华蓥山北部地下水系统及其对隧道涌水的影响研究

发布时间：2018-11-10 15:59

【摘要】：随着我国西部大开发战略的部署和实施,西部地区交通建设成为了重要的一环。华蓥山位于四川盆地东北部,是横亘于达州市西部的天堑,由于其特殊的地理位置,为南充、广安、达州三市的沟通交流增加了较大的难度,因此以隧道的方式穿越华蓥山北部地区最为直接便利。华蓥山北部地区的地层以三叠系和侏罗系为主,特别是三叠系中统雷口坡组和下统嘉陵江组地层以碳酸盐岩为主,从而造成岩溶现象非常发育,导致该区域地下水系统较为复杂多变。本文以华蓥山北部地区地质条件和南大梁高速公路华蓥山隧道涌水特征为基础,分析总结研究区内岩溶的发育特征、分布特征等,在水文地质的基础上分析该区内主要的渗流方式及其影响范围,结合该区内地下水渗流特征,分析华蓥山北部地区地下水系统对隧道涌水造成的影响,得出的主要结论如下:(1)研究区水文条件较为复杂,区域降水丰富,区域地形地貌形成良好的汇水空间,构造运动导致地层破碎,碳酸盐岩为岩溶发育提供基础,岩溶发育且成因多元,受构造、岩性、地形地貌等多种因素控制,各因素间也存在一定的关联,最终为地下水渗流提供了有利条件。(2)研究区的岩组含水类型可分为深埋藏型岩溶水、碳酸盐岩类的裂隙溶洞水及碎屑岩类孔隙裂隙水三种类型,而其中最主要的是碳酸盐岩类的裂隙溶洞水。其中,嘉陵江组和须家河组底部是区域富水性最好的岩组。研究区不同的可溶岩类的层序组合,使得其岩溶发育差异较大,大流量水点主要位于T2l和T1j的底部,形成集中排泄区。(3)研究区水文地质情况复杂,涌水组成也十分复杂,主要是由区域降水、溶洞水、地下暗河、碎屑岩类裂隙孔隙水等多种水体组成。地表径流、裂隙水、地下溶洞水、地下暗河及其他水体为隧道涌水的直接水源。(4)通过研究调查和数据分析,确定了研究区隧道涌水因素,包括区域降水、地表径流、地形地貌、地层岩性、地质构造等。采用正交法对隧道涌水因素进行了敏感性分析,确定了区域降水为影响隧道涌水最主要的因素。(5)运用Flow-3D流体模拟软件,对隧道开挖前后以及预期治理措施进行数值模拟,确定在隧道开挖前后地下水渗流的变化情况与程度,得出在研究区形成新的排泄基准面后,地下水渗流流量和流速均出现大幅度增加,进而引起隧道涌水量的增大。通过模拟在地表进行堵漏操作后地下水的渗流情况,确定在研究区进行地表堵漏是一种较为可行的方法。(6)根据研究区地下水系统特征及华蓥山隧道涌水特征,提出一些研究区隧道建设中的堵治水建议。
[Abstract]:With the deployment and implementation of the western development strategy, traffic construction in the western region has become an important part. Huaying Mountain is located in the northeast of Sichuan Basin. It is a natural graben in the western part of Dazhou City. Because of its special geographical location, it makes communication and exchange between Nanchong, Guangan, and Dazhou more difficult. Therefore, it is most convenient to tunnel through the northern part of Huaying Mountain. The strata in the northern Huayingshan area are dominated by Triassic and Jurassic, especially by carbonate rocks in the middle Triassic Leikoupo formation and the Lower Jialingjiang formation, resulting in the development of karst phenomena. The groundwater system in this area is complex and changeable. Based on the geological conditions in the northern part of Huaying Mountain and the characteristics of water gushing in Huayingshan Tunnel of Nandaliang Expressway, this paper analyzes and summarizes the characteristics of karst development and distribution in the study area. On the basis of hydrogeology, the main seepage modes and their influence range in this area are analyzed. Combined with the seepage characteristics of groundwater in this area, the influence of groundwater system on tunnel water inflow in the northern part of Huaying Mountain is analyzed. The main conclusions are as follows: (1) the hydrological conditions in the study area are relatively complex, the region is rich in precipitation, the regional topography and geomorphology form a good catchment space, the tectonic movement leads to formation fragmentation, and carbonate rocks provide the basis for karst development. Karst is developed and has multiple genesis, which is controlled by many factors, such as structure, lithology, topography and geomorphology. Finally, it provides favorable conditions for groundwater seepage. (2) the water bearing types of rock formation in the study area can be divided into three types: deep buried karst water, carbonate rock fissure cave water and clastic rock pore fissure water. Among them, the most important is the carbonate rock fissure cavern water. The bottom of Jialingjiang formation and Xujiahe formation is the best water-rich rock formation in the region. The sequence assemblages of different soluble rocks in the study area make the karst development different, and the large discharge water points are mainly located at the bottom of T2l and T1j, forming a concentrated drainage area. (3) the hydrogeological conditions and the water gushing composition in the study area are complex, too. It is mainly composed of regional precipitation, cave water, underground river, clastic rock fissure pore water and so on. Surface runoff, fissure water, underground cave water, underground river and other water bodies are the direct sources of tunnel water gushing. (4) through investigation and data analysis, the factors of tunnel water inflow in the study area are determined, including regional precipitation, surface runoff, etc. Landform, stratigraphic lithology, geological structure, etc. The sensitivity analysis of tunnel water gushing factors is carried out by orthogonal method, and the regional precipitation is determined as the most important factor affecting tunnel water inflow. (5) Flow-3D fluid simulation software is used. Numerical simulation is carried out on the tunnel before and after excavation as well as the expected treatment measures to determine the variation and extent of groundwater seepage before and after the tunnel excavation. After the formation of a new discharge datum level in the study area, The seepage flow and velocity of groundwater increase greatly, which leads to the increase of tunnel inflow. By simulating the seepage situation of groundwater after plugging operation on the surface of the earth's surface, it is determined that the method of surface plugging is a more feasible method in the study area. (6) according to the characteristics of groundwater system in the study area and the characteristics of water gushing in Huaying Mountain Tunnel, Some suggestions on water plugging in tunnel construction in the study area are put forward.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U453.61;P641.6

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