Small-curvature high-pier continuous steel box girder manufacturing and construction control method

Abstract

The application provides a small-curvature high-pier continuous steel box girder manufacturing and construction control method, and belongs to the technical field of curved steel box girder processing, and comprises the following steps: step 1, steel box girder unit element division; step 2, after the completion of the unit element division in step 1, steel inspection and testing are performed, welding materials are determined according to the welding process evaluation test results, and coating materials are selected; step 3, after the completion of the selection of the steel, welding and coating according to the regulations, computer three-dimensional lofting technology is adopted, computer-aided design is used, a three-dimensional model of the steel box girder is established, and accurate lofting of each component of the steel box girder is performed; step 4, after the completion of step 3, numerical control and automatic mode are adopted to perform steel cutting and flame cutting process evaluation according to the lofting data; step 5, a steel box girder installation process diagram is established by adopting BIM technology, and after the plate unit is cut and welded into a plate block in the rear field, the plate block is transported to a field assembly site for assembly and welding operation, and the block unit is integrally assembled on an assembly jig; and step 6, steel box girder jacking installation.

Description

Technical Field

[0001] The invention relates to the technical field of curved steel box girder processing and installation, and in particular to a method for manufacturing and controlling the construction of a continuous steel box girder with a small curvature and a high pier. Background Art

[0002] In the construction of highways, railways or urban bridges and roads, steel box girders are widely used in the superstructure of bridges due to their excellent mechanical properties and prefabrication. The mechanical properties of steel box girders have the following advantages: light weight, large elastic modulus, large bearing capacity, low cost; and they are easy to construct using a variety of different construction methods.

[0003] Nowadays, the construction situation of bridge construction projects is becoming increasingly complicated. On-site construction is restricted by the construction environment. The construction method must meet the requirements of bridge quality as well as the construction progress and cost requirements. For continuous steel box girder bridges with small curvature and high piers that are complex in bridge type and difficult to construct, the linear control of each segment is particularly important. Only by ensuring the accuracy of the linear curvature of each segment can the integrity of the small radius curved box girder be guaranteed. The plane curve radius of the steel box girder is too small, requiring high jacking synchronization performance, and the correction measures during the jacking process are a construction difficulty. Therefore, the present invention designs a method for the construction, manufacture and installation of steel box girders that is controlled from both the manufacturing and construction aspects to solve the above problems. Summary of the Invention

[0004] In response to the above-mentioned problems, the present invention proposes a method for manufacturing and construction control of continuous steel box girders with small curvature and high piers. With the help of BIM technology, from the initial unit component division to the manufacturing and installation of the overall box girder, the linearity of each segment of the steel box girder is accurately controlled, solving the problems of large manufacturing errors and difficult to control overall linearity in continuous steel box girder bridges with small radius curves.

[0005] The technical solution adopted in the present invention is:

[0006] The present invention provides a method for manufacturing and controlling a continuous steel box girder with a small curvature and a high pier, comprising the following steps:

[0007] Step 1: Divide the steel box girder into unit elements;

[0008] Step 2: After completing the unit component division in step 1, conduct steel inspection and testing, determine the welding materials based on the welding procedure qualification test results, and select the coating materials;

[0009] Step 3: After completing the selection of steel, welding and coating according to regulations, use computer 3D lofting technology and computer-aided design to build a 3D model of the steel box girder and accurately lay out each component of the steel box girder;

[0010] Step 4: After completing step 3, the steel cutting and flame cutting process evaluation is performed using CNC and automatic methods based on the layout data;

[0011] Step 5: Use BIM technology to create the steel box girder installation process drawing, and cut and weld the plate units into plate elements in the back field, and then transport them to the on-site assembly site for assembly and welding operations. The block units are assembled as a whole on the assembly cradle;

[0012] Step 6: Push-in installation of steel box girder.

[0013] In the above technical solution, further, in step 1, a steel box girder unit element model is established by computer to accurately divide the unit elements:

[0014] (1) The top plate of each ramp segment is divided into four unit elements, the bottom plate is divided into two unit elements, the web plate and diaphragm are each unit elements, and the cantilever beam is each component; the unit elements include panel elements, cantilever elements, bottom plate elements, diaphragm elements, web plate elements, U-rib elements, and T-rib elements;

[0015] (2) The top plate of each stage of the main line bridge is divided into five unit elements, the bottom plate is divided into three unit elements, the web plate and the diaphragm are each unit elements, and the cantilever beam is each component; its unit elements include top plate unit, diaphragm unit, web plate unit, bottom plate unit and cantilever beam.

[0016] In the above technical solution, further, after completing the division of the steel box girder unit elements according to step 1, the lofting process is as follows:

[0017] Step 301: Determine the theoretical size of the part blanking through computer mathematical lofting processing, and then determine the process size of the blanking processing based on the joint processing requirements and welding shrinkage;

[0018] Step 302: Then perform group analysis to determine the blanking method, analyze the material utilization rate, and start blanking for parts that meet the conditions;

[0019] (1) Cutting of panels, bottom plates and webs

[0020] When the face plate, bottom plate and web are in straight line form, the tolerance of blanking size is: the tolerance of length and width of single face plate, bottom plate and web is plus or minus 0.5mm. For face plate and bottom plate, the width direction of middle plate unit is plus 3mm process welding shrinkage, and for face plate and bottom plate, the width direction of both side plate units is plus 1.5mm process welding shrinkage. When the face plate, bottom plate and web are in curved form, the tolerance of blanking size is shown in the following table:

[0021]

[0022] (2) Cutting of main beam diaphragms and eaves diaphragms:

[0023] The length and width of the main beam diaphragms and cantilever diaphragms are allowed to have an error of plus or minus 0.5mm. The surrounding areas are deburred and polished, and the bevels are cut using a semi-automatic cutting machine in accordance with the process regulations.

[0024] (3) U-rib unit cutting

[0025] The material is cut using a semi-automatic cutting machine, with a dimensional deviation of ±1.0 mm and a diagonal deviation of <1.5 mm. The surrounding area is deburred and polished.

