Construction method of large-span corridor bailey frame based on midas model

Abstract

This invention relates to a construction method for a large-span Bailey bridge connecting corridor based on the Midas model, belonging to the field of large-span connecting corridor technology. The method includes: analyzing the stress on the basement roof slab based on the positioning coordinates of pre-embedded steel plates, drawing a foundation node layout diagram, and welding double-section steel foundation beams to form a force-transfer frame. This frame is vertically assembled with Bailey panel columns to form Bailey column units, and adjacent units are horizontally connected using channel steel connecting rods to construct a support skeleton. The stress and deformation of this skeleton are calculated using Midas software to obtain verification data, based on which Bailey crossbeams and longitudinal beams are hoisted to establish a high-altitude load-bearing platform. Finally, the platform is fixed to the I-beam distribution beams using clamping plates to create a distribution beam support layer. Based on this layer, a disc-lock scaffold is erected to complete the construction of the connecting corridor pouring platform. This method solves the problem that existing technical solutions often lack effective utilization assessment of underground space, leading to potential insufficient foundation bearing capacity during construction.

Description

Technical Field

[0001] This invention relates to the field of long-span connecting corridor technology, and in particular to a construction method for long-span connecting corridor Bailey bridges based on the midas model. Background Technology

[0002] In modern building construction, especially for the construction of connecting corridors in large public buildings and high-rise buildings, traditional methods often rely on on-site scaffolding and the use of extensive formwork support systems to complete concrete pouring. These methods not only consume significant time and manpower, but also pose substantial challenges to the stability and safety of large-span structures. For example, when arranging foundation nodes and welding double-section steel foundation beams on the basement roof slab, existing technical solutions often lack an effective assessment of the utilization of underground space, potentially leading to insufficient foundation bearing capacity during construction. This directly affects the safety and durability of the entire building structure.

[0003] However, a significant drawback of existing technologies in constructing long-span connecting corridors is the difficulty in precisely controlling the stability of the connections between Bailey bridge column units, especially in high-altitude working environments. Due to the complex and variable nature of construction sites, traditional connection methods are prone to displacement or deformation, thus affecting the overall structural stability. This instability increases the risks during construction and may lead to safety hazards during subsequent use. To address this issue, this invention proposes a construction method for long-span Bailey bridges based on the Midas model. Through precise calculation and simulation, the stability of the connections between components is ensured, thereby improving the safety and reliability of the entire connecting corridor structure. Summary of the Invention

[0004] The purpose of this invention is to at least partially solve one of the technical problems existing in the prior art.

[0005] To achieve the above objectives, this invention provides a construction method for large-span Bailey bridges based on the Midas model, comprising the following steps:

[0006] Based on the positioning coordinates of the embedded steel plate, the stress analysis of the basement roof slab is carried out to obtain the foundation node layout diagram. Based on the foundation node layout diagram, the double-section steel foundation beam is welded to form the foundation force transmission frame.

[0007] The basic force transmission frame and the Bailey panel combination column are vertically assembled to form a Bailey column unit, and the channel steel connecting rod is horizontally connected to the adjacent Bailey column unit to form a column support frame.

[0008] The stress and deformation of the column support frame are calculated using Midas software to generate Bailey beam verification data. Based on the Bailey beam verification data, the Bailey crossbeams and Bailey longitudinal beams are hoisted and erected to form a high-altitude load-bearing platform.

[0009] The high-altitude bearing platform is fixed to the I-beam distribution beam with clamps to form a distribution beam support layer, and a disc-type scaffold is erected based on the distribution beam support layer to form a connecting corridor pouring platform.

[0010] Furthermore, based on the positioning coordinates of the embedded steel plate, a stress analysis was performed on the basement roof slab to obtain the foundation node layout diagram, including:

[0011] Based on the positioning coordinates of the embedded steel plate, the basement roof slab is meshed using the finite element analysis method to obtain the roof slab mesh model;

[0012] A concentrated load transmitted by a Bailey bridge is applied to the top plate mesh model to obtain stress distribution data for each node of the top plate. The stress distribution data includes the stress values ​​of each node in the X, Y, and Z directions.

[0013] Based on the stress distribution data, stress concentration areas are determined, and node densification is performed on the stress concentration areas. Finite element calculations are then performed again to obtain optimized stress distribution data.

[0014] Based on the optimized stress distribution data, the locations of foundation nodes that meet the bearing capacity requirements of the basement roof slab are determined, and a foundation node layout diagram is drawn based on the foundation node locations.

[0015] Furthermore, the welding construction of the double-section steel foundation beams based on the aforementioned basic node layout diagram to form the foundation force transmission frame includes:

[0016] The node coordinates of the basic node layout diagram are extracted to obtain the three-dimensional coordinate data of the basic nodes. Based on the three-dimensional coordinate data of the basic nodes, the double-section steel foundation beam is cut into sections to obtain steel foundation beam components. The steel foundation beam components are then pre-assembled and positioned to determine the relative positional relationship of each component.

[0017] Through welding, the pre-assembled and positioned steel foundation beam components are welded based on their relative positional relationships to obtain a preliminary welded force transmission frame structure. The weld quality of the preliminary welded force transmission frame structure is then inspected and the joints are reinforced to obtain a foundation force transmission frame that meets the load-bearing requirements.

[0018] Furthermore, the vertical assembly of the basic force transmission frame and the Bailey panel composite column to form a Bailey column unit includes:

[0019] The dimensions of the basic force transmission frame are measured to obtain frame dimension data. Based on the frame dimension data, the Bailey panel combination columns are pre-selected and matched and pre-assembled to obtain the assembled Bailey panel combination columns.

[0020] The basic force transmission frame and the assembled Bailey panel column are vertically assembled using a high-strength bolt connection process to form a Bailey column unit.

[0021] Furthermore, the horizontal connection of the channel steel connecting rod to the adjacent Bailey column unit to form a column support frame includes:

[0022] The spacing between adjacent Bailey column units is measured to obtain column spacing data. Based on the column spacing data, the channel steel connecting rod is cut to obtain the channel steel connecting rod component.

[0023] The channel steel connecting rod component is pre-bent to obtain a pre-bent channel steel connecting rod, and the pre-bent channel steel connecting rod is horizontally connected to the adjacent Bailey column unit by bolt connection process to obtain a preliminary connected column structure.

[0024] The levelness data of the column structure is detected. If the levelness data is not within the preset range, the column structure is fine-tuned based on the levelness data to obtain the column support frame.

[0025] Furthermore, the stress and deformation calculation of the column support frame using Midas software to obtain Bailey beam verification data includes:

[0026] Based on the actual structural parameters of the column support frame, the column support frame is geometrically modeled to obtain a frame geometric model. The frame geometric model is then divided into elements and numbered with nodes to obtain a standardized frame model.

[0027] The standardized skeleton model was subjected to design load conditions using Midas software to obtain skeleton load response data. Stress extraction analysis was then performed on the skeleton load response data to obtain skeleton stress distribution data.

[0028] Based on the stress distribution data of the skeleton, displacement calculation is performed on the standardized skeleton model to obtain skeleton deformation data. The skeleton stress distribution data and skeleton deformation data are then verified for compliance to obtain Bailey beam verification data.

[0029] Furthermore, the step of performing displacement calculations on the standardized skeleton model based on the skeleton stress distribution data to obtain skeleton deformation data includes:

[0030] The preliminary displacement values ​​of each node of the standardized skeleton model are calculated based on the skeleton stress distribution data.

