Research The Construction Technology Of Prevention Tunnel Face Collapse Under High Water Pressure

Since China’s reform and opening up, in order to adapt to the rapid development ofcontemporary society, built a lot of tunnel engineering. And in the process of theconstruction of a tunnel, there are many problems. Constraints of tunnel collapse is oneof the most common problems in tunnel engineering.Constraints of tunnel collapsefactors include geological hydrology factors, construction factors, design factors and theunderstanding and management factors. In this paper, we study the problem of theinfluence of water pressure on tunnel stability constraints, and then puts forward therelevant prevention and control measures of construction.In order to solve this problem, this paper puts forward simulated by finitedifference software FLAC3D tunnel excavation, the water pressure is how to influencethe stability of the tunnel constraints. And this article main research content is asfollows:①different grades of highway tunnel under high water pressure of surroundingrock under the action of the mechanical behavior of surrounding rock near theconstraints and stable situation analysis, and evaluation;②study under high water pressure, different grade of surrounding rock of highwaytunnel constraints of losing stability critical value;③different size constraints of road tunnel under high water pressure near themechanical behavior of surrounding rock and its stability analysis and evaluation;④study under high water pressure, different size constraints of highway tunnel oflosing stability critical value;⑤constraints in greater than losing critical effect on the stability of water pressurevalue, how construction plan; Constraints in less than losing critical effect on thestability of water pressure value, how the construction plan.After FLAC3D numerical simulation, the middle section is obtained, the big crosssection, three kinds of heavy section tunnel sections under the usual three, four, fivesurrounding rock tunnel of constraints of critical instability of water pressure value; Aswell as a variety of the highway tunnel under high water pressure under the condition ofthe mechanical behavior of surrounding rock near the constraints. And constraints ofhighway tunnel in tunnel instability of critical water pressure value of a certainmechanical behavior analysis and evaluation; Constraints put forward in the water pressure is less than the instability of water pressure is the critical value, can consider tosupport after excavation construction scheme; But when the water pressure is greaterthan the constraints instability of water pressure is the critical value, you must take toconstraints for supporting first and then the excavation construction scheme.