【作者】 丛苹；

【导师】 李清富； 张鹏；

【作者基本信息】 郑州大学 ， 水工结构工程， 2012， 硕士

【摘要】 施工期公路隧道结构是否安全可靠,关系到结构的使用是否满足设计的预定功能要求,是否造成不必要的人员与财产损失。本文在前人工作的基础上,针对施工期隧道结构安全问题做了以下几个方面的工作：(1)在分析隧道施工过程的受力状态、现代支护结构原理的基础上,结合目前隧道常见的病害,分析了工程地质条件、施工方法的选择、爆破效果、衬砌支护时机、支护结构的施工质量等对施工期隧道结构安全的影响。(2)简单介绍了有限单元法的原理,归纳总结了有限单元法基本的计算步。闸述了有限单元法对隧道施工过程的模拟思路及实现方法,讨论了有限元法主要采用“开挖卸载模拟”与“外边界加载法”的思路,并针对“开挖卸载模拟”思路,比较了“反转应力释放法”与“地应力自动释放法”的优缺点,指出本文采用后者的理由。(3)以某公路隧道工程为例,采用ABAQUS有限元分析软件对受力较复杂的V级浅埋、V深埋、IV级深埋隧道,分别采用预留核心土法开挖、上下台阶法开挖的施工过程进行了数值模拟,分析了不同围岩、不同埋深、不同施工方法下,围岩、锚杆支护结构和衬砌结构的受力特性,为施工的安全提供更加合理的技术支持。(4)从地质勘探技术、开挖技术、初期支护、防水层施工、二衬施工注浆回填和施工管理角度阐述了隧道施工过程的控制要点,以期达到施工安全、经济合理、确保质量的要求。更多还原

【Abstract】 The safety and reliability of the highway tunnel structures in construction can ensure that the tunnel structures meet the reservation function requirement of the design during their service life, which will prevent unnecessary personnel and property losses. Based on the previous work, this thesis has conducted the following studies concentrated on the safety of the tunnel structures during construction:(1) Based on the analysis of the modem supporting theory and mechanical properties of the surrounding rock in tunnel construction, the thesis proposed the influence factors which have effect on the safety of the tunnel structures during construction and discussed the influencing mechanism. The influence factors include the engineering geology condition, the selected construction method, the effect of excavation blasting, the opportunity of lining supported, the quality of the lining structure, and so on.(2) Based on the brief introduction of the basic principle and the basic steps of the calculation of the finite element method, The simulation and implementation ideas of the finite element method on the construction progress of the tunnel structures were discussed. Two simulation methods "Excavation Unloading Simulation" and "Outer Boundary Loaded Method" on the tunnel structures in construction were presented. Besides, the two styles of "Excavation Unloading Simulation" were compared, which are "Releasing method of reversed stress" and "Automatically releasing method of ground stress". Based on the advantages and disadvantages of the two styles, the latter was applied in this thesis.(3) Taken some highway tunnel as example which has three type of depths including V level of the shallow cover, V level and IV level of deep, the construction methods of excavating up and down steps and reserving core were simulated applying the ABAQUS finite element software. In addition, the mechanical characteristics of surrounding rock, shotcrete and the second lining were analyzed with different surrounding rock, cover depths and construction method, which presents reasonable technical supports on the design and construction of the tunnel structures. (4) In order to ensure that the tunnel structures meet the requirements of construction safety, economy and construction quality, the key points of the construction process control of the tunnel were put forward, which include geological exploration technology, excavation technology, the primary support, waterproof layer, the second lining, backfill grouting, and so on.更多还原