小净距隧道后行洞爆破开挖对先行洞初支的影响研究

发布时间：2018-03-22 23:04

本文选题：小净距隧道　切入点：先行洞　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：在交通运输领域中的高等级公路建设无疑是龙头性产业,同样也在改善人民生活质量中起着重要作用。在山区高等级公路建设中,由于地形和地质条件的限制条件较多,使得相邻近隧道间的净距在设计时不能满足规范的要求,因此小净距隧道应运而生。小净距隧道在爆破开挖时会产生能量波,引起爆破点的附近洞室产生巨大的振动,因此在小净距隧道的施工过程中,必须做好先行洞和后行洞的爆破设计和爆破振动监测,才能有效的保证施工的安全。本文以重庆市双碑隧道工程为依托,首先对现场隧道爆破振动监测数据进行分析,然后运用瞬态有限元分析软件MIDAS/GTS,建立双碑隧道工程的数值模拟模型,研究在不同工况条件下隧道后行洞爆破开挖时,隧道先行洞的初期支护结构动力响应规律,下列为具体研究的问题:①研究小净距隧道在不同埋置深度条件下,后行洞爆破开挖时,其先行洞初期支护结构振动速度变化规律,及各关键点的振动规律。②研究小净距隧道先行洞采用不同的支护形式时,后行洞爆破开挖引起的先行洞初期支护的速度和位移变化规律。③研究小净距隧道掌子面在不同纵向间距下,后行洞爆破对先行洞初期支护的影响,得到合理纵向间距与隧道开挖宽度之间的关系,为同类型的隧道爆破设计提供一定指导。④研究小净距隧道在不同围岩级别情况下,后行洞爆破对先行洞初期支护的影响,以及先行洞初期支护振速沿纵向方向的变化规律。
[Abstract]:The construction of high-grade highways in the field of transportation is undoubtedly a leading industry and also plays an important role in improving the quality of life of the people. In the construction of high-grade highways in mountainous areas, there are many restrictions due to the terrain and geological conditions. The net distance between adjacent tunnels can not meet the requirements of the specification in design, so the small net distance tunnel emerges as the times require. When the tunnel is excavated by blasting, it will produce energy wave, which will cause huge vibration in the nearby cavern of blasting point. Therefore, in the construction process of small clear distance tunnel, the blasting design and blasting vibration monitoring of first and rear tunnel must be done well in order to ensure the safety of construction effectively. Firstly, the monitoring data of blasting vibration in the field tunnel are analyzed, and then the numerical simulation model of double-tablet tunnel engineering is established by using the transient finite element analysis software Midas / GTS.When the tunnel is excavated after blasting under different working conditions, The dynamic response law of the initial supporting structure of the tunnel advance tunnel is as follows. The following is the specific research question: 1 to study the variation law of the vibration velocity of the supporting structure in the early stage of the tunnel under the condition of different buried depth of the tunnel with small net distance and when the tunnel is excavated by blasting. And the vibration law of each key point. 2. When the tunnel with small clear distance adopts different supporting forms, Study on the change of the velocity and displacement of the initial support of the first tunnel caused by the blasting excavation of the rear tunnel; the influence of the blasting on the initial support of the advance tunnel under the different longitudinal spacing of the face of the tunnel with small net distance. The relationship between the reasonable longitudinal spacing and the width of tunnel excavation is obtained, which provides certain guidance for the design of the same type of tunnel blasting. 4. The influence of the rear tunnel blasting on the initial support of the advance tunnel under different surrounding rock levels is studied. And the variation law of the initial supporting speed along the longitudinal direction.
【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】：U455.6

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