超前导坑再扩挖隧道施工方法研究
发布时间：2019-02-27 20:56
【摘要】：随着我国交通行业的快速发展,全国兴起了隧道建设的高潮,越来越多的大断面隧道相继涌现,加之全国各地的地铁轻轨建设也陆续上马,这些分布在城市中心的大断面隧道对于隧道施工过程中的围岩稳定和爆破振动提出了更高的要求。超前导坑再扩挖工法能够减少对未开挖围岩的扰动,维持围岩的稳定。同时超前导坑再扩挖工法以其在爆破减震方面的独特优势,日益被人们认识和接受。另外超前导坑再扩挖工法可以利用TBM机开挖先行导坑,再用钻爆法扩大至设计断面。由于TBM机的直径不依赖于隧道设计断面,所以可以比较好的解决TBM机的循环使用问题。由于对超前导坑再扩挖工法的研究还比较少,所以本文对于这种工法进行了研究,主要研究内容和研究成果如下:①详细介绍了超前导坑再扩挖工法国内外研究的现状和目前存在的问题,从而确定了本文研究的方向。②对超前导坑法的施工流程、优缺点以及施工过程中应该注意的事项进行了简要的阐述,然后从适用条件、工期、造价等方面将超前导坑再扩挖工法与其他施工方法进行对比,对超前导坑再扩挖工法特点进行了进一步阐述。③对于导坑开挖完成之后主隧道的扩挖问题,本文中提出了三种施工方案,并就四级和五级围岩条件下应用ANSYS程序对三种扩挖方案进行了模拟分析。对各工况隧道关键点的变形和应力进行了对比分析,提出了三种扩挖方案分别适用的围岩地质条件。④从理论和对试验数据的分析论证了导坑的作用:导坑为爆破作业提供了临空面,可以减小对未开挖岩体的扰动,起到减震的作用,同时可以减少隧道的炸药使用量。⑤与全断面爆破开挖相对比,利用ANSYS/LS-DYNA软件分别就超前导坑再扩挖工法炸药量降低10%、20%和30%三种情况研究了炸药量降低值与振动速度的关系,从而对工程实践提供理论指导。⑥针对某超前导坑法施作的隧道工程实例进行了数值模拟。
[Abstract]:With the rapid development of the transportation industry in China, the high tide of tunnel construction has sprung up throughout the country, and more large cross-section tunnels have emerged one after another. In addition, subway light rail construction in various parts of the country has also been launched one after another. These large section tunnels distributed in the center of the city put forward higher requirements for the stability of surrounding rock and blasting vibration in the course of tunnel construction. This method can reduce the disturbance to the unexcavated surrounding rock and maintain the stability of the surrounding rock. At the same time, it has been recognized and accepted by people day by day because of its unique advantage in blasting vibration reduction. In addition, the TBM machine can be used to excavate the pilot pit and then the drilling and blasting method can be extended to the design section. Because the diameter of TBM machine does not depend on the tunnel design section, it can solve the recycling problem of TBM machine. Because there is little research on the method of reexpanding and digging in advance guide pit, this paper has carried on the research to this kind of construction method. The main research contents and achievements are as follows: (1) the present situation and existing problems of the research on the method of leading-way pit re-expansion are introduced in detail, thus the research direction of this paper is determined. (2) the construction process of the lead-through pit method is introduced in detail. The advantages and disadvantages as well as the matters needing attention in the construction process are briefly expounded, and then the construction method of leading guide pit and other construction methods are compared with other construction methods from the aspects of applicable conditions, time limit, cost and so on. In this paper, three construction schemes are put forward for the expansion and excavation of the main tunnel after the completion of the excavation of the guide pit, and the characteristics of the reexpanding excavation method of the leading pit are further expounded in this paper. Three kinds of expansion and excavation schemes are simulated and analyzed by ANSYS program under the conditions of grade 4 and grade 5 surrounding rock. The deformation and stress of key points in tunnel under various working conditions are compared and analyzed. In this paper, three kinds of expansion and excavation schemes are put forward, which are applicable to the geological conditions of surrounding rock. 4. From the analysis of theoretical and experimental data, the function of the pilot pit is demonstrated: the pilot pit provides an empty surface for blasting operation, which can reduce the disturbance to the unexcavated rock mass. At the same time, it can reduce the use of explosives in the tunnel. 5 compared with the full-section blasting excavation, ANSYS/LS-DYNA software is used to reduce the explosive amount by 10% in the lead-through pit re-expansion excavation method, and the explosive amount of the tunnel is reduced by 10% in comparison with the full section blasting excavation. The relationship between the reduction value of explosive charge and vibration velocity is studied in three cases, 20% and 30%, thus providing theoretical guidance for engineering practice. 6 numerical simulation is carried out for a tunnel engineering example constructed by a preemptive tunnel pilot method.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.4
本文编号：2431571
[Abstract]:With the rapid development of the transportation industry in China, the high tide of tunnel construction has sprung up throughout the country, and more large cross-section tunnels have emerged one after another. In addition, subway light rail construction in various parts of the country has also been launched one after another. These large section tunnels distributed in the center of the city put forward higher requirements for the stability of surrounding rock and blasting vibration in the course of tunnel construction. This method can reduce the disturbance to the unexcavated surrounding rock and maintain the stability of the surrounding rock. At the same time, it has been recognized and accepted by people day by day because of its unique advantage in blasting vibration reduction. In addition, the TBM machine can be used to excavate the pilot pit and then the drilling and blasting method can be extended to the design section. Because the diameter of TBM machine does not depend on the tunnel design section, it can solve the recycling problem of TBM machine. Because there is little research on the method of reexpanding and digging in advance guide pit, this paper has carried on the research to this kind of construction method. The main research contents and achievements are as follows: (1) the present situation and existing problems of the research on the method of leading-way pit re-expansion are introduced in detail, thus the research direction of this paper is determined. (2) the construction process of the lead-through pit method is introduced in detail. The advantages and disadvantages as well as the matters needing attention in the construction process are briefly expounded, and then the construction method of leading guide pit and other construction methods are compared with other construction methods from the aspects of applicable conditions, time limit, cost and so on. In this paper, three construction schemes are put forward for the expansion and excavation of the main tunnel after the completion of the excavation of the guide pit, and the characteristics of the reexpanding excavation method of the leading pit are further expounded in this paper. Three kinds of expansion and excavation schemes are simulated and analyzed by ANSYS program under the conditions of grade 4 and grade 5 surrounding rock. The deformation and stress of key points in tunnel under various working conditions are compared and analyzed. In this paper, three kinds of expansion and excavation schemes are put forward, which are applicable to the geological conditions of surrounding rock. 4. From the analysis of theoretical and experimental data, the function of the pilot pit is demonstrated: the pilot pit provides an empty surface for blasting operation, which can reduce the disturbance to the unexcavated rock mass. At the same time, it can reduce the use of explosives in the tunnel. 5 compared with the full-section blasting excavation, ANSYS/LS-DYNA software is used to reduce the explosive amount by 10% in the lead-through pit re-expansion excavation method, and the explosive amount of the tunnel is reduced by 10% in comparison with the full section blasting excavation. The relationship between the reduction value of explosive charge and vibration velocity is studied in three cases, 20% and 30%, thus providing theoretical guidance for engineering practice. 6 numerical simulation is carried out for a tunnel engineering example constructed by a preemptive tunnel pilot method.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.4
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