[0026] In the above technical solution, further, in step 5, the steel box girder assembly process is as follows:

[0027] Step 501: Using BIM technology to simulate the segmented assembly of the steel box girder, and obtain the installation coordinates of the tire frame and the beam segment;

[0028] Step 502: Mark the marking lines for positioning each unit, the plate center line, the beam section center line, and the angle positioning control line on the ground.

[0029] Step 503: Positioning the tire frame on the base plate unit: First, position the central reference base plate unit, then position the positioning lines of the base plate units on both sides. Align the longitudinal and transverse positioning reference lines of the base plate unit with the corresponding lines on the ground sample line. Secure the base plate unit and the assembled tire frame with a mounting plate.

[0030] Step 504: Assembling the diaphragm units: Determine the position of the diaphragm units according to the diaphragm positioning lines of the bottom plate units. When assembling, assemble the diaphragm units in the middle first, and then assemble the diaphragm units on both sides last. After the diaphragms are assembled, use angle steel for temporary support. After the overall assembly is qualified, spot weld the welds between the diaphragm units and the bottom plate units.

[0031] Step 505: Web unit assembly: Position and assemble according to the web positioning lines of the bottom plate unit. First, assemble the web on one side and spot weld the welds between it, the bottom plate unit, and the bulkhead unit. Continue to assemble the web unit on the other side. After the web unit is assembled, insert the web longitudinal ribs through the bulkhead holes and control the perpendicularity of the longitudinal ribs to the web unit.

[0032] Step 506: Assemble the top plate unit: Assemble the top plate unit based on the vertical and horizontal baselines of the bottom plate unit, ensuring the horizontal baseline alignment accuracy and vertical baseline offset value. The other top plate units are assembled in sequence based on the middle bottom plate. After the box body size inspection is qualified, start welding the connection welds between the top plate and adjacent components;

[0033] Step 507: After the welds at various locations of the steel box beam block have passed the flaw detection, the welding deformation of the beam block is corrected.

[0034] In the above technical solution, further, the key welding steps in the steel box girder assembly process are as follows:

[0035] (1) Welding of panel, floor and web units

[0036] The steel box girder panel, floor and web units are welded by semi-automatic CO2 gas shielded welding;

[0037] (2) Diaphragm unit welding

[0038] The common diaphragm is first welded to the butt weld of the manhole stiffening rib, then welded to the fillet weld around the manhole stiffening rib, and finally welded to the cantilever beam bearing rib; the fillet weld of the manhole stiffening rib is segmented and re-welded using small specification welding process parameters; the manhole stiffening rib at the fulcrum is symmetrically welded by segmented re-welding or skip welding.

[0039] In the above technical solution, further, in step 6, the distributed computer network control system is used to control the walking jacking device to realize forward jacking, the control system includes 2 master control consoles and 6 pump stations, corresponding to 12 walking jacking devices, each pump station controls 2 sets of walking jacking devices, and a matching sensor group, each set of walking jacking device is composed of 1 vertical jacking top, 1 horizontal jacking top and 2 correction jacking tops, corresponding displacement sensors and pressure sensors.

[0040] In the above technical solution, further, the synchronization control process of the distributed computer network control system is as follows:

[0041] (1) Pre-jacking: after all the structures are off the ground, the following adjustments need to be made: the position and load record of each point; compare the actual load of each point with the theoretically calculated load, and adjust the load parameters of each point according to the actual load; read the long distance sensor and set the parameters in the master control console control program; the master control console enters the automatic operation program and jacks the steel box girder as a whole;

[0042] (2) Official jacking: the pump pressure value is set in advance according to the design jacking load; during the jacking process, the measurement personnel measure the accurate data of each jacking point through the long distance sensor, and the master control console controls the jacking error within 10mm through the long distance sensor feedback distance signal, thereby controlling the synchronous jacking of all jacks;

[0043] (3) Observation of jacking process: the synchronous displacement sensor, the monitoring of jacking synchronization, the working state of the pier and the hydraulic oil cylinder, the cumulative jacking force conversion value, and the synchronization of each support jacking need to be observed;

[0044] (4) Angle control of jacking device: the jacking direction of all jacking positions should be unified during the jacking process, and should be continuously adjusted under different working conditions, the center line of the front jacking pier and the tail jacking pier is the jacking direction;

[0045] (5) Correction and adjustment during the jacking process of the main line bridge and ramp bridge: During the jacking process, the step correction amount of each pier must be measured manually, and the measured value and the calculated value must be reviewed and adjusted. The adjusted data must be input into the control jacking correction system in a timely manner to ensure that the steel box girder moves forward according to the designed line shape;

[0046] (6) Prevent slipping on the longitudinal slope during jacking construction.

[0047] In the above technical solution, further, the process of pushing the steel box girder forward is as follows:

[0048] Step 1: The equipment is in place and in the initial state;

[0049] Step 2: The vertical top returns, the vertical top is separated from the bottom of the beam, and the load is completely transferred to the slide box;

[0050] Step 3: Push the slide box horizontally to drive the beam forward for one step;

[0051] Step 4: Use the vertical jack to lift the beam out of the slide box, completing the force system conversion;

[0052] Step 5: The horizontal jack returns without load, resets and waits;

[0053] Step 6: Vertical top return, transfer the load to the slide box and return to the initial state.

[0054] In the above technical solution, further, the correction value during the jacking process of the main line bridge and the ramp bridge is calculated as follows:

[0055] According to the pushing direction, point A, the center of the tail of the steel box girder, is pushed to point B. However, in fact, point A of the steel box girder must go to the next work station point C, and points B and C are in the center normal direction of this part. The line between points B and C is the correction value of this part, and the pushing is formed into AC, thereby obtaining the correction values ​​L5, L4, and L3 of the pushing piers at different points; the step amount of the walking pushing equipment used is 400mm, and the step correction amount of its pier column position = L5 / (AC / 400), and AC / 400 represents the step correction amount of the adjacent pier.

[0056] In the above technical solution, further, the anti-slip measures for the longitudinal slope of the jacking construction are as follows:

[0057] Near the inner H-shaped steel web, an anti-slip assembly is set every 2m. The anti-slip assembly includes a steel rod and a limiter. The upper and lower wing plates of the H-shaped steel web are perforated. The steel rod passes through the perforations on the upper and lower wing plates and is connected to the upper and lower wing plates through the limiter.