[0031] Based on the preliminary displacement values ​​of each node, the overall displacement trend of the standardized skeleton model is analyzed to obtain the overall displacement trend.

[0032] When the displacement direction of a single node deviates from the overall flexural deformation direction of the structure according to the overall displacement trend, the abnormal node displacement values ​​in the preliminary displacement values ​​of each node are corrected based on the overall displacement trend to obtain the corrected node displacement values. Based on the corrected node displacement values, the standardized skeleton model is subjected to local displacement refinement calculation to obtain local refined displacement data.

[0033] Based on the local refined displacement data, the standardized skeleton model is subjected to deformation morphology simulation to obtain a skeleton deformation morphology diagram. The deformation data of each key part of the skeleton in the skeleton deformation morphology diagram is then extracted to obtain skeleton deformation data.

[0034] Furthermore, based on the local refined displacement data, the standardized skeleton model is subjected to deformation morphology simulation to obtain a skeleton deformation morphology diagram, including:

[0035] The local refined displacement data is classified into node displacements to obtain a displacement set divided by node position. The displacement set is then transformed using a three-dimensional coordinate mapping method to obtain the three-dimensional coordinate data of each node after deformation. Based on the three-dimensional coordinate data, the node position of the standardized skeleton model is updated to obtain a preliminary deformed skeleton model.

[0036] The unit connection relationship of the preliminary deformable skeleton model is checked to obtain a deformable skeleton model with normal connection. The overall shape is drawn based on the deformable skeleton model with normal connection to obtain the preliminary skeleton deformation shape diagram.

[0037] The key parts of the preliminary skeleton deformation morphology diagram are marked to obtain the skeleton deformation morphology diagram.

[0038] Furthermore, the process of hoisting and erecting the Bailey beams and Bailey longitudinal beams based on the Bailey beam verification data to form a high-altitude load-bearing platform includes:

[0039] The Bailey beam verification data is used to plan the lifting point positions of the Bailey crossbeam and Bailey longitudinal beam to obtain the lifting point coordinate data. Then, the force analysis of the lifting point coordinate data is performed to obtain the force distribution data of each lifting point.

[0040] Based on the force distribution data of each lifting point, the lifting path is planned for the Bailey crossbeam and Bailey longitudinal beam to obtain the lifting path parameters. The Bailey crossbeam and Bailey longitudinal beam are then initially lifted by the lifting equipment according to the lifting path parameters to obtain the Bailey beam structure that has been initially lifted and positioned.

[0041] The Bailey beam structure that has been initially hoisted and positioned is monitored in real time using a laser displacement sensor to obtain attitude monitoring data. When the attitude monitoring data exceeds the preset attitude control threshold, the hoisting parameters of the hoisting equipment are dynamically adjusted based on the attitude monitoring data.

[0042] The Bailey bridge crossbeams and longitudinal beams are precisely hoisted and erected using hoisting equipment according to the hoisting parameters, forming a high-altitude load-bearing platform.

[0043] Furthermore, the step of fixing the high-altitude bearing platform to the I-beam distribution beam with clamps to form a distribution beam support layer, and then erecting a disc-lock scaffold based on the distribution beam support layer to form a connecting corridor pouring platform, includes:

[0044] The flatness of the contact surface of the high-altitude bearing platform is tested to obtain flatness data. Based on the flatness data, the high-altitude bearing platform is ground or padded to obtain a flat contact surface.

[0045] The flat contact surface and the I-beam distribution beam are fixed by a plate connection process to obtain a preliminary fixed distribution beam structure. The connection strength of the preliminary fixed distribution beam structure is then tested to obtain connection strength data.

[0046] When the connection strength data is not within the preset connection strength threshold, the nodes of the initially fixed distribution beam structure are reinforced based on the connection strength data to obtain the reinforced distribution beam support layer, and the load-bearing capacity of the distribution beam support layer is checked to obtain load-bearing capacity check data.

[0047] Based on the load-bearing capacity verification data, the disc-lock scaffold is erected according to the erection plan to obtain the erection parameters. The disc-lock scaffold is then erected on the distribution beam support layer using the erection parameters to obtain the corridor pouring platform.

[0048] This invention provides a construction method for a large-span Bailey bridge corridor based on the Midas model, comprising: performing stress analysis on the basement roof slab based on the positioning coordinates of pre-embedded steel plates to obtain a foundation node layout diagram; welding double-section steel foundation beams based on the foundation node layout diagram to form a foundation force transmission frame; vertically assembling the foundation force transmission frame with Bailey panel composite columns to form Bailey column units; horizontally connecting channel steel connecting rods with adjacent Bailey column units to form a column support skeleton; performing stress and deformation calculations on the column support skeleton using Midas software to generate Bailey beam verification data; hoisting and erecting Bailey crossbeams and Bailey longitudinal beams based on the Bailey beam verification data to form a high-altitude bearing platform; and fixing the high-altitude bearing platform to the I-beam distribution beam with clamping plates to form a... The system consists of a distribution beam support layer, upon which a disc-lock scaffold is erected to form a connecting corridor pouring platform. This addresses the problem that existing technical solutions often lack effective utilization assessment of underground space, leading to potential insufficient foundation bearing capacity during construction. It utilizes Midas software to perform refined stress and deformation calculations on the support frame, obtaining accurate Bailey beam verification data. This provides a reliable technical basis for the hoisting of Bailey beams and longitudinal beams, avoiding structural overloading or material waste that may result from traditional experience-based construction. Furthermore, it enables the vertical assembly of Bailey panel composite columns and the foundation force transmission frame, and connects adjacent column units horizontally into a whole using channel steel connecting rods, forming a column support frame with high spatial stiffness. This significantly enhances the resistance to lateral displacement and instability during construction. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a schematic diagram of the construction method of a large-span Bailey bridge based on the midas model in one embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of a standardized skeleton model in one embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of the stress deformation of the column support frame in one embodiment of the present invention;

[0053] Figure 4 This is a schematic diagram of Bailey beam verification in one embodiment of the present invention;

[0054] Figure 5This is a schematic diagram of the deformation of a Bailey beam in one embodiment of the present invention;

[0055] Figure 6 This is a schematic diagram of the foundation beam in one embodiment of the present invention.

[0056] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0057] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0058] The following describes in detail, with reference to the accompanying drawings, a construction method for a large-span Bailey bridge based on the midas model according to an embodiment of the present invention. First, the construction method for a large-span Bailey bridge based on the midas model according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0059] Figure 1 This invention provides a construction method for a large-span Bailey bridge based on the Midas model, comprising the following steps:

[0060] Step S1: Perform stress analysis on the basement roof slab based on the positioning coordinates of the embedded steel plate to obtain the foundation node layout diagram, and weld the double-section steel foundation beams based on the foundation node layout diagram to form the foundation force transmission frame.

[0061] Specifically, during the initial stress analysis, based on the positioning coordinates of the embedded steel plates given in the design drawings, the corresponding structural areas are delineated on the basement roof slab. Finite element modeling is then used to input parameters such as concrete strength, slab thickness, and soil load to simulate the concentrated and distributed forces during the actual construction phase. This yields the magnitude and transmission path of the reaction forces at each key point, leading to the creation of a foundation node layout diagram. Next, according to the locations shown in this layout diagram, the double-section steel foundation beams are laid out and positioned on-site, and then fixed to the embedded steel plates by welding. The welds must meet the Class II weld standard to ensure a strong connection, forming a foundation load-transfer frame that can progressively transfer the upper load to the main basement structure. For example, in a commercial complex corridor project with a span of 42 meters, this method was used to determine the locations of eight main support nodes, making it possible for the lower support system and the upper Bailey bridge to work together.

