Construction method for steel-first and concrete-second steel bar connecting structure of permanent-temporary combined station joint

Abstract

The invention discloses a construction method for a steel-first and concrete-second steel bar connecting structure of a permanent-temporary combined station node, which comprises the following steps of: analyzing the maximum allowable error of a steel bar connecting area, and determining the mounting position of a movable head; the jack at the supporting position is pre-supported, and error adjustment is carried out; detachable temporary movable heads are installed on the two sides of the supporting end at the permanent-temporary combined station plate wall joint, and steel connection is conducted firstly; connecting a post-mixing joint at a supporting position; pouring concrete at the supporting position; and removing the adjustable head to finish node construction. The efficient and accurate steel bar connecting plate wall joint structure and the construction method are achieved, and the problems that in a traditional connecting mode, error adjustment is difficult, and the construction efficiency is low are effectively solved; the accuracy and reliability of steel bar connection are improved, and an efficient and reliable steel bar connection solution is provided for construction of the assembly type station.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fabricated underground structure, and particularly relates to a steel-concrete connection structure construction method for a permanent-temporary combined station node. BACKGROUND

[0002] In recent years, fabricated underground structures are widely used in the construction of subway stations due to their short construction period, small environmental impact, and controllable quality. Permanent-temporary combined fabricated stations regard the temporary supporting components such as diaphragm walls and precast supports as part of the permanent main structure, further optimizing the construction process and cost. In the traditional construction process of permanent-temporary combined fabricated stations, the use of precast supports for phased installation can reduce hoisting obstacles, but the steel bar connection still relies on traditional technology, making it difficult to solve the connection failure problem caused by assembly errors. Similarly, in other related research on fabricated station construction technology, C-shaped and T-shaped pieces are used to achieve rapid assembly of precast diaphragm walls, and subsequent joints are grouted, but the connection details between the steel bars and the cast-in-place concrete are not involved in the process, leaving a weak link in the stress.

[0003] In the construction of fabricated underground structures, the traditional method mainly has the following limitations in steel bar connection technology: First, the error adjustment capability is insufficient: precast components have assembly difficulties during hoisting, and traditional welding or mechanical sleeves have low tolerance for steel bar position, complex process and difficulty in adapting to dynamic construction needs, leading to inconvenient connection node construction or anchoring failure due to stress concentration during use.

[0004] Second, the construction efficiency is low: traditional welding requires a lot of manual operation and is difficult to adapt to the dense steel bar mesh layout of fabricated stations due to space limitations; although the grouting sleeve can achieve semi-automatic connection, the grouting material takes a long time to solidify, affecting the construction rhythm.

[0005] Third, the connection reliability is insufficient: for key stress parts such as structural tensile longitudinal reinforcement, ordinary mechanical joints have insufficient fatigue resistance and seismic performance, and molten joints are sensitive to construction environment (such as temperature and humidity), which can easily cause quality problems.

[0006] In existing technologies, for example, the "steel-concrete combined section" of the hybrid girder cable-stayed bridge uses precast bridge components and anchor cables for coordinated construction, but its steel bar connection method relies on post-cast concrete wrapping and cannot be directly applied to underground spaces such as fabricated stations; the concave-convex mortise grouting technology developed for fabricated station construction has high requirements for construction accuracy and is difficult to adjust the accuracy of steel bar connection.

[0007] In summary, the steel bar connection technology of the existing assembled station still faces multiple challenges in precision, efficiency and reliability. Therefore, a joint quick connection method that combines error adjustment, high-performance materials and modular process is urgently needed to meet the construction needs of the permanent and temporary combined assembled station in complex underground combined structure conditions. SUMMARY

[0008] The present application is proposed to solve the problems existing in the prior art, and the purpose is to provide a construction method of a steel bar connection structure of a permanent and temporary combined station node.

[0009] The technical solution of the present application is: a construction method of a steel bar connection structure of a permanent and temporary combined station node, comprising the following steps: A. Analyzing the maximum allowable error of the steel bar connection area to determine the installation position of the adjustable head and the adjustable steel; B. Pre-supporting the jacks at the support position and adjusting the error through the adjustable steel; C. Installing detachable temporary adjustable heads and adjustable steels on both sides of the support end at the permanent and temporary combined station panel wall node to perform steel connection first; D. Performing post-mixed joint connection at the support position; E. Pouring concrete at the support position; F. Removing the adjustable heads and the adjustable steels to complete the node construction.

