破裂岩体承压注浆加固力学特性试验研究

Mechanical characteristics of confined grouting reinforcement for cracked rock mass

在完整岩样单轴压缩试验的基础上,采用自制注浆系统对破裂岩样进行了承压注浆加固和固结体的力学特性试验,并利用KH-3000视频仪对注浆加固前后岩样的微观结构进行了观测和分析。研究结果表明:破裂岩样存在大量的贯穿裂隙,岩样破坏以张拉破坏为主;承压注浆后,破裂岩样的张拉和倾斜破裂面得到了不同程度的充填和固结,其强度与破裂岩样残余强度相比有较大的提高,但强度恢复系数不高;承压注浆能够促进破裂岩样的变形由脆性向延性转化,并使其侧向变形和轴向变形趋于协调;围压水平对浆液注浆量、岩样径向应变、注浆固结体强度及强度恢复系数有着很大影响,随着围压的增大,加固效果显著增强。

In this paper, based on the uniaxial compression test of intact rock samples, the confined grouting reinforcement of cracked rock samples were carried out, and the mechanical properties of grouting reinforced samples were also tested by using self-made grouting system. Meanwhile, the mi-crostructures of cracked rock samples before and after grouting reinforcement were observed by KH-3000 Videomicroscopy. The results show that there are a lot of interpenetrated fissures in cracked samples, and the fracture mechanisms of samples are mainly the tensile failure. Compared with residual strength, the strength of grouting reinforced samples are increased at different degrees due to the filling and consolidation of fracture planes, but the strength recovery coefficient is not high. In addition, the confined grouting reinforcement can promote the transformation of cracked rock samples deformation from brittleness to ductility, and make the lateral and vertical deformation tend to coordination. More-over, the confining pressure has great effect on grouting amount, radial stain, strength of grouting rein-forced samples and strength recover coefficient, and the reinforcement effect can be improved signifi-cantly by increasing the confining pressure.