A method for matching construction of a deck system and arch height of a half-through steel pipe arch bridge and the arch bridge

Abstract

This invention provides a construction method and bridge for high-precision matching of the deck system and arch height in a mid-span steel pipe arch bridge. The steps are: 1. Reserved length for longitudinal beams; 2. Reserved length for splicing plates; 3. On-site measurement and longitudinal beam matching; 4. On-site drilling of splicing plates. This invention addresses the problems of non-perpendicularity between the mid-span section of the bridge deck system and the mid-span hangers of the arch rib, and misalignment of the theoretical connection positions between the lower chord hangers of the arch rib and the bridge deck system, by using a reserved length approach. Through an innovative model of "pre-reserved length + on-site measurement + dynamic adjustment," it provides a high-precision and high-efficiency solution for the construction of mid-span steel pipe arch bridges. It achieves high-precision vertical matching between the bridge deck system and the arch rib hangers, improving structural safety, construction efficiency, and economy; it eliminates the deviation between theoretical models and actual conditions, optimizes the structural stress system, and reduces rework risks and costs, thus possessing broad application value.

Description

Technical Field

[0001] This invention belongs to the technical field of bridge erection or assembly methods, specifically relating to a construction method for precise matching of the deck system and arch height of a mid-span steel pipe arch bridge, and the arch bridge itself. Background Technology

[0002] The core structure of a mid-span steel pipe arch bridge includes the arch rib, the bridge deck system, and the suspenders connecting the two. The pre-embedding of the arch foot and the erection of the arch rib are critical procedures in the construction of mid-span steel pipe arch bridges. This process is technically challenging and easily affected by environmental factors, processes, surveying techniques, and construction management. These factors can inevitably cause deviations in the design mileage of the mid-span suspenders of the arch rib and the lower chord columns of the arch rib. Such mileage deviations can lead to spatial non-perpendicularity between the mid-span section of the bridge deck system and the mid-span suspenders of the arch rib, and misalignment of the theoretical connection positions between the lower chord columns of the arch rib and the bridge deck system. To address these issues, the following improved technical solutions are proposed. Summary of the Invention

[0003] The technical problem solved by this invention is to provide a construction method and arch bridge for precise matching of the deck system and arch height of a mid-span steel pipe arch bridge. By using the method of reserving length and adding extra space, this invention solves the problems of non-perpendicularity between the mid-span section of the existing bridge deck system and the mid-span hanger of the arch rib, and misalignment of the theoretical connection position between the lower chord hanger of the arch rib and the bridge deck system.

[0004] The technical solution adopted in this invention is a construction method for precisely matching the deck system and arch height of a mid-span steel pipe arch bridge, comprising the following steps:

[0005] Step 1, Reserve the process length of the longitudinal beam: Determine the number and quantity of the longitudinal beams that need to be lengthened, drill bolt holes at the non-length extension end of the longitudinal beam, and reserve at least 150mm of un-drilled section at the length extension end.

[0006] Step 2, Reserve for splice plate process allowance: Determine the splice plate number and quantity corresponding to the longitudinal beam, reserve at least 10mm length of process allowance on the splice plate, and pre-drill half of the bolt holes at the processing plant.

[0007] Step 3, On-site measurement and longitudinal beam cutting: After the concrete inside the steel pipe arch reaches the design strength, measure the center distance of the mid-span hangers, calculate the longitudinal length of the bridge deck system hoisting segment perpendicular to the hangers, and determine the longitudinal beam cutting length; draw the cutting position line with the transverse baseline as the reference, cut the reserved section of the longitudinal beam, and drill the calculated bolt hole group parallel to the transverse baseline.

[0008] Step 4: On-site drilling of splice plates: According to the hoisting sequence of the bridge deck system, use the splice plates with half of the holes already drilled at the bridge site to complete the drilling of the remaining bolt holes of the splice plates.

[0009] In the above technical solution, further: the measurement results of the center distance of the mid-span hangers in step 3 are used to correct the longitudinal beam cutting length to ensure that the bridge deck system is perpendicular to the arch rib hangers.

[0010] In the above technical solution, further: the calculation method for step 3, which calculates the longitudinal length of the bridge deck system hoisting segment perpendicular to the hangers by measuring the center distance of the mid-span hangers, is determined based on the geometric relationship between the bridge deck system and the hangers.

[0011] In the above technical solution, further: step 3 uses a semi-automatic trolley to cut the reserved section of the longitudinal beam.

[0012] In the above technical solution, further: in step 4, the splicing plate is drilled using an on-site positioning drilling process, and the alignment accuracy of the bolt holes between the splicing plate and the longitudinal beam is controlled by a high-precision measuring device.

[0013] In the above technical solution, further: the longitudinal beam is a steel box beam or truss beam structure; the splicing plate is a high-strength steel plate; and the bolt hole group is processed by CNC machine tool.

[0014] Furthermore, in the above technical solution, the construction method is applicable to mid-span steel pipe arch bridges with a span of 100m or more.

[0015] This invention also claims protection for a mid-span steel pipe arch bridge, wherein the mid-span steel pipe arch bridge is an arch bridge constructed by any of the aforementioned construction methods, and the arch bridge includes bridge deck system hoisting segments and arch rib hoisting segments; the bridge deck system hoisting segments include hanger beams, column beams, end beams, secondary beams, main longitudinal beams, secondary longitudinal beams, splicing plates, and high-strength bolts; the arch rib hoisting segments include upper dumbbells, lower dumbbells, web members, support cylinder pads, support cylinders, internal stiffeners of the support cylinders, steel guide tubes, and hangers, and the arch rib hoisting segments are vertically connected to the bridge deck system hoisting segments via hangers.

[0016] Advantages of this invention compared to existing technologies:

[0017] 1. This invention adjusts the longitudinal length of the bridge deck system hoisting segments to ensure that the bridge deck system remains perpendicular to the predetermined arch rib suspenders and that the connection positions of the bridge deck system suspender crossbeams and the lower chord columns are not spatially misaligned. This allows the overall structure to better adapt to the deformation and stress of the arch ribs, ensuring the overall stability and uniform stress distribution of the structure, and ensuring that the suspenders are at a safe and reasonable distance from the steel guide tubes during subsequent working conditions.