[0058] Beneficial effects of the present invention:

[0059] 1. The present invention uses the linear control manufacturing process of the curved steel box girder bridge with the help of BIM technology. During the manufacturing process, the single-box double-chamber cross-section box girder and the single-box three-chamber cross-section of the small curved steel box girder are complex in structure, and the processing linearity, pre-arch and airtightness require high precision. Therefore, with the help of BIM technology, the processing technology and assembly process of the box girder are visually simulated and numerically simulated and analyzed, and the jacking process is strictly monitored and controlled to form standardized processes and quality control technical requirements to ensure the processing quality and construction accuracy of the beam bridge.

[0060] 2. This invention utilizes a distributed computer network control system to achieve jacking installation of steel box girders. Jacking control primarily relies on displacement control, supplemented by thrust force. Horizontal jacking on different piers is synchronized, and when the difference in displacement between the jacking jacks on each pier exceeds a set value (3mm), the corresponding flow rate is reduced or increased. Vertical jacking, lifting the main girder off the cushion beam and retracting it back onto the cushion beam, are synchronized. Pressure transmitters are installed on each jacking device (vertical jacking jack), allowing the computer to monitor load changes at each load point and accurately coordinate load distribution across the entire system. The maximum pressure at each load point and the maximum pressure differential between load points on the same pier can be set via a field controller or a main console. The control core utilizes a PLC for sensor data acquisition, logical processing, and control signal output, enabling coordinated control of the hydraulic jacks. An industrial touchscreen interface is used for human-computer interaction, enabling real-time monitoring of jack movements, setting control parameters, and recording data.

[0061] 3. During the installation stage of the steel box girder, the present invention carries out construction control from the aspects of pre-pushing, formal pushing, pushing process observation, pushing equipment angle control, and main line bridge pushing process correction and adjustment to ensure the stability and safety of the pushing main structure.

[0062] 4. This invention incorporates an anti-slip structure on the longitudinal slope of the jacking construction. A 95mm steel rod is restrained on the upper and lower flanges of the H-shaped steel web by a retaining member, which is calculated to withstand a force of 30 tons. This effectively prevents slippage. Furthermore, the anti-slip member is connected by bolts, allowing for quick removal and transfer to the next anti-slip position for reuse without affecting the hauling stroke, ensuring rapid and efficient hauling. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0064] Figure 1 It is a schematic diagram of the composition of the steel box girder unit;

[0065] Figure 2 This is the flow chart for cutting steel box beams;

[0066] Figure 3 Manufacturing process for steel box girder assembly;

[0067] Figure 4 This is a schematic diagram of the assembly of the base plate unit blocks;

[0068] Figure 5 This is a schematic diagram of the assembly of the diaphragm unit;

[0069] Figure 6 This is a schematic diagram of web unit assembly;

[0070] Figure 7 Schematic diagram of top plate unit assembly.

[0071] Figure 8 Elevation diagrams before and after the mainline bridge is pushed up; (a) before the mainline bridge is pushed up; (b) after the mainline bridge is pushed up.

[0072] Figure 9 Schematic diagram of the main line bridge after adjustment; (a) elevation; (b) plan.

[0073] Figure 10 It is a working condition where pushing does not correct the deviation.

[0074] Figure 11 This is the flow chart for pushing the steel box girder forward.

[0075] Figure 12 Schematic diagram of the passive limit device.

[0076] Figure 13 It is a top view of the passive limit device.

[0077] Figure 14 This is a schematic diagram of the anti-slip structure.

[0078] Figure 15 Schematic diagram of the limiter.

[0079] Among them, 1. bottom plate unit; 2. diaphragm unit; 3. web unit; 4. top plate unit; 5. cantilever beam; 6. center bottom plate unit positioning line; 7. side bottom plate unit positioning line; 8. diaphragm positioning line; 9. web positioning line; 10. top plate unit longitudinal and transverse positioning lines; 11. bottom plate unit top plate longitudinal and transverse positioning lines; 12. steel rod; 13. horizontal steel plate; 14. semi-cylinder limit part; 15. right wing plate; 16. rubber pad; 17. bracket; 18. guide wheel. DETAILED DESCRIPTION

[0080] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0081] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0082] See also Figure 1 The present invention specifically provides a method for manufacturing and controlling a continuous steel box girder with a small curvature and a high pier, comprising the following steps:

[0083] Step 1: Divide the steel box girder into unit elements;

[0084] Step 2: After completing the unit component division in step 1, conduct steel inspection and testing, determine the welding materials based on the welding procedure qualification test results, and select the coating materials;

[0085] Step 3: After completing the selection of steel, welding and coating according to regulations, use computer 3D lofting technology and computer-aided design to build a 3D model of the steel box girder and accurately lay out each component of the steel box girder;

[0086] Step 4: After completing step 3, the steel cutting and flame cutting process evaluation is performed in a CNC and automatic manner according to the layout data;

[0087] Step 5: Use BIM technology to create the steel box girder installation process drawing, and cut and weld the plate units into plate elements in the back field, and then transport them to the on-site assembly site for assembly and welding operations. The block units are assembled as a whole on the assembly cradle;

[0088] Step 6: Push-in installation of steel box girder.

[0089] In step 1, a computer is used to establish a steel box girder unit element model and accurately divide the unit elements:

[0090] (1) The top plate of each ramp segment is divided into four unit elements, the bottom plate is divided into two unit elements, the web plate and diaphragm are each unit elements, and the cantilever beam is each component; the unit elements include panel elements, cantilever elements, bottom plate elements, diaphragm elements, web plate elements, U-rib elements, and T-rib elements;

[0091] (2) The top plate of each stage of the main line bridge is divided into five unit elements, the bottom plate is divided into three unit elements, the web and the transverse plate are unit elements respectively, and the cantilever beam is a component respectively; the unit elements include a top plate unit, a partition plate unit, a web unit, a bottom plate unit and a cantilever beam, as shown in Figure 1

[0092] After the unit element division of the steel box girder is completed according to step 1, the lofting process is as follows (as shown in the figure):

[0093] Step 301: The theoretical size of the part is determined by computer mathematical lofting processing, and then the process size of the blanking processing is determined according to the joint processing requirements and the welding shrinkage;

[0094] Step 302: Then group analysis is performed to determine the blanking mode, and then the material utilization rate is analyzed, and for the parts that meet the conditions, the blanking is started;

[0095] Among them, the compensation amount is determined according to: welding process test, part processing requirements; Group analysis content: part blanking mode, part processing mode, unit element demand for parts, component demand for unit elements; Material utilization rate analysis: numerical control blanking parts are analyzed by numerical control programming software, and non-numerical control blanking parts are judged according to the area proportion of computer lofting. The project is approved by the total work after the implementation of the non-compliant material.

