Treatment Technique Of Tunnel Disaster Caused By Groundwater

Tunnel because of surface water infiltration, groundwater seepage, karst water, will result in the sudden water tunnel excavation, the sudden mud SLOPE slump, collapse, shallow groundwater depletion, surface subsidence, invasion of surrounding rock deformation limit corrosion of concrete lining the tunnel disaster. Serious consequences of these disasters, great harm and delay the construction period, lower cost, resulting in adverse social impact, will result in serious loss of life and property. Therefore, it is necessary to the tunnel on groundwater and the relationship between the common understanding of disaster analysis, and effective control measures to achieve during the tunnel construction and operation of disaster prevention, mitigation, treatment disaster purposes. The study has important practical significance and academic value.This paper combines the project "limestone, sandstone and mudstone District Highway Tunnel Water Inflow Prediction and treatment technology research," in documentation in the field, based on the expressway in Chongqing Shi Fu Feng typical fruit trees in the tunnel, Jianfengling Pine floor tunnel and the tunnel as the background, through the theoretical achievements of researchers from home and abroad, to the different stages of construction on the site, due to a variety of tunnel disasters caused by groundwater depth analysis of research, the Treatment of geological problemsof these programs, Used to guide the design and construction.Specific summarized as follows:1. For the low water table slope of unsaturated Yang, rainfall infiltration in the groundwater level caused SLOPE unsaturated zone above the water pressure is temporarily increased, reduced suction and reduce the shear strength of unsaturated soils; the same time, in a stable certain areas above the groundwater level transient saturated zone may occur, resulting in additional water load transient. In fact this sub-transient groundwater movement and the resulting additional water load transient often become non-saturated edge of slope instability in the controlling factors in the rainy season.2. Tunnel water inflow is due to tunnel excavation, the destruction of the original fractured rock aquifer in which groundwater seepage field and stress field of the dynamic equilibrium system. Fractured rock aquifer in order to maintain the stability of their own will through the seepage of groundwater movement in fractured rock aquifer with groundwater seepage field and stress field coupling between, so that the energy stored in groundwater seepage from the new channel to the fluid The form of instantaneous release of high-speed transport.3. With the increase of pore water pressure of surrounding rock, rock expanded plastic damage, when the surrounding rock in the pore water pressure near the critical pressure, the tunnel surrounding rock in a non-stable equilibrium state; groundwater seepage on the effectiveness of soil skeleton and other produce The role will affect the strength of soil; another plus water swelling clay, and lack of supporting factors such as the superposition of parameters, resulting in rock deformation may exceed the value of design reserved.4. Groundwater as an important geological agent, and the interaction between rock, one rock changed the physical, chemical and mechanical properties; the other hand, changes in groundwater own physical, mechanical properties and chemical composition. Moving water and produces three kinds of rock role that the physical, chemical and mechanical effects, these effects are often decisive collapse of the tunnel effect.5. Tunnel entrance with rocks weathered, self-stability of poor geological conditions; human brush Singapore, destroy the natural balance of the construction method; combined with rain water infiltration, deterioration of the cover to activate the potential slip surface, through the effective Discharge of surface water To prevent rainwater infiltration, and through the pile of retaining, a fundamental solution to the hole from the edge of the collapse of slope.6. Shallow tunnels covered with thin, arching from the poor, the initial deformation, caused by the excavation of rock relaxation easy to extend the range to the surface, such as the stress field and seepage field and coordinate by the depth of water and other large Characteristics, by increasing the bearing capacity, consolidation of rock, improve support parameters, grouting and other measures can effectively prevent surface subsidence, gushing water and other disasters.7. UnkNown deep section of the tunnel more unfavorable geological, rock-level change frequently, once a disaster greater impact on staff machines, through the radial reinforcement Grouting in rock fissure water, facilities and care for temporary invert arch, shortened Second, between the lining and the beginning of the construction space lining, encryption, advanced short pipe roof bolts and construction measures such as deep section of the large deformation, landslides, gushing water and other disasters, significant effectThe innovation of this paper is to summarize the three highway projects Fu Fung Shek tunnel construction of the tunnel construction for the hole, Shallow, deep period of time characteristics of different water hazards, its development and evolution of seepage were systematically Numerical simulation and theoretical analysis, combined with field test results, a set of systems for tunnel construction to the various stages of geological disasters caused by groundwater control measures, thereby Fu Fung Shek project and similar projects the tunnel construction of the tunnel provides guidance.