A subway open cut station main body structure steel node assembly design method and system

Abstract

The application discloses a kind of subway open cut station main structure steel node assembly design method and system, belong to underground engineering technical field, including the following steps: using load structure method to calculate the bending moment of basic group under subway open cut station typical section, determine low bending moment area;The steel cage of main structure is implemented three-dimensional modular prefabrication, using longitudinal segmentation and transverse block three-dimensional block mode;Prefabricated module installation follows the assembly sequence of bottom plate, side wall, middle plate, top plate;Design the joint position and connection form of longitudinal distribution bar and module main bar.The application realizes the design of fabricated steel module, relies on longitudinal segmentation and transverse block mode, 1.5m modulus and large block adaptation scheme, combined with the fine connection design of module main bar and longitudinal distribution bar, the joint is arranged in low bending moment area, to ensure the integrity of structure and assembly efficiency;Finally form the whole chain technical standard covering design, production, construction.

Description

Technical Field

[0001] This invention belongs to the field of underground engineering technology, and in particular relates to a design method and system for assembling steel reinforcement nodes in the main structure of a subway open-cut station. Background Technology

[0002] In China, the main structure of open-cut subway stations is still dominated by traditional cast-in-place reinforced concrete technology. However, this technology has significant inherent defects: on-site rebar binding requires a large amount of manpower and is constrained by the limited underground working space, lighting and ventilation conditions, which not only leads to low construction efficiency and poor control over the construction period, but also easily causes inconsistent quality of rebar binding due to differences in manual operation. At the same time, it is accompanied by the problem of high raw material loss rate, which increases project costs and is contrary to the concept of green building.

[0003] To overcome this bottleneck, prefabricated steel cage technology, which combines standardized factory prefabrication with on-site modular assembly, is gradually being promoted. This model, which involves processing modules in the factory and then assembling them on-site before casting, significantly reduces on-site work and dependence on confined underground spaces. Furthermore, it is more suitable for the complex and irregular structural requirements of subway stations than traditional fully prefabricated concrete components. However, the industry has not yet developed a dedicated design method for prefabricated steel cage assembly for subway stations. Existing prefabricated technologies are mostly general solutions that do not fully consider the characteristics of subway retaining structures (such as pile bracing, diaphragm walls with internal support systems) and construction scenario limitations (lifting capacity, working space). This results in a lack of refined design at prefabricated module connection nodes, insufficient adaptation in key aspects such as corner main reinforcement anchorage and longitudinal distribution reinforcement lap splicing, making it difficult to balance structural integrity, connection reliability, construction efficiency, and project economy.

[0004] To address the aforementioned issues, patent CN118979589A discloses a prefabricated rebar cage module connection unit and its usage method. The core of this method involves constructing connection units using slotted angle steel and channel steel, self-locking rebar, and connecting steel plates to achieve rebar cage module docking and reduce the difficulty of manual alignment. However, this solution has practical limitations: each rebar must be individually inserted into the self-locking device for fixation, a cumbersome and repetitive process that increases labor costs and prolongs assembly time, making it unsuitable for large-scale scenarios with stringent efficiency requirements, such as subway projects.

[0005] Patent CN119531552A discloses a steel profile connection device and construction method suitable for integrated steel reinforcement in nuclear islands, proposing the use of C-shaped steel profiles to connect and fix the steel cage. Steel trusses are set between adjacent layers of steel mesh, and C-shaped or H-shaped steel is welded and fixed at the connection points, solving the problems of misalignment and inability to connect horizontal steel profiles with equal strength. However, C-shaped and H-shaped steel profiles are expensive and cannot be widely used.

[0006] Patent CN118531839A discloses a prefabricated subway station and its construction method. The core of this method is to splice multiple prefabricated components end to end to form a circumferential assembly unit, which constitutes the overall station structure. This solves the problems of insufficient flexibility and inconvenient construction associated with traditional prefabricated components. However, this solution does not specify the mechanical properties at the segment cut-off points and does not avoid the peak bending moment area of ​​the structure, making it difficult to effectively guarantee the overall load-bearing strength of the station structure.

