节点文献
淤泥质地层地下通道暗挖施工风险分析与地层加固研究
Construction Risk Analysis and Stratum Improvement for Underground Passage Tunneling in Muddy Stratum
【作者】 李昌友;
【作者基本信息】 中南大学 , 土木工程, 2014, 博士
【摘要】 摘要:如何确保淤泥质地层中的地下工程施工安全是工程界迫切需要解决的技术难题。本文针对淤泥质地层地下通道暗挖施工技术,依托多个市区地下人行通道工程实例,采用理论分析、数值模拟和现场工程验证等手段进行研究,提出了淤泥质地层改良加固方案及施工工艺并在现场得到检验,主要内容如下:(1)通过文献调研总结了我国城市淤泥质地层分布特征,分析了淤泥质地层的工程特性及在该地层进行暗挖隧道施工难点。(2)采用风险管理手段建立了淤泥质地层地下通道暗挖施工风险评估模型,进行了相应的风险分析,揭示了风险源,提出了施工风险控制措施。(3)扩展应用岩土工程稳定性分析的极限分析上限有限元法,展开多种参数条件下的地层稳定性分析,探讨了加固圈厚度和加固参数等因素对隧道横断面稳定性的影响,获得了暗挖隧道地层失稳破坏特征,论证了包含加固圈的淤泥质地层暗挖隧道稳定性、破坏规律和加固机理,提出了地层注浆加固建议。(4)在淤泥质地层工程特性及暗挖隧道地层失稳破坏特征研究基础上,分析现有的地层加固改良方法的具体特征,明确各种地层加固改良方法的适用条件。(5)以多个典型的淤泥质地层地下通道工程现场实例为依托,分别采用上限有限元法和有限差分法数值计算手段,分析了暗挖通道地层稳定性和结构变形与安全性。从施工角度讨论了工程外部环境条件、淤泥质地层具体特性、以及暗挖工法的实施难点,在工程现场实施并检验以WSS注浆为主、TSS注浆为辅、并结合拱部大管棚的综合地层预加固方案及施工工艺。图127幅,表72个,参考文献147篇。
【Abstract】 Abstract:How to ensure safety of shallow tunneling construction in the muddy stratum is a key problem that should be settled in engineering circles. The construction technology subject for shallow tunneling method in the muddy stratum is described and investigated by adopting methods of theoretical analysis, numerical modeling and practical construction site etc., taking underground passage construction as examples in several urban areas. The optimized construction technology of improved and reinforced method is tested in construction site. The main content of the paper is shown as following:(1) Through document investigation, data collection etc. muddy stratum distribution of cites in our country is summarized. Engineering characteristics of muddy stratum in typical area, and difficulties of construction technology for shallow tunneling method in the muddy stratum are analyzed.(2) Using risk management means, risk assessment model for shallow tunneling construction in the muddy stratum is established to analyse corresponding risk to reveal source of risk. Then, then corresponding risk control measures is put forward.(3) Using finite element upper bound solution with application to stability analysis in geotechnical engineering in different parameters condition, effects of different reinforced circle range and reinforced parameters on stability for cross section of tunnel are studied. It’s obtained that stratum with unstable failure characteristics in shallow tunnel. Through summary of stability of shallow tunneling method in the muddy stratum, failure law and reinforced mechanism, grouting reinforced suggestion for construction cite reference is presented.(4) On the basis of engineering features of muddy stratum and unstable failure characteristics, the current specific features of improved reinforced methods for of stratum is analyzed. The suitable condition for improved reinforced methods of different stratum is clarified.(5) Relying on underground passage with feature of typical muddy stratum construction examples, strata stability, structure deformation, and security of shallow tunnel are investigated by adapting upper bound finite element method and finite difference method numerical methods. Then construction external environmental condition, specific features of muddy stratum, and difficulties of shallow tunneling method is clarified. It’s mainly used WSS grouting method with TSS grouting method and arch pipe shed method as subsidiary and pre-reinforcement stratum method, and its application in construction site was verified.
【Key words】 Muddy stratum; stability of stratum; ground settlement; construction risk; stratum improvement; finite elementupper bound solution;