A construction method for tunnels passing through railways

Abstract

The invention discloses a construction method for a railway under a tunnel. The construction method is characterized in that dewatering deep wells are arranged; water at a water-rich drift sand layer section of an excavated tunnel is introduced into the dewatering deep wells, and is extracted out of the dewatering deep wells, so that pressure-bearing underground water in a construction area is drained, and therefore, the water level and depth in the center of a construction area are effectively controlled to achieve construction requirements under a water-free environment, phenomena of sand drifting and piping are avoided, and the stability of an excavation face is ensured. Besides, according to the method, cover plates and retaining walls are arranged at the two sides of a railway subgrade, and side slopes between the retaining walls and the railway subgrade are filled with concrete, so that cover plate sections are formed at the two sides of the railway subgrade; and tunnel extraction is divided into open excavation, cover excavation and underground excavation, so that the underground excavation length is reduced, and therefore, the construction risks are reduced.

Description

technical field [0001] The invention relates to a tunnel construction method, in particular to a tunnel construction method passing under a railway. Background technique [0002] In my country's early urban construction planning, many urban railways are located in the suburban areas. With the advancement of urbanization and urbanization, the existing railways have seriously affected the smooth flow of urban roads, and there are a large number of plane location conflicts. It is urgent to solve urban roads and railway level crossings. implementation to improve traffic congestion in the city. However, most of the southern and coastal cities in my country are built by mountains and rivers, and the geological conditions are complex. Most of the existing railway lines are under the water-rich and thick sand layers. Under the harsh geological conditions of these water-rich and thick sand layers, roads are built. It is very difficult to construct a large-span shallow tunnel. Not only...

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Problems solved by technology

However, most of the southern and coastal cities in my country are built by mountains and rivers, and the geological conditions are complex. Most of the existing railway lines are under the water-rich and thick sand layers. Under the harsh geological conditions of these water-rich and thick sand layers, roads are built. It is very difficult to construct large-span shallow tunnels. Not only is excavation soil collapse prone to occur, but it is also likely to affect the operation of existing lines. It is difficult to ensure the safety of existing lines during the construction process.

[0003] In order to avoid the impact of the tunnel on the existing lines, a certain distance must be maintained between the tunnel passing under the railway and the railway subgrade, which leads to a longer length of the tunnel, a larger length of tunnel excavation, and long pipe sheds that are poured into the railway subgrade Possibility, high construction risk