[0018] 2. The process of reserving additional length in this invention can provide an opportunity to adjust and compensate for the bridge deck mileage accuracy control caused by the accumulation of errors during the manufacturing and construction processes, reduce the accumulation of errors during manufacturing and construction, improve the level of accuracy control, improve construction efficiency, reduce the number of times and time that hoisting equipment moves on the arch, and reduce construction risks.

[0019] 3. The construction method of this invention provides a high-precision and high-efficiency solution for the construction of mid-span steel pipe arch bridges through the innovative model of "process reservation + on-site measurement + dynamic adjustment".

[0020] 4. This invention measures the center distance of key mid-span hangers and corrects the longitudinal beam cutting length to achieve high-precision vertical matching between the bridge deck system and the arch rib hangers, significantly improving structural safety, construction efficiency, and economy; it eliminates the deviation between theoretical models and actual conditions, optimizes the structural stress system, reduces rework risks and costs, and provides a reliable precision control scheme for the construction of mid-span steel pipe arch bridges, which has broad application value.

[0021] 5. This invention employs a semi-automatic trolley for cutting the reserved section of the longitudinal beam. By combining mechanical automation with manual assistance, it significantly improves construction accuracy, efficiency, and safety. High-precision cutting ensures structural compatibility; adjustable tracks allow for multi-angle cutting, dynamically adapting to site conditions and enhancing construction flexibility; fast cutting speed enables continuous operation, shortening the construction period; reduced manual operation lowers labor intensity and improves safety; cutting parameters are recorded and linked with the BIM model, ensuring data traceability and supporting quality control. This semi-automatic trolley cutting solution for the reserved section of the longitudinal beam, with its core advantages of high precision, high efficiency, and high safety, solves the problems of low precision, poor efficiency, and high risk associated with traditional manual cutting. Its data traceability and BIM linkage further enhance quality control, providing a replicable and scalable standardized solution for bridge construction, with significant economic and social benefits.

[0022] 6. This invention significantly improves the reliability, construction efficiency, and quality stability of steel structure connections through a closed-loop control system of "dynamic positioning - precise drilling - real-time verification"; dynamically adapts to on-site deformation to ensure alignment accuracy; high-precision measuring equipment improves hole matching; reduces cumulative errors to ensure structural integrity; shortens the construction cycle and reduces rework costs; enhances structural safety and extends service life; and adopts on-site positioning and drilling technology, using high-precision measuring equipment to achieve dynamic alignment of bolt holes between splicing plates and longitudinal beams, solving the problems of low accuracy and high rework rate caused by the inability of traditional pre-drilled holes to adapt to on-site deformation. Its core advantages of sub-millimeter accuracy, efficient operation, and enhanced structural safety provide a replicable and scalable precision connection solution for steel structure construction, with significant economic and social benefits.

[0023] 7. This invention, by clearly defining the materials of the longitudinal beams and splice plates and the processing methods of the bolt hole groups, forms a complete chain of technical optimization from structural selection to material application and processing technology, significantly improving the load-bearing capacity, processing accuracy, construction efficiency, and long-term durability of steel structures. Through three core advantages—structural selection optimization, material performance improvement, and processing accuracy control—it achieves high load-bearing capacity, high precision, high efficiency, and long service life of steel structure connections. This technology combination has been verified in fields such as long-span bridges and high-rise buildings, and has significant economic and social benefits, representing an important innovative direction in the field of steel structure construction. Attached Figure Description

[0024] Figure 1 This is a schematic diagram showing the adjustment of the length of the bridge deck system hoisting segments;

[0025] Figure 2 To determine the number and quantity of longitudinal beams required for the extended process;

[0026] Figure 3 A schematic diagram is provided to reserve the process quantity for the longitudinal beam;

[0027] Figure 4(a) shows the allowance for the process quantity of splicing panels. Figure 1 ;

[0028] Figure 4(b) shows the schematic diagram of the process allowance for splicing panels. Figure 2 ;

[0029] Figure 4(c) shows the schematic diagram of the process allowance for splicing panels. Figure 2 ;

[0030] Figure 4(d) shows the allowance for process quantity in splicing panels. Figure 2 ;

[0031] Figure 5 This is an enlarged schematic diagram of the actual center distance of the mid-span hangers of the arch rib;

[0032] Figure 6(a) is a schematic diagram of the longitudinal beam cutting position line.

[0033] Figure 6(b) is a schematic diagram of the bolt hole group drilled in the longitudinal beam;

[0034] Figure 7(a) shows the on-site drilling setup for splicing panels. Figure 1 ;

[0035] Figure 7(b) shows the on-site drilling setup for spliced ​​panels. Figure 2 ;

[0036] Figure 7(c) shows the on-site drilling setup for spliced ​​panels. Figure 3 ;

[0037] Figure 7(d) is a schematic diagram of on-site drilling for splicing panels;

[0038] Figure 8 This is a schematic diagram of the on-site splicing of the longitudinal beams;

[0039] Figure 9 This is a flowchart of the construction method of the present invention;

[0040] Figure 10 This is the main view of the arch rib hoisting segment;

[0041] Figure 11 for Figure 10 AA view of the dumbbells;

[0042] Figure 12 for Figure 10 BB view of the lower dumbbell;

[0043] Figure 13 for Figure 10 FF view;

[0044] Figure 14 for Figure 13 GG view;

[0045] Figure 15 This is a structural schematic diagram of the relevant bridge deck hoisting segments;

[0046] In the diagram: 1-Longitudinal beam, 2-Splicing plate, 3-Hanging rod, 301-Hanging rod 10, 302-Hanging rod 11, 4-Horizontal baseline, 5-Cutting position line, 6-Bridge deck hoisting segment, 7-Arch rib hoisting segment, 601-Column crossbeam, 602-End crossbeam, 603-Secondary crossbeam, 604-Main longitudinal beam, 701-Upper dumbbell, 702-Lower dumbbell, 703-Web member, 704-Support cylinder pad, 705-Support cylinder, 706-Support cylinder internal stiffener, 707-Steel guide tube. Detailed Implementation

[0047] The following will refer to the appendices in the embodiments of the present invention. Figure 1-15 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0048] A construction method for precisely matching the deck system and arch height of a mid-span steel pipe arch bridge, taking a mid-span steel pipe arch bridge with twenty hangers 3 as an example, includes the following steps (e.g. Figure 9 (as shown)

[0049] Step 1, Reserved process allowance for longitudinal beams: (e.g.) Figure 1 , Figure 2 , Figure 3 (As shown) Determine the number and quantity of the longitudinal beam 1 that needs to be lengthened. Drill bolt holes at the non-length-addition end of the longitudinal beam 1, and reserve at least 150mm of un-drilled section at the length-addition end.

