盾构隧道管片内力分布特性数值模拟分析

发布时间：2019-01-07 07:57

【摘要】：近年来,世界上隧道工程的大量建设极大促进了盾构隧道相关技术水平的进步,各个国家在盾构法施工过程中结构的设计及计算方面不断的发展,形成了较为有效的方法。而由于不同土层环境下盾构管片计算模型以及盾构管片附近载荷计算方法的选用并没有统一规定,因此各种数值计算方法在隧道及地下工程中涌现出来。本文以沈阳地铁隧道一号线沈阳站附近盾构隧道地质条件为参考,对盾构隧道设计中常用的三种管片内力计算方法进行了归纳和分析。基于土力学理论土压力的计算方法,提出了计算管片内力分布新的荷载一结构模型。分析了不同接头形式、隧道埋深、管片直径、土体弹性模量及泊松比对盾构管片内力特性的影响。考虑盾构隧道施工中产生的地应力释放,采用有限元法模拟了不同地层应力释放率条件下的盾构隧道管片的内力分布。将有限元模拟的盾构隧道施工引起的地表沉降与现场观测值的对比,确定了某地铁隧道施工引起的地应力释放率。根据材料力学中梁弯曲的平面假设,推导了盾构隧道双层衬砌结构弯矩分配比例的解析表达式。采用有限元方法数值模拟了盾构隧道双层衬砌结构2个典型的例子,解析解与有限元数值模拟的弯矩分配比例基本一致,验证了所推导解析解的正确性。研究了盾构隧道管片一次衬砌与二次衬砌内力特性之间的关系；以高水压大埋深琼州海峡海底隧道为例,分析了深埋隧道松弛土压力理论对盾构管片内力的影响情况。
[Abstract]:In recent years, a large number of tunnel projects in the world have greatly promoted the progress of the technology level of shield tunneling. Various countries have been developing in the design and calculation of the structure in the process of shield tunneling construction, and a more effective method has been formed. However, there are no uniform rules on the selection of shield segment calculation model and load calculation method near shield segment under different soil conditions, so various numerical calculation methods have emerged in tunnel and underground engineering. Taking the geological conditions of shield tunnel near Shenyang Station of Shenyang Metro Tunnel No. 1 as a reference, this paper sums up and analyzes three common methods for calculating the internal force of shield tunnel in the design of shield tunnel. Based on the calculation method of soil pressure in soil mechanics theory, a new load-structure model for calculating the distribution of internal forces in segments is proposed. The effects of different joint types, tunnel depth, segment diameter, elastic modulus of soil and Poisson ratio on the internal force characteristics of shield segment are analyzed. Considering the in-situ stress release in shield tunnel construction, the internal force distribution of shield tunnel segments under different stress release rates is simulated by finite element method. By comparing the ground subsidence caused by the shield tunnel construction simulated by the finite element method with the observed values in the field, the in-situ stress release rate caused by the construction of a subway tunnel is determined. According to the plane hypothesis of beam bending in material mechanics, the analytical expression of moment distribution ratio of shield tunnel double-layer lining structure is derived. Two typical examples of double-layer lining structure of shield tunnel are numerically simulated by finite element method. The results show that the analytical solution is in good agreement with the bending moment distribution ratio of finite element numerical simulation, which verifies the correctness of the analytical solution. The relationship between the primary lining of shield tunnel segment and the internal force characteristics of secondary lining is studied, and the influence of relaxation earth pressure theory of deep buried tunnel on the internal force of shield tunnel segment is analyzed, taking Qiongzhou Channel Tunnel with high water pressure and large buried depth as an example.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U455.43

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