地裂缝对高速铁路桥梁影响的模型试验研究

发布时间：2019-03-07 21:33

【摘要】：地裂缝这一地质灾害已严重的威胁到我国高速铁路的建设。本文背景为拟建的贯穿山西南北，连接陕西西安的大西客运专线。该线将穿越以典型活断裂和地裂缝发育的“汾渭地堑系”，会严重威胁大西高铁的建设。而我国目前对关于高铁桥梁跨越地裂缝所受影响方面的研究少之又少。因此，本文对高铁桥梁跨越地裂缝的影响机理研究不仅具有十分重要的理论研究意义，而且为工程的安全施工带来极为重要的参考依据。本文首先对大西高铁沿线的区域地质情况进行了简要的描述；然后以水秀地裂缝为地裂缝原型，通过比例尺为1：20的物理模型试验对高速铁路桥梁45°角度斜交穿越地裂缝带时桥梁受力变形特征、破坏模式以及影响范围进行研究；最后，通过有限元软件MIDAS/GTS对高速铁路桥梁45°角度斜穿地裂缝进行数值模拟计算，所得结果与物理模型试验相对比，并提出对高铁桥梁跨越地裂缝带减灾措施方面的建议。模型试验的结果和数值模拟的辅助结果可在设计及施工安全方面为大西高铁的顺利建成通车提供有力的科学理论依据。本文研究得到的主要结论有：（1）地裂缝带主要对跨越其的高铁桥梁结构产生影响，，主要应变部位为箱梁和轨道，而对于钢筋混凝土桩、承台、桥墩则影响不大；（2）桥梁模型破坏范围为上盘113cm，下盘82cm，影响范围为上盘147cm，下盘82cm，设防范围为229cm；（3）本试验桥梁跨度是可行的并可以通过优化钢筋混凝土桩、加大承台和桥墩尺寸、加强桥梁结构防落梁设计达到为桥梁结构减灾效果，通过改善混凝土配比等措施抵御不可抗力的地质灾害；（4）建立监测预警系统来长期观测桥梁变形，以及时应对地裂缝活动所带来的影响。
[Abstract]:Ground fissures, a geological hazard, have seriously threatened the construction of high-speed railway in China. The background of this paper is the planned Daxi passenger dedicated line running through the north and south of Shanxi and connecting Xi'an, Shaanxi Province. This line will traverse the "Fen-Wei graben system" developed by typical live faults and ground fissures, which will seriously threaten the construction of the Daxi high-speed railway. At present, there is little research on the influence of high-speed railway bridge crossing ground crack in our country. Therefore, this paper not only has a very important theoretical significance to study the influence mechanism of high-speed railway bridge crossing ground cracks, but also has a very important reference for the safety construction of the project. Firstly, this paper gives a brief description of the regional geological conditions along the Daxi high-speed railway. Then, taking Shuixiu ground fissures as the prototype of ground fissures, the mechanical deformation characteristics, failure mode and influence range of high-speed railway bridges crossing the ground fracture zone at 45 掳angle are studied by physical model test at 1:20 scale. Finally, the finite element software MIDAS/GTS is used to simulate and calculate the 45 掳angle cross-ground cracks of high-speed railway bridges. The results are compared with the physical model tests, and some suggestions are put forward for the disaster reduction measures of high-speed railway bridges crossing the ground fracture zone. The results of the model test and the auxiliary results of the numerical simulation can provide a powerful theoretical basis for the successful completion of the Daxi high-speed railway in terms of design and construction safety. The main conclusions obtained in this paper are as follows: (1) the ground crack zone mainly affects the structure of the high-speed railway bridge crossing it, the main strain position is box girder and track, but for reinforced concrete pile, cap, pier has little effect; (2) the damage range of bridge model is 113 cm in the upper disk, 82 cm in the lower disk, 147 cm in the upper disk, 82 cm in the lower disk, and 229 cm in the defensive range. (3) the span of the bridge in this experiment is feasible and can be reduced by optimizing the reinforced concrete pile, increasing the size of cap and pier, and strengthening the design of anti-fall beam of bridge structure. Through improving the proportion of concrete and other measures to resist the geological disasters of force majeure; (4) establish monitoring and early warning system to observe long-term bridge deformation in order to deal with the influence of ground fissures in time.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.13;U446

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