1. School of Mechanics and Architecture Engineering,China University of Mining and Technology (Beijing),Beijing　 100083,China;2. State Key Laboratory for Geomechanics and Deep Underground Engineering,Beijing　 100083,China;3. Jizhong Energy Fengfeng Group,Handan　 056000,China

深井注浆围岩内部结构复杂而隐蔽,目前尚缺乏对其强度等特性定量测试分析的有效方法,通过三轴压力相似模型试验,制作了高应力深井破坏软岩等效试件,采用优化的浆液配比和自主研发的MYZJ-2型实验室液压注浆系统对破坏软岩进行了实验室注浆试验,测试注浆后试件单轴抗压强度,利用CT扫描技术对注浆试件裂隙变化情况进行了观测研究,并分析了试件内部裂隙分形维数变化规律。研究结果表明,采用水灰比1∶0.6,膨润土比例为水泥重量4%的超细水泥浆液对等效破坏泥岩试件注浆加固后,试件承载能力得到一定程度恢复,且峰后残余强度较注浆前提高约40%,韧性能力提高,试件内部裂隙基本被浆液填充,裂隙分形维数由注浆前1.385减小到注浆后1.074,注浆效果较好。

Because of the complication and concealment of grouted soft rocks in deep mines,no effective method is available to quantitatively analyze the strength and the other behaviors. To solve the problem,firstly,equivalent speci- mens of soft rocks destructed by the high pressure in deep mines are made by the similarity model experiments of triax- ial pressure. Secondly,all the specimens are grouted by self-developed MYZJ-2 pressure grouting system with opti- mized grout ratio. CT scan and uniaxial pressure experiments are,then,conducted to discover the crack state and uni- axial compressive strength of the specimens. Finally,microscopic behaviors of grouted soft rocks in deep mines,inclu- ding strength,development rules and fractal dimension of cracks,have been analyzed based on the experimental data. The results show that after being grouted by superfine cement grout with water cement ratio of 1 ∶ 0. 6 and bentonite cement ratio of 0. 04 ∶ 1,the strength and toughness of destructed soft rocks increases. Thus the residual strength in- creases 40% compared with specimens before grouting. The cracks are mostly filled with the value of fractal dimension reducing from 1. 385 to 1. 074.

国家自然科学基金资助项目(51134025,51274204)；博士研究生拔尖创新人才培育基金资助项目(800015Z6A8)；

Yang Renshu,Xue Huajun,Guo Dongming,et al. Laboratory grouting experiment based CT analysis of grouted soft rocks in deep mines [J]. Journal of China Coal Society,2016,41(2):345-351.