[0010] Further, step A analyzes the maximum allowable error of the steel bar connection area to determine the installation position of the adjustable head and the adjustable steel, and the specific process is as follows: First, according to the structural design requirements, the minimum lap length S of the steel bar and the maximum error length L of the diaphragm wall construction are considered to calculate the maximum allowable error S+L of the steel bar connection area; Then, according to the calculated maximum allowable error S+L of the steel bar connection area, the adjustable head and the adjustable steel are fixed by applying pressure through the jack; Finally, the adjustable steel with appropriate length is set, and the adjustable head and the adjustable steel are placed between the precast beam and the diaphragm wall to determine the installation position of the adjustable head and the adjustable steel.

[0011] Further, step B pre-supports the jacks at the support position and adjusts the error through the adjustable steel, and the specific process is as follows: First, during the assembly process of the precast beam and the precast diaphragm wall, the jacks are used to pre-support the support nodes of the two to apply pre-axial force; Then, the error control during the assembly process is realized by adjusting the size of the pre-axial force and the length of the adjustable steel.

[0012] Further, step C installs detachable temporary adjustable head and adjustable steel at both sides of the support end of the permanent and temporary combined station board wall node, and carries out steel connection in advance, and the specific process is as follows: First, detachable temporary adjustable head and adjustable steel are installed at the support of the joint between the prefabricated ground wall and the prefabricated beam of the permanent and temporary combined station; Then, the length of the adjustable steel is adjusted according to the actual error between the board wall nodes, and the jack is tightened; Finally, the steel connection in advance at the joint is realized through the temporary adjustable head and the adjustable steel.

[0013] Further, the adjustable head is arranged in parallel at both sides of the temporary corbel support end of the prefabricated beam.

[0014] Further, step D carries out the post-mixed joint connection of the support position, and the specific process is as follows: First, the prefabricated beam is placed at the shear groove position of the prefabricated beam, and the steel bar connection at the board wall node connection is carried out; Then, the waist reinforcement, stirrup and tensile reinforcement of the prefabricated beam and the prefabricated ground wall are aligned and overlapped; Finally, the longitudinal reinforcement in the tensile area and the longitudinal reinforcement in the compression area are mechanically connected by using adjustable error joints.

[0015] Further, the longitudinal reinforcement connection position in the tensile area adopts UHPC high-strength concrete or self-compacting concrete material, and is jointly stressed with the anchoring connection of the steel bar and the sleeve, to realize the consolidation connection at the board wall node.

[0016] Further, step E pours concrete at the support position, and the specific process is as follows: First, after the steel bar connection is completed, the concrete is poured; Then, the adjustable head and the adjustable steel are reserved until the concrete structure reaches the standard strength.

[0017] Further, step F removes the adjustable head and the adjustable steel, and completes the node construction, and the specific process is as follows: The adjustable head and the adjustable steel are removed, and the temporary corbel is chiseled off, so as to avoid adverse effects on the subsequent permanent structure.

[0018] The beneficial effects of the present application are as follows: The present application is particularly suitable for rapid and accurate connection of steel bars in the construction of prefabricated underground structures. By using the joint with adjustable error and high-performance material connection technology, the present application realizes rapid connection of the board wall node in the construction process of the permanent and temporary combined prefabricated station, while ensuring the stability and stress performance of the joint connection structure.

[0019] The application effectively solves the problems of error adjustment difficulty, low connection efficiency and high cost in the traditional station diaphragm wall panel wall node connection method, and improves the construction efficiency and quality. An efficient and reliable node connection solution is provided for the assembly type station construction. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 is the connection front view of the adjustable head and the fixed end of the panel wall in the application; Fig. 2 is the connection plan view of the adjustable head and the fixed end of the panel wall in the application; Fig. 3 is a schematic view of the UHPC joint in the application; Among them: 1, prefabricated diaphragm wall; 2, prefabricated diaphragm wall connecting steel plate; 3, adjustable head; 4, adjustable expansion steel; 5, corbel connecting steel plate; 6, post-poured layer; 7, temporary corbel; 8, prefabricated beam; 9, longitudinal reinforcement in tension zone; 10, steel bar adapter; 11, waist reinforcement; 12, prefabricated diaphragm wall shear groove; 13, longitudinal reinforcement in compression zone; 14, stirrup; 15, prefabricated beam shear groove; 16, tie bar; L represents the lap length, and S represents the axial error range. DETAILED DESCRIPTION

