不同岩石强度裂隙岩体约束自应力浆液加固试验研究与应用

Test and application of self-stress slurry reinforcement for fractured rock masses with different strength

  • 摘要: 基于课题组提出的裂隙岩体自应力浆液加固方法,考虑岩石强度对自应力浆液−岩体耦合效果的影响,选取井下砂岩、炭质泥岩、砂质泥岩、煤为研究对象,进行不同岩石强度预制裂隙岩体的普通浆液和自应力浆液加固对比试验,分析岩石强度对注浆加固效果的影响;多角度探索约束自应力浆液对岩体裂隙界面的复合加固作用,揭示浆液自应力的加固机理;通过多个不同岩石强度的工程围岩案例,分析自应力浆液体系对不同岩石强度工程围岩的宏观加固效果。结果表明:自应力浆液对软硬岩等不同岩石强度裂隙岩体的加固效果均大于普通浆液,随着岩石强度变弱,注浆对裂隙岩体的加固修复程度逐渐降低,注浆加固岩体试样逐渐由沿着对角线方向的剪切破坏向劈裂崩解破坏过渡;浆液自应力改善了浆−岩界面的约束受力状态,通过增大摩擦力提高了界面的抗剪强度;浆−岩2种介质的接触连接效果被提升,自应力浆−岩界面的胶结密度明显大于普通浆−岩界面;自应力浆液结石晶体颗粒分布更均匀,密实性及力学性能均明显优于普通浆液。超细硅质自应力浆液体系在破碎软岩巷道、相对硬岩巷道、松软煤帮等工程加固中均取得了良好的效果。

     

    Abstract: Based on the self-stress slurry reinforcement method for fractured rock mass proposed by the authors, considering the influence of rock strength on the coupling effect of self-stress slurry and rock mass, the paper selected underground sandstone, carbonaceous mudstone, sandy mudstone, and coal as the research objects. Then, the comparative tests of reinforcing fractured rock mass with different strength by ordinary slurry and self-stress slurry were carried out to further analyze the influence of rock strength on grouting reinforcement effect. The composite reinforcement effect of restrained self-stress slurry on the rock mass fracture interface was investigated from multiple angles to reveal the reinforcement mechanism of slurry self-stress. Through several engineering cases of different rock strength, the macroscopic reinforcement effect of the self-stress slurry system on the engineering surrounding rock with different rock strength was analyzed. The results showed that the reinforcement effect of self-stress slurry on the fractured rock masses with different strength, such as soft and hard rock, was greater than that of ordinary slurry. As the strength of the rock mass became weaker, the repair degree of slurry to the fractured rock mass was gradually reduced, and the grouting reinforced rock mass specimens gradually transited from shear failure along the diagonal direction to splitting collapse failure. The self-stress of the slurry improved the restrained state of the slurry-rock interface, and then increased the shear strength of the interface by increasing the friction force. The contact connection effect of the two mediums of slurry and rock had been improved. The cementation density of self-stress slurry-rock interface was significantly higher than that of ordinary slurry-rock interface. The crystal particle distribution, compactness and mechanical properties of self-stress slurry stone were obviously better than those of ordinary slurry. The ultra-fine siliceous self-stress slurry system had achieved good results in the reinforcement of broken soft rock roadways, relatively hard rock roadways, and soft coal wall.

     

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