【摘要】 通过对不同含水状态砂岩进行单轴压缩声发射试验,对比分析了不同含水状态和不同损伤表征的砂岩损伤特征.试验结果表明:干燥状态时,低应力阶段,损伤曲线非常平缓,当处于损伤急速增加阶段时,损伤曲线呈多个阶跃上升,较为陡峭;天然含水状态时,损伤曲线开始增长较快,之后进入平静期,曲线较为平缓,临近破坏时,曲线有所上升,但上升幅度较干燥状态小;饱和含水时,低应力阶段也是出现损伤值上升较快,然后进入较长的平静期,临近破坏时损伤曲线变化较小,岩石基本上无破坏征兆.结果表明:砂岩含水率越高,声发射越集中分布于砂岩破坏瞬间,破坏前兆越不显著,破坏时表现出的脆性破坏越明显,声发射参量表征的损伤较应变表征的砂岩损伤更合理.更多还原

【Abstract】 By experimenting on the sandstone of different moisture content in acoustic emission of uniaxial compression, the sandstone’s damage characteristics in different moisture content and different damage symptoms are contrasted. The results prove that the damage curve is very smooth in the dry status and low-stressed stage; however the damage curve is rather steep when the damage increases sharply,and the damage curves rise by more than one step; in the natural state of water, the damage curve is growing rapidly firstly,then it turns into the tranquil period in which the damage curve is relatively smooth, it increases when it is close to destruction, but the amplitude of increasing is lower than that of the dry state; In the saturated state, at the beginning the damage curve increases sharply in low-stressed stage, then it brings into a longer tranquil period, the damage curve changes less near destruction, the rocks hardly have any damage symptoms. The conclusions are : with the increasing of sandstone moisture content,the acoustic emission distributes in the moment of sandstone destruction intensively; the less obvious the former symptoms of damage is,the more obvious the brittle failure during destroying will be; the damage of symptoms in the acoustic emission parameter is more reasonable than the sandstone damage of strain parameters.更多还原