为深入探究两淮矿区典型砂质泥岩劈裂注浆起裂机制，研制了常规三轴劈裂注浆试验装置，开展了类砂质泥岩浆压致裂起裂压力模型试验，基于试验结果分析了岩石强度与应力状态对注浆起裂压力、裂缝扩展形态影响规律，揭示了砂质泥岩劈裂注浆起裂机制。研究表明：起裂压力与岩石抗压强度呈正相关，且岩石抗压强度越高，劈裂路径越复杂；起裂压力对围压的敏感程度远高于轴压，且应力差 Δσ =σ V −σ H 越大，裂缝形态越规整；孔压三轴条件下，封闭裸孔段浆压致裂法确定的岩石抗拉强度值约为单轴抗拉强度的 2.5倍。该研究结果可为今后类似岩层劈裂注浆参数设计与施工提供参考。To further explore the fracture initiationmechanism of fracture grouting in typical sandy mudstone from Huainan andHuaibei mining areas in China

a conventional triaxial fracture grouting testdevice was developed

and the model test of fracture initiation pressure ofslurry fracturing in similar material of sandy mudstone was carried out. Basedon the test results

the influences of rock strength and stress state ongrouting fracture initiation pressure and fracture propagation pattern wereanalyzed

and the fracture initiation mechanism of fracture grouting in sandymudstone was revealed. The results show that there is a positive correlationbetween the initiation pressure and the compressive strength of rock; the largerthe compressive strength of the rock is

the more complex the fracturing pathis. The sensitivity of fracture initiation pressure to confining pressure ismuch greater than that of axial pressure; the larger the stress difference Δσ = σ V −σ H is

the more regular the fracture shape is. Under thetriaxial condition of pore pressure

the rock tensile strength determined byslurry fracturing method in sealed open hole section is approximately 2.5 timesthe uniaxial tensile strength. The research results can provide a reference forthe design and construction of fracture grouting in similar rock strata in thefuture.