水和加载条件对岩石材料的强度有很大的影响，但高应变率下饱水岩石的动态特性研究仍十分缺乏。通过对干燥和饱水砂岩进行压缩试验，发现：干燥和饱水砂岩的动态压缩强度都随着应变率的增加而增大，且饱水岩石表现出更强的率相关性。引入干燥岩石强度与饱水岩石强度的比值(水影响因子WAF)来描述不同应变率下水对岩石压缩强度的影响。在静态压缩条件下 WAF 约为1.38，随着应变率的增加 WAF 不断减小。当应变率达到190 s?1时，WAF减小至0.98，表明高应力率时饱水岩石的压缩强度可以大于干燥岩石的压缩强度。进而，基于滑移裂纹模型，讨论了水和应变率对岩石特性的双重影响，为实验结果提供了较好解释。
The strength of rock materials is largely affected by water and loading conditions, but there are few studies on mechanical properties of saturated rocks at high strain rates. Through compressive tests on dry and saturated sandstone specimens, it was found that the dynamic compressive strength of both dry and saturated sandstone specimens increased with the increase of strain rates. The saturated rock specimens showed stronger rate dependence than the dry ones. The water affecting factor (WAF), as the ratio of the strength under dry state to that under saturated state, was introduced to describe the influence of water on the compressive strength at different strain rates. The WAF under static load was close to 1.38, and decreased with the increase of strain rate. When the strain rate reached 190 s?1, the WAF reduced to 0.98. It indicates that the compressive strength of saturated specimens can be higher than that of dry ones when the strain rate is high enough. Furthermore, the dual effects of water and strain rate on the strength of rock were discussed based on sliding crack model, which provided a good explanation for the experimental results.
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