[0062] Step S2: Vertically assemble the basic force transmission frame and the Bailey panel combination column to form a Bailey column unit, and horizontally connect the channel steel connecting rod to the adjacent Bailey column unit to form a column support skeleton.

[0063] Specifically, the assembly of Bailey column units is carried out after the foundation load-bearing frame is completed. During construction, the individual Bailey beams are first placed vertically, aligned with the connection points on the foundation beams, and tightened with high-strength bolts through the node plates. The columns are then spliced ​​upwards section by section. Generally, each combined column is composed of two to three Bailey sections stacked together. During the assembly process, a theodolite is used to control the verticality deviation to be no more than 1 / 1000. After adjacent Bailey column units are erected, they are horizontally connected at the same elevation using pre-cut channel steel connecting rods. The two ends of the channel steel are welded with perforated ear plates, and then fixed to the side chords of the Bailey sections with bolts. This connects multiple independent columns into a whole. For example, in the aforementioned 42-meter span commercial corridor project, a total of 6 Bailey column units were set up, symmetrically arranged on both sides of the corridor axis, with denser installation in the middle sections with larger spans. A channel steel connecting rod is installed horizontally every 3 meters. The type of channel steel used is #10, which effectively ensures the spatial stability of the frame.

[0064] Step S3: The stress and deformation of the column support frame are calculated using midas software to generate Bailey beam verification data. Based on the Bailey beam verification data, the Bailey crossbeams and Bailey longitudinal beams are hoisted and erected to form a high-altitude load-bearing platform.

[0065] Specifically, before modeling, the dimensions, material parameters, and connection methods of the column support frame measured on-site are input into the Midas software. The element type is selected as beam element to simulate the chords and web members of the Bailey bridge, and the nodes are treated as hinged. The boundary conditions are set as the top surface of the foundation force transmission frame is fixed. Then, the loads are applied step by step, including the self-weight of the Bailey beam, the weight of the subsequent distributed beams, and the construction live load, and the load is combined according to the most unfavorable working condition. After the calculation is completed, the stress ratio and node displacement data of each component are exported to form a Bailey beam verification data table, focusing on the mid-span bending moment zone and the parts with large shear forces near the supports. For example, in the 42-meter corridor project, the original design adopted a single-layer arrangement of standard 321 type Bailey bridge panels, but the verification found that the stress ratio at the mid-span of the longitudinal beam reached 1.08, which exceeded the allowable value of the specification. Therefore, it was adjusted to a double-row overlapping arrangement. After recalculation, the stress ratio was reduced to 0.86, which met the requirements. Based on this adjusted verification data, the on-site organization began to hoist the Bailey crossbeams and longitudinal beams, using tower cranes to position them in sections, connecting them into a whole with high-strength bolts, and finally building a stable and reliable high-altitude bearing platform.

[0066] Step S4: Fix the high-altitude bearing platform to the I-beam distribution beam with clamps to form a distribution beam support layer, and erect the disc-lock scaffold based on the distribution beam support layer to form a connecting corridor pouring platform.

[0067] Specifically, after the high-altitude support platform is formed, the I-beam distribution beams are installed. These I-beams are typically I20a or I25b models, arranged at 1.2-meter intervals, perpendicular to the main span of the connecting corridor. When each distribution beam is in place, both ends rest on the upper flange of the Bailey beam, secured from above with specially designed U-shaped clamps and double nuts. The width of the clamps must match the bottom width of the I-beam to prevent lateral slippage. After all distribution beams are fixed, a relatively integral distribution beam support layer is formed, with its flatness deviation controlled within ±10mm. Within m; then, the positioning points of the disc-lock scaffold uprights are marked on this support layer, and the scaffolds are erected in steps of 900mm×900mm. The bottom sweeping bar is no more than 350mm from the bottom, and a layer of horizontal bars is set every 1.5 meters upwards. The height of the free end of the top of the scaffold does not exceed 500mm. For example, in the construction of the aforementioned 42-meter commercial corridor, a total of 18 distribution beams were set up to support the entire disc-lock scaffold. The final corridor pouring platform successfully withstood the dynamic and static loads during concrete pouring without any obvious settlement or deformation.

[0068] In a specific embodiment, a stress analysis is performed on the basement roof slab based on the positioning coordinates of the embedded steel plate to obtain a foundation node layout diagram, including:

[0069] Based on the positioning coordinates of the embedded steel plate, the basement roof slab is meshed using the finite element analysis method to obtain the roof slab mesh model;

[0070] A concentrated load transmitted by a Bailey bridge is applied to the top plate mesh model to obtain stress distribution data for each node of the top plate. The stress distribution data includes the stress values ​​of each node in the X, Y, and Z directions.

[0071] Based on the stress distribution data, stress concentration areas are determined, and node densification is performed on the stress concentration areas. Finite element calculations are then performed again to obtain optimized stress distribution data.

[0072] Based on the optimized stress distribution data, the locations of foundation nodes that meet the bearing capacity requirements of the basement roof slab are determined, and a foundation node layout diagram is drawn based on the foundation node locations.

[0073] Specifically, after obtaining the positioning coordinates of the embedded steel plates provided by the design institute, a 3D model of the basement roof slab is first created in the structural calculation software. During modeling, basic information such as the slab thickness, concrete grade C35, overburden thickness, and known wall loads are input. Then, the entire slab surface is meshed, generally using quadrilateral shell elements. The initial mesh size is controlled at around 500mm; too coarse will affect accuracy, while too fine will result in excessive computation. This step yields the preliminary roof slab mesh model. Next, the force transmitted down by the Bailey bridge columns needs to be considered. This force is a concentrated load and must be distributed based on the previously estimated total construction load. For example, if a column is expected to bear a pressure of 480kN, a downward Z-direction force is applied at the node corresponding to the center of the embedded steel plate. Simultaneously, considering a certain eccentricity, a small amount of horizontal components in the X and Y directions are added to simulate the swaying effect that may occur during actual hoisting. After the first calculation, checking the cloud map usually reveals red high-temperature areas directly below the columns and at the corners of the slab, which are stress concentration areas. The results cannot be directly accepted at this point; local adjustments are needed for these areas. Specifically, the original 500mm mesh is reduced to 200mm or even 100mm in areas of sudden stress change, and finer units are re-divided, especially at locations where the bottom reinforcement might yield. The boundary conditions remain unchanged, and the calculation is repeated. The optimized stress distribution data from the second calculation shows that the original principal tensile stress of 2.8MPa has decreased to 1.9MPa, meeting the design value for the tensile strength of C35 concrete. Only then can the final stress values ​​of each node in the X, Y, and Z directions be used, combined with the reinforcement details, to determine which locations can be considered reliable foundation nodes. For example, in one project, one of the originally planned six column locations was near the post-cast strip. Calculations revealed that the Z-direction displacement at this location was too large, reaching 8.7mm, exceeding the allowable deformation limit. Therefore, this foundation node was moved 1.3 meters north to the solid slab area, and after recalculation, the displacement decreased to 3.2mm. Once all the eligible locations are determined, a plan view is drawn using CAD according to the actual axis relationship, clearly marking the number and coordinates of each foundation node. This drawing is the foundation node layout diagram on which the subsequent welding of the double-section steel foundation beam is based.