[0050] Step 2, Reservation of process allowance for splicing plate: (as shown in Figure 4) Determine the number and quantity of splicing plate 2 corresponding to the longitudinal beam 1, reserve at least 10mm of process allowance on splicing plate 2, and pre-drill half of the bolt holes at the processing plant.

[0051] Step 3, On-site measurement and longitudinal beam matching: (e.g.) Figure 5(As shown in Figure 6) After the concrete inside the steel pipe arch reaches the design strength, measure the center distance of the mid-span hangers 3, calculate the longitudinal length of the bridge deck system hoisting segment 6 perpendicular to the hangers 3, and determine the cutting length of the longitudinal beam 1; draw the cutting position line 5 with the transverse baseline 4 as the reference, cut the reserved section of the longitudinal beam 1, and drill the calculated bolt hole group parallel to the transverse baseline 4 (as shown in Figure 6).

[0052] Step 4: On-site drilling of splice plates: According to the hoisting sequence of the bridge deck system, use the splice plate 2 with half of the holes already drilled at the bridge site to complete the drilling of the remaining bolt holes of the splice plate 2 (as shown in Figure 7).

[0053] It should be noted that the construction method of the present invention significantly improves the matching accuracy, construction efficiency and structural safety of the bridge deck system and the arch rib through key steps such as process quantity reservation, on-site measurement and cutting, and dynamic drilling.

[0054] Traditional methods rely on the theoretical hanger spacing from design drawings. However, in actual construction, factors such as arch rib deformation and concrete shrinkage can cause deviations between the hanger center distance and the design value. After the concrete inside the steel pipe arch reaches its design strength, the center distance of the hangers at mid-span is measured on-site, and the longitudinal length of the bridge deck system hoisting segment 6 is calculated accordingly. The cutting length of the longitudinal beam 1 is dynamically adjusted based on the measured data to eliminate the deviation between theoretical calculations and the actual structure, ensuring that the geometric matching accuracy between the bridge deck system and the arch rib is within ±2mm, and avoiding stress concentration or loosening of connections due to dimensional errors. The longitudinal beam cutting position line 5 is drawn with the transverse baseline 4 as a reference, and bolt hole groups are drilled parallel to the transverse baseline 4 to ensure that the transverse position of the longitudinal beam 1 cutting surface and the bolt hole group is strictly aligned, avoiding bridge deck system distortion or splicing difficulties due to transverse deviation, and improving the overall linear smoothness.

[0055] In this design, bolt holes are drilled at the non-length extension end of longitudinal beam 1, while at least 150mm of undrilled section is reserved at the length extension end. During factory processing, precise control of the total longitudinal beam length is unnecessary; only the accuracy of the holes at the non-length extension end needs to be ensured, reducing manufacturing difficulty. After on-site cutting, the length of the undrilled section can be flexibly adjusted to adapt to the measured spacing of the hangers, avoiding material waste due to processing errors. For splicing plate 2, at least 10mm of process allowance is reserved, and half of the bolt holes are pre-drilled at the factory, with the remaining holes drilled on-site. During factory processing, matching all longitudinal beam holes is unnecessary, reducing processing time. On-site drilling can be dynamically adjusted according to the actual longitudinal beam hole positions, ensuring complete alignment of the bolt hole groups between splicing plate 2 and longitudinal beam 1, improving splicing quality.

[0056] In traditional methods, the bolt holes of the splice plate 2 and the longitudinal beam 1 must be perfectly matched in the factory. However, on-site construction may cause hole misalignment due to factors such as temperature changes and arch rib deformation. To address this, splice plates 2 with half-drilled holes are used on-site. The remaining holes are drilled according to the actual longitudinal beam hole positions, eliminating the cumulative error between factory processing and on-site installation, ensuring the bolt hole alignment accuracy is within ±1mm. This avoids bolt installation failures or loose connections due to hole misalignment, improving structural safety. The drilling sequence of the splice plates is dynamically adjusted according to the bridge deck hoisting sequence, ensuring that each splice plate 2 is perfectly matched with the longitudinal beam 1 of the currently hoisted segment, avoiding hole misalignment problems caused by changes in the hoisting sequence. The reserved sections of the longitudinal beam and the additional material of the splice plates can be cut according to actual needs, avoiding material scrap due to dimensional errors, increasing material utilization by more than 10%, and reducing project costs.

[0057] Therefore, this invention provides a high-precision and high-efficiency solution for the construction of mid-span steel pipe arch bridges through the innovative model of "process reservation + on-site measurement + dynamic adjustment", which has significant technical and economic advantages.

[0058] In the above embodiment, further: the measurement objects of the center distance of the mid-span hangers 3 in step 3 include hangers 10 301 and hangers 11 302. The measurement results are used to correct the cutting length of the longitudinal beam 1 to ensure that the bridge deck system is perpendicular to the arch rib hangers 3.

[0059] It should be noted that this method effectively eliminates geometric deviations, achieves high-precision vertical matching, optimizes structural stress, improves safety, compensates for the effects of arch rib deformation, increases the fault tolerance rate, reduces the accumulation of construction errors, simplifies the construction process, and improves efficiency.

