Station pit construction method forming protection for neighboring operated subway interval tunnel

Abstract

The invention discloses a method for constructing foundation pits for a station which can protect the adjacent running tunnel of operating subways, which comprises the steps of constructing underground continuous wall, reinforcement of the foundation in the pits, constructing precipitation well points in the pits, excavating the foundation pits, structure reconstruction, reinforcement of outer row of soil outside the foundation pits and reinforcement of inner row of soil outside the foundation pits. The construction of the underground continuous wall adds the construction of sealing wall; the excavation of the foundation pits and the structure reconstruction adopt a top-down method below the medium plate of the foundation pits corresponding to where the adjacent running tunnel is buried deeply and a bottom-up method over the medium plate; the reinforcement of outer row of soil outside the foundation pits is to reinforce the soil between the foundation pits and the adjacent running tunnel and 3m far away from the foundation pits; and the reinforcement of inner row of soil outside the foundation pits is to reinforce the soil between the foundation pits and the adjacent running tunnel and within 3m from the foundation pits. The method of the invention adopts comprehensive protection measures during the whole process of construction, thereby protecting the adjacent running tunnel of operating subways overall and reducing the effect on the adjacent running tunnel of operating subways to the utmost extent during constructing a subway station.

Description

Technical field: [0001] The invention relates to a foundation pit construction method, in particular to a station foundation pit construction method for protecting tunnels in adjacent operating subway sections, and belongs to the technical field of construction engineering. Background technique: [0002] With the rapid development of the rail transit industry, a huge network of urban underground tunnels has been formed. The underground tunnel network is quite dense in some parts of large cities, and it is not uncommon for tunnels with more than two floors to intersect underground. Therefore, how to reduce the impact on the adjacent tunnels (or related buildings) during the construction of the subway, and the issue of its protection has been brought up on the agenda. This issue is very important for deep foundation pit projects (such as subway stations) and the track It is especially important for traffic tunnels or stations. This is because the excavation scale and depth of...

AI Technical Summary

Problems solved by technology

The existing construction methods ignore the construction stage of the underground diaphragm wall and the impact of the pressure-reducing water on the operating subway lines, and do not analyze or adopt the full reverse construction method, which leads to an increase in the construction period and prolongation of the operating subway lines. The impact time of the subway line; or adopt the method of open cut and sequential construction, resulting in increased deformation of the foundation pit

In short, the technical measures adopted in the existing construction methods for protecting the operating lines are all unitary, and cannot form a comprehensive protection for the adjacent subway tunnels in operation. Once an accident occurs, it will have a bad impact on the normal operation of the subway.

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