System and method for reinforcing envelop enclosure for shield tunneling beneath existing subway station

Abstract

The invention discloses a system and method for reinforcing an envelop enclosure for shield tunneling beneath an existing subway station. The system comprises a first reinforcing area, a second reinforcing area, a third reinforcing area, a submersible precipitation well and a standby confined water precipitation well, wherein the first reinforcing area is a jet grouting pile reinforcing area which is arranged on the outer side of the existing station, is away from the envelop enclosure on the other side of a foundation pit of a newly built station, and is constructed very close to the envelop enclosure; the second reinforcing area is a freezing method reinforcing area which is constructed very close to a subway envelop enclosure shared by the existing station and the newly built station, and the reinforcing area is close to one side of the existing station; the third reinforcing area is a single-row rodin jet pile (RJP) reinforcing area constructed very close to the subway envelop enclosure shared by the existing station and the newly built station, and the reinforcing area is close to one side of the newly built station; the submersible precipitation well is arranged inside the foundation pit of the newly built station; and the standby confined water precipitation well is arranged outside the foundation pit of the newly built station and serves as a confined water level observation hole. By means of the system and method, the self stability and bearing capacity of soil very close to the envelop enclosure can be effectively improved, the risks of water bursting and sand bursting in case of shield entry and arrival are reduced, and the influence on operation of the existing station is reduced.

Description

technical field [0001] The invention relates to the technical field of urban rail transit shield construction and other municipal engineering, in particular to a system and method for reinforcing shield tunnels passing through existing subway station enclosure structures. Background technique [0002] With the rapid development of urban rail transit construction, it is not uncommon for shield tunneling to pass through the enclosure structure of foundation pits of newly built stations during construction. It is also widely used to reinforce the enclosure structure when shield tunnels enter and exit the tunnel, and the related technologies are relatively mature. However, the cross-transfer of underground railways is becoming more and more frequent, and the newly-built stations are adjacent to the existing stations, and there are few reinforcement schemes for shield tunneling under the existing stations while passing through their enclosure structures. [0003] The construction...

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Problems solved by technology

[0005] The purpose of the present invention is to construct the shield under the existing station and through its enclosure structure under the harsh geological conditions such as silt layer, silty clay layer, silt layer and silty clay layer, which contain water or are pressurized water. In order to solve the problems such as water gushing, sand gushing and excessive settlement, a safe and reliable reinforcement system and method for shield tunneling under the existing subway station enclosure structure can be provided, which can effectively improve the self-stability and bearing capacity of the soil adjacent to the enclosure structure. reduce the risk of water and sand gushing when the shield enters the tunnel and arrives at the station, and reduces the impact on the operation of existing stations

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