[0007] Therefore, there is an urgent need for a systematic steel reinforcement assembly technology solution that adapts to the characteristics of the retaining structure and construction scenario limitations of open-cut subway stations. This solution should scientifically plan the module division to avoid peak bending moment areas and optimize the connection form of key nodes to balance convenience and economy, thereby fundamentally ensuring the integrity of the structure and construction efficiency, and filling the technical gap in the field of subway-specific steel reinforcement assembly design. Summary of the Invention

[0008] Addressing the issue that existing subway station main structures still rely primarily on traditional cast-in-place reinforced concrete construction, which suffers from low construction efficiency, difficulty in controlling assembly precision, and insufficient structural integrity in the cast-in-place model, and that existing prefabricated technologies have not specifically addressed the inherent defects of the cast-in-place process, this invention proposes a systematic design method for the assembly of reinforcing steel bars at complex nodes in open-cut subway stations. This method utilizes three core technologies—mechanically adapted segmentation technology, steel bar connection technology, and large / small segmentation schemes—to replace traditional on-site binding operations. This achieves factory prefabrication of complex steel bar nodes, standardized on-site assembly, and control over structural integrity, fundamentally solving the pain points of cast-in-place processes, such as reliance on manual labor, low efficiency, and inconsistent quality.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A method for assembling steel reinforcement nodes in the main structure of a subway open-cut station, applicable to pile-braced support systems or composite support systems with diaphragm walls and internal bracing, includes the following steps: 1. Low bending moment region identification and modular block planning (S1) The load-structure method is adopted, and based on the transverse two-dimensional load-structure coupling analysis model, the bending moment value of a typical section of a subway open-cut station under the basic combination of loads is calculated. The basic combination of loads includes the standard combination of water and soil pressure, ground surcharge, and structural self-weight. Based on the bending moment calculation results of the above typical sections, the location of the inflection point of the structure is extracted. The bending moment is calculated according to the standard of ±0.05H, where H is the corresponding structural story height in meters, and the low bending moment area is determined. This low bending moment area is used as the key basis for the division of reinforcement modules. The steel cage of the main structure is prefabricated in three dimensions using a three-dimensional modular design with longitudinal segmentation and transverse block division. A longitudinal steel reinforcement module segmentation scheme is developed in combination with the form of pile bracing or diaphragm wall with internal support. A transverse steel reinforcement module division scheme is developed in combination with the cross-sectional bending moment distribution characteristics calculated by the load structure method and the retaining structure scheme.

[0010] 2. Modular assembly sequence design (S2): The on-site installation of prefabricated modules strictly follows the assembly sequence of the base plate, side walls, middle plate, and top plate. By reasonably interleaving the procedures, a stable spatial force system is formed, ensuring the safety and continuity of the construction process.

[0011] 3. Rebar Joint Design (S3) Based on the steel reinforcement module division scheme, the joint positions and connection forms of the longitudinal distribution bars and module main bars are designed in a targeted manner to ensure assembly efficiency and structural integrity; the joint positions are strictly set in the aforementioned low bending moment area to avoid the impact of the bending moment peak area on the connection reliability.

[0012] Furthermore, the segmentation scheme of the longitudinal reinforcement modules described in step S1 satisfies the following technical constraints: (1) The longitudinal segment length L1 adopts a modular size control system, and the standard segment size is determined in integer multiples of 1.5m, using a module of 1.5m; (2) The length of the longitudinal segment L1 must satisfy L1≤S min (S) min (The smaller value between the spacing of concrete supports and the spacing of steel supports) is used to achieve mechanical compatibility with the support system; (3) The overlap length of adjacent modules is ≥35d (d is the diameter of the main reinforcement, in mm), and the segmentation points of each module are located in the low bending moment area to ensure the continuity of the structure under stress.

[0013] Furthermore, the transverse reinforcement module division scheme described in step S1 must simultaneously meet the following three conditions: (1) Prefabricated modules are divided according to the structural parts of the base plate, side walls and top plate, which facilitates high-precision jig processing and standardized production in the factory; (2) Based on the bending moment envelope diagram calculated by the load structure method, the range of the peak bending moment area of ​​the structure should be clearly defined. The cut-off point at the block location must avoid the peak area to ensure the rationality of the stress on the block structure. (3) Strictly control the weight and size of each steel cage, adapt to the on-site hoisting equipment capacity and transportation conditions, and avoid construction inconvenience caused by excessively large or heavy modules.

