Study On The Cracking Law Of Hydraulic Diversion Concrete Lining

Hydraulic tunnel are hidden underground engineering, has its own particularity.Once the excavation changes pluton original equilibrium state, it will cause the holesnear the stress redistribution. And led to the deformation of the rock mass, serious oreven collapse, so the hydraulic tunnels need to set the permanent lining. Currently, forstructural analysis and numerical simulation of hydraulic tunnel, has achieved goodresults. But for the comparative analysis of different shapes hydraulic tunnel structure,the impact of different High cross-ratio on the lining. Their analysis is notcomprehensive enough and systems. Currently, most studies only for a project instance,and not be a comprehensive and systematic comparative analysis, leading to study one-sided. So it is necessary for the lining structure analysis and shape optimization research,provide a theoretical basis for the design and construction of hydraulic tunnel.This article is based on a tunnel project in Cixi City, Yao River as an example,using the finite element software to create a variety of hydraulic tunnel model, doing thefollowing aspects of the research arounding the tunnel shape and the High cross-ratio ofthe Horseshoe type.1. Using the method of structural mechanics analysis of the stress and displacementdistribution of the city gate type hydraulic tunnel in condition I (rock pressure+theweight of the lining). Then compared with the finite element results, illustrate thereliability of the results.2. Using ABAQUS software to create a city gate hydraulic tunnel model,comparative analysis of the stress and displacement in different conditions, the stressand displacement of the different High cross-ratio of the tunnel in condition II (rockpressure+the weight of the lining+External water pressure).3. Using ABAQUS software to create an optimized hydraulic tunnel model,comparative analysis of the stress and displacement of the tunnel using lining bottomcorner with transitional arc chamfering optimized in condition II.4. Using ABAQUS software to create a horseshoe type hydraulic tunnel model,comparative analysis of the size of the stress and displacement distribution of the citygate and horseshoe type tunnel.Through analysis, we found the tunnel structure in compression, only the lining ofthe foot of a wall area there will be small-scale tension. For the lining bottom corner stress concentration, the whole structure of the force and deformation were improved bytransition arc chamfering. The lining of the maximum tensile, compressive stress inStructural mechanics calculations is less than the finite element calculations. City gatetype hydraulic tunnel focus on tensile strength and vertical displacement, it isrecommended to select a larger high-span ratio; consideration in the case of lateraldeformation, it is recommended to choose a smaller high-span ratio. City gate type andhorseshoe-shaped hydraulic tunnel during force-deformation comparison in theconditions of this article, it is recommended to select a horseshoe shape in the actualconstruction.