土木工程专业英语论文

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Karst tunnel technology

Abstract:Karst is a geological phenomenon, which is often encountered in Tunnel Construction.it will easily lead to gushing water excavation face suddenly mud, rock

and supporting structure deformation, crack and collapse, the impact of the construction progress, endangering the safety of construction, the destruction of the surrounding environment. In this paper, the principle of the karst, explore the tunnels of different types of karst treatment, in addition, and the engineering example is introduced.

Key words : Tunnel; Karst; Example projects

1 Overview

Karst is an overview of surface water and groundwater for soluble rock (carbonate rocks, sulfuric acid rock, halogen salts, etc.) for chemical erosion, and the role of the collapse of mechanical damage, handling, formed by deposition of surface and subsurface erosion phenomenon known. Since then, we can see the definition : Karst have three major conditions : first, soluble rock Karst is the material basis. For example, the tunnel through limestone, dolomite, marl, and gypsum, mirabilite, rock salt and other strata, subject to possible ground water erosion, dissolved limestone in the main role. Dolomite mainly through infiltration - dissolution - decomposition - leaching-collapse occurred destruction. Second, the geologic structure and the formation of a vastly different set of karst types of diversity. Rock structure, structure and stratigraphic occurrence, exposure, thickness, fractured, folded, joints, fractures, weak layers, degree of weathering and other geological features of karst decision and magnitude different. Under normal circumstances, the syncline structure than anticline structure karst strong syncline structure of the nuclear karst strongly than wings, anticline structure than the two wings of the nuclear karst strong; When the tunnel through the Karst formation of joints, fractures, fault structure discontinuities, the easy solution gap encountered, control solution, caves, cavities or underground river. Third, the surface water and groundwater recharge, runoff, infiltration and the cycle is karst formation and development of the necessary conditions. Valley, depression, karst basins, shaft, funnel water sink in Liuzitian site, surface water pooling, infiltration, Stratum easily in the runoff with the horizontal and vertical seepage zone and stay with the deep, and the groundwater recharge cycle karst formation to create the necessary conditions for free when groundwater or erosion of CO2, SO4- the larger content, enhancing the development of karst.

2001 started the Chongqing-Huaihua line length 624.523km, there were more than 20 tunnels Block 7km tunnel over which seven, the majority of tunnel through