[0014] Furthermore, the horizontal segmentation adopts two scenario-based adaptation schemes, as follows: a. Small-block system: includes factory-prefabricated top slab corner modules, bottom slab support corner modules, and side wall reinforcement modules, middle slab reinforcement modules, small-block top slab reinforcement modules, and bottom slab reinforcement modules that need to be tied on site; this solution is suitable for general hoisting equipment with a hoisting capacity of <25t and construction conditions with limited working space; b. Large-block system: This system includes prefabricated large-block top slab reinforcement modules and bottom slab support corner modules. The remaining modules that need to be tied on-site are side wall reinforcement modules, middle slab reinforcement modules, and bottom slab reinforcement modules. This solution is suitable for construction conditions with large hoisting equipment with a hoisting capacity of ≥25t and open working spaces.

[0015] Furthermore, the connection method of the main reinforcement of the module in step S3 is selected from mechanical connection, sleeve grouting connection, steel section connection or welding, and the specific technical requirements are as follows: (1) The joint grade of the mechanical connection shall not be lower than Grade I; (2) The welding length is 10d for single-sided welding or 5d for double-sided welding (d is the diameter of the main reinforcement bar, in mm); (3) The joint rate of the same cross section shall not exceed 50% to ensure the overall mechanical performance and connection reliability of the structure.

[0016] Furthermore, the connection methods for the longitudinal distribution bars mentioned in step S3 include mechanical connection, lap splicing, welding, or U-shaped lap splicing, with specific technical requirements as follows: (1) The joint grade of the mechanical connection shall not be lower than Grade I; (2) The lap length of the binding is Lae (seismic anchorage length); (3) The welding length is 10d for single-sided welding and 5d for double-sided welding (d is the diameter of the distribution rib, in mm); (4) The joint rate of the same cross section shall not exceed 50%, taking into account both connection stability and assembly efficiency.

[0017] A complex steel reinforcement node assembly design system for the main structure of a subway open-cut station, constructed based on the above design method, includes: The bending moment calculation and region determination module is configured to establish a transverse two-dimensional load structure analysis model using the load structure method, calculate the bending moment value of a typical section of a subway open-cut station under basic combined action, extract the inflection point of the structure and define the low bending moment region according to ±0.05H, where H is the corresponding structural story height in meters, and provide mechanical basis for module segmentation. Modular division module: The configuration is to formulate a 1.5m longitudinal modular segmentation scheme and two scenario-based block systems for the transverse large / small, to ensure that the module division is adapted to the bending moment distribution characteristics, the form of the retaining structure and the on-site construction conditions; Assembly and joint design module: Configured with a preset assembly sequence of base plate, side walls, middle plate and top plate, design the connection form and joint position of main reinforcement and longitudinal distribution reinforcement of the module, clarify the technical parameters of various connections, and ensure the integrity of the structure and assembly efficiency.

