基于SHPB的不同含水状态砂岩动态响应

为研究不同含水状态岩石力学性质的变化规律,并保证仅受含水量这一单一因素的影响,以砂岩作为试验材料,制备饱和系数分别为2.82%、52.11%、100%的干燥、半饱和、饱和三种不同含水状态的岩石试样,进行静载以及8种不同冲击能量作用下的动力学性质的研究.通过试验可知:在静载作用下,相比干燥岩石,半饱和、饱和岩石试样的应力-应变曲线随含水量增加出现了峰值明显降低的现象,抗压强度分别降低了8.12%、19.26%.动载作用下,随应变率的增加,3种岩石强度均呈现不同程度的线性变化,应力-应变曲线出现右移及峰值增加的现象,且干燥岩石与含水岩石在卸载阶段有明显不同的两种趋势,特别是在卸载第二阶段.而在相同冲击能量作用下,岩石的含水量越大,其破碎程度越大.

Dynamic response of sandstones with different water contents based on SHPB

To study the changing law of rock mechanics under different water conditions and to ensure that the water content was the sole factor, sandstone was used as the experimental material. Three different kinds of rock samples were prepared with different moisture states whose average saturation coefficients were 2. 82%, 52. 11%, 100%, i. e. , dry, semi-saturated, and saturated. The mechanical properties of the rocks were dynamically tested under the action of static load and eight kinds of impact energy. The experi-mental results reveal that under static load, compared with dry rock, the stress-strain curves of half-saturated and saturated rock sam-ples show decreasing peaks with increasing water content, and their compressive strengths decrease by 8. 12% and 19. 26%, respec-tively. Under dynamic loading, with increases in strain rate, the strengths of the three samples show a linear change in different de-grees, the stress-strain curves shift to the right, and the peak values increase. The dry and water-bearing rocks exhibit two obviously different trends in the unloading stage, especially in the second stage of unloading. Also, under the same impact energy, as the water content of the rock increases, the degree of fragmentation also increases.