近水平红砂岩隧道钻爆法施工超欠挖控制技术研究

【作者】 黄金旺；

【导师】 阳军生； 周应麟；

【作者基本信息】 中南大学 ， 建筑与土木工程， 2010， 硕士

【摘要】 近水平层状围岩中进行钻爆施工,层间存在软弱夹层,光面爆破效果较差,难以形成设计要求的拱形轮廓,渣堆中大块率高,超、欠挖现象严重。本文采用理论分析、数值模拟、现场测试相结合的研究方法,对近水平层状围岩隧道钻爆法施工超欠挖控制问题进行系统研究,达到了控制工程超欠挖、节约生产成本、提高开采作业效率的目的。主要研究内容包括：(1)从层状岩体的三类结构面入手,研究了层状岩体的典型地质特征,分析了各种结构面对层状岩体工程性质的影响；在此基础上,对隧道层状岩体的变形破坏类型、破坏特征及破坏机理进行了探讨。(2)通过炸药破岩机理以及应力波通过节理、夹层传播规律来分析产生超欠挖现象的原因,研究发现节理、软弱夹层在很大程度上影响了爆炸应力波以及爆生气体对岩石的作用,使光面爆破抵抗线以及岩石裂纹扩展方向发生变化,从而产生不规整的爆破轮廓线。(3)基于光面爆破设计的基本原理,针对近水平层状红砂岩钻爆施工超欠挖控制中存在的主要问题,结合爆破开挖进行现场爆破测试,从而对爆破参数进行优化,逐步调整并最终提出不同围岩条件下炮眼布置图及其爆破设计参数,达到了合理控制超欠挖的目的。(4)对隧道围岩原爆破方案和改进的爆破方案的隧道围岩动力稳定性和地震动效应进行了分析和比较,研究表明改进的爆破方案减小了对隧道围岩的地震动效应和屈服区域,能够一定程度上控制超挖,具有较大的优越性和科学性。(5)归纳了超欠挖的危害、超欠挖的影响因素,并鉴于现场钻爆施工的方便性及可操作性,提出了从提高钻孔精度、控制装药参数、规范装.药结构和加强施工管理四方面来控制近水平层状红砂岩隧道的超欠挖。更多还原

【Abstract】 The effort of smooth blasting is bad when blasting in nearly horizontal layered rockmass with interlayer. It is difficult to formulate arch outline and big block rate is high while excessive and deficient excavate are universal. Using the combined research method of theory analysis, numerical simulation and field measurement, this paper have made a comprehensive study of the control technology of overbreak-underbreak in nearly horizontal layered rockmass. So it could reach the goal of controlling the overbreak, reducing the trial cost improving the eficient of underground excavation and so on. The contents of main research work include:(1) Based on three kinds of typical joints of layered rock masses, geologic features and structure effect on layered rock masses engineering are analyzed. Then failure types and failure mechanism of layered rock masses are further discussed.(2) This paper has analysis the reason of excessive and deficient excavate from the mechanism of rock blasting and the law of stress wave spreading through joint and interlayer. Research has proved that joint and weak interlayer has influenced the function of blasting on rock to a great extent which is caused by blasting stress wave and gas. The direction of resist ling of smooth blasting and rock crack expanding has changed. Therefore the unsmoothed outline is produced.(3) Based on the basic principle of smooth blasting design, according to the main problems in control of overbreak-underbreak for drilling and blasting in nearly horizontal layered rockmass, combined with on-site blasting test, then the parameters are optimized, and gradually adjust and eventually put forword blasting borehole layout and design parameters for different surrounding rocks, therefore, the overbreak-underbreak can be controlled reasonably.(4) The dynamic stability of surrounding rock and ground motion effects were analyzed and compared between original and improved blasting program, studies have shown improved program reduces shock effect and yield region in tunnel surrounding rock, can control overbreak-underbreak to a certain extent, so with great superiority and scientific.(5) This paper summed up the harm and the impact of overbreak-underbreak. In view of the the convenience and operability of field construction, we proposed four aspects to control the overbreak-underbreak of nearly horizontal layered red sandstone as follows:improve the accuracy of drilling, control charge parameters, standard charge structure and strengthen the construction management.更多还原