[0021] Hereinafter, the application will be described in detail with reference to the drawings and examples: As Figs. 1 to 3 shown, a first steel then mixed steel bar connection structure construction method of permanent and temporary combined station node includes the following steps: A. Analyzing the maximum allowable error of the steel bar connection area to determine the installation position of the adjustable head 3 and the adjustable steel 4; B. Pre-supporting the jacks at the support position, and adjusting the error through the adjustable steel 4; C. Installing detachable temporary adjustable heads 3 and adjustable steels 4 on both sides of the support end at the permanent and temporary combined station panel wall node to perform first steel connection; D. Performing post-mixed joint connection at the support position; E. Pouring concrete at the support position; F. Removing the adjustable head 3 and the adjustable steel 4 to complete the node construction.

[0022] Step A analyzes the maximum allowable error of the steel bar connection area to determine the installation position of the adjustable head 3 and the adjustable steel 4, and the specific process is as follows: First, according to the structural design requirements, the minimum lap length S of the steel bar and the maximum error length L of the diaphragm wall construction are considered comprehensively, and the maximum allowable error S+L of the steel bar connection area is calculated; Then, according to the calculated maximum allowable error S+L of the steel bar connecting area, pressure is applied by a jack or the like to fix the adjustable head 3 and the adjustable steel bar 4. Finally, the adjustable steel bar 4 with a proper length is arranged, and the adjustable head 3 and the adjustable steel bar 4 are arranged between the prefabricated cross beam 8 and the prefabricated diaphragm wall 1 to determine the installation position of the adjustable head 3 and the adjustable steel bar 4.

[0023] In step B, the jack at the pre-supporting position is pre-supported, and the error is adjusted by the adjustable steel bar 4, and the specific process is as follows: Firstly, the pre-supporting node of the prefabricated cross beam 8 and the prefabricated diaphragm wall 1 is pre-supported by using the jack to apply the pre-axial force. Then, the error control in the assembling process is realized by adjusting the size of the pre-axial force and the length of the adjustable steel bar 4.

[0024] Specifically, the adjustable steel bar 4 is arranged between the diaphragm wall and the prefabricated cross beam 6 to connect the two, and the adjustable steel bar 4 is a steel bar or a steel pipe with different modules. A jack is arranged at one end of the adjustable steel bar 4, and the assembling error is adjusted by the jack and the adjustable steel bar to realize the error control in the assembling process.

[0025] In step C, the detachable temporary adjustable head 3 and the adjustable steel bar 4 are arranged between the prefabricated diaphragm wall 1 and the prefabricated cross beam 8 of the permanent and temporary combined station to realize the steel connection, and the specific process is as follows: Firstly, the detachable temporary adjustable head 3 and the adjustable steel bar 4 are arranged at the support of the joint between the prefabricated diaphragm wall 1 and the prefabricated cross beam 8 of the permanent and temporary combined station. Then, the length of the adjustable steel bar 4 is adjusted according to the actual error between the panel wall joints, and the jack is used for pre-tightening. Finally, the steel connection at the joint is realized by the temporary adjustable head 3 and the adjustable steel bar 4.

[0026] The adjustable head 3 is arranged on both sides of the temporary corbel 7 supporting end of the prefabricated cross beam 8.

[0027] Specifically, the adjustable head 3 is as shown in Fig. 1 , Fig. 2 The height of the adjustable head 3 in the wall height direction is obtained by calculating the height + height error.

[0028] The adjustable head 3 is connected and fixed with the prefabricated diaphragm wall 1 through the pre-buried connecting steel plate 2 in the wall. On the other side, the temporary corbel 7 is arranged on both sides of the prefabricated cross beam 8, and the other end of the adjustable head 3 is fixed through the corbel connecting steel plate 5.