[0060] Specifically, hangers 10 301 and 11 302 were used as measurement objects. Their center distances were measured using a total station or laser rangefinder. Based on the measured data, the longitudinal beam cutting length was corrected to eliminate hanger spacing errors caused by arch rib deformation. This ensured that the longitudinal beam length strictly matched the actual hanger distribution, preventing the bridge deck system from being non-perpendicular to the arch rib due to hanger spacing deviations, thus preventing longitudinal stress concentration or loosening of connections. When calculating the longitudinal length of the bridge deck system hoisting segment based on the measured center distance of hangers 3, it was mandatory that the axis of longitudinal beam 1 be perpendicular to the axis of hanger 3. This ensured that the bridge deck load was vertically transferred to hangers 3 through longitudinal beam 1, avoiding additional bending moments in the hangers due to inclined transmission, improving the overall structural stress rationality, and extending the service life of the connection between hangers 3 and longitudinal beam 1.

[0061] If the bridge deck system is not perpendicular to the hanger 3, the load transfer path deviation will generate secondary stress, leading to local fatigue damage to the longitudinal beam 1 or hanger 3. The length of the longitudinal beam 1 is corrected by measuring the center distance of hanger 3 to ensure perpendicularity. This eliminates the long-term impact of secondary stress on the structure and reduces the risk of longitudinal beam cracking or hanger breakage. Vertical alignment ensures that the bridge deck system and arch rib form a stable "arch-beam-hanger" collaborative force-bearing system, improving the dynamic response stability of the bridge under live loads (such as vehicle loads) and avoiding structural swaying or resonance caused by perpendicularity deviation.

[0062] The arch rib may undergo nonlinear deformation under the influence of concrete shrinkage, creep, or temperature gradients, causing the center distance of the hangers to change in real time. The center distance of the hangers is measured after the concrete inside the steel tube arch reaches its design strength to capture the final deformation state of the arch rib. This adapts to the long-term deformation of the arch rib and avoids matching errors caused by discrepancies between the theoretical model and the actual condition. Using hangers 10 301 and 11 302 as key control points, the overall bridge deck length is corrected through local measurements. This avoids global alignment deviations caused by the accumulation of errors in single segments.

[0063] Traditional methods rely on the spacing of the hangers as specified in the design drawings. If the actual deviation exceeds the standard, the hangers need to be dismantled and reworked, leading to delays in the construction period. By dynamically adjusting the length of the longitudinal beam 1 by measuring the center distance of hanger 3, "one-time matching and cutting" can be achieved. After applying this technology in a certain project, the rework rate of longitudinal beam 1 dropped from 12% to 0%, and the construction period was shortened by 7 days. By clearly defining the two hangers at the mid-span (such as 10 301 and 11 302) as the measurement benchmark, the data collection and processing standards are unified, reducing reliance on operator skills and improving the replicability of construction.

[0064] Therefore, by measuring the center distance of key mid-span hangers 3, such as hangers 10 and 11, and correcting the longitudinal beam cutting length, this technical solution achieves high-precision vertical matching between the bridge deck system and the arch rib hangers, significantly improving structural safety, construction efficiency, and economy. It eliminates the deviation between the theoretical model and the actual condition, optimizes the structural stress system, reduces rework risks and costs, and provides a reliable precision control scheme for the construction of mid-span steel pipe arch bridges, possessing broad application value.

[0065] In the above embodiments, further: step 3 is based on the geometric relationship between the bridge deck system and the hangers 3, and the calculation method for calculating the longitudinal length of the bridge deck system hoisting segment 6 perpendicular to the hangers 3 by measuring the center distance of the mid-span hangers 3 is determined.

[0066] It should be noted that the following steps are included:

[0067] Step 301: Measure the center distance of the mid-span hangers 3: Select key mid-span hangers 3, such as hangers 10 301 and 11 302, as the measurement benchmark, and measure their center distance L using a total station or laser rangefinder. 实测The measured error should be ≤ ±1mm to ensure data reliability. Measurements should be taken when the arch rib concrete has reached its design strength and the temperature is stable to avoid measurement deviations caused by concrete shrinkage, creep, or temperature gradients.

[0068] Step 302: Establish a geometric relationship model: The model assumes that the bridge deck system is perpendicular to the hanger 3, that is, the angle between the axis of the bridge deck system and the axis of the hanger is 90°. The hangers 3 are symmetrically distributed at mid-span, and the longitudinal length L of the bridge deck system hoisting segment 6 is... 节段 Distance L from the center of the boom 实测 The geometric constraints are satisfied. That is, the longitudinal length L of the bridge deck system hoisting segment 6 is derived from the geometric relationships according to the design dimensions. 节段 With L 实测 The relationship.

[0069] Step 303, Correct the longitudinal beam cutting length: Based on the measured center distance L of the hangers. 实测 Based on geometric relationships, determine the precise cutting length L of the longitudinal beam. 配切 .

[0070] Step 304, Verification and Adjustment: Three-dimensional coordinate verification: Measure the three-dimensional coordinates of the ends of the bridge deck system hoisting segment 6 using the BIM model or a total station to verify its perpendicularity to the hanger 3. Dynamic adjustment: If the perpendicularity deviation is found to exceed the standard (e.g., > ±0.5°), the center distance of the hanger 3 needs to be remeasured and the length of the longitudinal beam 1 adjusted until the requirements are met.

[0071] The above-mentioned scheme employs high-precision geometric control to eliminate structural hazards. Based on measured center-to-center distances of the hangers 3, the length of the longitudinal beam 1 is dynamically corrected, avoiding matching errors caused by discrepancies between the theoretical model and actual conditions. This ensures the bridge deck system is perpendicular to the hangers, eliminating secondary stresses caused by load transfer due to inclination. Measurements are taken after the arch rib concrete reaches its design strength, capturing its final deformation state to compensate for the effects of concrete shrinkage, creep, or temperature gradients. This prevents changes in the hanger center-to-center distance due to long-term arch rib deformation, ensuring long-term vertical matching between the bridge deck system and hangers 3, adapting to arch rib deformation, and improving structural durability. Traditional methods rely on the hanger 3 spacing in the design drawings; if actual deviations exceed standards, dismantling and rework are necessary, leading to construction delays. This invention simplifies the construction process and reduces rework risks. Vertical matching ensures that the bridge deck load is vertically transferred to the hangers 3 through the longitudinal beam 1, avoiding additional bending moments in the hangers 3 and local fatigue damage to the longitudinal beam 1. This improves the stability of the "arch-beam-hanger" collaborative load-bearing system and reduces the risk of structural swaying under dynamic response. Using the two mid-span hangers as key control points, a standardized measurement and calculation process is established to reduce reliance on operator skills. Data sharing is achieved in real time through BIM models or digital construction platforms to improve the efficiency of multi-trade collaboration.

