中文摘要：

岩石材料的宏观力学特性与其内部细观结构演化有十分密切的关系，对典型难溶盐岩钙芒硝在盐溶液溶浸环境下力学特性弱化和细观结构演化进行研究，初步揭示其力学特性弱化的细观机制。研究发现：在盐溶液溶浸作用下，由于矿体胶结物中亲水性矿物吸水膨胀崩解、钙芒硝中硫酸盐的溶解、化学反应离子交换、氯离子侵蚀损伤等因素的作用，钙芒硝孔隙率随“溶液浓度”和时间的变化而非线性演化，从而导致力学特性严重弱化。在盐溶液中溶浸20d，钙芒硝强度弱化系数低至0．1～O．2。由于钙芒硝矿体内泥质胶结成分的水理水化作用，泥质部分膨胀或崩解，钙芒硝矿体变形表现出应变软化与韧性破坏特征。细观结构演化结果表明，盐溶液溶浸作用下，难溶钙芒硝孔、裂隙演化缓慢，但在淡水溶液中孔隙演化速度是半饱和与饱和溶液中的数倍甚至数百倍。淡水中溶浸48h后孔隙率高达16．62％，是原始状态孔隙率的9倍；半饱和盐溶液溶浸48h后，孔隙率是原始状态的3倍，而饱和溶液溶浸48h后，孔隙率增幅仅为2．8％。孔隙率变化主要是由于钙芒硝矿体中硫酸盐的溶解和结晶，胶结物成分（主要为伊利石、蒙脱石）的水理、膨胀，这也是钙芒硝力学特性弱化的根本原因。本研究对深入认识可溶岩（包括钙芒硝）物理力学特性弱化，并指导盐类矿床原位溶浸开采及层状盐岩溶腔油气储库建造等相关工程实践，具有重要理论意义与应用价值。

英文摘要：

The internal meso-structure development of rock material contributes a lot to its macroscopic mechanical properties. The mechanical properties weakening mechanism and internal meso-structure development of typical glauberite soaked in brine are studied; and the mechanism of mechanical properties weakening is revealed. It is found that under the actions of swelling and disintegration of hydrophilic mineral in the cement of the rock, the dissolution of sulfate, the ion exchange and the chloride ion erosion damage, etc., the porosity ofglauberite soaked in brine is changed nonlinearly with the solution concentration and soaking time. So, the mechanical properties weakens. The strength weakening coefficient decreases to 0.1 -0.2 after the glauberite being soaked in brine for 20 d. Because of the water effect and hydration, the argillaceous content contained in the glauberite would swell or disintegrate. So the deformation of glauberite shows the characteristics of strain softening and ductile from the original brittle behavior. The meso-structure development results also show that the pores in glauberite soaked in brine develop more slowly than that in pure water. The pores development rate in fresh water is several to hundreds of times as that in brine. The porosity of glauberite soaked in water for 48h increases to 16.62%, which is 9 times of that of natural state. And the porosity of glauberite soaked in half saturated solution for 48 h is 3 times of its na~tral state. However, the porosity of glauberite soaked in saturated solution for the same time has an increase of only 2.8%. The change of porosity is mainly due to dissolution and hydration of sulfate in the glaubetire, the water effect and cement of hydrophilic minerals（mainly glimmerton and smectite contents） swelling. These are definite reasons for the mechanical property weakening of the glauberite. The research results are significant either for study of physico-mechanical properties of the glauberite or for in situ leaching mining of salt deposits an