[0018] The beneficial effects of this invention are as follows: 1. Spatial and temporal coordination to ensure construction feasibility: Through the coordinated design of the support system and the main structure, the construction sequence of the retaining structure and the main structure is integrated to form a stable and open construction space, effectively solving the pain points of narrow underground working space and limited hoisting, and providing basic guarantee for the hoisting of steel reinforcement modules; 2. Scientifically adapted block design, taking into account stress and scenario: The longitudinal section adopts a 1.5m modular segmentation, and the transverse section provides two block systems, large and small. This not only avoids the peak bending moment area of ​​the structure by dividing the block into low bending moment areas to ensure the rationality of the stress of the block structure, but also adapts to construction scenarios with different hoisting capabilities and working spaces, thus improving the universality of the technical solution. 3. Improved construction efficiency and quality: The standardized assembly process for the base slab, side walls, middle slab, and top slab is clearly defined. The construction continuity is ensured by interleaving the process. Compared with the traditional cast-in-place process, the amount of on-site manual binding is greatly reduced, and the error of manual operation is reduced. This not only improves construction efficiency, but also enhances the stability of the steel bar connection quality, while reducing raw material waste, which is in line with the concept of green building. 4. Flexible connection methods to adapt to complex working conditions: It provides three main reinforcement connection methods for modules, namely mechanical connection, sleeve grouting connection and steel section connection, as well as longitudinal distribution reinforcement connection technology such as U-shaped lap splice. It can be flexibly selected according to on-site construction conditions and cost budget, which solves the problem of single connection method and poor adaptability of existing technologies. 5. Resolving core industry contradictions and filling technological gaps: Successfully resolved the three core contradictions in prefabricated construction of subway open-cut stations—the contradiction between factory prefabrication precision and on-site assembly errors, the contradiction between modular construction and structural integrity, and the contradiction between industrialized construction and adaptability to irregular structures. Formed a full-chain technical standard covering design-production-construction, filled the technological gap in the field of subway-specific steel reinforcement assembly design, and promoted the transformation and upgrading of subway engineering construction mode towards industrialization and intelligence. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1A design flowchart for a design method and system of steel reinforcement node assembly design for the main structure of a subway open-cut station; Figure 2 This is a schematic diagram of a pile-braced or diaphragm wall with internal bracing enclosure structure. Figure 3 This is a typical bending moment diagram of an arched cross-section; Figure 4 This is a structural diagram of an internal support plus small block system; Figure 5 This is a structural diagram of a modular system with increased internal support. Figure 6 It is the main structural reinforcement connection structure.

[0021] Figure 7 It is a typical connection form of the main reinforcement bars of the main structure.

[0022] Figure 8 This is a schematic diagram of a U-shaped lap joint connection structure with longitudinally distributed ribs.

[0023] In the figure: 1-Drilled piles, 2-Internal support structure support system, 3-Main structure, 4-Low bending moment area, 5-Small segment top slab reinforcement module, 6-Bottom slab reinforcement module, 7-Middle slab reinforcement module, 8-Side wall reinforcement module, 9-Top slab corner module, 10-Bottom slab corner module, 11-Large segment top slab reinforcement module, 12-Main reinforcement connection, 1301-Straight threaded sleeve connection, 1302-Double spiral sleeve connection, 1303-Straight threaded sleeve connection. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] See attached document Figure 1-8 This invention provides a design method for assembling steel reinforcement nodes in the main structure of a subway open-cut station, applicable to the main structure 3 of a subway open-cut station using a pile-supported system or a diaphragm wall plus internal bracing retaining structure 2, comprising the following steps: S1. Using the load-structure method, based on the transverse two-dimensional load-structure coupling analysis model, the bending moment value of a typical section of a subway open-cut station under the basic combination of loads is calculated. The basic combination of loads includes the standard combination of water and soil pressure, ground surcharge, and structural self-weight. Based on the bending moment calculation results of the above typical sections, the location of the inflection point of the structure is extracted. The bending moment is calculated according to ±0.05H, where H is the corresponding structural story height in meters. The standard for determining the low bending moment region 4 is used as the key basis for dividing the reinforcement modules. S2. The steel cage of the main structure 3 adopts a modular prefabrication mode of longitudinal segmentation and transverse block; in combination with the type of the enclosure structure, a longitudinal steel module segmentation scheme is formulated, and in combination with the low bending moment area 4 and the type of enclosure structure, a transverse steel module division scheme is formulated. S3. Design the joint locations and connection methods for longitudinal distribution reinforcement and module main reinforcement; S4. The steel reinforcement modules are assembled on site in the order of bottom slab, side walls, middle slab, and top slab to form the main structural steel reinforcement skeleton.

[0026] The module division in step S2 satisfies: 1. The structural stress characteristics of a transversely segmented structure conforming to the cross-sectional bending moment distribution; 2. The longitudinal segment length L1 is controlled by modular dimensions and satisfies L1≤S min S min The concrete support spacing S 砼 Spacing S with steel support 钢 The minimum value in.

[0027] The overlap length of adjacent modules in the longitudinal segment is ≥35d, where d is the diameter of the main reinforcement in mm, and the segmentation points of each module are all located within the low bending moment region 4.