[0029] The temporary adjustable head 3 is arranged on both sides of the support end to provide a space for reserving the error in advance. The temporary corbel 7 and the anti-falling corbel are arranged at the adjustable head 3 to enhance the stability of the structure.

[0030] The prefabricated cross beam 8 is provided with a post-cast layer 6.

[0031] Step D is to connect the post-mixed joint at the support position, and the specific process is as follows: First, the prefabricated cross beam 8 is placed at the position of the prefabricated beam shear groove 15 to connect the steel bars at the plate wall joint; Then, the prefabricated cross beam 8 and the waist rib 11, hoop rib 14 and tension rib 16 of the prefabricated ground wall 1 are aligned and overlapped; Finally, the longitudinal rib 9 in the tension area and the longitudinal rib 13 in the compression area are mechanically connected using an adjustable error joint.

[0032] The mechanical method can be, but is not limited to, cold extrusion joint, sleeve and rib extrusion joint, etc.

[0033] The longitudinal rib 9 in the tension area is connected to the UHPC high-strength concrete or self-compacting concrete material, which is jointly stressed with the anchoring connection of the steel bar and the sleeve to realize the consolidation connection at the plate wall joint.

[0034] Specifically, as shown in Fig. 3 The longitudinal rib 9 in the tension area resists bending moment and interface shear force; the ground wall is provided with a steel bar adapter 10 for connecting the steel bars; the waist rib 11 resists torque, and the tension rib 16 performs horizontal connection, and the hoop rib 14 resists joint shear force.

[0035] Specifically, during the steel bar overlapping process, L represents the overlapping length, and S represents the axial error range.

[0036] Specifically, the plate wall joint forms a prefabricated ground wall shear groove 12 at the corresponding connection position, and correspondingly, the end face of the prefabricated cross beam 8 forms a prefabricated beam shear groove 15.

[0037] Step E is to pour concrete at the support position, and the specific process is as follows: First, after completing the steel bar connection, pour the concrete; Then, keep the live head 3 and the adjustable steel bar 4 until the concrete structure reaches the standard strength.

[0038] Step F is to remove the live head 3 and the adjustable steel bar 4 to complete the joint construction, and the specific process is as follows: Remove the live head 3 and the adjustable steel bar 4, and chisel off the temporary corbel 5 to avoid adversely affecting the subsequent permanent structure.

[0039] More specifically, the pre-applied axial force of the jack is fed back in real time through a pressure sensor, the jack adjusts the pre-branching precision, controls the error, and ensures that the axial deviation of the assembled component meets the design requirements. Ensure accurate positioning before subsequent steel bar connection during the implementation of "steel first and then mix".

[0040] Specifically, the high-performance cementing material connection in step C adopts UHPC high-strength concrete or self-compacting concrete to connect the joints at the tension longitudinal reinforcement 9 of the component, and an adjustable grouting sleeve joint is used to realize error adjustment by changing the sleeve length, and the joint at the steel bar connection is gripped by the grouting material under the action of the high-performance cementing material, and the stress is reliable.

[0041] Ordinary steel bars are small in size and easy to bend, so ordinary mechanical connection modes such as cold extrusion joints, sleeve and reinforcement extrusion joints are used to control the connection error and ensure the connection strength and durability.

[0042] The above specific embodiments only provide a schematic and are not restrictive, the method defined herein can be transformed in other forms without departing from the purpose of the application and the scope protected by the claims, and all belong to the protection scope of the application.

Claims

1. A construction method for a steel-first followed by concrete reinforcement connection structure at a permanent and temporary combined station node, characterized in that: The following steps are involved: A. Analyze the maximum allowable error of the steel bar connection area and determine the installation position of the movable head (3) and the adjustable steel (4); B. The jack at the pre-supported top support position is adjusted for error through the adjustable steel (4); C. Install a detachable temporary joint (3) and an adjustable steel section (4) on both sides of the support end of the permanent-temporary combined station wall node to perform a steel connection; D. Make the post-mixing joint connection at the support position; E. Pour concrete at the support position; F. Remove the movable head (3) and the adjustable steel (4) to complete the node construction.