[0096] (1) Panel, bottom plate, web blanking

[0097] ① When the panel, bottom plate and web are in straight line form, use numerical control cutting machine or semi-automatic cutting machine for blanking. The size allowance deviation during blanking: the length and width of single panel, bottom plate and web allow error of ±0.5mm. The width direction of the middle plate unit of the panel and bottom plate adds 3mm of process welding shrinkage, and the two side plate units of the panel and bottom plate add 1.5mm of process welding shrinkage.

[0098] ② When the panel, bottom plate and web are in curved form, use numerical control cutting machine for blanking. The size allowance deviation during blanking is shown in the following table:

[0099]

[0100] (2) Main beam transverse plate, eave partition plate blanking:

[0101] The length and width of the main beam transverse plate and the eave partition plate allow error of ±0.5mm, the peripheral area is deburred and polished, and the semi-automatic cutting machine is used to open the groove according to the process requirements;

[0102] (3) U rib unit blanking

[0103] Use semi-automatic cutting machine for blanking, size deviation ±1.0mm, diagonal deviation <1.5mm, and the peripheral area is deburred and polished.​

[0104] Note: Surface and bottom plate and web extensions are calculated as approximately 100mm longer. The plate width tolerance is less than 2mm. Wave deformation greater than 3mm / m and horizontal bending greater than 3mm within 6m after cutting should be corrected. When cutting left and right webs, the height deviation at corresponding locations should be less than 1.0mm, and pre-camber should be applied as designed.

[0105] The cutting parts are as follows:

[0106] (1) For steel materials that have been pre-treated with shot blasting and sprayed with primer before cutting, the test pieces for flame cutting process assessment should also be coated with the same primer.

[0107] (2) For the test piece for flame cutting process assessment, when the thickness is 20mm, the results of the process assessment are also applicable to various thicknesses of steel less than 20mm; when the thickness is 40mm, the results of the process assessment are also applicable to various thicknesses of steel greater than 20mm but less than 40mm; when the thickness is greater than 40mm, the process assessment should be carried out separately at each 5mm level.

[0108] (3) Beveling and pad processing

[0109] ① Opening the bevel

[0110] a. The groove is cut using a small automatic groove machine. After processing, the groove angle should be positive. For partial penetration welds, the groove depth should also be positive.

[0111] b. The groove surface should be smooth and flat. If the edges are too deep, they should be ground smooth in advance or ground first, then repaired with qualified welding materials, and then ground flat.

[0112] c. When making the base weld for full penetration butt welds with grooves, it is required to use a special welding ceramic gasket or a steel backing on the reverse side to ensure the quality of the full penetration weld.

[0113] d. For details on groove size and groove type, please refer to the steel box girder welding process document.

[0114] ②Pad processing

[0115] a. Check the size of the incoming material.

[0116] b. Use a semi-automatic cutting machine to cut the material and grind the surrounding area to make it smooth.

[0117] c. Plane the bevel, plane the support plate (the surface that connects to the steel box beam) into a bevel that fits tightly with the bottom plate of the steel box beam, and plane the other side into a flat surface. (You can also use a horizontal milling machine to mill the bevel)

[0118] d. Check the accuracy of dimensions and the slope of the inclined surface.

[0119] e. After the support plate is processed, mark it with an oil-based pen.

[0120] The overall assembly process of steel box girder is as follows Figure 3 As shown, BIM technology was first used to simulate the segmented assembly of steel beams to determine the installation coordinates of the cradle and beam segments. A total station was used in the cradle area to mark the ground with (vertical and transverse) marking lines for positioning each unit, the plate centerline, the beam segment centerline, and angular positioning control lines. These marking lines are called landmark lines, and the template must be leveled with a level before welding.

[0121] The assembly process is as follows:

[0122] Step 501: Using BIM technology to simulate the segmented assembly of the steel box girder, and obtain the installation coordinates of the tire frame and the beam segment;

[0123] Step 502: Mark the marking lines for positioning each unit, the plate center line, the beam section center line, and the angle positioning control line on the ground.

[0124] Step 503: Positioning the tire frame on the base plate unit: first locate the center base plate unit positioning line, then locate the positioning lines of the two side base plate units, align the longitudinal and transverse positioning reference lines of the base plate unit with the corresponding lines on the ground sample line, and fix the base plate unit and the assembled tire frame with a mounting plate;

[0125] Step 504: Assembling the diaphragm units: Determine the position of the diaphragm units according to the diaphragm positioning lines of the bottom plate units. When assembling, assemble the diaphragm units in the middle first, and then assemble the diaphragm units on both sides last. After the diaphragms are assembled, use angle steel for temporary support. After the overall assembly is qualified, spot weld the welds between the diaphragm units and the bottom plate units.

[0126] Step 505: Web unit assembly: Position and assemble according to the web positioning lines of the bottom plate unit. First, assemble the web on one side and spot weld the welds between it, the bottom plate unit, and the bulkhead unit. Continue to assemble the web unit on the other side. After the web unit is assembled, insert the web longitudinal ribs through the bulkhead holes and control the perpendicularity of the longitudinal ribs to the web unit.

[0127] Step 506: Assemble the top plate unit: The top plate unit is aligned with the vertical and horizontal positioning lines of the top plate unit and the vertical and horizontal positioning lines of the floor unit top plate, ensuring the horizontal baseline alignment accuracy and vertical baseline offset value. The other top plate units are assembled in sequence based on the middle top plate. After the box body size inspection is passed, the connection welds between the top plate and adjacent components are started;

[0128] Step 507: After the welds at various locations of the steel box beam block have passed the flaw detection, the welding deformation of the beam block is corrected.