[0028] The connection method of the main reinforcement of the module is selected from mechanical connection, sleeve grouting connection, steel section connection or welding; among them, the joint level of mechanical connection shall not be lower than Class I, the welding length shall be 10d for single-sided welding or 5d for double-sided welding, where d is the diameter of the main reinforcement in mm, and the joint rate of the same section shall not exceed 50%.

[0029] The connection forms of longitudinal distributed reinforcement include mechanical connection, lap splice, welding, and U-shaped lap splice; among them, the joint grade of mechanical connection shall not be lower than Grade I, the lap splice length shall be Lae, the welding length shall be 10d for single-sided welding and 5d for double-sided welding, where d is the diameter of the main reinforcement in mm, and the joint rate of the same section shall not exceed 50%.

[0030] The horizontal partitioning uses two adaptation schemes: a. Small segment system: includes top plate corner module 9, bottom plate support corner module 10, side wall reinforcement module 8, middle plate reinforcement module 7, small segment top plate reinforcement module 5, bottom plate reinforcement module 6, suitable for general hoisting equipment with hoisting capacity <25t and working space-constrained conditions. b. Large segment system: includes prefabricated large segment top slab reinforcement module 11 and bottom slab support corner module 10. The remaining modules that need to be tied on site are side wall reinforcement module 8, middle slab reinforcement module 7 and bottom slab reinforcement module 6. It is suitable for large hoisting equipment with a hoisting capacity of ≥25t and open working space conditions.

[0031] In step S3, the precast modules of the main reinforcement of the module are connected to the cast-in-place module reinforcement through mechanical connection, sleeve grouting connection or steel section connection, and the joint position is strictly set within the low bending moment region 4 calculated by the load structure method.

[0032] In step S3, the longitudinal distribution bars are connected by U-shaped lap joints.

[0033] A complex steel reinforcement node assembly design system for the main structure of a subway open-cut station includes: Bending moment calculation and region determination module: The load structure method is used to calculate the bending moment of typical sections and determine the low bending moment region 4; Modular division of modules: Developing a longitudinal segmentation scheme and a transverse large / small block system to adapt to bending moment distribution and enclosure structure 2; Assembly and joint design module: Set the assembly sequence of the base plate, side walls, middle plate and top plate, and design the connection form of the main reinforcement and longitudinal distribution reinforcement of the module.

[0034] Example 1: Pile-braced or diaphragm wall with internal bracing retaining structure system A design method and system for assembling steel reinforcement nodes in the main structure of a subway open-cut station is disclosed, primarily applicable to pile-supported systems or diaphragm wall with internal bracing retaining structures. Taking the pile-supported system of Xianshan Road Station on Qingdao Metro Line 15 as an example, as follows... Figure 2 The retaining structure consists of Φ1000@1400mm bored piles 1 plus three layers of internal bracing 2. The first layer is an 800×1000mm reinforced concrete bracing, arranged at a standard spacing of 9m; the second and third layers are Φ800×20mm steel bracing, arranged at a standard spacing of 3m. The main structure 3 adopts a column-free, large-span arch structure.

[0035] The type of retaining structure (pile-supported / diaphragm wall system) has a significant impact on the steel reinforcement engineering of the station's main structure, mainly in three aspects: ① the construction joints must correspond spatially with the support axis; ② the precast steel cage division must meet the support spacing module requirements; ③ the hoisting process must adapt to the clearance limitations of the support system. Taking the steel support system of Xianshan Road Station as an example, its longitudinal center distance is 3m. After deducting the steel support pipe diameter (800mm) and the hinge head construction size (200mm), the effective working space is only 2m. Based on this constraint, the constraint L1≤S min The optimal longitudinal block size for a precast steel cage is determined to be a 1.5m module.

