【作者】 徐恒国；

【导师】 黄明利；

【作者基本信息】 北京交通大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 随着土木工程在我国的蓬勃发展,预计21世纪初至中叶将是我国大规模建设地下工程的年代,与此相关,也会涌现出大量的岩土工程技术问题需要解决。在市区修建大断面隧道工程,其地层软弱富水的复杂工程地质条件、暗挖隧道结构呈洞群系统的复杂工程施工条件、近邻建筑物和管线密布的复杂工程边界条件而言,进行隧道工程的施工,其施工难度和风险极大,地表沉降机理及施工所引起的地表沉降分布形态也极为复杂,施工所引起的地面沉陷将有可能危及周围建筑设施和地下管线等的安全,造成严重的经济损失和社会影响。因此,如何在隧道施工过程中有效可靠地预计和动态地控制施工所引起的地面沉陷和变形,实现信息化动态施工,以保护工程沿线建筑物和地下管线的安全,已成为城市地下工程建设中必须解决的一项重要课题。本文基于大量的文献和广泛的实践,籍助厦门海底隧道浅滩段实测资料,利用现场试验、理论分析和数值模拟等多种研究手段,对大断面隧道浅埋暗挖法施工技术和变形分配控制理论进行了全面而系统的深入研究,并结合实际工程对本文的研究思想进行了应用研究,取得了一系列有益于理论和实践的研究结果。1)在隧道施工所引起的地表沉降的预计中,合理地模拟隧道的开挖支护施工过程以及各种支护措施的力学效果是至关重要的。2)通过对现场试验研究内容的精心设计,系统研究了浅埋暗挖法隧道工作面在开挖通过观测主断面前、通过中、通过后地层的响应规律。全面分析了围岩的应力与变形的分布特征及其变化规律。3)为了研究复杂群洞隧道工程施工所引起的地表沉降问题,针对地下工程施工过程的非线性特点,以地表沉降作为施工控制目标,结合动态规划原理,建立了群洞隧道开挖顺序优化的数学模型,对大断面隧道多导洞的开挖顺序进行动态优化。4)为了确保施工所引起的地表沉降在控制标准内,提出了变形分配控制理论,实现了动态信息化施工。更多还原

【Abstract】 It is predicted that a great deal of urban underground engineering will be constructed at early-middle period in the 21st century based on flourish civil engineering foreground nowadays, and at one time many geotechnical problems will also come forth. As far as complicated geologic condition with weak watery strata, complex construction condition with multi-tunnel system and complex environmental condition with adjacent to building and pipeline are concerned, difficulty and risk of construction are very great and the mechanism of ground settlement and its distribution are also very complex. Large land subsidence value induced by construction of large cross—section tunnel can lead to that road surface, buried pipe lines and buildings and so on are damaged. Furthermore, bad economic loss and social effect can be brought about. As a result, it is an urgent realistic problem that land subsidence induced by tunneling is forecasted and controlled so as to realize information and dynamic construction and ensure the safety of close-by building and buried pipeline.Based on vast literatures and extensive practices, the construction technology and the stratum deformation prediction and controlling theory in large cross—section tunnel construction with multi-hole was investigated , by local experimentation, theory analysis and numerical simulation. Its application was carried thoroughly, and a series of results were obtained.Firstly, it is very important that construction process of excavation and support and mechanical effect of supporting structure are simulated reasonably as far as land subsidence induced by tunneling is forecasted.Secondly, by a series of sites test, the earth responded rules which tunneling face of SCTM passed through observation main-transect during its frontage, backside and same position were studied systematically. The distributing characters of the earth stress and its distortion were analyzed in an all-round way.Thirdly, to study of land subsidence on complex multi-tunnel system engineering, in virtue of nonlinear characteristic of construction route in underground engineering, mathematical model of optimal excavation sequence aiming to land subsidence is built on basis of dynamic programming theory. Furthermore, the optimize theory is applied in large cross—section tunnel construction with multi-hole.Fourthly, in order to ensure land subsidence by excavation is less than settlement control standard, this paper presents the stratum deformation prediction and controlling theory, realizing information and dynamic construction更多还原