[0129] In order to ensure the overall linear shape of the steel box girder and the matching between each block during the assembly stage, after the plate units are cut and welded into plate elements in the back field, they are transported to the on-site assembly site for assembly and welding operations, and the following contents are determined based on the welding process assessment test: according to the steel used in the steel box girder beam components, the welding material brand and specification are selected; the welding method, welding position and welding sequence are determined; reasonable welding process parameters are determined; reasonable groove form and size are determined; the welding section length, welding section spacing and weld toe height of the tack welding corresponding to different steel grades and different welding joint forms are determined.

[0130] The steel box girder segment is a fully welded structure, which produces large welding deformation and residual stress. During the manufacturing process, under the premise of ensuring the quality of the weld, the main method used is high-purity gas shielded welding process with small welding deformation and small weld shrinkage, CO2 gas shielded welding with a purity greater than 99.9%.

[0131] Welding process parameters and requirements: The web, anchor plate and pressure plate of the steel box girder are the main force-transmitting components. The connecting welds are all full penetration welds, and grooves with less deposited metal and less deformation after welding should be used as much as possible.

[0132] For the connection welds between the anchor box bearing plate and the web unit, the weld toes shall be hammered after welding to reduce stress concentration. The hammering temperature shall be no less than 65°C.

[0133] The connecting welds between the web unit and the top plate unit, bottom plate unit and the cross-partition at the cable must be fully penetrated according to the design requirements. For the fillet welds of the groove welding, when the fillet size is not given, it is generally advisable to take a value of not less than 1.5(t)1 / 2, where t is the thickness of the thicker weld of the two welds.

[0134] The longitudinal and transverse butt welds of the top plate unit and bottom plate unit, and the welds between the outer web and the top plate, as well as the inclined bottom plate are all Class I penetration welds, and grooves with less deposited metal and less post-weld deformation are used as much as possible.

[0135] The fillet welds between the U-rib unit and the top plate unit and bottom plate unit are welded with a single-sided V-groove weld, and the penetration depth is not less than 0.8 times the plate thickness. When conducting process evaluation or welding performance tests on such welds, at least 10 weld sections should be cut at the same time to check whether the weld penetration meets the requirements. The welding gap between the longitudinal (transverse) partition and the top plate within the driving lane is required to be less than 2mm. Before the U-rib unit is produced by cold processing, a process test should be carried out, and it is required that there should be no cracks on the outer edge of the fillet. Before welding the U-rib unit to the bridge deck, its inner side should be painted, and all manually free cuts should be polished smooth; for process holes during the construction process, they must be cut at the designated design location and restored to their original state after the construction is completed. The welds should be inspected as Class I penetration welds, and the surface should be polished smooth.

[0136] Preheating and postweld heat treatment The preheating temperature before welding should be determined by welding test and welding procedure qualification. The preheating range is generally 80-100mm on each side of the weld, and the temperature is measured within 30-50mm from the weld. The preheating temperature before carbon arc gouging is the same as that during welding. In order to prevent the occurrence of lamellar tearing in T-joint, special attention should be paid to the preheating effect on the side of thick plate during preheating. For the positioning welding of Q345C steel plate with thickness≥25mm, preheating should be carried out before formal welding, and the preheating temperature is about 80-120℃, and the preheating range is 50-80mm on both sides of the weld.

[0137] The distributed computer network control system is used to control the forward jacking of the walking jacking device in step 6. The control system includes 2 master control consoles and 6 pump stations, corresponding to 12 walking jacking devices. Each pump station controls 2 sets of walking jacking devices, and is matched with a sensor group. Each set of walking jacking device is composed of 1 vertical jacking jack, 1 horizontal jacking jack, and 2 correction jacks. Corresponding displacement sensors and pressure sensors are provided.

[0138] The master control console can remotely control each field controller, display the oil pressure and displacement of each jack, and display the jacking distance of each pier on both sides. It has data saving function and fault alarm function, and automatically stops when the pre-set travel or load limit is reached. It can remotely control each field controller, display the oil pressure and displacement of each jack, set the maximum travel and maximum pressure of the jack, and remotely start and stop the pump station, pressure, and control the pump station to complete various actions. In the online state, all operations are completed by the master computer, and the field controller only performs emergency stop operation. It also has data saving function and fault alarm function, and automatically stops when the pre-set travel or load limit is reached.

[0139] The synchronization control process of the distributed computer network control system is as follows:

[0140] (1) Pre-jacking: After all the structures are lifted off the ground, the following adjustments need to be made: record the position and load of each point; compare the actual load of each point with the theoretically calculated load, and adjust the load parameters of each point according to the actual load; set the readings of the long distance sensors; set the parameters in the master control console control program, and enter the automatic operation program of the master control console to jacking the whole steel box girder;

[0141] (2) Formal jacking: The pump pressure value is pre-set according to the design jacking load; during jacking, the measurement personnel measure the accurate data of each jacking point through the long distance sensors, and the master control console controls the jacking error within 10mm through the distance signal feedback of the long distance sensors, thereby controlling the synchronous jacking of all jacks;

[0142] (3) Pushing process observation: need to observe the synchronous displacement sensor, monitor the pushing synchronization, the working state of the support pier and hydraulic cylinder, the cumulative pushing force conversion value of the first time, the synchronization of each support pushing;

[0143] (4) Angle control of pushing device: after the steel box girder segment welding is completed, the steel box girder pushing construction is carried out. The pushing device is arranged with 2 sets of walking pushing equipment on each pier cap beam where the pushing equipment is needed. 14 sets of pushing equipment work simultaneously for a main line bridge. In order to ensure the effectiveness of pushing, the pushing direction of all pushing positions should be unified during pushing process, and should be continuously adjusted under different working conditions, so as to minimize the influence of deviation during the running of curved bridge. The center line connecting the center of the front pushing pier and the center of the rear pushing pier is the pushing direction. As shown in the elevation view of the main line bridge before and after pushing. Figure 8

[0144] The steel box girder pushing process is as follows:

[0145] First step: equipment in place, in initial state, as shown ina; Figure 11

[0146] Second step: vertical top back stroke, vertical top disengages from the beam bottom, load is completely transferred to the sliding box, as shown inb; Figure 11

[0147] Third step: horizontal top pushing sliding box drives beam body to push forward one step, as shown inc; Figure 11

[0148] Fourth step: vertical jack lifting, makes the beam body disengage from the sliding box, completes the force system conversion, as shown ind; Figure 11

[0149] Fifth step: horizontal jack empty load back stroke, reset and wait, as shown ine; Figure 11

[0150] Sixth step: vertical top back stroke, load is transferred to the sliding box, back to initial state.