[0036] Example 2: Calculation of Internal Forces in the Main Structure A two-dimensional transverse load structure analysis model was established using the load-structure method to obtain the bending moment diagram of a typical arched section (Figure 3). By calculating the bending moment value under the standard combination of water and soil pressure, ground surcharge, and structural self-weight, the low bending moment region 4 of the main structure 3 of the station was extracted. The positioning of the center line of the segment joint must meet the dual control standards: ① The theoretical inflection point (zero bending moment) ±0.05H range, where H is the corresponding structural floor height in meters, to ensure that the segment avoids the peak bending moment area; ② The module weight within the feasible construction area is ≤25t (including lifting equipment), which is suitable for on-site hoisting safety requirements. The combination of the two ensures that the segment is both mechanically reasonable and constructionally feasible. Taking the bending moment envelope diagram of the typical section of Xianshan Road Station as an example, the low bending moment region 4 corresponding to the characteristic inflection point in the bending moment diagram is selected and divided into segments. Figure 4 The small segmented rebar module scheme shown is similar to Figure 5 The large-block steel reinforcement module scheme is shown.

[0037] Example 3: Small-block prefabricated module scheme According to the bending moment diagram of the main structure 3 of the station, as follows: Figure 3 Considering the construction constraint that the module weight is ≤25t (including lifting equipment), a steel reinforcement block plan for main structure 3 is formulated, such as... Figure 4 As shown. The top slab corner module 9 and the bottom slab corner module 10 adopt prefabricated steel cages. The cast-in-place area includes small segmented top slab 5, middle slab 7, small segmented bottom slab 6, and side walls 8. The prefabricated modules and the cast-in-place area can be connected through steel connection nodes to achieve rapid assembly and structural continuity control.

[0038] Example 4: Large-block prefabricated module scheme According to the bending moment diagram of the main structure (3) of the station (e.g.) Figure 3 ), and formulate a large-block steel reinforcement scheme for main structure 3 (such as Figure 5(As shown). The factory prefabricates large-segment top slab reinforcement modules 11 and bottom slab support corner modules 10 using high-precision jigs, minimizing on-site work. On-site work only involves binding the side wall reinforcement modules 8, middle slab reinforcement modules 7, and bottom slab reinforcement modules 6, simplifying on-site procedures. The boundaries of all modules are optimized using load-structure calculations, strictly avoiding peak bending moment areas and falling within low bending moment regions 4, ensuring the continuity of stress in the segmented structure and the overall load-bearing capacity.

[0039] Example 5: Connection Structure Precast modules are connected to the cast-in-place reinforcement using mechanical connections, grouted sleeve connections, or steel connection nodes. The joint locations are strictly within the low-bending-moment zone 4, achieving both rapid assembly and ensuring structural continuity and mechanical reliability. Figure 6 As shown. Among them, the recommended mechanical connection for the main reinforcement of the module is using straight threaded sleeves with both positive and negative threads, and double threaded sleeves (e.g., Figure 7 As shown), this type of connection effectively improves the adaptability of the allowable error when the rebar cage is connected, reduces the difficulty of on-site assembly and alignment, and further improves the assembly efficiency and connection quality stability of the prefabricated rebar modules. The longitudinal distribution bars adopt a U-shaped lap connection, with straight threaded sleeve connection 1301, double spiral sleeve connection 1302, and straight threaded sleeve connection 1303 (as shown). Figure 8 As shown in the figure, the lap length is set to 350mm, which meets the requirements of seismic anchorage and structural force transmission, while taking into account the connection stability and ease of assembly, and is consistent with the lap splicing technical specifications of longitudinal distributed bars in claims 5 and 8.

[0040] The above descriptions are merely specific embodiments of the present invention, and common knowledge regarding the specific structures and characteristics of the solutions is not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

[0041] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0042] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A design method for the assembly of steel reinforcement nodes in the main structure of a subway open-cut station, applicable to the main structure of a subway open-cut station using a pile-braced support system or a diaphragm wall plus internal bracing retaining structure support system, characterized in that, Includes the following steps: S1. Using the load-structure method, based on the transverse two-dimensional load-structure coupling analysis model, the bending moment value of a typical section of a subway open-cut station under the basic combination of loads is calculated. The basic combination of loads includes the standard combination of water and soil pressure, ground surcharge, and structural self-weight. Based on the bending moment calculation results of the above typical sections, the location of the inflection point of the structure is extracted. The bending moment is calculated according to ±0.05H, where H is the corresponding structural story height in meters, to determine the low bending moment area. This low bending moment area is used as the key basis for the division of reinforcement modules. S2. The steel cage of the main structure adopts a modular prefabrication mode of longitudinal segmentation and transverse block division; in combination with the type of the enclosure structure, a longitudinal steel reinforcement module segmentation scheme is formulated, and in combination with the low bending moment area and the type of enclosure structure, a transverse steel reinforcement module division scheme is formulated. S3. Design the joint locations and connection methods for longitudinal distribution reinforcement and module main reinforcement; S4. The steel reinforcement modules are assembled on site in the order of bottom slab, side walls, middle slab, and top slab to form the main structural steel reinforcement skeleton.

