明挖深基坑下卧多层隧道施工关键技术研究

发布时间：2018-01-08 12:12

本文关键词：明挖深基坑下卧多层隧道施工关键技术研究　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着城市化进程的飞速发展,城市综合交通枢纽换乘向立体换乘方向发展已成为大趋势。城市枢纽工程因条件限制,很多地段无法明挖或全明挖,以及为避免深大基坑,形成地下立体结构体。随着城市轨道交通的发展,大量的上跨下穿区间隧道成为必然。目前对于这种多层上跨下穿区间隧道施工可借鉴的经验较少,因此展开明挖深基坑下卧多层隧道施工关键技术研究对我国的城市化建设有重要的意义。本文以重庆沙坪坝交通枢纽综合改造工程为依托,展开了以下研究:1、基于位移判定准则对基坑与下卧隧道和下卧隧道与底部交叉隧道两种近接形式进行影响分区划分,考虑多层隧道的交叠作用,提出了多层隧道交叠影响分区计算方法,并验证了计算方法的适用性。2、基于强度折减法得到了基坑下卧近接隧道围岩破坏模式,提出了下卧浅埋隧道荷载计算方法,并根据底部交叉隧道地质特点,给出了底部交叉隧道荷载计算方法。3、分别对基坑下卧单层隧道和下卧两层隧道进行了施工时序、施工工法和开挖步距比选,综合比较了地表沉降、中夹岩应力、支护结构应力和位移等指标,给出了合理的施工时序、施工工法和开挖步距建议。4、研究了机械开挖和爆破开挖单洞围岩松动圈分布规律,探明了爆破对水平平行和上下重叠隧道中岩柱(岩板)的影响,并给出了爆破开挖中岩柱(岩板)安全控制标准和加固措施。
[Abstract]:With the rapid development of urbanization, it has become a major trend that urban comprehensive transportation hub transfer to three-dimensional transfer direction. Due to the constraints of urban hub engineering, many areas can not be excavated or fully excavated. And in order to avoid deep and large foundation pit and form underground three-dimensional structure, with the development of urban rail transit. A large number of upper span and lower cross interval tunnels become inevitable. At present, there is less experience for the construction of this multi-story upper span and lower span interval tunnel. Therefore, it is of great significance to carry out the research on the key technology of underground multi-layer tunnel construction in open excavation deep foundation pit. This paper relies on the comprehensive reconstruction project of Shapingba transportation hub in Chongqing. The following research is carried out: 1. Based on the displacement criterion, the paper divides the near connection between foundation pit and underside tunnel and bottom cross tunnel, and considers the overlapping effect of multi-layer tunnel. The method of multi-layer tunnel overlapping influence zoning is proposed and the applicability of the calculation method is verified. Based on the strength reduction method, the failure mode of surrounding rock of adjacent tunnel under foundation pit is obtained. In this paper, a method for calculating the load of a shallow buried tunnel is put forward, and a method of calculating the load of a cross tunnel at the bottom of the tunnel is given according to the geological characteristics of the cross tunnel at the bottom. The construction sequence, construction method and excavation step distance of single-layer tunnel and two-story tunnel are compared, and the indexes of ground subsidence, mid-rock stress, support structure stress and displacement are compared. The reasonable construction time sequence, construction method and excavation step distance suggestion. 4 are given, and the distribution law of loose zone of surrounding rock in mechanical excavation and blasting excavation is studied. The effect of blasting on rock column (rock slab) in horizontal parallel and upper and lower superimposed tunnels is investigated, and the safety control standard and reinforcement measures of rock column (slab) in blasting excavation are given.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.4

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