[0151] (5) Deviation correction adjustment in main line bridge and ramp bridge pushing process

[0152] Deviation correction adjustment in main line bridge pushing process: after the main line bridge cap beam is widened, the whole main line bridge is considered as approximately straight pushing, two segments are pushed at a time, no deviation correction is needed when 6-8 spans are pushed, when the guide beam reaches No. 5 pier, the pushing is paused, the whole body is rotated, the guide beam end is adjusted 1.5m to the left side (forward direction) to move, GL17 is adjusted 1.5m to the right side. Adjust the deviation after the pushing is completed. Details Figure 9 ​① Due to the walking jacking during the construction process, the steel box girder needs to be pushed forward along the designed circular curve; however, the performance characteristics of the walking jack itself can only be pushed longitudinally for a stroke, and then pushed horizontally to correct the deviation, so that the steel box girder can move forward according to the designed line shape of the curved bridge during the pushing process.

[0153] ②Correction and adjustment during the pushing process

[0154] Taking into account factors such as different friction resistance of various parts of the walking jack during the implementation of the jacking process, there may be some deviations in the step correction amount. During the jacking process, the step correction amount of each pier must be measured manually, and the measured value and the calculated value must be reviewed and adjusted. The adjusted data must be input into the control jacking correction system in a timely manner to ensure that the steel box girder moves forward according to the designed line.

[0155] Correction and adjustment of ramp bridge during jacking process: The offset of each stroke of the ramp bridge has been marked according to the simulation of the step diagram to guide the construction. Figure 10 As shown, due to the walking jacking during the construction process, the steel box girder needs to be pushed forward along the designed circular curve; but the performance characteristics of the walking jack itself can only be pushed longitudinally for a stroke, and then pushed horizontally to correct the deviation, so that the steel box girder can move forward according to the designed line shape of the curved bridge during the pushing process.

[0156] Because the ramp and mainline bridge jacking sections are long and both have more than two curves, the cap beams need to be widened. Furthermore, the jacking system needs to be moved laterally during the jacking process. The mobile jacking system utilizes a combination of manual labor and a manual hoist.

[0157] Table 2 Correction values ​​of each pier of BK0+505 ramp bridge under jacking working condition

[0158]

[0159] Table 3 Correction values ​​of each pier column of DK0+516 ramp bridge under jacking working condition

[0160]

[0161] Table 4 Correction values ​​of each pier column in the jacking working condition of BK0+014 ramp bridge

[0162]

[0163] Table 5 Correction values ​​of each pier of K0+674 ramp bridge under jacking working condition

[0164]

[0165] ①Calculation method of the deviation correction value of each pier column jacking working condition

[0166] like Figure 10As shown, only the top pushing without rectification of the working condition, according to the direction of the top pushing (blue line shown), the box girder tail center A point is pushed to B point. But our requirement is that the box girder A point must be to the next station C point, and B point and C point are in the center normal direction of the site, and the line BC between them is the rectification value of the site. And the top pushing stroke is AC, and the rectification value of the different top pushing pier in the figure is L5, L4, L3.

[0167] Because the top pushing process is step by step, in order to make the box girder deviation tend to be minimum value in the process of top pushing, then the method of rectifying once in each top pushing step is adopted, which will divide the rectification value evenly in each step rectification.

[0168] The step amount of the step pushing equipment adopted is 400mm, so the step rectification amount of the pier column is: step rectification amount (mm) = L5 / (AC / 400) (step rectification amount of the first pier). (Formula explanation: if the total rectification amount of AC point is L5, AC divided by 400mm is the total number of times of top pushing, the total deviation amount of a certain area ÷ total top pushing times = step rectification amount)

[0169] ②Top pushing process rectification adjustment

[0170] Considering that the step rectification amount may have some deviation due to different frictional resistance of each part of the step type jack and other factors in the process of top pushing implementation, the step rectification amount of each pier column must be measured by manual during the top pushing process, and the measured value and the calculated value are reviewed and adjusted, and the adjusted data is input into the control top pushing rectification system in time, to ensure that the steel box girder advances according to the designed line type.

[0171] (6)Top pushing construction longitudinal slope anti-slip measures

[0172] According to the design drawing query, the design longitudinal slope of ramp bridge BK0+505 is 3.95% uphill, the design longitudinal slope of ramp bridge DK0+516 (steel box girder section) is -1.7%, the longitudinal slope of K0+674 main line bridge steel box girder section is 1% (uphill), the first longitudinal slope of BK0+014 main line bridge is -3.95%, the second longitudinal slope is 1.0%, the variable slope point mileage is BK0+120 (the starting 13m range of the 5th span steel box girder) steel box girder section longitudinal slope is 1% (uphill).

[0173] B ramp bridge and top pushing section of main line bridge are uphill construction, and B ramp bridge dragging construction has separate anti-slip measures;

[0174] D ramp top pushing is 1.7% downhill, the maximum support reaction force is 2109KN, and the maximum horizontal component of the single point of top pushing is ; the friction force is The friction force is three times the horizontal component force, which has a large safety factor. After the bridge is completed, there is also a longitudinal slope of 1.7%. When pushing, the support area is close to the support area. In the absence of a large external force, the bridge will not automatically slip. Therefore, the pushing process is safe.