2. The method for assembling steel reinforcement nodes in the main structure of a subway open-cut station according to claim 1, characterized in that, The module division in step S2 satisfies: (1) The structural stress characteristics of the transversely segmented structure conforming to the cross-sectional bending moment distribution; (2) The longitudinal segment length L1 is controlled by modular dimensions and satisfies L1≤S min S min The concrete support spacing S 砼 Spacing S with steel support 钢 The minimum value in.

3. The method for assembling steel reinforcement nodes in the main structure of a subway open-cut station according to claim 2, characterized in that, The overlap length of adjacent modules in the longitudinal segment is ≥35d, where d is the diameter of the main reinforcement bar in mm, and the segmentation points of each module are all located within the low bending moment region.

4. The method for assembling steel reinforcement nodes in the main structure of a subway open-cut station according to claim 1, characterized in that, The connection method of the main reinforcement of the module can be selected from mechanical connection, sleeve grouting connection, steel section connection or welding; among them, the joint level of mechanical connection shall not be lower than Class I, and the welding length shall be 10d for single-sided welding or 5d for double-sided welding, where d is the diameter of the main reinforcement, and the unit is mm.

5. The method for assembling steel reinforcement nodes in the main structure of a subway open-cut station according to claim 1, characterized in that, The connection methods for longitudinal distributed reinforcement include mechanical connection, lap splice, welding, and U-shaped lap splice; among them, the joint grade of mechanical connection shall not be lower than Grade I, the lap splice length shall be Lae, the welding length shall be 10d for single-sided welding and 5d for double-sided welding, where d is the diameter of the main reinforcement, and the unit is mm.

6. The method for assembling steel reinforcement nodes in the main structure of a subway open-cut station according to claim 1, characterized in that, The horizontal partitioning uses two adaptation schemes: a. Small segment system: includes top plate corner module, bottom plate support corner module, as well as side wall reinforcement module, middle plate reinforcement module, small segment top plate reinforcement module, and bottom plate reinforcement module. It is suitable for general hoisting equipment with hoisting capacity <25t and working conditions with limited working space. b. Large-block system: Includes prefabricated large-block top slab reinforcement modules and bottom slab support corner modules. The remaining modules that need to be tied on site are side wall reinforcement modules, middle slab reinforcement modules, and bottom slab reinforcement modules. It is suitable for large hoisting equipment with a hoisting capacity of ≥25t and open working space conditions.

7. The method for assembling steel reinforcement nodes in the main structure of a subway open-cut station according to claim 1, characterized in that, In step S3, the precast modules of the main reinforcement of the module are connected to the cast-in-place module reinforcement through mechanical connection, sleeve grouting connection or steel section connection, and the joint position is strictly set in the low bending moment area calculated by the load structure method.

8. The method for assembling steel reinforcement nodes in the main structure of a subway open-cut station according to claim 1, characterized in that, In step S3, the longitudinal distribution bars are connected by U-shaped lap joints.

9. A design system for assembling complex steel reinforcement nodes in the main structure of a subway open-cut station, characterized in that, The design method according to any one of claims 1-8 includes: Bending moment calculation and zone determination module: The load structure method is used to calculate the bending moment of typical sections and determine the low bending moment zone; Modular division of modules: Developing longitudinal segmentation schemes and transverse large / small block systems to adapt to bending moment distribution and enclosure structure; Assembly and joint design module: Set the assembly sequence of the base plate, side walls, middle plate and top plate, and design the connection form of the main reinforcement and longitudinal distribution reinforcement of the module.

Images