Construction method of earth pressure balance shield arrival in subsurface tunnel in complex formation

Abstract

The invention provides a construction method of earth pressure balance shield arrival in a subsurface tunnel in a complex formation. The construction method comprises the following steps that S1) isolated stone and/or a boulder region in the formation is determined through physical detection, the isolated stone and/or a boulder in the region are separated through breaking holes; S2) the shield arrival end head in the subsurface tunnel is reinforced to form an end head reinforcing region; S3) the shield launching and tunneling are carried out, before a shield tunneling machine reaches a presetdistance position distanced from the end head of the subsurface tunnel, the subsurface tunnel of the preset distance section is manually excavated, and a concrete retaining wall is constructed at a tunnel face of the preset arrival position of the shield tunneling machine, a tunnel is closed; S4) the soil body reinforcement condition and the water seepage condition of a tunnel wall are determinedthrough an observation hole, and corresponding treatment is carried out; S5), the shield tunneling machine is continuously excavated and penetrates through the concrete retaining wall, after the shield tunneling machine enters the end head reinforcing area and reaches the stop position, the shield tunneling machine is stopped, and gaps between a shield body of the shield tunneling machine and thetunnel wall are filled through grouting operation; and S6) the shield tunneling machine is subjected to in-tunnel shell abandoning and disassembly operation.

Description

technical field [0001] The invention relates to the technical field of deep-buried tunnels, in particular to a construction method for earth pressure shields in complex strata to receive in tunnels. Background technique [0002] In tunnel construction, earth pressure shield excavation and reception technology in water-rich pebble stratum is becoming more and more mature, but in water-rich and large-size pebble-boulder mixed soil stratum, the case of shield receiving into the underground excavation chamber is relatively rare. For example: In the construction of a small-diameter water conservancy tunnel, the original design was to use the mining method for underground excavation construction, but in the excavated section, due to the influence of the underground "water bag", adverse geological conditions such as mud inrush and water gushing occurred many times in the tunnel , considering the safety of the project, the construction of this section of the tunnel was changed from ...

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Problems solved by technology

[0002] In tunnel construction, earth pressure shield excavation and reception technology in water-rich pebble stratum is becoming more and more mature, but in water-rich and large-size pebble-boulder mixed soil stratum, the case of shield receiving into the underground excavation chamber is relatively rare. For example: In the construction of a small-diameter water conservancy tunnel, the original design was to use the mining method for underground excavation construction, but in the excavated section, due to the influence of the underground "water bag", adverse geological conditions such as mud inrush and water gushing occurred many times in the tunnel , considering the safety of the project, the construction of this section of the tunnel was changed from the original mining method to the shield construction method. Due to the complex geological and hydrological conditions in the water-rich and large-sized pebble boulder stratum, the shield tunnel received into the closed underground excavation There are relatively large construction risks and technical difficulties in the cavern, and a complete set of construction methods has not yet been formed

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