[0175] The main line bridge and ramp bridge are mainly corrected by the correction jack during the lateral correction process. In order to prevent sudden excessive lateral displacement during the lateral correction process, the passive limit device is used to limit the position. The passive limit device is as follows: Figure 12 He Ru Figure 13 As shown, it includes a connecting bracket and a guide wheel. The connecting bracket is installed on the pier cap beam and is located at the narrow side end of the pier. The guide wheel is installed at the end of the connecting bracket, and its rolling direction is consistent with the pushing direction of the curved bridge steel box girder. When the pushing offset of the curved bridge exceeds the limit offset, the side of the beam section will hit the guide wheel, changing the moving direction of the curved bridge.

[0176] Each pier is equipped with two sets of hydraulic roller passive limiters, each with a reaction force of 60 tons. During jacking, the passive limiters are approximately 20 cm from the box girder web. At least four guide wheels are provided, symmetrically arranged laterally and capable of horizontal rotation. When the curved bridge beam deflects beyond its limit, the side of the beam hits the guide wheels, limiting its movement in that direction. The rotation of the guide wheels also changes the direction of the curved bridge's jacking movement.

[0177] like Figure 14 As shown in the figure, the anti-slip measures for the longitudinal slope of the jacking construction are as follows: an anti-slip component is set every 2m near the inner H-shaped steel web. The anti-slip component includes a steel rod and a limiter. 100mm through-holes are opened on the upper and lower wing plates of the H-shaped steel web. The 95mm steel rod passes through the through-holes on the upper and lower wing plates and is connected to the upper and lower wing plates through the limiter.

[0178] like Figure 15 As shown, the limiting member includes a horizontal steel plate with a semi-cylindrical limiting portion provided on its side surface. Left and right wing plates are symmetrically arranged on either side of the semi-cylindrical limiting portion. After the steel rod passes through the upper and lower wing plates of the H-shaped steel web, a limiting member is symmetrically installed on the left and right sides of the steel rod. The semi-cylindrical limiting portion is attached to the outside of the steel rod. To increase the friction between the semi-cylindrical limiting portion and the steel rod, a frosted surface or a rubber pad is provided in the arc groove of the semi-cylindrical limiting portion. The two symmetrical semi-cylindrical limiting portions fit symmetrically, completely enveloping the steel rod. The two fitted left / right wing plates are fixed with multiple bolts. The horizontal steel plate is connected to the H-shaped steel arc plate with bolts, thereby limiting the vertical position of the steel rod. Each towing stroke is 1.9m. When the anti-slip measure is almost reached, the towing is paused, and the anti-slip measure is removed before continuing to the next towing stroke. Bolt fixing is fast to install and easy to disassemble.

[0179] The above description is only used to illustrate the technical solution of the present invention and is not intended to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for manufacturing and controlling the construction of a continuous steel box girder with a small curvature and a high pier, characterized in that: The following steps are involved: Step 1: Divide the steel box girder into unit elements; Step 2: After completing the unit component division in step 1, conduct steel inspection and testing, determine the welding materials based on the welding procedure qualification test results, and select the coating materials; Step 3: After completing the selection of steel, welding and coating according to regulations, use computer 3D lofting technology and computer-aided design to build a 3D model of the steel box girder and accurately lay out each component of the steel box girder; Step 4: After completing step 3, the steel cutting and flame cutting process evaluation is performed in a CNC and automatic manner according to the layout data; Step 5: Use BIM technology to create the steel box girder installation process drawing, and cut and weld the plate units into plate elements in the back field, and then transport them to the on-site assembly site for assembly and welding operations. The block units are assembled as a whole on the assembly cradle; Step 6: Push-in installation of steel box girder; In step 1, a computer is used to establish a steel box girder unit element model and accurately divide the unit elements: (1) The top plate of each ramp segment is divided into four unit elements, the bottom plate is divided into two unit elements, the web plate and diaphragm are each unit elements, and the cantilever beam is each component; the unit elements include panel elements, cantilever elements, bottom plate elements, diaphragm elements, web plate elements, U-rib elements, and T-rib elements; (2) The top plate of each stage of the mainline bridge is divided into five unit elements, the bottom plate is divided into three unit elements, the web plate and diaphragm are each unit elements, and the cantilever beam is each component; the unit elements include top plate unit, diaphragm unit, web plate unit, bottom plate unit and cantilever beam; After completing the division of the steel box girder unit elements according to step 1, the lofting process is as follows: Step 301: Determine the theoretical size of the part blanking through computer mathematical lofting processing, and then determine the process size of the blanking processing based on the joint processing requirements and welding shrinkage; Step 302: Then perform group analysis to determine the blanking method, analyze the material utilization rate, and start blanking for parts that meet the conditions; (1) Cutting of panels, bottom plates and webs When the face plate, bottom plate and web are in straight line form, the tolerance of blanking size is: the tolerance of length and width of single face plate, bottom plate and web is plus or minus 0.5mm. For face plate and bottom plate, the width direction of middle plate unit is plus 3mm process welding shrinkage, and for face plate and bottom plate, the width direction of both side plate units is plus 1.5mm process welding shrinkage. When the face plate, bottom plate and web are in curved form, the tolerance of blanking size is shown in the following table: (2) Cutting of main beam diaphragms and eaves diaphragms: The length and width of the main beam diaphragms and cantilever diaphragms are allowed to have an error of plus or minus 0.5mm. The surrounding areas are deburred and polished, and the bevels are cut using a semi-automatic cutting machine in accordance with the process regulations. (3) U-rib unit cutting The material is cut using a semi-automatic cutting machine, with a dimensional deviation of ±1.0 mm and a diagonal deviation of <1.5 mm. The surrounding area is deburred and polished.

