干湿循环下pH值对砂岩静态单轴力学特性的影响

为研究不同pH值溶液干湿循环作用对砂岩力学性能劣化的影响,采用pH值为3、5、6.5(蒸馏水)和7的4种溶液对砂岩进行干湿循环作用,对经历0次(干燥状态)、1次、10次和20次干湿循环作用的砂岩进行纵波波速测定、吸水率试验、XRD试验和单轴抗压试验.试验结果表明:pH值相同时,随着干湿循环次数的增加,砂岩试件的单轴抗压...

Effect of pH Value on Static Uniaxial Mechanical Properties of Sandstone under Dry-Wet Cycle

In order to study the effect of dry-wet cycles of solutions with different pH values on the deterioration of mechanical properties of sandstone, four solutions with pH values of 3, 5, 6.5 (distilled water) and 7 were used to perform dry-wet cycles on sandstone. Sandstone specimens with 0 times (dry state), 1 times, 10 times and 20 times of dry-wet cycles were subjected to longitudinal wave velocity measurement, water absorption test, XRD test and uniaxial compression test. Test results show that under the same pH value of the solution, the uniaxial compressive strength of sandstone specimens decreases gradually with the increase of dry-wet cycles. When the number of dry-wet cycles is the same, as the pH value of solution decreases, longitudinal wave velocity of sandstone specimens decreases, water absorption gradually increases, the internal mineral composition changes, and uniaxial compressive strength gradually decreases and tends to be stable. The deterioration of sandstone specimens under dry-wet cycles of acidic solution are more serious than that of neutral solution, and the lower the pH value is, the greater the deterioration is.