Abstract: In order to determine the optimal plan for improving the strata and pipeline reinforcement of large-diameter shield tunnels, digital seismometer micro motion detection technology was used to comprehensively analyze the distribution and density of the strata in the reinforcement area. At the same time, unit excavation energy consumption technical indicators were introduced to evaluate the construction efficiency of each reinforcement plan. Numerical simulation was conducted to study the disturbance of pore stress in the strata during shield tunneling under different reinforcement plans, and the control effect of different reinforcement methods on seepage disturbance. The research results show that: the reinforcement of construction piles has the worst control effect on pipeline settlement due to the unreinforced shallow soil, followed by sleeve valve pipes. Combination grouting reinforcement can significantly improve the control effect on pipeline settlement. Through micro-motion detection, it can be seen that sleeve valve pipe grouting has a better filling effect on shallow clay layers, while MJS construction method piles can effectively compensate for the shortcomings of sleeve valve pipe grouting reinforcement, which has good adaptability to the cohesive soil layer between crushed stones and the lower silt rock layer, can effectively strengthen the compactness of the formation and reduce the permeability coefficient. By analyzing the changes in shield tunneling construction efficiency before and after reinforcement, it can be concluded that the uniformity of the strata in the sleeve valve pipe reinforcement section is poor, with large fluctuations in unit energy consumption and actual loss values of the strata. The compaction and uniformity of the strata after MJS grouting reinforcement are relatively high, and the working face in the reinforcement area is also relatively stable, which is conducive to controlling surface settlement and deviation from the tunnel axis.

Key words: tunnel engineering; comparison of reinforcement effects; numerical simulation; pipeline reinforcement; physical detection

摘要： 为了确定大直径盾构隧道地层改良和管线加固最优方案，采用数字地震仪微动检测技术对加固区地层分布和密实度进行了综合分析，同时引入单位掘进能耗技术指标对各加固方案的施工效率进行评价，并通过数值模拟研究了不同加固方案下，盾构掘进时地层孔隙应力的扰动情况和不同加固方法对控制渗流扰动的控制效果，研究结果表明：工法桩加固由于未加固浅层土体，对管线沉降的控制效果最差，袖阀管次之，组合注浆加固则能显著提升对管线沉降的控制效果;通过微动探测可知，袖阀管注浆对浅层黏土地层填充效果较好，MJS工法桩则能有效弥补袖阀管注浆加固的不足，对碎石夹黏性土层与下部粉砂岩层的适应性较好，能有效加强地层密实度，减少渗透系数;分析加固前后的盾构施工效率变化可知，袖阀管加固段的地层均匀性较差，单位能耗、地层实际损失值波动较大，MJS注浆加固后的地层密实度较高、均匀性较好，该加固区工作面也较为稳定，有利于控制地表沉降与隧道轴线偏差。

关键词: 隧道工程；加固效果比选；数值模拟；管线加固；物理探测