盾构隧道松散地层可控注浆机制及工程应用

发布时间：2018-03-12 11:15

本文选题：隧道工程　切入点：盾构隧道　出处：《岩石力学与工程学报》2017年09期 　论文类型：期刊论文

【摘要】：盾构穿越松散地层时,需事先采用开挖(钻孔)回填、压力注浆、旋喷加固等方式对地层进行预处理,以保证盾构施工安全。针对盾构掘进的要求,基于传统袖阀管注浆工艺可控的特点,结合研制的2种可控浆液(可控填料和可控水泥膏状浆液),提出一种具有操作性强、提管便利、加固范围可控以及加固体强度适宜等优点的双控注浆新方法。依据双控注浆新方法的工作原理,重点推导了可控浆液扩散方程及可控填料封孔止浆可控表达式,并定量分析可控浆液的扩散和止浆能力,最后将研究成果成功应用于越江盾构隧道松散地层注浆工程。研究成果表明:提出的可控注浆方法可行,注浆后地层连续性和整体性得到了显著提高,加固区域内检查孔取芯过程钻进平稳,回水正常,芯样完整,加固体28 d抗压强度与渗透系数均达到设计标准;理论推导虽与现场实测值存在一定误差,但能满足工程要求;结合理论推导和现场试验结果,为达到最佳注浆效果,单次注入可控填料封孔高度应综合考虑孔深与分段次数,且不宜大于15 m,径向扩散距离应小于孔排距的25%,可控填料塑性强度宜控制在0.3~0.5 MPa。
[Abstract]:In order to ensure the safety of shield tunneling, it is necessary to pre-treat the stratum by excavation (drilling) backfill, pressure grouting, rotary jet reinforcement and so on, in order to ensure the safety of shield tunneling, so as to meet the requirements of shield tunneling. Based on the characteristics of controllable grouting technology of traditional sleeve valve pipe, combined with two kinds of controllable slurry (controllable filler and controllable cement paste slurry) developed, a new kind of slurry with high maneuverability and convenient pipe lifting is put forward. Based on the working principle of the new method, the diffusion equation of controlled grouting and the controllable expression of sealing grouting with controllable packing are derived. Finally, the research results are successfully applied to the grouting engineering of the loose stratum in the tunnel of the cross-river shield tunnel. The research results show that the proposed method is feasible. After grouting, the continuity and integrity of stratum are improved significantly. The core sample is intact with normal backwater and steady drilling in the check hole in the strengthened area. The compressive strength and permeability coefficient of the solid in 28 days are up to the design standard. The theoretical derivation can meet the engineering requirements although there is a certain error between the theoretical derivation and the field measured value. In order to achieve the best grouting effect, the hole depth and the number of sections should be considered comprehensively in the single injection controllable packing hole height in combination with the theoretical derivation and the field test results. The radial diffusion distance should be less than 25% of the pore spacing, and the plastic strength of the controllable packing should be controlled at 0.3 ~ 0.5 MPa.
【作者单位】：中南大学土木工程学院;中铁十四局集团隧道工程有限公司;长沙理工大学水利学院;
【基金】：“十三五”国家重点研发计划课题(2016YFC0802504) 中南大学中央高校基本科研业务费专项资金资助(2016zzts075)~~
【分类号】：U455.43

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