The Research On The Load Reduction Law And Application Of Measrues On Lining External Water Load Of Deeply Bureed Tunnel In Project Of Han-to-wei Water Transfer

Han nutrient-laden water diversion tunnel through the qinling mountains with a longdistance excavation. Because of these, the surrounding rock geological structure of thisproject is complicated and the underground water level is so high. In this case the seepagefield and stress field is very high in the process of tunnel excavation and lining leading thecoupling effect between stress and seepage become significant. Under the condition ofcoupling, lining on web of load action is no longer simple make water pressure processing,also need to consider seepage deformation of surrounding rock;Accordingly, web loadresponse law of lightening had the new change. In this paper, the mechanic of external waterload and the law of reduction of it is researched using the theory of solid-fluid coupling whichconsider the seepage body force and coefficient dynamic evolution law and considering therock-lining as massive structure, and than analogue simulating the excavation, grouting andlining by ABAQUS. Firstly,the two-dimensional finite element model of the whole structureof surrounding rock–lining is set up with the model parameters, boundary conditions tosimulate the process of excavation and lining. Based on the fluid-solid coupling theory, theresponse mechanism of the rock-lining structure of external water load is analysised.Then on the basis of the original model, the grouting drainage are simulated, by effectcontrast of plans of grouting circle infiltration parameters and location of drain pipe length,number, arrangement plan analysis based on the response mechanism to research thereduction law of water load. At last, based on the concept of dynamic construction, athree-dimensional finite element model is established. It reflect the space and timecharacteristics of the tunnel during the construction and provide Dynamic prediction resultsfor the project taking the dynamic process of mutual influence amount tunnel face, lining andnot lining surrounding rock while excavating. Through the above research, this paperconcluded as follows: Firstly, take surrounding rock and lining structure as a whole joint bearing, under thecoupled action of seepage field, stress field and seepage body force in surrounding rock willalso indirectly ACTS on the lining structure. In the process of lining construction, excessivewater pouring into the lining template, take material, unset the defects of structure andtransform the seepage properties of the lining structure and lining on the stress distribution ofdisadvantage. Those are produced by groundwater seepage, when dealing with the lining ofhigh web load should be considered the existence of these two effects.Secondly, in order to reduce the environmental impact, the coefficient of permeability ofgrouting circle suggest take1/40of the surface of surrounding rock. Grouting circle andlining the permeability coefficient ratio less than1, the lightening efficiency expand twicegrouting measures, but will increase1.04times of lining extrusion stress of surrounding rock.It is better to improve the grouting circle’s stiffness or setting the reserved deformation andsoft cushion layer. When more than one drain decorate the top drain of lightening effect is thelargest, but its lightening effect depends on grouting circle and lining, the permeabilitycoefficient ratio between0.2~1.6when the best effect, and can it be made into furtherlightening grouting circle, but when the greater than5will increase stress on the lining.Template for lining pouring waterproof and drainage and waterproof additive is used in theeffective measures for the prevention and control of seepage failure.Thirdly, the three-dimensional model for real-time simulation for the dynamicconstruction can guarantee the safety of the engineering design and construction to bereasonable. Considering the material properties of anisotropic and spatial variability, the finiteelement calculation model needs to be combined with field monitoring, real-time distributionof groundwater investigation, parameter inversion of the surrounding rock and the interiormaterial test. Monitoring, inversion, test and simulation should be combined with each other.