚀的相同裂纹排列方式试件的试验结果比较,受化学溶液腐蚀与未受化学溶液腐蚀试件裂纹扩展破坏过程差异的主要原因为化学溶液对试件产生了腐蚀及软化作用,而未受化学溶液腐蚀试件的破坏则为脆性破坏。试验研究结果证明了该系统的科学性和先进性。

MESO-MECHANICAL EXPERIMENT OF MICROFRACTURING PROCESS OF ROCK UNDER COUPLED MECHANICAL-HYDROLOGICAL-CHEMICAL ENVIRONMENT

A new meso-mechanical testing system is developed to carry out the experiment of microfracturing process of rocks under the coupled mechanical-hydrological-chemical environment. The image of microfracturing process of the specimen under triaxial or uniaxial compression can be observed and recorded digitally. The loading system is servo-controlled. The microfracturing process of limestone specimen under uniaxial compression with the coupled mechanical-hydrological-chemical environment is recorded by using the testing system. As an example,the results of the specimen soaked in chemical solution of NaCl of 0.01 mol/L and pH = 7 are analyzed. The cracking velocity of cracks at length and width directions is also calculated. The results are compared with those of the specimens without chemical corrosion. The comparison indicates that the testing system is applicable and chemical corrosion can reduce strength of rock and accelerate cracking of cracks.