不同载荷水平砂岩吸水特性实验研究

Experimental Study of Absorption Characteristic of Sandstone Under Different Load Level

针对边坡岩体受损后吸水特性发生变化进而导致稳定性降低的问题,选取三峡库区典型砂岩为研究对象,对不同载荷水平砂岩的吸水特性进行实验研究,结果表明:随着时间的增加,砂岩吸水曲线水位高度上升速率逐渐减小,并最终趋于稳定;随着载荷水平的逐渐升高,砂岩吸水率先减小后增加,当载荷水平较高导致岩样出现裂缝后,岩样吸水能力极大提高,短时间内水位高度迅速上升.岩样的吸水曲线水位高度局部较高区域恰好在主裂缝附近,而较多的小裂缝处的水位高度线分布散乱.该研究揭示出可根据岩体表观吸水曲线特征来预测岩体内部结构变化情况.

In view of the case that absorption characteristic of slope rock mass after damage was changed which leads to lower stability;taking the typical sandstone in the Three Gorges Reservoir area as the research object,the water absorption test of the sandstone is carried out under the different load levels.The results show that,with the increasing of time,the rise rate of water level of sandstone gradually decreased,and finally became stable.With the increasing of load level,the water absorption rate of sandstone decreased first and then increased.After the cracks appeared,the absorption capacity of rock sample improved greatly and water level height raised rapidly in a very short period of time.The water elevation of water absorption curve appeared the local maximum region.And the local maximum region is near the main cracks;but the distribution of the water elevation of water absorption curve at more small cracks is scattered.The research results reveal that it can forecast the internal structure change of rock mass according to the apparent absorption curve features.