基于生态平衡的隧道地下水渗控方法及限排水标准研究

发布时间：2019-05-05 05:46

【摘要】：隧道埋设于地下,往往被地下水所包围,对地下水的控制尤为重要。过量排放地下水易造成地下水位下降,生态环境破坏等危害,而对于地下水位较高的隧道,全封堵地下水衬砌无法承受过大水压力,如何确定一个合理的既能保护生态环境免遭破坏又使衬砌承受合理水压的地下水排放量是一直未能很好解决的问题。为此,本文以地下水动力学理论为基础,对隧道围岩涌水量计算方法进行研究；在考虑渗透系数随深度非线性变化的基础上,对非均质各向同性围岩涌水量计算方法进行了分析,并考虑了注浆圈及衬砌的影响；引入生态学、农学中有关植被生态需水的概念,采用井流理论、面井法等方法对维持生态平衡条件下地下水的限排量计算方法及隧道的限排水标准进行研究。通过以上理论推导及实例分析,主要取得了如下研究成果： (1)采用地下水动力学中的井流理论,基于地下水运动的质量守恒、能量守恒定律,推导考虑流速的涌水量计算公式,并进一步得出了隧道施作注浆圈及衬砌后的涌水量计算公式。通过分析得出考虑流速涌水量小于不考虑流速情况下涌水量,但流速效应对涌水量影响不显著,而考虑流速的衬砌水压力则大于不考虑流速情况下衬砌水压力。通过参数分析得出能经济有效降低隧道涌水量的注浆圈渗透系数及厚度的范围值。分析了衬砌外水压力与地下水排放量大小之间的关系。 (2)考虑渗透系数随深度非线性变化,推导了非均质各向同性围岩涌水量计算公式,与已有计算方法结果较接近。通过分析得到考虑岩体渗透系数随深度非线性变化后涌水量的变化趋势及变化规律,所获成果可以对隧道的选址提供依据。得出考虑围岩渗透系数非线性变化情况下注浆堵水参数计算公式,由于渗透系数一般随隧道埋深增大而减小,在进行注浆堵水时应考虑到这种变化,以避免设计的注浆圈渗透系数大于围岩渗透系数而不能达到堵水的目的。 (3)从地下水平衡的角度出发,引入生态学、农学中植被生态需水的概念,控制地下水位最大降深在植被正常生长所允许范围内,推导出地下水降水漏斗体积计算公式,结合隧道围岩参数得出地下水总排放量,与降雨补给量进行比较,得到恢复隧址区原始地下水位所允许的排放量。对于运营期隧道,推导了隧址区地下水位动态变化反分析公式,通过对堵水限排隧道排水量的监测,结合隧道围岩与初衬渗透系数等参数,可反分析得出地下水位,为地下水位的实时监控提供依据。 (4)将井流理论中面井法引入到隧道地下水位降深计算中,得到隧道影响范围内任一点地下水位降深计算公式。提出了保持地下水平衡条件下地下水排放量确定方法。在考虑隧道双孔地下水位降深叠加的基础上得到分离式隧道限排量计算方法,对比分析了单孔隧道与分离式隧道限排量之间的关系。 (5)在保护生态及维持地下水平衡的前提下,选取常见的岩土层渗透系数、给水度及地下水头高度范围值,应用排水量与地下水位降深关系式提出了对于地下水可有效控制情况下满足大多常见山岭隧道的地下水限排标准。对于地下水无法有效控制的隧道,提出了限制排水量确定方法。
[Abstract]:The tunnel is buried in the ground, often surrounded by the ground water, and the control of the groundwater is particularly important. the overdischarge of the underground water is easy to cause the groundwater level to fall, the ecological environment is destroyed and the like, and for a tunnel with higher water table level, the full-plugging underground water lining can not bear the large water pressure, How to determine a reasonable groundwater discharge which can protect the ecological environment from the damage and the reasonable water pressure of the lining is a problem that has not been solved well. Based on the theory of groundwater dynamics, this paper studies the calculation method of the water inflow of the surrounding rock of the tunnel. Based on the nonlinear change of the permeability coefficient with the depth, the method of calculating the water inflow of the heterogeneous isotropic surrounding rock is studied. In this paper, the influence of the grouting ring and the lining is considered, the concept of the ecological water demand of the vegetation in the ecological and agricultural studies is introduced, and the method for calculating the limit displacement of the underground water under the condition of maintaining the ecological balance and the limit drainage standard of the tunnel are carried out by adopting the method of well flow theory and surface well method. Based on the above theory and the case analysis, the main results are as follows: Fruit: (1) Using the theory of well flow in the groundwater dynamics, based on the mass conservation and energy conservation law of the groundwater movement, the water inflow meter considering the flow velocity is derived. The formula is calculated and the water inflow meter after the tunnel is applied as the grouting ring and the lining is further obtained. The calculation formula is based on the analysis that the water inflow is less than that of the flow rate without considering the flow rate, but the effect of the flow rate effect on the water inflow is not significant, and the lining water pressure considering the flow rate is greater than that of the lining under the condition that the flow rate is not considered The water pressure is obtained through the analysis of the parameters, and the permeability coefficient and the thickness of the grouting