钻爆施工小间距隧道稳定性研究及控制

发布时间：2018-04-01 19:23

本文选题：小间距隧道　切入点：爆破施工　出处：《北京交通大学》2014年硕士论文

【摘要】：随着交通基础建设的飞速发展,铁路复线隧道、城市双线隧道、在既有隧道附近以及中间开挖新隧道等工程的不断涌现,出现了许多小间距隧道。目前,由于山岭隧道本身的环境特点,钻爆法仍然是其最主要的施工方法。在小间距隧道施工过程中,爆破开挖会不可避免地对邻近隧道围岩和支护结构的稳定性造成巨大损害。因此,研究和控制爆破对小间距隧道围岩和衬砌稳定性的不利影响成为隧道工程和爆破工程亟待解决的重点和难点问题。本文运用岩土弹塑性力学理论分析了小间距隧道的受力机理,运用岩石爆破力学的分析方法推导了小间距隧道爆炸应力波的传播方程和隧道边墙的运动方程,并以北京怀柔区头道穴小间距隧道为工程背景,在收集和分析了大量爆破监测数据的基础上,利用ANSYS有限元软件建立实际工程的三维有限元模型,运用瞬态动力分析方法对爆破荷载作用下的小间距隧道动力响应进行分析,主要取得的研究成果如下： (1)通过现场监测数据与数值模拟结果的对比,验证了有限元模型参数取值的正确性,并通过对有限元模型动力响应结果的分析,得到了先行隧道衬砌的位移、振动速度以及应力的变化规律,发现了隧道拱脚处和轮廓不连续处易出现应力集中,确定了先行隧道的迎爆侧边墙和中岩柱位置是小间距隧道爆破作用下的薄弱部位,应对此处进行重点监测和保护； (2)通过对比分析不同工序下先行隧道衬砌的振动速度、位移和应力的动力响应结果,验证了先行隧道预留迎爆侧下台阶土体对减小隧道最大振速的良好效果,提出了有利于小间距隧道减震隔震的开挖工序。
[Abstract]:With the rapid development of traffic infrastructure, there are many small spacing tunnels in railway double-track tunnels, urban double-track tunnels, excavation of new tunnels in the vicinity of existing tunnels and in the middle, and so on.At present, because of the environmental characteristics of mountain tunnel itself, drilling and blasting method is still the most important construction method.In the process of small spacing tunnel construction, blasting excavation will inevitably cause great damage to the stability of surrounding rock and supporting structure of adjacent tunnel.Therefore, to study and control the adverse effects of blasting on the surrounding rock and lining stability of small spacing tunnels has become an important and difficult problem to be solved urgently in tunnel engineering and blasting engineering.In this paper, the stress mechanism of small spacing tunnel is analyzed by using the theory of geotechnical elastic-plastic mechanics, and the propagation equation of explosion stress wave and the motion equation of side wall of tunnel are derived by the method of rock blasting mechanics.On the basis of collecting and analyzing a large number of blasting monitoring data, the 3D finite element model of practical engineering is established by using ANSYS finite element software, taking the small spacing tunnel of Tou Dao Cave in Huairou District, Beijing as the engineering background.The transient dynamic analysis method is used to analyze the dynamic response of small spacing tunnels under blasting load. The main research results are as follows:1) through the comparison between the field monitoring data and the numerical simulation results, the correctness of the parameters of the finite element model is verified, and the displacement of the tunnel lining is obtained through the analysis of the dynamic response results of the finite element model.The variation law of vibration velocity and stress shows that stress concentration is easy to occur at the arch foot and discontinuous contour of the tunnel, and the position of the side wall and the middle rock column of the first tunnel is the weak part under the blasting action of the small spacing tunnel.Priority monitoring and protection should be carried out here;2) by comparing and analyzing the dynamic response results of vibration velocity, displacement and stress of tunnel lining under different working procedures, it is proved that the soil of the lower step of the reserved blasting side of the advance tunnel can reduce the maximum vibration velocity of the tunnel.The excavation procedure is put forward which is beneficial to the isolation of small spacing tunnels.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.41;U452.1

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