CN-116220048-B - Construction method of reverse pulling system of temporary horizontal steel support of reverse construction method underground space

Abstract

The invention provides a construction method of a reverse pulling system of a temporary horizontal steel support in a reverse construction method underground space, which comprises the steps of installing the temporary horizontal steel support between a supporting structure and an adjacent steel upright post after the earth excavation of the last layer of an underground foundation pit is completed, respectively fixing a lock fixing end on two sides of the steel upright post and a lock fixing end on the steel upright post, respectively fixing one ends of two prestressed cables to the corresponding lock fixing ends, obliquely pulling the other ends of the two prestressed cables upwards towards the supporting structure, combining the two prestressed cables into a strand to pass through a B1 plate, obliquely upwards pulling the two prestressed cables towards the direction of the steel upright post, fixing and tensioning the steel upright post after passing through the B0 plate to form the reverse pulling system of the prestressed cable, effectively counteracting the lateral horizontal force caused by the temporary horizontal steel support, reducing the lateral deformation of the supporting structure due to 'space-time effect', and ensuring the safety of the underground structure in the reverse construction method foundation pit.

Inventors

• PAN GUOQING
• CHEN RONG
• YU YALEI
• QI JIANWEN
• SHI HONGBING

Assignees

• 上海建工二建集团有限公司

Dates

Publication Date

20260512

Application Date

20221220

Claims (9)

1. 1. The construction method of the reverse pulling system of the temporary horizontal steel support of the reverse construction method underground space is characterized by comprising the following steps of: Step 1, after the earth excavation of the last layer of the underground foundation pit is completed, a temporary horizontal steel support is arranged between a supporting structure and an adjacent steel upright post so as to transfer lateral horizontal force of the supporting structure; Step 2, wrapping steel plates at the connecting joints of the steel upright posts and the temporary horizontal steel supports, respectively fixing a lock fixing end at two sides of each wrapping steel plate, and respectively fixing one ends of two prestressed cables to the corresponding lock fixing ends; and 3, pulling the other ends of the two prestressed cables obliquely upwards towards the direction of the supporting structure, combining the two prestressed cables into a strand to penetrate through the underground one-layer floor slab, pulling the strand obliquely upwards towards the direction of the steel upright post, penetrating through the top plate, fixing and tensioning the strand to form a prestressed cable counter-pulling system.
2. 2. The method for constructing a reverse pulling system of a temporary horizontal steel support for a top-down construction method underground space according to claim 1, wherein the outer-covered steel plate comprises three steel plate members which are vertically arranged, the three steel plate members are respectively arranged on three sides of the steel upright, two steel plate members are parallel to the temporary horizontal steel support, one ends of the two steel plate members are respectively connected with two ends of the other steel plate member, and a lock fixing end is symmetrically fixed on the two steel plate members.
3. 3. The method of reverse-pulling a temporary horizontal steel support for a top-down method subterranean space according to claim 2, wherein the three vertically disposed steel plate members form a U-shaped structure, and the other steel plate member is disposed on a side of the steel upright remote from the temporary horizontal steel support.
4. 4. The method for constructing a reverse pulling system for temporary horizontal steel supports in a top-down method underground space according to claim 1, wherein in the step 1, the temporary horizontal steel support end portion is made of a steel plate embedded part and a lower bracket.
5. 5. The method for constructing a reverse pulling system for temporary horizontal steel support in a top-down method underground space according to claim 1, wherein a first through hole for two prestressed cables to pass through is formed in the underground one-layer floor slab, and a second through hole for two prestressed cables to pass through is formed in the top plate.
6. 6. The method for constructing a reverse-pulling system for temporary horizontal steel support in a top-down method underground space according to claim 5, wherein the pre-stressing cables and the steel columns form a triangular structure.
7. 7. The method of reverse-pulling a temporary horizontal steel support for a top-down method subterranean space according to claim 5, wherein the first through-hole is equidistant from the support structure and the steel column, and the second through-hole is disposed adjacent to the steel column.
8. 8. The method of constructing a reverse-pulling system for temporary horizontal steel support in a topdown underground space of claim 5, wherein the first through-hole is vertically disposed.
9. 9. The method for constructing a reverse pulling system for temporary horizontal steel support in a top-down method underground space according to claim 5, wherein the second through holes are arranged obliquely upward, and the upper ends of the second through holes are closer to the steel upright posts than the lower ends of the second through holes.

