第三系富水粉细砂地层大断面隧道综合施工技术研究

发布时间：2018-09-11 10:24

【摘要】：依托在建的兰渝铁路桃树坪隧道,研究大断面客专隧道穿越第三系富水粉细砂层综合施工技术,解决隧道施工中存在降水和施工稳定性问题,主要完成的工作及取得的研究成果如下:(1)通过对桃树坪隧道水文地质条件的分析,初步确定了隧道施工中可采用的降水措施;通过现场的施工实践,最终采用真空轻型井点降水、深井降水、超前降水互相结合的综合降水方案,实现了富水粉细砂地层的有效降水,为隧道的开挖创造了有利的施工环境。(2)根据桃树坪隧道的地质情况,结合大断面隧道的施工方法,初步确定了交叉中隔壁法、双导洞超前法和双立柱工法三种施工方案。(3)采用数值模拟对三种工法的施工过程进行施工分析,对比研究的不同工法施工中围岩位移变化、应力变化以及支护结构受力和变形特性的变化。数值分析表明,双导洞超前法开挖产生的拱顶沉降远小于CRD法和双立柱法产生的拱顶沉降,双导洞超前法产生的拱顶沉降是CRD法产生沉降的58%,是双立柱工法产生沉降的73%。基于数值模拟分析,确定了双洞超前法为最佳的施工方案。(4)跟踪隧道的施工,选取典型断面进行隧道施工动态响应的监测;现场监测数据分析表明,采用的双导洞超前工法对于围岩的稳定性有较好的效果,能很好的适应富水粉细砂地层的施工。
[Abstract]:Based on the Taoshuping tunnel of the Lanzhou-Chongqing railway, this paper studies the comprehensive construction technology of the large-section tunnel through the Tertiary water-rich silty sand layer, and solves the problems of precipitation and construction stability in the tunnel construction. The main work and research results are as follows: (1) through the analysis of the hydrogeological conditions of Taoshuping Tunnel, the paper preliminarily determines the precipitation measures that can be used in the tunnel construction, and through the field construction practice, Finally, the effective precipitation of water-rich silty sand formation is realized by adopting the integrated precipitation scheme of vacuum light well point precipitation, deep well precipitation and advanced precipitation. It creates a favorable construction environment for tunnel excavation. (2) according to the geological conditions of Taoshuping tunnel and the construction method of large section tunnel, the method of crossing middle and next door is preliminarily determined. (3) the construction process of the three construction methods is analyzed by numerical simulation, and the displacement changes of surrounding rock in different construction methods are compared and studied. Stress change and the change of stress and deformation characteristics of supporting structure. Numerical analysis shows that the dome settlement produced by the double guide tunnel advance method is much smaller than that by the CRD method and the double column method, and the double guide tunnel advance method is the 58 settlement produced by the CRD method and the 73th settlement produced by the double column construction method. Based on the numerical simulation analysis, the two-hole advance method is determined as the best construction plan. (4) track the tunnel construction, select the typical section to monitor the dynamic response of the tunnel construction, the field monitoring data analysis shows that, The double guide tunnel advance method has a good effect on the stability of surrounding rock and can adapt well to the construction of water-rich silty sand strata.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.4

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