不同处理工艺下微生物对岩石裂缝加固效果影响

随着微生物诱导碳酸钙沉淀（MICP）技术在岩石裂缝修复领域研究的深入，该技术在实际工程中的应用也日渐广泛。为深入研究不同处理工艺条件、胶结液浓度对MICP技术加固岩石裂缝效果的影响，采用蠕动泵注浆和浸泡灌浆两种不同工艺对岩石裂缝加固进行室内试验，确定最优微生物加固岩石裂缝工艺。经试验得出最优的处理工艺条件参数，并在此基础上开展不同胶结液浓度（0.5、0.7和1.0 mol/L）条件下微生物浸泡灌浆加固岩石裂缝试验，进行胶结液浓度对加固效果影响的量化分析。结果表明:相同胶结液浓度条件下，蠕动泵注浆工艺和浸泡灌浆工艺加固岩石裂缝后界面抗剪强度分别为0.28和0.89 kPa，后者约为前者的3.2倍；浸泡灌浆处理工艺条件下胶结液浓度对加固后岩石试样界面抗剪强度影响显著，随着胶结液浓度的增大，加固与未加固裂缝界面黏聚力的比值呈线性增长。不同形状岩样的试验结果表明，圆柱体岩样加固后裂缝界面黏聚力增长速度要明显高于长方体岩样。

Effect of microorganism on rock crack reinforcement under different treatment technologies

In recent years, the research of microbial induced calcium carbonate precipitation (MICP) technology in the field of rock fracture repair has become more and more in-depth, and is gradually applied to the practical engineering field. In order to deeply study the effects of different treatment conditions and different cement concentrations on the effect of rock crack reinforcement by MICP technology, two different processes of peristaltic pump grouting and immersion grouting were used to carry out indoor tests on rock cracks, and determine the optimal process of rock crack reinforcement by microorganisms. Based on the above test results, the optimal treatment process parameters were obtained. On this basis, the test of rock crack reinforcement by microbial immersion grouting under different cement solution concentrations (0.5 mol/L, 0.7 mol/L and 1.0 mol/L) was carried out, and the quantitative analysis of the influence of cement solution concentration on the reinforcement effect was carried out. The results show that under the same cement concentration, the interfacial shear strength of rock cracks strengthened by peristaltic pump grouting process is about 0.28 kPa, the interfacial shear strength of rock cracks strengthened by immersion grouting process is about 0.89 kPa, and the interfacial shear strength of rock samples strengthened by immersion grouting is about 3.2 times that of rock samples repaired by peristaltic pump grouting. Under the condition of immersion grouting, the concentration of cement solution has a significant effect on the interfacial shear strength of reinforced rock samples. The ratio of interface cohesion between reinforced fracture and unreinforced rock sample increases linearly with the increase of cement solution concentration. For different shapes of rock samples, the results show that the growth rate of fracture interface cohesion of cylinder rock samples is significantly higher than that of cuboid rock samples.