[0074] In a specific embodiment, the welding construction of the double-section steel foundation beams based on the basic node layout diagram to form a foundation force transmission frame includes:

[0075] The node coordinates of the basic node layout diagram are extracted to obtain the three-dimensional coordinate data of the basic nodes. Based on the three-dimensional coordinate data of the basic nodes, the double-section steel foundation beam is cut into sections to obtain steel foundation beam components. The steel foundation beam components are then pre-assembled and positioned to determine the relative positional relationship of each component.

[0076] Through welding, the pre-assembled and positioned steel foundation beam components are welded based on their relative positional relationships to obtain a preliminary welded force transmission frame structure. The weld quality of the preliminary welded force transmission frame structure is then inspected and the joints are reinforced to obtain a foundation force transmission frame that meets the load-bearing requirements.

[0077] Specifically, after obtaining the basic node layout drawing, the first step is to open the drawing using CAD software and extract the X, Y, and Z three-dimensional coordinates of each basic node one by one. This data cannot be used directly for processing; it must be verified in conjunction with the axis control points measured on-site. For example, if the design drawing of a certain corridor project uses relative coordinates, it must be converted into the absolute coordinate system used on the construction site to avoid errors in material cutting dimensions. After confirming that the coordinates are correct, the cutting length of the double-section steel foundation beam is calculated based on the spatial distance between two adjacent nodes. Considering the welding shrinkage, a allowance of 1.5 to 2 mm is generally reserved for each weld. The steel material is usually Q345B H-beams with a cross-sectional dimension of H400×200×8×13, which is precisely cut by a professional processing plant using a CNC flame cutting machine, requiring the cut to be flat and burr-free. After the components arrive on site, welding is not performed immediately. Pre-assembly is done first, placing two steel sections side-by-side on the same horizontal plane, with the spacing as per the design drawings. Temporary clamps are used for fixation. The alignment of all connection ends is then checked against the layout drawing, especially at corners where the angled beams are bent. An angle deviation is verified using a total station; only if it is within acceptable limits can the next process begin. After confirming the correct relative positions of the components during pre-assembly, formal welding begins. E50 series welding rods are used, and manual arc welding is performed in sections. First, the fillet welds on both sides of the web are welded, followed by the flange connections. The welding sequence must be symmetrical to prevent structural distortion due to thermal deformation. After the preliminary welded load-bearing frame structure is formed, it cannot be put into use directly. Weld quality inspection is mandatory, primarily using visual inspection combined with ultrasonic testing. Special attention is paid to checking for porosity, slag inclusions, or lack of fusion defects in the joint areas. The sampling rate should be no less than 20%, and all Class I welds must be inspected. Any non-conforming areas are immediately repaired by removing the original weld with carbon arc gouging before re-welding. For main nodes subjected to high stress, such as those bearing concentrated forces transmitted by Bailey columns, additional steel ribs were welded on after inspection for node reinforcement. The reinforcing steel plates were 12mm thick and fully welded to the original steel to improve local compressive and shear resistance. After all procedures were completed, the overall geometric dimensions were re-measured to ensure no significant deformation. Only then could the final foundation load-bearing frame meet the requirements for subsequent load transfer. Figure 6 As shown, the maximum combined stress of the foundation beam is 141 MPa ≤ fd1 = 205 MPa, and the maximum shear stress is 72 MPa ≤ fyd1 = 125 MPa. The results meet the strength requirements. Here, fd1 represents the maximum combined stress of the foundation beam, and fyd1 represents the maximum shear stress of the foundation beam.

[0078] In a specific embodiment, the vertical assembly of the basic force transmission frame and the Bailey panel composite column to form a Bailey column unit includes:

[0079] The dimensions of the basic force transmission frame are measured to obtain frame dimension data. Based on the frame dimension data, the Bailey panel combination columns are pre-selected and matched and pre-assembled to obtain the assembled Bailey panel combination columns.

[0080] The basic force transmission frame and the assembled Bailey panel column are vertically assembled using a high-strength bolt connection process to form a Bailey column unit.

[0081] Specifically, before commencing vertical assembly, the completed and accepted foundation load-bearing frame is measured on-site. Using a steel tape measure and level, the span, diagonal difference, and elevation consistency between each support surface are checked point by point, and the actual frame dimensions are recorded. This step is crucial because slight deformations are inevitable after on-site welding, and the dimensions on the drawings cannot be relied upon entirely. For example, in a 42-meter connecting corridor project in a commercial complex, a lateral offset of 18mm was found at one node. Failure to correct this would directly affect the installation accuracy of the upper Bailey bridge. After obtaining the actual data, the Bailey panel combination columns are pre-selected and matched. A standard 321 type Bailey panel is 3048mm long and 1500mm high. Based on the required support height of 7.8 meters, it is calculated that each column needs to be composed of five Bailey panels. However, considering slight fluctuations in the foundation top elevation, some columns require fine-tuning using four panels plus an adjustment section. After selection, a pre-assembly inspection is conducted in an open area. The selected Bailey panels are laid flat and joined together, temporarily secured with standard connecting pins. The straightness of the chords and the twisting of the web members are checked. A feeler gauge is used to measure the gap between the node plates; gaps exceeding 2mm require correction before use. Hoisting is only permitted after confirmation. Once hoisted into place, the bottom of the Bailey panel assembly column is aligned with the predetermined position on the foundation load-bearing frame. Typically, a limiting steel plate or angle steel is pre-welded to the top surface of the frame for guidance and positioning to prevent misalignment. M30 high-strength bolts (strength grade 8.8S) are used for connection. At least four bolts are used at each node, tightened in a cross-shaped sequence from the center outwards. The initial tightening torque is controlled at 200 N·m, and the final tightening reaches 450 N·m. Each bolt is checked with a torque wrench to ensure uniform stress. The bolt insertion direction should be kept consistent for easy later inspection and maintenance. The entire vertical assembly process must be carried out during the day in good lighting conditions. Workers at height must wear safety harnesses. The verticality of each column must be checked with a theodolite after completion, with an allowable deviation of no more than H / 1000 and no more than 15mm. The completed Bailey column unit should be stable and free from swaying, providing reliable support for the subsequent horizontal connection of the channel steel connecting rods. The "H" mentioned above represents the design height of the Bailey column unit, which is the vertical height from the top surface of the foundation load-bearing frame to the top of the Bailey panel assembly column, in millimeters (mm). This is a key parameter for measuring the vertical geometric accuracy and stability control of the structure, ensuring that the overall structural stability meets the dual control requirements of the temporary support system's bearing capacity and deformation.

[0082] In a specific embodiment, the horizontal connection of the channel steel connecting rod to the adjacent Bailey column unit to form a column support frame includes:

[0083] The spacing between adjacent Bailey column units is measured to obtain column spacing data. Based on the column spacing data, the channel steel connecting rod is cut to obtain the channel steel connecting rod component.

[0084] The channel steel connecting rod component is pre-bent to obtain a pre-bent channel steel connecting rod, and the pre-bent channel steel connecting rod is horizontally connected to the adjacent Bailey column unit by bolt connection process to obtain a preliminary connected column structure.

