基于注浆试验的深井软岩CT分析

Laboratory grouting experiment based CT analysis of grouted soft rocks in deep mines

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 isavailable 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 bentonitecement 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 dimensionreducing from 1. 385 to 1. 074.