2. The method for constructing a steel-first followed by concrete reinforcement connection structure for a permanent and temporary combined station node according to claim 1, characterized in that: Step A: Analyze the maximum allowable error of the steel bar connection area and determine the installation position of the movable head (3) and the adjustable steel (4). The specific process is as follows: First, based on the structural design requirements, the minimum lap length S of the steel bars and the maximum error length L of the ground-connected wall construction are comprehensively considered to calculate the maximum allowable error S+L of the steel bar connection area; Then, according to the calculated maximum allowable error S+L of the steel bar connection area, pressure is applied by a jack to fix the movable head (3) and the adjustable steel section (4); Finally, an adjustable steel section (4) of appropriate length is set, and the movable head (3) and the adjustable steel section (4) are placed between the prefabricated crossbeam (8) and the ground-connected wall, and the installation positions of the movable head (3) and the adjustable steel section (4) are determined.

3. The method for constructing a steel-first followed by concrete reinforcement connection structure for a permanent and temporary combined station node according to claim 1, characterized in that: Step B: The jack at the pre-support position is adjusted for error by means of the adjustable steel (4). The specific process is as follows: First, during the assembly process of the prefabricated crossbeam (8) and the prefabricated ground connection wall (1), a jack is used to apply a pre-axial force to the supporting nodes of the two for pre-supporting; Then, the error control of the assembly process is achieved by adjusting the magnitude of the pre-axial force and the length of the adjustable steel section (4).

4. The method for constructing a steel-first followed by concrete reinforcement connection structure for a permanent and temporary combined station node according to claim 1, characterized in that: Step C: Install a detachable temporary joint (3) and an adjustable steel section (4) on both sides of the support end of the permanent-temporary combined station wall node to perform the steel connection. The specific process is as follows: First, a detachable temporary joint (3) and an adjustable steel section (4) are installed at the supports at the nodes of the prefabricated ground connection wall (1) and the prefabricated crossbeam (8) of the permanent-temporary combined station; Then, the length of the adjustable steel section (4) is adjusted according to the actual error between the plate wall nodes, and the steel section (4) is tightened by a jack; Finally, the steel connection at the node is achieved through a temporary flexible joint (3) and an adjustable steel section (4).

5. The method for constructing a steel-first followed by concrete reinforcement connection structure for a permanent and temporary combined station node according to claim 4 is characterized in that: The movable head (3) is arranged in parallel on both sides of the supporting end of the temporary corbel (7) of the prefabricated beam (8).

6. The method for constructing a steel-first followed by concrete reinforcement connection structure for a permanent and temporary combined station node according to claim 1, characterized in that: Step D is to connect the post-mixing joint at the support position. The specific process is as follows: First, the precast beam (8) is placed in the precast beam shear groove (15) and the steel bars at the slab-wall node connection are connected; Then, the waist reinforcement (11), stirrups (14), and tension bars (16) of the prefabricated crossbeam (8) and the prefabricated ground connecting wall (1) are aligned and overlapped; Finally, the longitudinal reinforcement in the tension zone (9) and the longitudinal reinforcement in the compression zone (13) are mechanically connected using adjustable error joints.

7. The method for constructing a steel-first-then-concrete reinforcement connection structure for a permanent and temporary combined station node according to claim 6, characterized in that: The connection position of the longitudinal reinforcement (9) in the tension zone is made of UHPC high-strength concrete or self-compacting concrete material, and is subjected to force together with the anchor connection of the reinforcement and the sleeve to achieve a consolidated connection at the plate-wall node.

8. The method for constructing a steel-first followed by concrete reinforcement connection structure for a permanent and temporary combined station node according to claim 1, characterized in that: Step E: Pour concrete at the support position. The specific process is as follows: First, after completing the steel bar connection, pour the concrete; Then, the movable head (3) and the adjustable steel section (4) are retained until the concrete structure strength reaches the standard.

9. The method for constructing a steel-first followed by concrete reinforcement connection structure for a permanent and temporary combined station node according to claim 1, characterized in that: Step F: Remove the movable head (3) and the adjustable steel (4) to complete the node construction. The specific process is as follows: Remove the movable head (3) and the adjustable steel (4), and chisel out the temporary corbel (5) to avoid adverse effects on the subsequent construction of the permanent structure.

Images