【作者】 韦良文；

【导师】 张庆贺；

【作者基本信息】 同济大学 ， 结构工程， 2007， 博士

【摘要】 伴随着城市化进程,日益拥挤的交通使地下铁道等其它一些交通隧道的建设成为城市发展的必然,现代城市对地下交通隧道建设在数量和质量上都有了更高的要求。相对于盾构隧道施工建设状况,我国在盾构工法特别是大型泥水盾构隧道施工技术等方面还存在许多问题,其中较为突出的是施工中地层土体失去稳定性问题。对于泥水盾构施工过程中土体稳定性研究尚缺乏足够的认识,探索泥水盾构工法的土体稳定性规律既是生产实践需求,也具有一定的理论研究价值。本文依托于上海复兴东路越江隧道、翔殷路越江隧道及西藏南路越江隧道工程并参考大量文献,对泥水盾构施工中存在的开挖面稳定性、盾尾拖出管片的土体坍塌及隧道上浮现象以及出洞段土体稳定性进行了研究,主要工作和研究成果如下:（1）分析泥水介质平衡开挖面微观机理及泥膜形成条件与形成过程;基于泥水盾构隧道开挖面失稳形式,建立改进的楔型体模型,考虑滑动面的形状、泥水渗入地层影响及产生超孔隙水压影响,对模型各参数进行敏感性分析;（2）经过主要原材料优选试验、造浆率试验、抗污染试验及抑制分散岩屑回收率试验及现场配制研发了聚合物正电胶（PMS）泥浆;初步分析了聚合物正电胶（PMS）泥浆平衡开挖面土体的机理,根据聚合物正电胶（PMS）泥浆复兴东路工程试验监测结果,获得了良好的工程使用效果;（3）对同步注浆材料进行了10组浆液第一阶段配比试验,得到了浆液配方技术参数如坍落度、稠度、密度、泌水率、收缩率及pH值,经比较确定3组可注性好的浆液配方;对其进行直剪试验、固结压缩试验,确定其粘聚力c、内摩擦角φ,压缩系数α_v1-2及压缩模量E_s1-2,并进行了3d、7d、28d的单轴抗压强度试验,确定浆液不同龄期的抗压强度;在第一阶段的基础上由市政二公司提供现场施工材料,并进行含添加剂的浆液各项指标的试验研究,并优选配方,确定了现场采用的浆液配方;（4）分析盾尾脱出管片后盾尾上覆土失稳原因及泥水盾构隧道上浮影响因素;建立泥水盾构隧道上浮简化弹性地基梁模型,并分析隧道纵向刚度、地基反力系数及上浮力的确定方法;采用上述方法应用本文研究的同步注浆浆液参数计算了翔殷路隧道上浮量,并与监测结果作了对比分析;提出有效控制泥水盾构隧道上浮的工程措施;（5）分析工作井端头土体加固原则、加固范围及常用加固方法;采用板块强度理论分析加固土体强度,采用滑移失稳理论和土体极限平衡理论分析加固土稳定性。最后结合一具体算例进行计算,并与有限元结果进行比较。更多还原

【Abstract】 With the development of urbanization, it is necessary that traffic tunnels like subway become more and more important because of increasingly crowded traffic, and modern city requires higher demands on underground traffic tunnels not only in magnitude and also in quality. There consists of many problems in shield tunneling especially slurry shield tunneling contrast to the fast development and great demands of shield tunnels, in which the most important is the unstable condition of soil body. So it is of practice demand and of great theoretical significance to explore the stability rule of soil body of the slurry shield tunneling.Bases on Project East Fu-xing Road tunneling, Project Xiang-yin Road tunneling and Project South Sitsang East Road tunneling, the rules of face stability , the soil collapse after the shield tail pulled out of segment and the tunnel floating, stability of the soil body around starting shaft are investigated. The major works and results of this dissertation are as follows:（1） The microcosmic mechanism of slurry balancing face, the formation factor and course of filtercake are analyzed; Based on the unstable face forms, the ameliorated wedge model is set up. The ameliorated wedge model can synthetically consists of influences of shape of the sliding face, slurry penetrating face soil and excess pore pressure. Parameter sensitivity is analyzed about the ameliorated wedge model.（2） It is found that the polymer and the Mixed Metal Hydroxide could depress the dispersibility of the clay, reinforce the stability of the sand and improve the characters of the slurry, then developed the Polymer-MMH Shield Slurry through material choice test, serosity-make ability test, anti-pollution test and restraining dispersive drillings recycling test. Used in Project East Fuxing Road Slurry Shield Tunneling, a filtercake with low porosity, compact and larger thickness was made. So the Polymer-MMH Shield Slurry System have the good utility, and can be extensively applied in the construction of the large-diameter slurry shield tunnel.（3） 10 synchronous grout proportioning tests are carried on, and tests on slump, consistency, density, bleeding rate, shrinkage ratio and pH value. According to this 3 synchronous grout proportions with good groutability are selected. After that, simple shear tests; consolidation tests are carried to determine the cohesion c, internal friction angleφ, the compression index a_ν12 and modulus of compressibility E_s1-2, and also uniaxial compression tests about the grout with curing age of 3d、7d、28d are carried to determine uniaxial compression strength at different curing age. Based on results of the first phase, tests are carried to determine every index of the grout with additives, and the better synchronous grout proportion is to be applied in the field.（4） The reasons of soil over shield tail losing stability and influencing factors of slurry shield tunnel floating are analyzed. A simplified elastic base beam for floating of slurry shield tunnel is put forword, and the longitudinal rigidity, foundation modulus and buoyancy to tunnel are determined respectively. It shows good effect with the elected grout to anti uplifting contrasting to the monitoring data in Project Xiang-yin Road tunneling. Lastly some effective meseases are put forward to control the floating of slurry shield tunnel.（5） The reinforcement principle, reinforcement range and common reinforcement methods are introduced briefly. It is to be analyzed the strength and stability demands of the reinforced soil body with thin board strength theory, slide theory and limit balancing theory, and checking computations are carried on a domestic slurry shield tunneling project, the computation results are compared to the FEM results.更多还原