列车脱轨撞击荷载下盾构隧道衬砌开裂力学行为研究

发布时间：2018-10-25 14:59

【摘要】：目前,高速列车的运行安全已经日益引起人们的高度关注,高速列车可能脱轨撞击有较大弯道和坡道的盾构隧道并导致隧道结构破坏这一现实威胁已在我国高速铁路建设背景下逐渐显现,有鉴于此,对于撞击荷载下盾构隧道衬砌的安全和稳定性评价显得尤为重要,本文建立了考虑动力边界条件、管片实体接头、管片三维接触、管片衬砌非线性开裂与接头螺栓非线性开裂的耦合模型,以此研究撞击荷载下盾构隧道衬砌的开裂力学行为,以及螺栓接头的动力响应,得到如下主要研究成果：(1)阐述了混凝土裂缝分析中常用的开裂模型,研究对比了各种开裂模型的特点及适用范围；选用基于扩展有限元法的开裂模型研究动态裂纹的扩展,并阐述了扩展有限法的基本理论,给出了扩展有限元法的单元数值积分方案,介绍了扩展有限元法在ABAQUS中的运用,分析了裂缝初始判定准则和扩展准则。(2)通过建立三维列车模型,获得列车撞击荷载特征曲线,提出了通过高斯多峰拟合的经验公式；建立单层管片衬砌的开裂模型,捕捉动态裂纹的扩展路径,研究了管片裂缝的产生区域、扩展时间以及扩展长度,分析了裂缝开度时程分布特点,揭示了管片接头、撞击位置与裂缝开展的关系；对比分析环向弯螺栓和纵向直螺栓的应力、变形、速度、加速度等动力响应特性。(3)通过建立双层衬砌盾构隧道模型,研究二次衬砌在撞击荷载下的开裂演化以及开度时程曲线,对比分析单、双层两种形式下的盾构隧道管片衬砌的开裂力学行为以及接头螺栓的动力响应,揭示了撞击荷载下二次衬砌对管片衬砌的保护作用以及在限制管片衬砌开裂所起作用。(4)基于单层管片衬砌开裂模型,对接头螺栓施加非线性开裂,研究接头螺栓处裂缝的开裂演化以及开度时程曲线,对比分析未引入螺栓开裂和引入螺栓开裂两种形式下盾构隧道管片衬砌的开裂力学行为,揭示螺栓开裂在管片衬砌动力开裂所起的作用。
[Abstract]:At present, the running safety of high-speed trains has attracted more and more attention. The realistic threat that high-speed trains may derail and impact shield tunnels with larger bends and ramps and cause tunnel structure damage has gradually appeared in the context of high-speed railway construction in China. It is very important to evaluate the safety and stability of shield tunnel lining under impact load. The coupling model of segment lining nonlinear cracking and joint bolt nonlinear cracking is used to study the cracking mechanics behavior of shield tunnel lining under impact load and the dynamic response of bolt joint. The main research results are as follows: (1) the crack models commonly used in crack analysis of concrete are expounded, and the characteristics and applicable scope of various crack models are compared, and the crack model based on the extended finite element method is selected to study the dynamic crack propagation. The basic theory of extended finite element method (EFEM) is expounded, the element numerical integration scheme of EFEM is given, and the application of EFEM in ABAQUS is introduced. The initial criterion and expansion criterion of crack are analyzed. (2) the characteristic curve of train impact load is obtained by establishing 3D train model, and the empirical formula of Gao Si multi-peak fitting is put forward, and the cracking model of single-layer segment lining is established. The propagation path of dynamic crack is captured, the producing region, propagation time and length of crack are studied, the distribution characteristics of crack opening time history are analyzed, and the relationship between segment joint, impact position and crack development is revealed. The dynamic response characteristics of toroidal bending bolts and longitudinal straight bolts are compared and analyzed. (3) by establishing a double-layer shield tunnel model, the cracking evolution and opening time history curve of secondary lining under impact load are studied. The cracking mechanics behavior of shield tunnel segment lining and the dynamic response of joint bolt are compared and analyzed. The protective effect of secondary lining on segment lining and its role in limiting the cracking of segment lining under impact load are revealed. (4) based on the cracking model of single-layer segment lining, nonlinear cracking of joint bolts is applied. The crack evolution and opening time history curve of joint bolt are studied. The cracking mechanical behavior of shield tunnel segment lining under two forms of unintroduced bolt crack and lead bolt crack is compared and analyzed. The effect of bolt cracking on dynamic cracking of segment lining is revealed.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U458;U451.4

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