高陡边坡落石作用对隧道棚洞的动力响应及抗冲击研究
发布时间：2019-02-14 08:47
【摘要】：成兰铁路是目前国内铁路建设史上线路穿越地质条件最为复杂的铁路,其穿越龙门山区和岷江上游的高山深谷区,沿线地形海拔高差达4000m,越岭段隧道比例占90%以上。其间遭遇落石灾害的挑战非常严峻。本文以此为背景,首先对典型的6座隧道洞口进行了调研,获取了这些洞口仰坡和落石的数据,计算得到了落石的冲击速度和影响范围。然后,在现场调研的基础上,利用动力有限元软件LS-DYNA对框架棚洞遭受落石冲击作用进行了模拟,主要包括：1框架棚洞在不同冲击能量下的动力响应；2轻质土相对于普通土的抗冲击性能研究；3框架棚洞的最优轻质土垫层厚度研究；在做了以上的工作之后,本文从结构形式出发提出了拱形棚洞的概念,并根据现场情况设计了拱形棚洞。同样,首先利用有限元软件LS-DYNA计算其在落石冲击下的力学量,并与框架棚洞进行对比研究。在对比研究的基础上,得到了拱形棚洞具有更加抗冲击的特性之后,设计了棚洞遭受落石冲击的室内模型试验,考虑了不同的工况,重点对拱圈各部分应变、冲击力、位移进行了监测,分析得到了各物理量的规律。最后对模型进行了破坏形态的研究,观察棚洞遭受损伤最严重的区域,为该结构在实际工程中的使用提供更加可靠的建议。最后结合数值模拟和模型试验的结果,给出拱形棚洞用于工程实际的相关指导意见。
[Abstract]:Chenglan Railway is the most complicated railway crossing geological conditions in the history of railway construction in China at present. It crosses the Longmen Mountain area and the high mountain and deep valley area of the upper reaches of Minjiang River. The elevation difference of topography along the railway line is up to 4000m, and the proportion of tunnel in Yueling section accounts for more than 90%. In the meantime, the challenge of falling stones is very serious. Based on this background, first of all, six typical tunnel openings are investigated, and the data of the slope and rock fall are obtained, and the impact velocity and influence range of the rock fall are calculated. Then, on the basis of field investigation, the dynamic finite element software LS-DYNA is used to simulate the rock falling impact of the frame shed tunnel. The main contents are as follows: 1 the dynamic response of the frame shed tunnel under different impact energy; (2) Research on impact resistance of light soil compared with ordinary soil, 3 study on optimum thickness of light soil cushion for frame shed tunnel; After doing the above work, this paper puts forward the concept of the arched shed cave from the structure form, and designs the arch shed cave according to the situation of the field. In the same way, the finite element software LS-DYNA is used to calculate the mechanical quantity under the impact of rock drop, and the results are compared with those of the frame shed tunnel. On the basis of comparative study, after obtaining that the arch shed tunnel has the characteristics of more shock resistance, the indoor model test of the shed tunnel subjected to rock fall impact is designed, considering different working conditions, focusing on the strain and impact force of each part of the arch ring. The displacement is monitored and the law of each physical quantity is obtained. Finally, the damage form of the model is studied, and the most damaged area of the shed hole is observed, which provides more reliable suggestions for the use of the structure in practical engineering. Finally, combined with the results of numerical simulation and model test, the relevant guidance of arch shed tunnel used in engineering practice is given.
【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】：U452
本文编号：2422047
[Abstract]:Chenglan Railway is the most complicated railway crossing geological conditions in the history of railway construction in China at present. It crosses the Longmen Mountain area and the high mountain and deep valley area of the upper reaches of Minjiang River. The elevation difference of topography along the railway line is up to 4000m, and the proportion of tunnel in Yueling section accounts for more than 90%. In the meantime, the challenge of falling stones is very serious. Based on this background, first of all, six typical tunnel openings are investigated, and the data of the slope and rock fall are obtained, and the impact velocity and influence range of the rock fall are calculated. Then, on the basis of field investigation, the dynamic finite element software LS-DYNA is used to simulate the rock falling impact of the frame shed tunnel. The main contents are as follows: 1 the dynamic response of the frame shed tunnel under different impact energy; (2) Research on impact resistance of light soil compared with ordinary soil, 3 study on optimum thickness of light soil cushion for frame shed tunnel; After doing the above work, this paper puts forward the concept of the arched shed cave from the structure form, and designs the arch shed cave according to the situation of the field. In the same way, the finite element software LS-DYNA is used to calculate the mechanical quantity under the impact of rock drop, and the results are compared with those of the frame shed tunnel. On the basis of comparative study, after obtaining that the arch shed tunnel has the characteristics of more shock resistance, the indoor model test of the shed tunnel subjected to rock fall impact is designed, considering different working conditions, focusing on the strain and impact force of each part of the arch ring. The displacement is monitored and the law of each physical quantity is obtained. Finally, the damage form of the model is studied, and the most damaged area of the shed hole is observed, which provides more reliable suggestions for the use of the structure in practical engineering. Finally, combined with the results of numerical simulation and model test, the relevant guidance of arch shed tunnel used in engineering practice is given.
【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】：U452
【参考文献】
相关期刊论文 前1条
1 杨其新，，关宝树;落石冲击力计算方法的试验研究[J];铁道学报;1996年01期
本文编号：2422047
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