富水分岔隧道涌水控制及施工问题研究

发布时间：2018-03-18 03:01

本文选题：分岔隧道　切入点：富水地区　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：分岔隧道因其在改善线型方面以及在一些特殊地形中具有其他隧道形式不可替代的作用而被广泛采用。已修建案例包括:沪蓉西高速公路隧道工程八字岭隧道;胶州湾海底隧道陆域接线段为满足主隧道与匝道的汇(分)流功能而设置大断面分岔形式;厦门市成功大道万石山隧道与既有钟鼓山隧道立体交叉;深圳地铁大一科区间预留2#接线隧道分岔段。因此,无论在中西部高山峡谷地段为节省桥梁工程投资还是立体换乘需要而修建的地铁车站、地下立交、城市快速路连接线工程均涉及分岔隧道。可以说我国已在分岔隧道建设方面积累了丰富的经验。但在已修建的分岔隧道中普遍存在施工方法单一、总体支护体系过强而局部位置又相对薄弱、已修筑衬砌产生大面积裂缝甚至漏水严重等问题。目前,我国的交通建设事业发展空间巨大,开展对分岔隧道修建技术的研究能够在拟建分岔隧道工程中避免已出现的问题,使分岔隧道在交通事业中发挥更大的作用。对富水隧道而言,在隧道开挖区域外一定范围注浆能够有效地封闭堵水,使加固圈范围内的围岩渗透系数降低,稳定性提高。因此,注浆堵水作为富水区隧道修建过程中防排水的重要措施之一,其注浆后的堵水效果及经济合理性具有重要的研究价值。本文依托深圳东部过境高速公路连接线工程,通过室内相似模型试验的手段对一定厚度情况下注浆圈渗透系数合理值进行研究,根据试验结果提出适用于本工程的注浆圈渗透系数。在此基础上,选取本工程谷对岭地区北线隧道分岔段,针对分岔隧道大断面段、连拱段、小净距段采用的施工工法及施工顺序进行流固耦合计算,得出适于工程隧道分岔段的合理施工工法与施工顺序。本文主要研究的内容及成果如下:(1)采用自主设计的围岩-注浆圈模拟装置,根据相似原理制备的围岩及注浆圈相似材料开展注浆圈合理渗透系数模型试验。试验通过测试一定厚度下不同渗透系数注浆圈对隧道涌水量的控制效果,在考虑经济性基础上得到注浆圈合理渗透系数。(2)基于流固耦合理论,选取本工程谷对岭地区北线隧道分岔段,针对大断面段采用的双侧壁导坑法与三台阶法、连拱段采用的三导洞法与无中导洞法、小净距段采用的台阶法与CD法进行建模计算。分别从位移、应力及孔隙水压力角度分析数值模拟结果,比选出大断面段、连拱段以及小净距段的优选工法。(3)建立隧道分岔段三维模型,考虑分岔段在不同开挖顺序下围岩的位移、应力、孔隙水压力以及塑性区变化情况。分别在大断面段、连拱段及小净距段选取监测断面对施工过程进行监测,对比两种施工工序,比选出优选施工顺序。
[Abstract]:Bifurcation tunnel is widely used because of its role in improving alignment and having irreplaceable role in other tunnel forms in some special terrain. Cases have been built, including: Baziling Tunnel of Hurongxi Expressway Tunnel Project; In order to meet the confluence (separation) function of main tunnel and ramp, a large section bifurcation form is set up in the land junction of Jiaozhou Bay Subsea Tunnel, and the intersection of Wanshi Mountain Tunnel and existing Zhonggu Mountain Tunnel in Xiamen City is also discussed. Therefore, no matter in the mountain canyons in the central and western regions of China, the subway station built to save investment in bridge construction or the need for three-dimensional transfer, the underground interchange is not only reserved for the branch section of Shenzhen Metro Line 1, but also reserved for the bifurcation section of the junction tunnel. Bifurcation tunnels are all involved in urban expressway connection projects. It can be said that our country has accumulated rich experience in the construction of bifurcation tunnels, but there is a single construction method in the bifurcation tunnels that have been built. The overall support system is too strong and the local position is relatively weak, and large area cracks and even serious water leakage have been produced in the built lining. At present, there is a huge space for the development of transportation construction in our country. The research on the construction technology of bifurcation tunnel can avoid the existing problems in the proposed bifurcation tunnel project, and make the bifurcation tunnel play a greater role in the traffic industry. Grouting in a certain range outside the tunnel excavation area can effectively seal water shutoff, reduce the permeability coefficient of surrounding rock and improve the stability of surrounding rock in the area of reinforcement circle. Therefore, grouting plugging is one of the important measures of water prevention and drainage in the construction of tunnel in water-rich area. The water shutoff effect and economic rationality after grouting have important research value. The reasonable value of permeability coefficient of grouting ring under certain thickness is studied by means of laboratory similar model test. Based on the test results, the permeability coefficient of grouting ring is put forward, which is suitable for this project. In this paper, the author selects the engineering valley for the bifurcation section of the north line tunnel in the mountain area, and carries on the fluid-solid coupling calculation for the large section section, the multi-arch section, the small net distance section of the bifurcation tunnel, the construction method and the construction sequence. The reasonable construction method and construction sequence suitable for the bifurcation section of engineering tunnel are obtained. The main contents and results of this paper are as follows: 1) the self-designed simulation device of surrounding rock and grouting ring is adopted. The model test of reasonable permeability coefficient of grouting ring is carried out based on the similar materials of surrounding rock and grouting ring prepared according to similarity principle. The control effect of grouting ring with different permeability coefficient on tunnel water discharge under certain thickness is tested. Based on the theory of fluid-solid coupling, this paper selects the diversion section of the north line tunnel in the north line of the mountain area in this project, aiming at the double-side wall tunnel method and the three-stage method used in the large section section, and obtains the reasonable permeability coefficient of the grouting ring on the basis of considering the economy. The numerical simulation results are analyzed from the angles of displacement, stress and pore water pressure, respectively, and the results of numerical simulation are compared with the selection of large section, from the angle of displacement, stress and pore water pressure. Three dimensional model of tunnel bifurcation section is established, considering the displacement, stress, pore water pressure and plastic zone variation of surrounding rock in different excavation sequence of bifurcation section. The construction process is monitored by selecting the monitoring section of the multi-arch section and the small net distance section. Compared with the two construction procedures, the optimal construction sequence is chosen.
【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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