富水复合地层盾构隧道开挖面渐进性失稳破坏机理

With the development of major urban transport infrastructure in China, shield construction is meeting with many problems and challenges including diversification of geological conditions, diversification of structural cross sections, normalization of river crossings and complicated construction environment, especially the large geological variability and the poor geological bodies in the formation of complex strata, all easily lead to excavation surface instability. In this project, the theoretical analysis, numerical simulation and experimental simulation are synthetically used to carry out research on the excavation surface instability evolution mechanism during shield construction in the water-rich composite strata, the spatial evolvement rule of whole excavation surface instability process including its occurrence, development and destruction. Then we build the three-dimensional rotating body destruction model of excavation surface instability, analyze the destruction mode and distribution law of excavation surface instability, build calculation method of critical support force in complex strata excavation surface instability with consideration of seepage effect and carry out progressive damage experiment of excavation surface instability in shield construction. We tend to reveal the evolution mechanism of excavation surface instability in shield construction under seepage-stress coupling effects and provide theoretical support for the control technology system of excavation surface instability in shield construction, which will be of great academic significance and engineering value in promoting the construction of urban rail transit project in China.

随着国家城市交通重大基础设施建设的发展，盾构法施工面临着地质条件多样化、结构断面多元化、越江跨海常态化、建设环境复杂化等诸多问题和挑战，特别是地质情况变异性大、不良地质体赋存的复合地层的存在，极易造成开挖面失稳事故，造成重大经济损失和人员伤亡。本项目采用理论分析、数值仿真、室内实验等综合手段，开展富水复合地层盾构施工开挖面渐进性失稳破坏演化机理研究，研究开挖面失稳发生、发展到破坏的施工全过程力学行为演化效应规律，构建复合地层盾构施工开挖面失稳三维旋转体破坏模型，分析开挖面失稳过程中的破坏模式和分布规律，建立考虑渗流作用影响的复合地层开挖面失稳临界支护力计算方法，开展盾构施工开挖面渐进失稳破坏试验，揭示渗流-应力耦合作用下盾构施工开挖面渐进性失稳破坏灾变演化机理，为盾构施工开挖面失稳防治技术体系提供理论支撑，对推动我国城市轨道交通工程的建设具有重要的学术意义和工程价值。

国家中长期发展规划中将交通基础建设摆在重要位置，而轨道交通工程是城市交通重大基础设施工程的生命线工程。目前，盾构法施工的地铁工程已成为我国城市轨道交通工程的重要方式，并逐渐成为城市现代化建设的重要符号。我国盾构技术发展起步晚，加之我国地域辽阔，工程地质差异大，盾构施工事故频发，在建和拟建的地铁工程施工过程中会遭遇大量的富水复合地层，极易造成开挖面失稳事故，造成重大经济损失和人员伤亡，对盾构施工开挖面失稳机理及控制技术提出了巨大挑战。因此，本项目具有广泛的应用前景。本项目围绕富水复合地层盾构施工开挖面渐进性失稳破坏机理的理论难题，依托济南地铁工程，揭示富水复合地层地质特征、岩土体结构力学效应规律及时空演化特征，建立考虑渗流作用影响的复合地层开挖面失稳临界支护力计算方法，揭示渗流-应力耦合作用下盾构施工开挖面渐进性失稳破坏灾变演化机理，结合实际工程加深对复杂地质条件盾构隧道开挖面失稳破坏机理的认识，为提高盾构施工开挖面失稳防治技术提供理论支撑，对推动我国城市轨道交通工程的建设具有重要的学术意义、广泛的应用前景和重要的实际应用价值。依托于该项目，课题组在国际、国内学术期刊上发表SCI、EI收录论文9篇，取得软件著作权1项，在审专利3项。培养博士研究生2名，培养硕士研究生3名。