裂隙岩体注浆结石体收缩变形与抗剪强度

The Shrinking Deformation and Shear Strength of Fractured Rock Grouting Stone

为了提高裂隙岩体的力学性能,保证工程的质量和安全,采用水玻璃-水泥混合注浆液对裂隙岩体进行加固。通过直剪试验、显微镜实时观测试验,研究注浆结石体的强度与变形特性,以此评价水玻璃-水泥混合液作为注浆材料的可行性。试验结果表明,水玻璃-水泥混合注浆液有效的提高了裂隙岩体的力学性能。水玻璃-水泥注浆溶液不但改变了裂隙岩体的微结构、裂隙率和岩体的物质组成成分,使岩体的致密度和强度增加;而且注浆溶液在岩体结构面中凝固后对结构面进行填充加固,有效的提高了注浆结石体的黏聚力c,增强了注浆结石体抵抗外力破坏的能力。裂隙率对注浆结石体的强度影响显著,随裂隙岩体裂隙率的增加,注浆结石体(裂隙岩体与注浆材料经过物理化学变化后形成的结合体)的抗剪强度减小;在裂隙率相差不大时,裂隙岩体的裂隙条数对注浆结石体的抗剪强度有重大影响,随着裂隙条数的增加,注浆结石体的抗剪强度减小。在注浆结石体抗剪强度减少过程中,注浆结石体的黏聚力c不断减小,内摩擦角φ基本保持不变。注浆结石体在第12 d时达到最佳抗剪强度,而水玻璃-水泥质量比为1.3∶1注浆液工程性能最为理想,期最佳抗剪强度为6.243 MPa。

In order to improve the mechanical properties of fractured rock mass, to ensure project quality and safety, water glass-cement slurry injection of fractured rock mass reinforcement, by direct shear tests, real-time microscopic observations were studied strength and deformation of grouting concretion, in order evaluate water glassfeasibility cement mixture as grouting material. The results showed that water glass-cement slurry injection effectively improve the mechanical properties of fractured rock mass. Water glass-cement grouting solution not only changes the microstructure of fractured rock mass, fracture rates and material composition of the rock, so that the density and strength of the rock mass increase and grouting solution solidified surface structure of the rock mass the ability to fill the surface structure reinforcement, effectively raising the grouting concretion cohesion c, enhanced grouting concretion resist external damage. Significant effect on the strength of the grouting concretion body fracture, with the increase of the fractured rock mass fracture rate, the shearing strength of the grouting concretion body decreased. When fracture rates were similar, article of the fractured rock mass fracture number of shear strength of the grouting concretion body has a significant impact, with the increase of fracture number, the shearing strength of the grouting concretion body decreased. Grouting stone in reducing the shear strength, grouting concretion of decreasing the cohesion c, internal friction angle ~ remains substantially unchanged. Grouting concretion body in 12 d to reach the best shearing strength, and quality of sodium silicate cement ratio 1.3：1 grout injection project performance is the most ideal, best shear strength is 6. 243 MPa.