Description

Construction method of reverse pulling system of temporary horizontal steel support of reverse construction method underground space Technical Field The invention relates to the technical field of reverse construction method underground space construction. Background The reverse construction technology is used as an effective economic means for sustainable urban underground space development and construction of an economic society, and is increasingly applied to projects such as super high-rise building basements, underground transportation hubs and the like, but the reverse construction technology also often faces the problem that the lateral deformation of the supporting structure is large before the foundation pit bottom plate is not formed. The invention provides a reverse pulling system suitable for a temporary horizontal steel support of a reverse construction method underground space, which solves the problem that the side deformation of a front supporting structure is not formed on a bottom plate of an underground foundation pit, and becomes a technical problem that the construction industry needs to further perfect and optimize. Disclosure of Invention The invention aims to invent a construction method of a reverse pulling system of a temporary horizontal steel support of a reverse construction method underground space, and solves the problem that a front supporting structure is not formed on a bottom plate of a foundation pit in the reverse construction method construction technology and lateral deformation is large. In order to solve the technical problems, the invention provides the following technical scheme: a reverse construction method of a reverse drawing system of a temporary horizontal steel support of a reverse construction method underground space comprises the following steps: Step 1, after the earth excavation of the last layer of the underground foundation pit is completed, a temporary horizontal steel support is arranged between a supporting structure and an adjacent steel upright post so as to transfer lateral horizontal force of the supporting structure; Step 2, wrapping steel plates at the connecting joints of the steel upright posts and the temporary horizontal steel supports, respectively fixing a lock fixing end at two sides of each wrapping steel plate, and respectively fixing one ends of two prestressed cables to the corresponding lock fixing ends; And 3, pulling the other ends of the two prestressed cables obliquely upwards towards the direction of the supporting structure, combining the two prestressed cables into a strand to pass through the B1 plate, pulling the strand obliquely upwards towards the direction of the steel upright post, fixing and tensioning the strand after passing through the B0 plate to form a prestressed cable counter-pulling system, and after the prestressed cable counter-pulling system is formed, effectively counteracting the lateral horizontal force brought by the temporary horizontal steel support, reducing the lateral deformation of the supporting structure caused by 'space-time effect', and ensuring the safety of the underground structure in the reverse construction method foundation pit construction process. Preferably, in the construction method of the reverse pulling system for the temporary horizontal steel support of the reverse construction method underground space, the outer-covered steel plate comprises three steel plate members which are vertically arranged, the three steel plate members are respectively arranged on three side surfaces of the steel upright post, two steel plate members are parallel to the temporary horizontal steel support, one ends of the two steel plate members are respectively connected with two ends of the other steel plate member, and lock fixing ends are symmetrically fixed on the two steel plate members. Preferably, in the construction method of the reverse pulling system of the temporary horizontal steel support of the reverse construction method underground space, the three steel plate members arranged vertically form a U-shaped structure, and the other steel plate member is arranged on the side, away from the temporary horizontal steel support, of the steel upright post. Preferably, in the construction method of the reverse pulling system for the temporary horizontal steel support in the reverse construction method underground space, in the step 1, the temporary horizontal steel support end portion adopts a steel plate embedded part and a lower bracket. Preferably, in the construction method of the reverse pulling system of the temporary horizontal steel support of the reverse construction method underground space, a first through hole for two prestressed cables to pass through is formed in the B1 plate, and a second through hole for two prestressed cables to pass through is formed in the B0 plate. Preferably, in the construction method of the reverse pulling system of the temporary horizontal steel support of