CN-122014279-A - Construction method of tunnel gate post-pouring ring beam for shield tunneling

CN122014279ACN 122014279 ACN122014279 ACN 122014279ACN-122014279-A

Abstract

The invention discloses a construction method of a post-pouring ring beam of a tunnel portal for shield tunneling, which comprises the steps of constructing a shield segment, enabling a last ring of segments to protrude out of a tunnel portal to form an annular extension section when constructing a last ring of segments, carrying out wall post-grouting on at least 5 ring of segments, binding a reinforcement cage of the post-pouring ring beam on the periphery of the annular extension section, enabling the reinforcement cage to be connected with an embedded steel ring on the periphery of the tunnel portal, pouring the post-pouring ring beam on a peripheral support die of the reinforcement cage, enabling the end face of the post-pouring ring beam to be flush with the end face of the annular extension section, and pouring the embedded steel ring into the post-pouring ring beam.

Inventors

ZHENG WENBO
SUN XIAOLI
ZHU CHANGYONG
CHEN WANCHUN
LEI BENJIAN
KANG LIMING
JIANG ZIHAN
WANG HAO
LI ZONGZHENG
CHEN PENGJIE

Assignees

中建八局轨道交通建设有限公司

Dates

Publication Date: 20260512
Application Date: 20260202

Claims (6)

1. The construction method of the gate post-pouring ring beam for shield tunneling is characterized by comprising the following steps: Step 1, constructing a shield segment, and enabling the last annular segment to protrude out of a hole to form an annular extension section when constructing the last annular segment; Step 2, grouting the last at least 5 ring canal slices after wall grouting; binding a reinforcement cage of a post-pouring ring beam on the periphery of the annular extension section, and connecting the reinforcement cage with an embedded steel ring on the periphery of the hole; And 4, pouring the post-pouring ring beam on the peripheral support die of the reinforcement cage, enabling the end face of the post-pouring ring beam to be flush with the end face of the annular extension section, and pouring the embedded steel ring.
2. The construction method of a post-pouring ring beam for a tunnel portal for a shield tunnel according to claim 1, wherein grouting residues scattered to the outer periphery of the annular extension section are cleaned after the step 2 is performed and before the step 3 is performed.
3. The construction method of a post-pouring ring beam for a tunnel portal for a shield tunnel according to claim 1, wherein after the step 2 is performed and before the step 3 is performed, a water-swellable rubber strip is arranged on the periphery of the annular extension section, and a water-swellable rubber strip is arranged on an end wall covered by the post-pouring ring beam design position.
4. The construction method of a post-pouring ring beam for a tunnel portal for a shield tunnel according to claim 1, wherein in the step 3, an anchor bar is used to connect the reinforcement cage and the pre-buried steel ring, so that one end of the anchor bar is welded and fixed to the pre-buried steel ring, and the other end is bound and connected with the reinforcement cage.
5. The construction method of a post-pouring ring beam for a tunnel portal for a shield tunnel according to claim 1, wherein the end wall covered by the post-pouring ring beam design position is reinforced when the step 3 is performed, and the reinforced bar is connected with the reinforced bar cage when the reinforced bar cage is bound.
6. The construction method of a post-cast ring beam for a tunnel portal for a shield tunnel according to claim 1, wherein a waterproofing agent is applied to a gap between the post-cast ring beam and the end wall after the step 4 is performed.

Description

Construction method of tunnel gate post-pouring ring beam for shield tunneling Technical Field The invention relates to the technical field of building construction, in particular to a tunnel portal post-pouring ring beam construction method for shield tunnel. Background And pre-burying a steel ring at the joint of the open cut end wall and the section tunnel before the shield enters and exits, and performing portal structure construction after the whole section shield section is constructed. The rigidity of the open cut structure is greatly different from that of the shield tunnel structure, soil is reinforced around the opening to avoid uneven settlement as much as possible, and deformation joint reinforcing rings are arranged when the shield enters and exits the opening. The structure of the tunnel portal is designed into a reinforced concrete structure, namely a post-pouring ring beam, the concrete grade is C40, and the impervious grade is P10. Through pre-buried steel loop at the entrance to a cave, pre-buried steel loop links to each other with post-cast ring roof beam, makes open cut structure and shield tunnel structure link as an organic wholely to increase the wholeness of portal structure. When the tunnel portal at the receiving end is used for constructing the post-pouring ring beam, the end part of the last ring segment is flush with the tunnel portal, so that reliable connection cannot be formed with the post-pouring ring beam, and meanwhile, the casting space of the post-pouring ring beam is occupied, so that the prior art firstly removes the whole ring of the last ring tube segment, and then the post-pouring ring beam is constructed, and the method occupies a construction period and has low efficiency. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides a construction method of a post-pouring ring beam of a tunnel portal for shield tunneling. In order to achieve the above purpose, the technical scheme adopted by the invention is a tunnel portal post-pouring ring beam construction method for shield tunneling, comprising the following steps: Step 1, constructing a shield segment, and enabling the last annular segment to protrude out of a hole to form an annular extension section when constructing the last annular segment; Step 2, grouting the last at least 5 ring canal slices after wall grouting; binding a reinforcement cage of a post-pouring ring beam on the periphery of the annular extension section, and connecting the reinforcement cage with an embedded steel ring on the periphery of the hole; And 4, pouring the post-pouring ring beam on the peripheral support die of the reinforcement cage, enabling the end face of the post-pouring ring beam to be flush with the end face of the annular extension section, and pouring the embedded steel ring. The construction method of the post-pouring ring beam of the tunnel portal for shield tunneling is further improved in that grouting residues scattered to the periphery of the annular extension section are cleaned after the step 2 is executed and before the step 3 is executed. The construction method of the post-pouring ring beam of the tunnel portal for shield tunneling is further improved in that after the step 2 is executed and before the step 3 is executed, water-swelling rubber strips are arranged on the periphery of the annular extension section, and the end walls covered by the design positions of the post-pouring ring beam are provided with the water-swelling rubber strips. The construction method of the tunnel gate post-pouring ring beam for shield tunneling is further improved in that in the step 3, the reinforcement cage and the embedded steel ring are connected by using the anchoring ribs, one end of each anchoring rib is welded and fixed to the embedded steel ring, and the other end of each anchoring rib is bound and connected with the reinforcement cage. The construction method of the post-pouring ring beam of the tunnel portal for shield tunneling is further improved in that when the step 3 is executed, the end wall covered by the design position of the post-pouring ring beam is planted with bars, and when the reinforcement cage is bound, the planted bars are connected with the reinforcement cage. The construction method of the post-pouring ring beam for the tunnel portal for shield tunnel exit is further improved in that after the step 4 is executed, a waterproof agent is painted at the gap between the post-pouring ring beam and the end wall. Compared with the prior art, the invention has the advantages that: Through when constructing last ring section of jurisdiction, make last ring pipe piece protrusion in the entrance to a cave, provide the connection basis for post-cast ring roof beam, the construction of post-cast ring roof beam of being convenient for avoids demolishing last ring section of jurisdiction simultaneously, has improved the efficiency of construction. Drawings In order to mor