[0085] The levelness data of the column structure is detected. If the levelness data is not within the preset range, the column structure is fine-tuned based on the levelness data to obtain the column support frame.

[0086] Specifically, after completing the vertical assembly of the Bailey column units, the next step is to connect them horizontally to enhance overall stability. First, the actual spacing between adjacent Bailey column units is measured using a steel ruler or laser rangefinder to determine the net distance between corresponding node plates of two columns. The actual column spacing data is recorded. Due to slight deviations in the on-site foundation load-bearing frame, the measured values ​​often differ from the theoretical design dimensions. For example, in a 42-meter span connecting corridor project, the designed spacing was 6.0 meters, but the measured results ranged from 5.982 meters to 6.015 meters. This necessitates that the channel steel connecting rods not be cut to a uniform length. Based on these measured data, the #10 channel steel is precisely cut in the processing yard, with each piece approximately 30mm shorter than the measured spacing, allowing for adjustment. Considering that some columns are not perfectly parallel or the building has an arc-shaped layout, the channel steel connecting rods need to be pre-bent. This is done using a cold bending process on a hydraulic pipe bending machine. The bending radius is determined based on the curvature of the site. For example, at the corner of the connecting corridor, the radius of curvature is 12 meters, and the corresponding channel steel needs to be bent into a corresponding arc to ensure that both ends can smoothly fit the node plates. After pre-bending, the pre-bent channel steel connecting rods are transported to the site for installation. M20 high-strength bolts are used for connection, passing through the pre-drilled holes on the connecting lugs welded to the ends of the channel steel and the side chords of the Bailey bridge. A regular wrench is used to tighten them initially, forming a preliminary connected column structure. At this point, final tightening is not rushed. Instead, a spirit level and a horizontal level are used to check the levelness of the connecting rods on that floor. If the height difference between the two ends of a member exceeds 5mm, it indicates that the column is tilted or has inconsistent elevation. For such situations, fine-tuning is required. This is done by adding steel plates to the lower node. The shim thickness is selected based on the deviation value, typically a combination of 2mm, 5mm, or 10mm. After adjustment, retighten the bolts. For severely uneven situations, the connection needs to be loosened, and the column's verticality recalibrated. After all adjustments are complete, recheck the overall geometry to ensure all connections are evenly stressed and free of gaps. Only then will the final column support frame possess sufficient spatial rigidity to bear subsequent upper loads. Furthermore, the stress deformation of the column support frame is as follows... Figure 3 As shown, the maximum combined stress is 130 Mpa < fd2 = 205 Mpa, and the maximum shear stress is 35 Mpa < fvd2 = 125 Mpa. Here, the above fd2 represents the maximum combined stress of the column support skeleton, and fvd2 represents the maximum shear stress of the column support skeleton.

[0087] In a specific embodiment, the stress and deformation of the column support skeleton are calculated by midas software to obtain the check data of the Bailey beam, including:

[0088] Based on the actual structural parameters of the column support skeleton, geometric modeling is performed on the column support skeleton to obtain a skeleton geometric model, and element division and node numbering are performed on the skeleton geometric model to obtain a standardized skeleton model;

[0089] The design load conditions are applied to the standardized skeleton model by midas software to obtain the skeleton load response data, and stress extraction and analysis are performed on the skeleton load response data to obtain the skeleton stress distribution data;

[0090] Based on the skeleton stress distribution data, displacement calculation is performed on the standardized skeleton model to obtain the skeleton deformation data, and compliance verification is performed on the skeleton stress distribution data and the skeleton deformation data to obtain the check data of the Bailey beam.

[0091] Specifically, before carrying out the stress and deformation calculation, first collect the actual structural parameters of the column support skeleton, including the type of Bailey sheet, the specification of the channel steel tie rod, the actual length and connection method of each component, as well as the measured column spacing and elevation data on site. These information cannot be simply applied according to the design drawings and must reflect the true construction status. Take the 42-meter corridor project of a commercial complex as an example. It is found through actual measurement that the distance between two columns is 17 mm more than the design value. This difference must be reflected during modeling, otherwise it will affect the accuracy of subsequent analysis. Based on these measured parameters, geometric modeling is carried out in midas software. The main stressed components are simulated using space beam elements. The web members of the Bailey sheet are treated as hinged, and the chord members are modeled continuously to form a complete skeleton geometric model. After modeling, element division is performed on all members. Generally, each standard 3.048-meter-long Bailey sheet is divided into two elements to ensure the calculation accuracy. At the same time, systematic numbering is performed on all nodes, starting from the bottom starting point and arranging them in sequence to avoid data confusion in the later stage. Finally, a standardized skeleton model available for calculation is obtained. Next, apply the design load conditions, mainly including the self-weight of the Bailey cross beam and longitudinal beam, the weight of the I-beam distribution beam, the load of the disk buckle support and formwork system, plus the construction live load, usually taking 2.5 kN / m 2The load is applied using the most unfavorable combination, such as applying additional loads concentrated in the mid-span area to simulate the peak value of concrete pouring. After running the calculation, the load response data of the skeleton is obtained, and the axial force, bending moment, and shear force values ​​of key sections are extracted from them. These values ​​are then further converted into stress values ​​for each element, forming the skeleton stress distribution data. Special attention is paid to the stress levels in the tension zone of the lower chord of the Bailey bridge and the compression zone at the bottom of the column. If the stress ratio at any point exceeds 0.95, it is considered a critical state. Based on this, displacement calculations are performed on the standardized skeleton model to check the overall deformation trend, paying particular attention to the vertical displacement and lateral drift of the top nodes. The specification requires that the maximum deflection should not exceed 1 / 400 of the span. For example, the original calculation results showed that the deformation at the mid-span of the third span reached 23mm, slightly exceeding the limit, requiring adjustment and reinforcement. Finally, the stress distribution data and deformation data of the framework were verified for compliance, comparing them with the "Steel Structure Design Standard" GB50017 and the Technical Specification for Bailey Bridge Use to determine whether the load-bearing capacity and stiffness requirements were met. All verified data were compiled and organized to form the final Bailey beam calculation data, which served as the technical basis for subsequent hoisting operations. In addition, a standardized framework model, such as... Figure 2 As shown, the data for the Bailey beam verification are as follows: Figure 4 As shown, different colors correspond to different stress distributions. Figure 4 The largest value is -282 MPa.

[0092] In a specific embodiment, the step of performing displacement calculations on the standardized skeleton model based on the skeleton stress distribution data to obtain skeleton deformation data includes:

[0093] The preliminary displacement values ​​of each node of the standardized skeleton model are calculated based on the skeleton stress distribution data.

[0094] Based on the preliminary displacement values ​​of each node, the overall displacement trend of the standardized skeleton model is analyzed to obtain the overall displacement trend.

[0095] When the displacement direction of a single node deviates from the overall flexural deformation direction of the structure according to the overall displacement trend, the abnormal node displacement values ​​in the preliminary displacement values ​​of each node are corrected based on the overall displacement trend to obtain the corrected node displacement values. Based on the corrected node displacement values, the standardized skeleton model is subjected to local displacement refinement calculation to obtain local refined displacement data.

[0096] Based on the local refined displacement data, the standardized skeleton model is subjected to deformation morphology simulation to obtain a skeleton deformation morphology diagram. The deformation data of each key part of the skeleton in the skeleton deformation morphology diagram is then extracted to obtain skeleton deformation data.

