武都西隧道地下水渗流分析与涌水控制措施研究

发布时间：2018-10-14 12:27

【摘要】：涌水灾害是隧道修建过程中备受关注的问题之一，近年来，随着隧道设计水平、施工技术和机械设备的不断提高和更新，大量长大深埋越岭隧道修建在重峦叠嶂、交通极不发达的西部地区，水灾给隧道施工和运营造成极大的安全隐患和巨大的经济损失，使得这一问题变得尤为突出和迫切需要解决。本文以成武高速武都西隧道为依托，针对涌水问题采用理论研究与分析、现场监测、现场试验、数值模拟相结合的方法综合研究，提出隧道涌水的主要因素是围岩裂隙连通性好、隧道修建在常年地下水位以下、含水围岩富水性好、地表水和地下水水文网发达、隧道埋深大以及山体植被覆盖稀少；运用四种方法预测隧道涌水量，得出地下水动力学法预测结果最接近实际涌水量；应用MIDAS-GTS数值软件分析计算隧道孔隙水压力、渗流速度及开挖后和注浆后应力、位移与渗流量的变化，注浆后岩体的渗流速度比开挖后减小了两个数量级，应力场分析表明，注浆后隧道围岩应力状态有了质的改善，径向的最小主应力在隧道开挖时最小，注浆后明显增大；切向最大主应力相反，毛洞开挖时最大，注浆后减小，支护后的应力最小。这是由于隧道注浆之后，很好的改善了岩体的工程特性，提高了其抵抗变形的能力，，降低了围岩应力释放。评价了注浆圈参数与渗流速度的关系并运用软件计算渗流量，采用参数厚度为5m、渗透系数为0.00232m/d的注浆圈时，不但能有效的控制渗流量，而且对于注浆材料和施工技术的要求也不高，较为经济合理；最后分析和提出了隧道防排水措施，武都西隧道采用超前帷幕注浆、初期支护、径向注浆、局部注浆、防水板、混凝土衬砌、中央排水管以及排水设施等控制措施，对隧道涌水、淋水、渗漏水和裂隙水综合治理，达到了预期的治理效果，整个隧道实现了不渗不漏，为今后类似地质条件的涌水隧道提供参考。
[Abstract]:Water gushing disaster is one of the most important problems in tunnel construction. In recent years, with the improvement and renewal of tunnel design level, construction technology and mechanical equipment, a large number of long and deep buried tunnels are built in the mountains. In the western region of underdeveloped traffic, the flood caused great safety hidden trouble and huge economic loss to tunnel construction and operation, which made this problem especially outstanding and urgent to be solved. Based on the Chengwu High Speed Wudu West Tunnel, this paper adopts the method of combining theoretical research and analysis, field monitoring, field test and numerical simulation to study the water gushing problem. It is pointed out that the main factors of tunnel water gushing are the good connectivity of surrounding rock fissure, the construction of tunnel below the perennial groundwater level, the good water content of water-bearing surrounding rock, the developed hydrological network of surface water and groundwater, the large buried depth of tunnel and the rare vegetation cover of mountain body. Four methods were used to predict tunnel water inflow, and the results of groundwater dynamics method were obtained to be the closest to actual water inflow, and the pore water pressure, seepage velocity and stress after excavation and grouting were calculated by MIDAS-GTS numerical software. With the change of displacement and seepage flow, the seepage velocity of rock mass after grouting is reduced by two orders of magnitude than that after excavation. The stress field analysis shows that the stress state of surrounding rock is improved qualitatively after grouting, and the radial minimum principal stress is minimized in tunnel excavation. The maximum principal stress in tangential direction is opposite to that after grouting, the maximum stress after excavation is maximum, the stress after grouting decreases, and the stress after support is the smallest. This is because after grouting, the engineering characteristics of rock mass are improved, the ability of resisting deformation is improved, and the stress release of surrounding rock is reduced. The relationship between grouting ring parameters and seepage velocity is evaluated, and the seepage flow is calculated by software. When the grouting ring with parameter thickness of 5 m and permeability coefficient of 0.00232m/d is used, the seepage flow can be controlled effectively. And the requirements for grouting materials and construction technology are not high, more economical and reasonable. Finally, the tunnel waterproof and drainage measures are analyzed and put forward. Wudu West Tunnel adopts advanced curtain grouting, initial support, radial grouting, partial grouting, waterproof board, Control measures such as concrete lining, central drainage pipe and drainage facilities, comprehensive treatment of tunnel gushing, sprinkling, leakage and fissure water have achieved the expected treatment effect, and the whole tunnel has achieved no seepage and leakage. It provides a reference for the water gushing tunnel with similar geological conditions in the future.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U453.6

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