注浆材料和预制裂纹缺陷角度对类岩石试件单轴抗压强度及破坏模式的影响

选用环氧树脂和纯水泥浆作为注浆材料，对含不同角度和不同注浆材料裂隙试样进行单轴压缩试验。试验结果表明，注浆材料和裂纹缺陷角度对类岩石试件单轴抗压强度及破坏模式具有重要影响；环氧树脂加固效果优于纯水泥浆，环氧树脂可以有效地消除预制裂纹尖端的应力集中；在裂纹缺陷角度很小( <30°)和角度很大( =90°)的情况下无论裂隙是注环氧树脂还是纯水泥浆，注浆效果都不明显，当 =60°时两种注浆材料的加固效果都很好。提出滑动裂纹模型，对注浆裂隙进行力学分析发现，含注浆裂隙试样的抗压强度随着注浆材料和完整材料胶结面摩擦系数和黏聚力的增大而增大，不同注浆材料和完整材料胶结面的摩擦系数和黏聚力不同，解释了为什么不同的注浆材料对注浆试样强度提升作用不同。研究成果为分析工程中注浆材料和裂纹缺陷角度对岩体强度的影响提供了一定的理论基础。

Effect of grouting materials and inclination angle of pre-existing flaw on uniaxial compressive strength and failure mode of rock-like specimens

Epoxy resin and cement paste are chosen as grouting materials, uniaxial compressive tests are conducted on the specimens containing single grout-infilled flaw having different inclination angles. Experimental results show that grouting materials and flaw inclination angle have a significant influence on the uniaxial compressive strength and failure mode of rock-like specimens. The reinforcement effect of epoxy resin is better than that of cement paste, epoxy resin can effectively eliminate the stress concentration of the tips of the grout-infilled flaw. Whether the flaw is grouted with epoxy resin or cement paste, grouting has little improvement in uniaxial compressive strength(UCS) when the flaw inclination angle is very small ( <30°) or very large ( =90°), however, reinforcement effect is significant when the flaw inclination angle is 60°. For the specimens containing single flaw grouted with epoxy resin and cement paste, the failure path dose not cut through the grouting materials but cut through the interface between grouting material and model material. Sliding crack model is proposed. This model indicates that the UCS of specimens increases with increasing cohesion and friction angle of the interface between grouting material and model material. Different grouting materials have different improvement on the cohesion and friction angle of the interface, which is the reason why different grouting materials have different improvement on the UCS of specimens. This study will provide a theoretical frame for analyzing the influence of grouting materials and the inclination angle of flaw on the strength of rock mass in engineering projects.