ring which can effectively reduce the water inflow of the tunnel can be obtained through the analysis of the parameters. Range value. The relationship between the outer water pressure of the lining and the discharge of the groundwater is analyzed. (2) Considering the non-linear variation of the permeability coefficient with the depth, the calculation formula of the water inflow of the heterogeneous isotropic surrounding rock is derived, and the calculation method is compared with that of the existing calculation method. The result is close to that of the tunnel. Through the analysis, the trend and the rule of the water inflow after the non-linear change of the permeability coefficient of the rock mass with the depth are considered, and the results obtained can be used for the selection of the tunnel. The calculation formula of the grouting water-plugging parameter under the condition of non-linear change of the permeability coefficient of the surrounding rock is obtained. Because the permeability coefficient is generally reduced with the increase of the buried depth of the tunnel, it should be taken into account when the grouting is blocked. To this change, the permeability coefficient of the designed grouting ring is greater than the permeability coefficient of the surrounding rock and cannot be achieved. (3) From the viewpoint of the balance of groundwater, the concept of the ecological water demand of the vegetation in the ecology and the agriculture is introduced, the maximum depth of the water table is controlled to be within the allowable range of the normal growth of the vegetation, and the leakage of the groundwater is derived. The calculation formula of the hopper volume, combined with the tunnel surrounding rock parameters, can obtain the total discharge of the underground water, and compared with the rainfall supply quantity to obtain the original groundwater level in the restoration tunnel site area. For the operation period tunnel, the anti-analysis formula for the dynamic change of the underground water level in the tunnel site is derived. Through the monitoring of the displacement of the water-blocking and discharge tunnel, combined with the parameters such as the tunnel surrounding rock and the permeability coefficient of the primary lining, the underground water table can be obtained by the inverse analysis, and the underground water table can be ground. and (4) the surface well method in the well flow theory is introduced into the underground water table reduction calculation of the tunnel, so that any point in the influence range of the tunnel is obtained The calculation formula of the lower water level is presented. The ground water equilibrium condition is put forward In this paper, the method for determining the emission discharge of the tunnel is obtained. Based on the superposition of the two-hole underground water level of the tunnel, the method for calculating the limit displacement of the separated tunnel is obtained, and the single-hole tunnel and the separation tunnel are compared and analyzed. (5) Under the premise of protecting the ecology and maintaining the balance of the ground water, the permeability coefficient of the common rock and soil layer and the water supply are selected in ord to meet that most common mountain in the case of the effective control of the groundwater, The groundwater limit discharge standard of the mountain tunnel. For tunnels that cannot be effectively controlled by the groundwater, refer to
【学位授予单位】：中南大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U453.6

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