[0072] Therefore, this solution uses a geometric control method driven by measured data. This technology provides a quantifiable and replicable precision control scheme for bridge construction, which significantly improves structural safety and construction efficiency, and has broad application prospects in the industry.

[0073] In the above embodiment, step 3 further involves using a semi-automatic trolley to cut the reserved section of the longitudinal beam 1.

[0074] It should be noted that the technical solution of using a semi-automatic trolley to cut the reserved section of the longitudinal beam significantly improves construction accuracy, efficiency, and safety through the combination of mechanical automation and manual assistance; high-precision cutting ensures structural compatibility; adjustable tracks allow for multi-angle cutting, dynamically adapting to site conditions and enhancing construction flexibility; fast cutting speed enables continuous operation, shortening the construction period; reduced manual operation lowers labor intensity and improves safety; cutting parameters are recorded and linked with the BIM model, ensuring data traceability and supporting quality control.

[0075] The semi-automatic trolley is equipped with a laser positioning system or CNC module, which can automatically perform cutting according to preset parameters such as cutting angle, length, and depth, with an error controlled within ±0.5mm, far superior to the ±2-3mm error of manual cutting. Parallel calibration of the trolley track with the longitudinal beam axis ensures that the cutting surface is perpendicular to the longitudinal beam axis, avoiding matching errors between the bridge deck system and the hangers due to cutting deviations. The semi-automatic trolley track can be quickly adjusted according to the actual position of the longitudinal beam, such as offsets caused by arch rib deformation or construction errors, without the need to re-fix the equipment, adapting to complex working conditions. By rotating the cutting head or adjusting the trolley posture, cutting at any angle within the range of 0° to 90° can be achieved, meeting the special geometric requirements of the connection between the longitudinal beam and the hanger. The semi-automatic trolley cutting speed can reach 0.5-1m / min, which is 3-5 times that of manual cutting (approximately 0.1-0.2m / min), reducing the cutting time for a single longitudinal beam from 30 minutes to 8 minutes. The trolley is equipped with an automatic tool changer or cooling system, allowing continuous operation for 4-6 hours without downtime, reducing interruptions caused by equipment adjustments. Operators only need to start the trolley and monitor parameters, eliminating the need for hand-held cutting tools to work at heights or in confined spaces, thus reducing fatigue injuries and the risk of falls from heights. The trolley is equipped with a dust collection device and a noise-reducing shell, reducing cutting dust concentration by 80% and noise levels from 95dB to 75dB, improving the working environment. The trolley has a built-in data acquisition module that records parameters such as cutting time, angle, and depth for each longitudinal beam, generating electronic reports for quality traceability. By importing longitudinal beam design data from the BIM model, the trolley can automatically generate cutting paths, avoiding manual input errors and ensuring consistency with the overall structure.

[0076] Therefore, the technical solution of using a semi-automatic trolley to cut the reserved section of longitudinal beam 1 solves the problems of low precision, poor efficiency, and high risk associated with traditional manual cutting by leveraging its core advantages of high precision, high efficiency, and high safety. Its data traceability and BIM linkage functions further enhance quality control, providing a replicable and scalable standardized solution for bridge construction, with significant economic and social benefits.

[0077] In the above embodiments, further: in step 4, the drilling of the splicing plate 2 adopts the on-site positioning drilling process, and the alignment accuracy of the bolt holes of the splicing plate 2 and the longitudinal beam 1 is controlled by high-precision measuring equipment.

[0078] It should be noted that the above solution, through a closed-loop control of "dynamic positioning - precise drilling - real-time verification," significantly improves the reliability, construction efficiency, and quality stability of steel structure connections. Dynamic adaptation to on-site deformation ensures alignment accuracy; high-precision measuring equipment improves hole matching; reduced cumulative errors ensure structural integrity; shortens the construction cycle and reduces rework costs; enhances structural safety and extends service life. The on-site positioning and drilling process, using high-precision measuring equipment, achieves dynamic alignment of bolt holes between splicing plate 2 and longitudinal beam 1, solving the problems of low accuracy and high rework rates caused by traditional pre-drilled holes' inability to adapt to on-site deformation. Its core advantages of sub-millimeter precision, efficient operation, and enhanced structural safety provide a replicable and scalable precision connection solution for steel structure construction, with significant economic and social benefits.

[0079] The longitudinal beam 1 may undergo slight deformation during welding, hoisting, or temperature changes. Traditional factory pre-drilling cannot capture this on-site deformation, easily leading to misalignment of the holes. On-site positioning and drilling utilizes high-precision equipment such as laser trackers and total stations, achieving a measurement accuracy of ≤±0.1mm. It collects the actual hole coordinates of the longitudinal beam 1 in real time, dynamically adjusting the drilling position of the splicing plate 2 to eliminate deformation errors. The equipment can simultaneously measure the X / Y / Z three-dimensional coordinates of the holes, ensuring complete spatial alignment of the bolt holes of the splicing plate 2 and the longitudinal beam 1, avoiding skewed holes or misalignments caused by planar projection errors.

[0080] The laser tracker boasts a measurement resolution of up to 0.01mm, far exceeding the accuracy of manual marking or template positioning, ensuring that the tolerances for bolt hole diameter and spacing are controlled within ±0.2mm. The equipment's built-in software automatically generates drilling paths and outputs hole position coordinate reports, avoiding manual input errors. It also supports comparison and verification with the BIM model, ensuring the accurate implementation of design intent.

[0081] In traditional processes, the hole position errors between longitudinal beam 1 and splice plate 2 can accumulate segment by segment, making it impossible to install the end bolts. On-site positioning and drilling, through a "segment-by-segment measurement and drilling" method, controls the error of each segment within an independent range, avoiding cumulative effects and ensuring the alignment consistency of bolt holes throughout the bridge. For complex nodes, such as the intersection of longitudinal beam 1 with crossbeams and diagonal braces, the equipment can simultaneously measure the hole positions of multiple components, achieving precise matching of "one hole to multiple parts" through spatial coordinate conversion, reducing stress concentration between connecting parts.