[0097] Specifically, after obtaining the stress distribution data of the skeleton, displacement calculations are immediately carried out. First, using the structural solver module of the Midas software, based on the material properties, section stiffness, and known nodal stress states of each element, the preliminary displacement values ​​of each node in the standardized skeleton model are calculated. These values ​​include components in the X, Y, and Z directions, with vertical (Z-direction) displacement being the focus. For example, in a 42-meter span connecting corridor project, the initial calculation results showed that the settlement of nodes 7 and 10 were 18.3 mm and 19.1 mm respectively, while nodes 8 and 9 in the middle span only showed 15.6 mm. This is inconsistent with the trend of maximum deflection at mid-span in conventional beam structures, raising concerns among technicians. Next, an overall displacement trend analysis is performed on the preliminary displacement values ​​of all nodes. By plotting the displacement envelope along the main span direction, it is observed whether it exhibits a smooth concave curve, i.e., a typical bending-deflection pattern. Once it is found that the displacement direction or amplitude of individual nodes deviates significantly from this trend, such as local upward arching or abrupt settlement, it is identified as an anomaly. In the above case, the issue of undersized displacements at nodes 8 and 9 was found to be caused by the channel steel connecting rod being mistakenly modeled as a rigid connection. It should actually be a semi-rigid hinged connection, leading to excessive local stiffness. To address this, the abnormal node displacement values ​​need to be corrected; the original output results cannot be directly used. The correction method involves adjusting the constraint conditions or stiffness coefficients of the corresponding elements based on the actual on-site construction and connection conditions, and then recalculating to obtain more realistic corrected node displacement values. Based on this, local displacement refinement calculations are performed in key areas such as the middle of large spans, load concentration points, and near supports. This involves densifying the mesh or improving solution accuracy to capture subtle deformation characteristics, thereby obtaining refined local displacement data. Finally, the software's post-processing function is used to map the corrected and refined displacement results onto the 3D model, generating an intuitive skeleton deformation morphology diagram. Different colors are used to distinguish the degree of deformation in the diagram, facilitating the identification of weak points. Deformation data of key parts of the skeleton, such as the mid-span of the Bailey beam, the top of the column, and the intersection of the diagonal braces, are extracted from the figure and summarized to form the final skeleton deformation data, which serves as an important basis for judging structural safety and guiding construction control.

[0098] In a specific embodiment, the step of simulating the deformation morphology of the standardized skeleton model based on the local refined displacement data to obtain a skeleton deformation morphology diagram includes:

[0099] The local refined displacement data is classified into node displacements to obtain a displacement set divided by node position. The displacement set is then transformed using a three-dimensional coordinate mapping method to obtain the three-dimensional coordinate data of each node after deformation. Based on the three-dimensional coordinate data, the node position of the standardized skeleton model is updated to obtain a preliminary deformed skeleton model.

[0100] The unit connection relationship of the preliminary deformable skeleton model is checked to obtain a deformable skeleton model with normal connection. The overall shape is drawn based on the deformable skeleton model with normal connection to obtain the preliminary skeleton deformation shape diagram.

[0101] The key parts of the preliminary skeleton deformation morphology diagram are marked to obtain the skeleton deformation morphology diagram.

[0102] Specifically, in the process of simulating the deformation morphology of the skeleton, the first step is to classify the nodal displacements of the local refined displacement data. This process involves classifying and organizing the displacement values ​​of all nodes according to their positions in the standardized skeleton model, forming displacement sets divided by node position. For example, in a bridge structure, the nodes of different parts such as piers, main beams, and stay cables can be classified separately to more accurately analyze the deformation of each part.

[0103] Next, the displacement set obtained above is transformed using a 3D coordinate mapping method. The core of this step is to calculate the new position of each node after deformation based on its original position and corresponding displacement value, thus obtaining the new coordinate data of each node in 3D space. For example, if a node was originally located at (10, 20, 30), and its displacement after deformation is (dx=2, dy=-1, dz=0.5), then its new coordinates become (12, 19, 30.5). After updating the coordinates of all nodes, the node positions of the standardized skeleton model can be updated, thereby constructing a preliminary deformable skeleton model.

[0104] Next, the element connections of the preliminary deformed skeleton model need to be checked. This step ensures that even after deformation, the elements in the skeleton model maintain correct connections without breaks or unreasonable intersections. If any problems are found in element connections, the positions of the relevant nodes need to be adjusted or the local refined displacement data needs to be re-evaluated according to the actual physical constraints until a deformed skeleton model with normal connections is obtained. For example, in steel structure buildings, if the displacement of a critical node causes unreasonable overlap between nearby components, the displacement value of that node needs to be appropriately corrected.

[0105] Finally, based on the normally connected deformable skeleton model, the overall shape is drawn, generating a preliminary skeleton deformation morphology diagram. This diagram not only shows the deformation of the entire skeleton structure under stress, but also requires annotation of key parts, such as the maximum deformation points, support points, and connection points, to help engineers quickly locate and assess potential risks. After completing these annotations, a detailed skeleton deformation morphology diagram is obtained, which is of great significance for assessing the safety performance of the structure and guiding subsequent design optimization.

[0106] In a specific embodiment, the process of hoisting and erecting the Bailey crossbeams and Bailey longitudinal beams based on the Bailey beam verification data to form a high-altitude load-bearing platform includes:

[0107] The Bailey beam verification data is used to plan the lifting point positions of the Bailey crossbeam and Bailey longitudinal beam to obtain the lifting point coordinate data. Then, the force analysis of the lifting point coordinate data is performed to obtain the force distribution data of each lifting point.

[0108] Based on the force distribution data of each lifting point, the lifting path is planned for the Bailey crossbeam and Bailey longitudinal beam to obtain the lifting path parameters. The Bailey crossbeam and Bailey longitudinal beam are then initially lifted by the lifting equipment according to the lifting path parameters to obtain the Bailey beam structure that has been initially lifted and positioned.

[0109] The Bailey beam structure that has been initially hoisted and positioned is monitored in real time using a laser displacement sensor to obtain attitude monitoring data. When the attitude monitoring data exceeds the preset attitude control threshold, the hoisting parameters of the hoisting equipment are dynamically adjusted based on the attitude monitoring data.

[0110] The Bailey bridge crossbeams and longitudinal beams are precisely hoisted and erected using hoisting equipment according to the hoisting parameters, forming a high-altitude load-bearing platform.

