摘要:
微生物诱导碳酸钙沉淀（MICP）技术弥补了传统加固方法流动性较弱、能耗高和污染环境的缺陷，逐渐被应用于加固岩体结构面。基于自主设计的灌输装置对岩体结构面进行注浆，获得不同加固次数、胶结液浓度和法向应力条件下的剪切力学与破坏特征，借助超声波仪、扫描电镜（SEM）、X射线衍射仪（XRD）和高分辨透射电镜（HRTEM）技术综合分析微观机理。结果显示：随着加固次数和法向应力的增加，抗剪强度均逐渐增加，胶结液浓度增加时，抗剪强度先增加后减小；结构面剪切破坏主要发生在碳酸钙间、碳酸钙与岩石颗粒间和岩石颗粒间，在加固20次、胶结液浓度1 mol/L、法向应力1 MPa的条件下，破坏区域较小；加固后试样声时值变化范围为34-50 μs，且不同因素的统计规律与剪切试验结果一致；微观分析表明，抗剪强度的提高与方解石晶型的良好发育及其较高的占比密切相关。结合MICP加固过程及剪切破坏过程，揭示微观晶体局部破裂的演变行为对结构面宏观剪切破坏过程的影响机制。本研究可为岩体加固工程方案的制定与优化提供参考依据。
Abstract:
The microbial induced calcium carbonate precipitation (MICP) technology addresses the shortcomings of traditional reinforcement methods, such as poor fluidity, high energy consumption, and environmental pollution, and is gradually being applied to reinforce rock joint. The rock joint was grouted using a self-designed infusion device to obtain the shear mechanical and failure characteristics under different reinforcement cycles, cementation solution concentrations and normal stresses. The microscopic mechanisms were comprehensively analyzed using ultrasonic testing, scanning electron microscopy (SEM), X-ray diffractometer (XRD) and high-resolution transmission electron microscopy (HRTEM) technologies. The results show that the shear strength of the specimens gradually increased with the increase in reinforcement cycles and normal stress, while the shear strength initially increased and then decreased with the increase in cementation solution concentration. The shear failure of the rock joints mainly included failure between calcium carbonate, between calcium carbonate and rock particles, and between rock particles. Under the conditions of 20 reinforcement cycles, 1 mol/L cementation solution concentration, and 1 MPa normal stress, the failure area of the specimens was relatively small. The variation range of the sonic time values of the specimens was 34 to 50 μs, and the statistical patterns under different factors were consistent with the shear test results. The microscopic analysis explained that the improvement in shear strength was due to the well-developed calcite crystal form and its high proportion. By combining the MICP reinforcement process and the shear failure process, the influence mechanism of the evolution behavior of local rupture of microscopic crystals on the macroscopic shear failure process of the rock joint was revealed. This study can provide a reference basis for the formulation and optimization of rock mass reinforcement engineering schemes.
百度学术
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