[0082] Traditional pre-drilling methods suffer from a rework rate of 15%–20% due to their inability to adapt to on-site deformation. This often involves enlarging or re-drilling holes, with rework costs of approximately 500–1000 yuan per hole, including labor, materials, and time delays. On-site positioning and drilling, verified through real-time measurement, achieves a first-time alignment success rate of ≥95%, reducing rework costs by over 90%. The equipment can simultaneously position and drill multiple spliced ​​panels, enabling a streamlined "measurement-drilling" process in conjunction with a CNC drilling machine. It can complete drilling for 50–80 bolt holes per day, achieving an efficiency 3–5 times that of traditional methods.

[0083] Among these issues, misalignment of bolt holes can lead to uneven stress on the connectors, causing fatigue cracks or bolt loosening. On-site positioning and drilling control hole position errors within the design tolerances, ensuring uniform distribution of bolt preload and reducing the risk of loosening under structural vibration. Precisely aligned bolt holes can reduce fretting wear at the connection points, delay the intrusion of corrosive media, and extend the service life of the steel structure, with an expected improvement of 10%–15%.

[0084] In the above embodiments, the longitudinal beam 1 is a steel box beam or truss beam structure; the splicing plate 2 is a high-strength steel plate; and the bolt hole group is processed by CNC machine tool.

[0085] It should be noted that this invention, by specifying the materials of the longitudinal beam 1 and the splicing plate 2, as well as the processing method of the bolt hole group, forms a complete chain of technical optimization from structural selection to material application and processing technology, significantly improving the load-bearing capacity, processing accuracy, construction efficiency, and long-term durability of steel structures. Through the three core advantages of optimized structural selection, improved material performance, and controlled processing accuracy, it achieves high load-bearing capacity, high precision, high efficiency, and long service life of steel structure connections. This combination of technologies has been verified in fields such as long-span bridges and high-rise buildings, and has significant economic and social benefits, representing an important innovative direction in the field of steel structure construction.

[0086] Among them, steel box girders are closed-section thin-walled structures with large moments of inertia. With the same material usage, their bending stiffness is 30%–50% higher than open sections (such as H-beams), making them suitable for longitudinal beams bearing vertical loads in long-span bridges or high-rise buildings. The closed section effectively resists torsion, preventing structural instability caused by eccentric loads or wind vibrations. For example, in cable-stayed or suspension bridges, the torsional stiffness of steel box girders is 2–3 times that of H-beams. Internal stiffening ribs, such as longitudinal stiffeners and transverse diaphragms, prevent local buckling of the web, maintaining structural integrity even under high stress, such as live loads and temperature stresses. Truss beams transfer loads through axial tension and compression in the members, resulting in high material utilization and a 40%–60% reduction in self-weight compared to solid-web beams, making them suitable for weight-sensitive applications. Truss beams can be prefabricated in sections and assembled on-site, with a high degree of standardization in the members, facilitating rapid assembly and adjustment. Steel box girders are suitable for scenarios with concentrated loads and dynamic loads. Their closed sections can evenly distribute the load and reduce stress concentration. Truss beams are suitable for scenarios with large spans and non-uniform loads. By adjusting the cross-sectional dimensions of the members, internal forces can be flexibly distributed to avoid local overload.

[0087] High-strength steel plates have a yield strength of 690–890 MPa, which is 2–2.6 times that of ordinary Q345 steel. Under the same load-bearing capacity, the thickness of splice plates can be reduced by 30%–50%. The fracture toughness of high-strength steel is superior to that of ordinary steel. Under alternating loads such as bridge vehicle loads and wind vibration, the crack propagation rate is reduced by more than 50%, significantly extending the life of splice joints. High-strength steel requires the use of low-hydrogen welding electrodes or gas shielded welding, combined with preheating and post-heat treatment, to avoid cold cracking. High-strength steel is prone to work hardening during cutting, punching, and other processing, increasing its hardness by 20%–30%. Precise control of CNC machine tools, such as low-speed cutting and cooling lubrication, is necessary to reduce the thickness of the hardened layer and ensure the edge strength of bolt holes. Welding high-strength steel can prevent cold cracking. High-strength steel is prone to work hardening during cutting and punching, increasing its hardness by 20%–30%. Precise control using CNC machine tools, such as low-speed cutting and cooling lubrication, is necessary to reduce the hardened layer thickness and ensure the edge strength of bolt holes. CNC drilling or milling machines can achieve positioning accuracy of ±0.05mm and repeatability of ±0.02mm, far exceeding that of ordinary drilling machines (±0.5mm) or template positioning (±0.3mm), ensuring that the tolerances for bolt hole diameter and spacing are controlled within ±0.1mm. Five-axis CNC machine tools can achieve precise machining of spatial oblique holes, suitable for complex nodes such as the intersection of longitudinal and transverse beams and diagonal braces, avoiding errors from manual adjustments. CNC machine tools can integrate automatic loading and unloading, drilling, and chamfering processes, with a single machine processing 150–200 bolt holes per day, which is 4–5 times that of manual drilling (30–40 holes per day). The first-pass yield rate of CNC machined holes is ≥98%, avoiding hole enlargement, welding repair, or scrapping of plates due to hole position deviations, and saving 10% to 15% of material costs per project.

[0088] The high load-bearing structure of the truss beams / steel box girders complements the lightweight design of the high-strength steel splice plates, reducing material usage by 20%–30% while ensuring structural safety. The high-precision bolt holes machined by CNC machine tools, combined with the dimensional stability of the high-strength steel splice plates, ensure uniform transmission of bolt preload, preventing structural loosening or fatigue failure due to hole position deviations. The high-precision bolt hole array reduces on-site adjustment time, and combined with the rapid welding process of the high-strength steel splice plates, shortens single-node assembly time by 50%–70%. The CNC machine tools can record the machining parameters of each bolt hole, such as coordinates, speed, and feed rate, enabling quality traceability through BIM modeling and meeting high-standard engineering acceptance requirements.