[0111] Specifically, before carrying out the hoisting operations of Bailey beams and longitudinal beams, the hoisting point locations are first planned based on the previously generated Bailey beam verification data. This verification data includes the bending moment distribution and shear force changes of each component under stress. Based on this, stress concentration areas are avoided, and hoisting points are set at locations with smaller bending moments and more uniform structural stress. For example, for a Bailey beam with a span of 12 meters, the hoisting points are usually placed approximately 2.8 meters from both ends to ensure hoisting balance and prevent excessive local deformation. The determined hoisting point coordinate data needs further stress analysis to calculate the actual load borne by each hoisting point during hoisting, including the component's self-weight and the influence of the dynamic coefficient, obtaining the stress distribution data for each hoisting point. This data is used to verify whether the sling load-bearing capacity meets the requirements. Then, based on the tower crane location, slewing radius, and the distribution of surrounding obstacles, and combined with the above stress distribution data, hoisting path parameters are formulated, specifying key control values ​​such as lifting height, luffing distance, and rotation angle to ensure a smooth and stable hoisting process. Taking a 42-meter commercial corridor project as an example, due to its proximity to existing buildings, the main beam hoisting needs to bypass the opening wall unit. The path is designed as a three-stage action: "lifting first, then translating, and then fine-tuning." During the formal hoisting, the signalman directs the tower crane to perform preliminary hoisting according to the predetermined path parameters, slowly lifting the Bailey beam off the ground and transporting it above the installation area. At this point, the beam is in a suspended state, forming the Bailey beam structure in preliminary hoisting and positioning. To avoid high-altitude docking errors, laser displacement sensors are used to monitor the beam's attitude in real time. The sensors are fixed to the supporting frame below, aligned with key measuring points on the bottom of the beam, and continuously collect changes in its spatial position to obtain attitude monitoring data, including horizontal tilt angle, torsional angle, and elevation deviation. If any data is found to exceed the preset attitude control threshold (such as tilt greater than 3‰ or torsion greater than 5mm), the operation is immediately suspended, and the hoisting parameters are dynamically corrected by adjusting the tower crane trolley travel or the main hook lifting speed to achieve fine-tuning and correction. After all indicators return to the allowable range, the beams are slowly lowered into position, ultimately completing the precise hoisting and erection. Once multiple beams are connected, a stable and reliable high-altitude load-bearing platform is formed. (The text then abruptly shifts to a seemingly unrelated topic: Bailey beam deformation...) Figure 5 As shown, the maximum combined stress of the Bailey beam deformation is 282 MPa ≤ fd3 = 305 MPa, and the maximum shear stress is 89 MPa ≤ fyd3 = 175 MPa. Here, fd3 represents the maximum combined stress of the Bailey beam deformation, and fyd3 represents the maximum shear stress of the Bailey beam deformation.

[0112] In a specific embodiment, the step of fixing the high-altitude bearing platform to the I-beam distribution beam with clamps to form a distribution beam support layer, and then erecting a disc-lock scaffold based on the distribution beam support layer to form a connecting corridor pouring platform, includes:

[0113] The flatness of the contact surface of the high-altitude bearing platform is tested to obtain flatness data. Based on the flatness data, the high-altitude bearing platform is ground or padded to obtain a flat contact surface.

[0114] The flat contact surface and the I-beam distribution beam are fixed by a plate connection process to obtain a preliminary fixed distribution beam structure. The connection strength of the preliminary fixed distribution beam structure is then tested to obtain connection strength data.

[0115] When the connection strength data is not within the preset connection strength threshold, the nodes of the initially fixed distribution beam structure are reinforced based on the connection strength data to obtain the reinforced distribution beam support layer, and the load-bearing capacity of the distribution beam support layer is checked to obtain load-bearing capacity check data.

[0116] Based on the load-bearing capacity verification data, the disc-lock scaffold is erected according to the erection plan to obtain the erection parameters. The disc-lock scaffold is then erected on the distribution beam support layer using the erection parameters to obtain the corridor pouring platform.

[0117] Specifically, after the high-altitude load-bearing platform is formed and passes acceptance, the installation of the I-beam distribution beams begins. First, the flatness of the contact area between the platform top surface and the distribution beams is tested. A 2-meter straightedge and feeler gauge are used to measure each section, recording the gap value at each point to form flatness data. If the local height difference exceeds 5mm, it needs to be addressed. For example, in a 42-meter span connecting corridor project, a Bailey longitudinal beam joint had a 7mm protrusion due to welding deformation, affecting subsequent installation. An angle grinder was used on-site to grind and smooth the area. Another low-lying point had a 4mm depression, so a matching Q235 steel plate with a thickness of 4.5mm was added to ensure even stress distribution. Only a flat contact surface obtained after these treatments can be used for subsequent fixing operations. Next, the clamping plate connection operation is performed. The clamping plates are custom-made U-shaped components, bent from 10mm thick steel plates, with an opening width slightly larger than the I-beam flange. After being inserted, they are tightened from the top using double screws. The screws pass through the pre-drilled holes in the platform crossbeam flanges and are locked with double nuts. After each I25b I-beam distribution beam is in place, at least three clamping plates are installed at both ends and mid-span to form a preliminary fixed distribution beam structure. At this point, the next process does not begin immediately. Instead, sampling inspections are conducted on the connection nodes. A torque wrench is used to verify the bolt tightening force, and the fit between the clamping plates and the steel beam is observed to determine if there are any loose connections or uneven pressure. The connection strength data is then compiled. If the measured anti-slip capacity of a node is found to be lower than the design requirement of 80kN, it is determined to be outside the preset connection strength threshold range, and node reinforcement is necessary. Common practices include welding triangular ribs to the sides of the clamping plates or changing the original single clamping plate to an upper and lower clamping plate structure to enhance constraint stiffness. After all nodes are reinforced, a reinforced distribution beam support layer is formed, and its overall load-bearing capacity is verified. A simulated concentrated load from the uprights of the scaffolding is applied to verify whether the maximum stress and deflection meet the requirements, obtaining load-bearing capacity verification data. After confirming safety, the parameters for erecting the disc-lock scaffold are planned based on the load distribution characteristics in the data. Key control values ​​such as the longitudinal and transverse spacing of the uprights (usually 900×900mm), the step distance of the horizontal bars (1.5m), and the height of the ground bars (≤350mm) are specified. The positioning is marked on the support layer of the distribution beam. The uprights are erected one by one according to the parameters, and the horizontal bars and adjustable supports are installed. Finally, the top elevation of the erected frame is consistent and the whole structure is stable, forming a concrete pouring platform for the connecting corridor.

Claims

1. A construction method for large-span Bailey bridges based on the Midas model, characterized in that, Includes the following steps: Based on the positioning coordinates of the embedded steel plate, the stress analysis of the basement roof slab is carried out to obtain the foundation node layout diagram. Based on the foundation node layout diagram, the double-section steel foundation beam is welded to form the foundation force transmission frame. The basic force transmission frame and the Bailey panel combination column are vertically assembled to form a Bailey column unit, and the channel steel connecting rod is horizontally connected to the adjacent Bailey column unit to form a column support frame. The stress and deformation of the column support frame are calculated using Midas software to generate Bailey beam verification data. Based on the Bailey beam verification data, the Bailey crossbeams and Bailey longitudinal beams are hoisted and erected to form a high-altitude load-bearing platform. The high-altitude bearing platform is fixed to the I-beam distribution beam with clamps to form a distribution beam support layer, and a disc-lock scaffold is erected based on the distribution beam support layer to form a connecting corridor pouring platform. Based on the positioning coordinates of the embedded steel plate, a stress analysis was performed on the basement roof slab to obtain the foundation node layout diagram, including: Based on the positioning coordinates of the embedded steel plate, the basement roof slab is meshed using the finite element analysis method to obtain the roof slab mesh model; A concentrated load transmitted by a Bailey bridge is applied to the top plate mesh model to obtain stress distribution data for each node of the top plate. The stress distribution data includes the stress values ​​of each node in the X, Y, and Z directions. Based on the stress distribution data, stress concentration areas are determined, and node densification is performed on the stress concentration areas. Finite element calculations are then performed again to obtain optimized stress distribution data. Based on the optimized stress distribution data, the locations of foundation nodes that meet the bearing capacity requirements of the basement roof slab are determined, and a foundation node layout diagram is drawn based on the foundation node locations. The process of calculating the stress and deformation of the column support frame using Midas software to obtain Bailey beam verification data includes: Based on the actual structural parameters of the column support frame, the column support frame is geometrically modeled to obtain a frame geometric model. The frame geometric model is then divided into elements and numbered with nodes to obtain a standardized frame model. The standardized skeleton model was subjected to design load conditions using Midas software to obtain skeleton load response data. Stress extraction analysis was then performed on the skeleton load response data to obtain skeleton stress distribution data. Based on the stress distribution data of the skeleton, displacement calculation is performed on the standardized skeleton model to obtain skeleton deformation data. The skeleton stress distribution data and skeleton deformation data are then verified for compliance to obtain Bailey beam verification data.

