【作者】 李超；

【导师】 郑刚；

【作者基本信息】 天津大学 ， 结构工程， 2010， 硕士

【摘要】 随着城市基础设施建设的迅速发展,浅埋暗挖法在城市地下铁道、地下街等地下工程中得到了广泛应用,但其理论研究却远远落后于工程实践。本文依托天津某工程,通过理论分析、数值模拟等手段,研究分析了浅埋暗挖隧道管棚超前支护和超前小导管注浆预加固的作用机理,并对暗挖隧道的整个施工过程进行数值模拟研究,得到以下一些结论:1、管棚预支护、超前小导管注浆加固土体、预留核心土等限制掌子面前方土体变形和维持掌子面稳定的措施,对控制地层位移、减小对周边环境的影响、保证隧道施工安全起到至关重要的作用。2、数值计算的结果表明:管棚的有无、土体的弹性模量、泊松比、注浆加固体的长度等因素对地层位移、地表沉降均有一定的影响;在数值分析中可以通过改变单元的弹性模量、泊松比等参数来模拟注浆加固体的作用;管棚支护能够抑制地层变形,超前小导管注浆能够提高掌子面的稳定性,使隧道开挖更安全。3、对隧道的整个施工过程进行数值模拟,通过分析地表沉降、地层位移、围岩塑性区发展变化趋势及管棚和初期支护的受力情况,验证了管棚预支护、超前小导管注浆加固能够满足工程控制地层变形的实际需要。本文的研究成果对该工程的施工具有理论指导意义,对其他类似的工程也具有借鉴意义。更多还原

【Abstract】 With the rapid development of urban infrastructure construction, shallow mining method is widely applied in underground projects such as metros, underground streets. However, the theoretical study is far behind engineering practice.Taking a project in Tianjin as the background, the mechanisms of pipe-roof pre-support and leading conduit pre-reinforce in shallow tunnels were analyzed by using theoretical analysis, numerical simulation and other research tools. And the whole construction procession of shallow tunnel was also simulated. Research obtained the following results:(1)Pipe roofs used to restrict the soil deformation, leading conduit pre-reinforcement and core soils used to maintain the tunnel face stability are very important to control the ground settlement, to reduce the impact on the surrounding environment and to provide the security for the construction work.(2)The calculated results show that pipe roofs, elastic modulus, Poisson’s ratio and the length of reinforcement can partly affect the ground settlement and the surface subsidence. It also indicates that the function of reinforcement can be taken into account by changing the elastic modulus and the Poisson’s ratio during the analysis. Pipe-roof support can restrain ground deformation and the leading conduit improves the stability of tunnel face, which makes the tunnel excavation process safer.(3)The tunnel construction procession is simulated. The development of surface subsidence, ground settlement, plastic zones and the force of pipe-roofs and tunnel initial support were analyzed, which verified that pipe-roof pre-support and leading conduit pre-reinforce in shallow tunnels can meet the requirements of ground deformation.The conclusions in this paper can give construction guidance for the actual project and also be referred by other similar projects.更多还原