【作者】 冯科；

【导师】 周晓军；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2013， 硕士

【摘要】 近年来,国家对西部地区的投入越来越大,西部经济也在飞速发展之中。然而,西部地区落后的交通状况也渐渐制约着其经济的进一步提升。要解决这个问题,势必要修建越来越多的铁路和公路交通。但是,在山岭重丘地形的西部地区修建交通线路将面临更多的山区自然灾害,高陡地形下危岩落石便是其中之一。棚洞作为防御危岩落石灾害的一种有效措施,正在发挥着越来越重要的作用,它的应用范围也在不断地扩展。面对复杂多变的地形地势,如何选择最适合实际工程的棚洞形式也是目前的研究重点。在已有的关于落石与棚洞的研究成果上,本文总结归纳了落石的定义、落石的产生因素,以及落石在发生后运动轨迹的理论推导公式。通过公式可算出落石的移运距离,再结合现有的5种落石冲击力计算的方法,可以从理论上得到隧道洞口段棚洞的需求尺寸及抗冲击强度。本文结合实际工程背景,通过理论计算和数值模拟,分析了山岭隧道洞口段不同形式的棚洞在不同荷载条件下的荷载响应。通过对比结构位移和应力分布情况来分析结构的合理性,最终认为拱墙形棚洞具有良好的承载效果。同时,考虑到棚洞自身通风照明效果,认为可在棚洞形式上进一步优化。从数值模拟的结果来看,在一定的荷载条件下,边墙位置设置合适开口的拱墙棚洞与封闭拱墙棚洞在承载能力上区别很小,开口棚洞完全可以替代封闭棚洞,同时具有更好的经济性。本文还对确定的棚洞结构进行了地震安全性分析,认为该棚洞在汶川地震中能够处于较安全状态。更多还原

【Abstract】 In recent years, our country has providing more and more investment’in the western region, results in a rapid development within this region. But the poor traffic conditions has gradually restricted its further increase. To solve this problem, it’s nessesary to build more and more traffic routes, like railway and highway. And then, the natural disasters which the newly builded roads would encounted should be considered in western region as there lots of mountain and heavy hill terrain in it. One of them is rock-fall form unstable rocks in high and steep terrain. As a effective measures to defense disasters caused by rock-fall, shed-tunnel is playing an increasingly important role, and its application is in constant expansion. Under a condition of the complex terrain, how to choose the most suitable form of shed-tunnel for the actual project is a focus of current research.Referencing to the existing research focused in rock-fall and shed-tunnel, this thesis review the definition and causes of rock-fall, and the theoretical formula about the trajectory of rock-fall after being produced. The displacement of the rock-fall could be figured out using those formulas, and coupled with the five existing methods to calculate the impacting force of rock-fall, we can get the theoretically size of shed-tunnel and its strength to resist impact.Considering the background of actual engineering, this thesis analyzes the response of shed-tunnel those have different forms under different load conditions by theoretical calculation and numerical simulation. After comparing the structural displacement and stress distribution during the rationality analysis of the structure, the result show that the arch-wall shed-tunnel has the best loading effect. At last, when considering the ventilation and lighting, there are some further optimization of arch-wall shed-tunnel. Judging from the results of numerical simulation, under a certain load, the shed-tunnel loading capacity just has a little distinction when using porous or imporous arch-wall. The conclusion is that we should choose the porous arch-wall shed-tunnel to completely replace the traditional ones, which has good loading capacity and better economical efficiency at the same time.In addition, this paper also have analysis the safety of shed-tunnel when it is in the earthquake. The results show that this shed-tunnel could keep a safe condition in Wen chuan earthquake.更多还原