2. The construction method for large-span Bailey bridges based on the Midas model according to claim 1, characterized in that, The welding construction of the double-section steel foundation beams based on the aforementioned basic node layout diagram to form a foundation force transmission frame includes: The node coordinates of the basic node layout diagram are extracted to obtain the three-dimensional coordinate data of the basic nodes. Based on the three-dimensional coordinate data of the basic nodes, the double-section steel foundation beam is cut into sections to obtain steel foundation beam components. The steel foundation beam components are then pre-assembled and positioned to determine the relative positional relationship of each component. Through welding, the pre-assembled and positioned steel foundation beam components are welded based on their relative positional relationships to obtain a preliminary welded force transmission frame structure. The weld quality of the preliminary welded force transmission frame structure is then inspected and the joints are reinforced to obtain a foundation force transmission frame that meets the load-bearing requirements.

3. The construction method for large-span Bailey bridges based on the Midas model according to claim 1, characterized in that, The vertical assembly of the basic force transmission frame and the Bailey panel composite column to form a Bailey column unit includes: The dimensions of the basic force transmission frame are measured to obtain frame dimension data. Based on the frame dimension data, the Bailey panel combination columns are pre-selected and matched and pre-assembled to obtain the assembled Bailey panel combination columns. The basic force transmission frame and the assembled Bailey panel column are vertically assembled using a high-strength bolt connection process to form a Bailey column unit.

4. The construction method for large-span Bailey bridges based on the Midas model according to claim 1, characterized in that, The method of horizontally connecting the channel steel connecting rod to the adjacent Bailey column unit to form a column support frame includes: The spacing between adjacent Bailey column units is measured to obtain column spacing data. Based on the column spacing data, the channel steel connecting rod is cut to obtain the channel steel connecting rod component. The channel steel connecting rod component is pre-bent to obtain a pre-bent channel steel connecting rod, and the pre-bent channel steel connecting rod is horizontally connected to the adjacent Bailey column unit by bolt connection process to obtain a preliminary connected column structure. The levelness data of the column structure is detected. If the levelness data is not within the preset range, the column structure is fine-tuned based on the levelness data to obtain the column support frame.

5. The construction method for large-span Bailey bridges based on the Midas model according to claim 1, characterized in that, The step of performing displacement calculations on the standardized skeleton model based on the skeleton stress distribution data to obtain skeleton deformation data includes: The preliminary displacement values ​​of each node of the standardized skeleton model are calculated based on the skeleton stress distribution data. Based on the preliminary displacement values ​​of each node, the overall displacement trend of the standardized skeleton model is analyzed to obtain the overall displacement trend. When the displacement direction of a single node deviates from the overall flexural deformation direction of the structure according to the overall displacement trend, the abnormal node displacement values ​​in the preliminary displacement values ​​of each node are corrected based on the overall displacement trend to obtain the corrected node displacement values. Based on the corrected node displacement values, the standardized skeleton model is subjected to local displacement refinement calculation to obtain local refined displacement data. Based on the local refined displacement data, the standardized skeleton model is subjected to deformation morphology simulation to obtain a skeleton deformation morphology diagram. The deformation data of each key part of the skeleton in the skeleton deformation morphology diagram is then extracted to obtain skeleton deformation data.

6. The construction method for large-span Bailey bridges based on the Midas model according to claim 5, characterized in that, The step of performing deformation morphology simulation on the standardized skeleton model based on the local refined displacement data to obtain a skeleton deformation morphology diagram includes: The local refined displacement data is classified into node displacements to obtain a displacement set divided by node position. The displacement set is then transformed using a three-dimensional coordinate mapping method to obtain the three-dimensional coordinate data of each node after deformation. Based on the three-dimensional coordinate data, the node position of the standardized skeleton model is updated to obtain a preliminary deformed skeleton model. The unit connection relationship of the preliminary deformable skeleton model is checked to obtain a deformable skeleton model with normal connection. The overall shape is drawn based on the deformable skeleton model with normal connection to obtain the preliminary skeleton deformation shape diagram. The key parts of the preliminary skeleton deformation morphology diagram are marked to obtain the skeleton deformation morphology diagram.

7. The construction method for large-span Bailey bridges based on the Midas model according to claim 1, characterized in that, The process of hoisting and erecting Bailey beams and Bailey longitudinal beams based on the Bailey beam verification data to form a high-altitude load-bearing platform includes: The Bailey beam verification data is used to plan the lifting point positions of the Bailey crossbeam and Bailey longitudinal beam to obtain the lifting point coordinate data. Then, the force analysis of the lifting point coordinate data is performed to obtain the force distribution data of each lifting point. Based on the force distribution data of each lifting point, the lifting path is planned for the Bailey crossbeam and Bailey longitudinal beam to obtain the lifting path parameters. The Bailey crossbeam and Bailey longitudinal beam are then initially lifted by the lifting equipment according to the lifting path parameters to obtain the Bailey beam structure that has been initially lifted and positioned. The Bailey beam structure that has been initially hoisted and positioned is monitored in real time using a laser displacement sensor to obtain attitude monitoring data. When the attitude monitoring data exceeds the preset attitude control threshold, the hoisting parameters of the hoisting equipment are dynamically adjusted based on the attitude monitoring data. The Bailey bridge crossbeams and longitudinal beams are precisely hoisted and erected using hoisting equipment according to the hoisting parameters, forming a high-altitude load-bearing platform.

8. The construction method for large-span Bailey bridges based on the Midas model according to claim 1, characterized in that, The process of fixing the high-altitude load-bearing platform to the I-beam distribution beam with clamps to form a distribution beam support layer, and then erecting a disc-lock scaffold based on the distribution beam support layer to form a connecting corridor pouring platform, includes: The flatness of the contact surface of the high-altitude bearing platform is tested to obtain flatness data. Based on the flatness data, the high-altitude bearing platform is ground or padded to obtain a flat contact surface. The flat contact surface and the I-beam distribution beam are fixed by a plate connection process to obtain a preliminary fixed distribution beam structure. The connection strength of the preliminary fixed distribution beam structure is then tested to obtain connection strength data. When the connection strength data is not within the preset connection strength threshold, the nodes of the initially fixed distribution beam structure are reinforced based on the connection strength data to obtain the reinforced distribution beam support layer, and the load-bearing capacity of the distribution beam support layer is checked to obtain load-bearing capacity check data. Based on the load-bearing capacity verification data, the disc-lock scaffold is erected according to the erection plan to obtain the erection parameters. The disc-lock scaffold is then erected on the distribution beam support layer using the erection parameters to obtain the corridor pouring platform.

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