[0089] In the above embodiments, the construction method is further applicable to mid-span steel pipe arch bridges with a span of 100m or more.

[0090] It should be noted that concrete-filled steel tube structures significantly improve the compressive strength and deformation resistance of the concrete through the confinement effect of the steel tubes within the core concrete. In bridges with spans exceeding 100m, this structural form effectively resists the bending moments and shear forces brought about by the large span, ensuring the bridge's load-bearing capacity and durability. Through-span arch bridges, with their rational arch rib design and cross bracing arrangement, significantly enhance the bridge's lateral stability. This stability is particularly important for bridges with spans exceeding 100m, effectively resisting the effects of external loads such as wind vibration and earthquakes. Steel tube arch ribs can be prefabricated in the factory and assembled on-site, achieving modular construction. This construction method greatly shortens the on-site construction cycle and improves construction efficiency. During construction, processes such as bridge pit excavation, foundation and concrete pouring, steel tube processing, hanger fabrication, and prefabrication of crossbeams and bridge decks can be carried out simultaneously, further saving construction time. Due to the reduction in material usage and the increase in construction efficiency, the project cost of concrete-filled steel tube arch bridges is significantly reduced. This is particularly significant for large bridge projects with spans exceeding 100m, resulting in substantial economic benefits.

[0091] This invention also claims protection for a mid-span steel pipe arch bridge, wherein the mid-span steel pipe arch bridge is an arch bridge constructed using any of the aforementioned construction methods, and the arch bridge includes a bridge deck hoisting segment 6 and an arch rib hoisting segment 7. The arch rib hoisting segment 7 is vertically connected to the bridge deck hoisting segment 6 via a hanger 3.

[0092] (like Figure 15 As shown, the bridge deck system hoisting segment 6 includes a suspender beam, a column beam 601, an end beam 602, a secondary beam 603, a main longitudinal beam 604, a secondary longitudinal beam, a splicing plate 2, and high-strength bolts.

[0093] Among them, the main longitudinal beam 604, as the core load-bearing component, is the main longitudinal load-bearing component of the bridge deck system. It directly bears the vehicle load, pedestrian load, and the weight of the bridge deck pavement layer, and transfers the load to the hanger crossbeam through bending deformation. It is spliced ​​with the secondary longitudinal beams by high-strength bolts, and the splice plate 2 covers the joint to ensure the continuity of longitudinal stiffness; the end is rigidly connected to the end crossbeam 602 to form a closed frame.

[0094] Secondary longitudinal beams: These assist the main longitudinal beams 604 in distributing loads, enhancing the lateral stiffness of the bridge deck system, and preventing local buckling. They are spaced apart from the main longitudinal beams and connected to the splice plates 2 via high-strength bolts to form a gridded support system.

[0095] As a lateral connection and hoisting support, the suspender beam serves as the connection point between suspender 3 and the bridge deck system, transferring vertical loads to the arch ribs while also bearing lateral wind loads and seismic forces. The upper part of the suspender beam is connected to the lower anchorage of suspender 3 via high-strength bolts, ensuring uniform transmission of preload. The lower part of the suspender beam is rigidly connected to the main longitudinal beam 604 and the secondary longitudinal beams, forming a T-shaped or I-shaped cross-section to enhance torsional resistance.

[0096] Column crossbeam 601: Located in the middle of the bridge deck system, it supports the columns and transmits vertical forces to the arch ribs, suitable for multi-span continuous systems. It is connected to the bottom flange of the column by high-strength bolts, and the top of the column is hinged to the dumbbell section under the arch rib, allowing for temperature deformation.

[0097] As a lateral stabilizer and boundary constraint, the end beam 602 closes both ends of the bridge deck system, resisting lateral bending and torque moments and preventing end instability. The end beam 602 is rigidly connected to the main longitudinal beam 604 and the secondary longitudinal beams, forming a rigid end frame; seismic blocks are installed at the ends of the end beam 602 to limit lateral displacement.

[0098] Secondary crossbeams 603: These are spaced apart between the main longitudinal beams 604 to enhance the lateral stiffness of the bridge deck system and distribute local loads. They are connected to the main longitudinal beams 604 and the secondary longitudinal beams by high-strength bolts, forming a spatial truss structure.

[0099] (like Figures 11 to 14 The arch rib hoisting segment 7 includes an upper dumbbell 701, a lower dumbbell 702, a web rod 703, a support cylinder pad 704, a support cylinder 705, a support cylinder internal stiffener 706, a steel guide tube 707, and a hoisting rod 3.

[0100] As the main structural element of the arch rib, the upper and lower dumbbell sections serve as the primary load-bearing components. Their dumbbell-shaped cross-sections (two steel tubes filled with concrete in between) enhance bending stiffness and reduce cross-sectional dimensions. The segments are connected by flanges and high-strength bolts, with inner lining pipes at the joints to ensure concrete continuity. The upper dumbbell is welded to the 707 steel conduit, while the lower dumbbell is rigidly connected to the 704 support cylinder pad.

[0101] Web member 703: Connects the upper and lower dumbbells, forming a truss-like arch rib, enhancing spatial stability and resisting lateral wind loads and seismic forces. It is connected to the upper and lower dumbbells via intersecting welds or gusset plates; the weld quality must meet Class I standards.

[0102] As a support and force transmission system, the support cylinder 705 serves as a vertical support member for the arch rib and bridge deck system, transmitting vertical forces to the foundation while restricting lateral displacement of the arch rib. Its lower part is rigidly connected to the foundation embedded parts, and its upper part is connected to the lower dumbbell 702 via the support cylinder pad 704. An internal stiffener 706 is installed within the support cylinder to prevent local buckling.

[0103] Steel conduit 707: Serves as the anchoring channel for boom 3, protecting the boom from environmental corrosion while transmitting preload. It is welded to the upper dumbbell and has an internal rubber shock-absorbing sleeve to reduce vibration transmission.

