水平层状围岩隧道优化爆破方案研究

发布时间：2018-04-14 19:14

本文选题：隧道 + 层状围岩　；参考：《重庆交通大学》2014年硕士论文

【摘要】：在公路、铁路隧道穿越山区地形时，时常遇到各种复杂的工程地质环境，尤其是当隧道穿越层状围岩时，隧道爆破后开挖轮廓线易形成矩形形状，同时出现不同程度的掉块，甚至产生坍塌等不利施工因素，这使得实际开挖轮廓线与设计开挖轮廓线有很大偏差。研究获得最优的爆破参数，使得层状软弱围岩地质条件隧道的实际开挖轮廓线与设计开挖轮廓线相符合，尽可能地减少超欠挖。隧道开挖爆破后的稳定性主要取决于岩体内不同地质结构的性质、空间变化以及开挖爆破过程中爆破作用对该地质结构的影响程度。研究分析爆破冲击动力作用对层状围岩隧道稳定的影响，有助于提高层状软弱围岩地质条件下隧道爆破施工技术与安全性。尤其是当隧道穿越软弱夹层时，穿过软弱夹层的炮孔对爆破后隧道设计轮廓线与隧道稳定性影响更为显著。因此，研究爆破冲击动力作用下对层状围岩隧道设计轮廓线与隧道围岩稳定性是一个亟待解决的新课题，也是岩石力学和爆破工程所关注的重点课题。本文通过爆炸与冲击动力学理论分析，对隧道穿越层状软弱围岩地质条件进行爆破参数优化。应用流体动力学和气液两相流动理论，分析隧道穿越层状围岩爆破过程中软弱夹层的移动，建立爆破过程中软弱夹层的运动力学分析模型。利用ANSYS/LS—DYNA3D有限元动力分析程序进行数值模拟，研究层状软弱围岩地质条件下不同布孔、不同装药量、药柱长度与直径之比对隧道开挖轮廓线影响。通过对层状围岩隧道爆破荷载作用下的层状围岩破坏研究，提出合理的层状围岩隧道优化爆破方案，通过数值模拟计算分析得到以下成果： 1.本文进行了层状围岩隧道爆破方案的优化设计，提出了层状围岩隧道爆破采用半管爆破技术或者在炮孔中装电子雷管相结合。 2．本文进行了层状围岩隧道五种优化爆破方案计算，，分析比较五种优化爆破方案在爆破后的塑性区与受力情况，得到了层状围岩隧道优化爆破的最佳方案。 3.分析比较五种优化爆破方案，可采用按最佳方案将布设炮孔、装药量以及半管爆破技术或者在炮孔中装电子雷管相结合，这种思想可推广到类似地层状围岩隧道爆破开挖过程。
[Abstract]:When the highway and railway tunnels pass through the mountainous terrain, they often encounter a variety of complex engineering geological environments, especially when the tunnel passes through the layered surrounding rock, the excavation contour of the tunnel is easy to form a rectangular shape after blasting, and at the same time, there are different degrees of falling blocks.Even some unfavorable construction factors, such as collapse, make the actual excavation contour deviate greatly from the design one.The optimal blasting parameters are obtained, which make the actual excavation contour of the tunnel under the geological conditions of layered soft rock consistent with the design of the excavation contour, and reduce the over-excavation as much as possible.The stability of the tunnel after blasting mainly depends on the properties of different geological structures in the rock, the spatial variation and the influence of blasting action on the geological structure during excavation and blasting.The influence of blasting impact force on the stability of layered surrounding rock tunnel is studied and analyzed, which is helpful to improve the construction technology and safety of tunnel blasting under the geological conditions of layered weak surrounding rock.Especially when the tunnel passes through the weak intercalation, the hole passing through the weak interlayer has a more significant effect on the tunnel design profile and tunnel stability after blasting.Therefore, it is a new task to study the design contour of layered surrounding rock tunnel and the stability of tunnel surrounding rock under the action of blasting impact force, and it is also the focus of attention in rock mechanics and blasting engineering.Based on the theoretical analysis of explosion and impact dynamics, the blasting parameters are optimized for the geological conditions of tunnel crossing soft rock.Based on the theory of hydrodynamics and gas-liquid two-phase flow, the movement of weak interlayer during tunnel blasting through layered surrounding rock is analyzed, and the kinematic mechanics analysis model of weak interlayer during blasting is established.By using the ANSYS/LS-DYNA3D finite element dynamic analysis program, the influence of different hole placement, different charge quantity and the ratio of the length and diameter of the charge column to the diameter of the tunnel excavation contour under the geological conditions of the layered soft surrounding rock is studied.By studying the failure of layered surrounding rock under blasting load of layered surrounding rock tunnel, a reasonable optimal blasting scheme for layered surrounding rock tunnel is put forward. The following results are obtained by numerical simulation and analysis:1.In this paper, the optimal design of the blasting scheme for layered surrounding rock tunnel is carried out, and the combination of half-tube blasting technique and electronic detonator installation in the blasting hole is put forward.2.In this paper, five optimal blasting schemes for layered surrounding rock tunnel are calculated. The plastic zone and stress of the five optimized blasting schemes after blasting are analyzed and compared, and the optimal blasting scheme for layered surrounding rock tunnel is obtained.3.By analyzing and comparing five kinds of optimal blasting schemes, we can combine the layout of blasting holes, charge quantity and half tube blasting technology or the installation of electronic detonators in the holes according to the best scheme. This idea can be extended to the blasting excavation process of similar layered surrounding rock tunnels.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.6

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