[0104] As a suspender system, suspender 3 connects the arch rib and the bridge deck system, transmitting vertical loads and adjusting the bridge deck alignment through cable adjustment technology. The upper end is connected to the steel conduit 707 via anchorage, and the lower end is connected to the suspender crossbeam via anchorage. High-strength parallel steel wire or steel strand is used, with an outer PE sheath for corrosion protection.

[0105] Furthermore, the splicing of the main longitudinal beam 604 with the secondary longitudinal beam, the connection of the hanger crossbeam with the main longitudinal beam 604, and the splicing of the arch rib segments all adopt high-strength bolt connections, combined with large hexagonal head or torsion shear type designs. The connection between the upper / lower dumbbells and the web rod 703, and the connection between the support cylinder 705 and the pad plate, are all welded connections. The connection between the hanger 3 and the steel guide tube 707, and the hanger crossbeam, are anchored connections.

[0106] Vehicle load → bridge deck pavement → main longitudinal beams / secondary longitudinal beams → suspender beams → suspender 3 → arch ribs → support cylinders → foundation, forming a clear three-dimensional force transmission system. The web member 703, together with the upper and lower dumbbells, forms a truss structure, increasing lateral stiffness by 40% and reducing wind vibration coefficient by 30% compared to a solid web arch. Arch rib segments are installed using cable hoisting, with a single segment weight ≤80t and hoisting accuracy ±5mm; bridge deck segments are installed using floating cranes, with a daily assembly capacity of up to 3 segments.

[0107] The present invention, through three major technologies—grid-supported bridge deck system, arch rib truss structure, and composite connection of high-strength bolts, welding, and anchorages—achieves high load-bearing capacity, safety factor ≥2.0, high durability, design life of 100 years, high construction efficiency, and a 30% reduction in construction period for spans ≥100m, providing a standardized solution for similar bridges.

[0108] In summary, this invention addresses the problems of non-perpendicularity between the mid-span of the bridge deck system and the mid-span hangers of the arch rib, and the misalignment of the theoretical connection positions between the lower chord hangers of the arch rib and the bridge deck system, by employing a reserved length extension method. The construction method of this invention, through an innovative model of "process reservation + on-site measurement + dynamic adjustment," provides a high-precision and high-efficiency solution for the construction of mid-span steel pipe arch bridges. It achieves high-precision vertical matching between the bridge deck system and the arch rib hangers, significantly improving structural safety, construction efficiency, and economy; it eliminates the deviation between theoretical models and actual conditions, optimizes the structural stress system, reduces rework risks and costs, and provides a reliable precision control scheme for the construction of mid-span steel pipe arch bridges, possessing broad application value.

[0109] It should be understood that although this specification describes one embodiment, it does not mean that the embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in this embodiment can also be appropriately arranged and combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A construction method for precisely matching the deck system and arch height of a mid-span steel pipe arch bridge, characterized in that, Includes the following steps: Step 1, Reserve the process length of the longitudinal beam: Determine the number and quantity of the longitudinal beam (1) that needs to be lengthened, drill bolt holes at the non-length extension end of the longitudinal beam (1), and reserve at least 150mm of un-drilled section at the length extension end; Step 2, process allowance for splicing plate: Determine the number and quantity of splicing plate (2) corresponding to the longitudinal beam (1), reserve at least 10mm length process allowance on splicing plate (2), and pre-drill half of the bolt holes at the processing plant; Step 3, On-site measurement and longitudinal beam cutting: After the concrete inside the steel pipe arch reaches the design strength, measure the center distance of the mid-span hangers (3), calculate the longitudinal length of the bridge deck system hoisting segment (6) perpendicular to the hangers (3), and determine the cutting length of the longitudinal beam (1); draw the cutting position line (5) with the transverse baseline (4) as the reference, cut the reserved section of the longitudinal beam (1), and drill the calculated bolt hole group parallel to the transverse baseline (4); Step 4: On-site drilling of splice plates: According to the hoisting sequence of the bridge deck system, use the splice plate (2) with half of the holes already drilled at the bridge site to complete the drilling of the remaining bolt holes of the splice plate (2).

2. The construction method according to claim 1, characterized in that: The measurement results of the center distance of the mid-span hanger (3) in step 3 are used to correct the cutting length of the longitudinal beam (1) to ensure that the bridge deck system is perpendicular to the arch rib hanger (3).

3. The construction method according to claim 1 or 2, characterized in that: Step 3 is determined by measuring the center distance of the mid-span hangers (3) and calculating the longitudinal length of the bridge deck system hoisting segment (6) perpendicular to the hangers (3). The calculation method is based on the geometric relationship between the bridge deck system and the hangers (3).

4. The construction method according to claim 1, characterized in that: Step 3 uses a semi-automatic trolley to cut the reserved section of the longitudinal beam (1).

5. The construction method according to claim 1, characterized in that: In step 4, the splicing plate (2) is drilled using an on-site positioning drilling process, and the alignment accuracy of the bolt holes between the splicing plate (2) and the longitudinal beam (1) is controlled by a high-precision measuring device.

6. The construction method according to claim 1, characterized in that: The longitudinal beam (1) is a steel box beam or truss beam structure; the splicing plate (2) is a high-strength steel plate; the bolt hole group is processed by CNC machine tool.

7. The construction method according to claim 1, characterized in that: The construction method described herein is applicable to mid-span steel pipe arch bridges with a span of 100m or more.

8. A mid-span steel pipe arch bridge, characterized in that: The mid-span steel pipe arch bridge is an arch bridge constructed by any of the construction methods described in claims 1-7. The arch bridge includes a bridge deck hoisting segment (6) and an arch rib hoisting segment (7). The bridge deck hoisting segment (6) includes a hanger beam, a column beam (601), an end beam (602), a secondary beam (603), a main longitudinal beam (604), a secondary longitudinal beam, a splicing plate (2), and high-strength bolts. The arch rib hoisting segment (7) includes an upper dumbbell (701), a lower dumbbell (702), a web member (703), a support cylinder pad (704), a support cylinder (705), a support cylinder internal stiffener (706), a steel guide tube (707), and a hanger (3). The arch rib hoisting segment (7) is vertically connected to the bridge deck hoisting segment (6) via the hanger (3).

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