2. The method for manufacturing and controlling the construction of a continuous steel box girder with a small curvature and a high pier according to claim 1, characterized in that: In step 5, the steel box girder assembly process is as follows: Step 501: Using BIM technology to simulate the segmented assembly of the steel box girder, and obtain the installation coordinates of the tire frame and the beam segment; Step 502: Marking lines for positioning each unit, plate center lines, beam segment center lines, and angle positioning control lines on the ground; Step 503: Positioning the tire frame on the base plate unit: first locate the center base plate unit positioning line, then locate the positioning lines of the two side base plate units, align the longitudinal and transverse positioning reference lines of the base plate unit with the corresponding lines on the ground sample line, and fix the base plate unit and the assembled tire frame with a mounting plate; Step 504: Assembling the diaphragm units: Determine the position of the diaphragm units according to the diaphragm positioning lines of the bottom plate units. When assembling, assemble the diaphragm units in the middle first, and then assemble the diaphragm units on both sides last. After the diaphragms are assembled, use angle steel for temporary support. After the overall assembly is qualified, spot weld the welds between the diaphragm units and the bottom plate units. Step 505: Web unit assembly: Position and assemble according to the web positioning lines of the bottom plate unit. First, assemble the web on one side and spot weld the welds between it, the bottom plate unit, and the bulkhead unit. Continue to assemble the web unit on the other side. After the web unit is assembled, insert the web longitudinal ribs through the bulkhead holes and control the perpendicularity of the longitudinal ribs to the web unit. Step 506: Assemble the top plate unit: The top plate unit is aligned with the vertical and horizontal positioning lines of the top plate unit and the vertical and horizontal positioning lines of the floor unit top plate, ensuring the horizontal baseline alignment accuracy and vertical baseline offset value. The other top plate units are assembled in sequence based on the middle top plate. After the box body size inspection is passed, the connection welds between the top plate and adjacent components are started; Step 507: After the welds at various locations of the steel box beam block have passed the flaw detection, the welding deformation of the beam block is corrected.

3. The method for manufacturing and controlling the construction of a continuous steel box girder with a small curvature and a high pier according to claim 2, characterized in that: The key welding processes in the assembly of steel box girders are as follows: (1) Welding of face plate, bottom plate and web plate elements The steel box girder face plate, bottom plate and web elements are welded using semi-automatic CO2 gas shielded welding; (2) Welding of diaphragm units For ordinary cross-partitions, the butt welds of the manhole stiffeners are welded first, then the fillet welds around the manhole stiffeners are welded, and finally the cantilever beam pressure ribs are welded; the fillet welds of the manhole stiffeners are welded in sections using small standard welding process parameters; the cross-partition stiffeners at the fulcrum are welded symmetrically using section-by-section welding or skip welding.

4. The method for manufacturing and controlling the construction of a continuous steel box girder with a small curvature and a high pier according to claim 2, characterized in that: In step 6, a distributed computer network control system is used to control the walking jacking device to achieve forward pushing. The control system includes 2 main control consoles and 6 pump stations, corresponding to 12 walking jacking devices. Each pump station controls 2 sets of walking jacking devices and matching sensors. Each set of walking jacking device consists of 1 vertical jacking jack, 1 horizontal jacking jack and 2 correction jacks, with corresponding displacement sensors and pressure sensors.

5. The method for manufacturing and controlling the construction of a continuous steel box girder with a small curvature and a high pier according to claim 4, characterized in that: The synchronous control process of the distributed computer network control system is as follows: (1) Pre-pushing: After the entire structure is off the ground, the following adjustments need to be made: record the position and load of each point; compare the actual load of each point with the theoretical calculated load, and adjust the load parameters of each point according to the actual load; read and set the long-distance sensor; set the parameters in the control program of the main console, and the main console enters the automatic operation program to carry out the overall jacking of the steel box girder; (2) Formal jacking: The pump source pressure value is pre-set according to the designed jacking load; during the jacking process, the measurement personnel use the long-distance sensor to measure the accurate data of each jacking point, and the main console feeds back the distance signal through the long-distance sensor to control the jacking error within 10mm, thereby controlling all jacks to push synchronously; (3) Observation of the jacking process: It is necessary to observe the synchronous displacement sensor, monitor the jacking synchronization, the working status of the pier and the hydraulic cylinder, the propulsion force conversion value accumulated once, and the synchronization of each pier jacking; (4) Angle control of the pushing device: The pushing direction of all pushing positions should be unified during the pushing process, and should be continuously adjusted under different working conditions. The line connecting the center of the front pushing pier and the center of the rear pushing pier is the pushing direction; (5) Correction and adjustment during the jacking process of the main line bridge and ramp bridge: During the jacking process, the step correction amount of each pier must be measured manually, and the measured value and the calculated value must be reviewed and adjusted. The adjusted data must be input into the control jacking correction system in a timely manner to ensure that the steel box girder moves forward according to the designed line shape; (6) Anti-slip measures on the longitudinal slope during jacking construction.

6. The method for manufacturing and controlling the construction of a continuous steel box girder with a small curvature and a high pier according to claim 5, characterized in that: The process of pushing the steel box girder forward is as follows: Step 1: The equipment is in place and in the initial state; Step 2: The vertical top returns, the vertical top is separated from the bottom of the beam, and the load is completely transferred to the slide box; Step 3: Push the slide box horizontally to drive the beam forward for one step; Step 4: Use the vertical jack to lift the beam out of the slide box, completing the force system conversion; Step 5: The horizontal jack returns without load, resets and waits; Step 6: Vertical top return, transfer the load to the slide box and return to the initial state.

7. The method for manufacturing and controlling the construction of a continuous steel box girder with a small curvature and a high pier according to claim 5, characterized in that: The correction value during the jacking process of the mainline bridge and ramp bridge is calculated as follows: According to the pushing direction, point A, the center of the tail of the steel box girder, is pushed to point B. However, in fact, point A of the steel box girder must go to the next work station point C, and points B and C are in the center normal direction of this part. The line between points B and C is the correction value of this part, and the pushing is formed into AC, thereby obtaining the correction values ​​L5, L4, and L3 of the pushing piers at different points; the step amount of the walking pushing equipment used is 400mm, and the step correction amount of its pier column position = L5 / (AC / 400), and AC / 400 represents the step correction amount of the adjacent pier.

8. The method for manufacturing and controlling the construction of a continuous steel box girder with a small curvature and a high pier according to claim 5, characterized in that: The anti-slip measures for the longitudinal slope during jacking construction are as follows: Near the inner H-shaped steel web, an anti-slip assembly is set every 2m. The anti-slip assembly includes a steel rod and a limiter. The upper and lower wing plates of the H-shaped steel web are perforated. The steel rod passes through the perforations on the upper and lower wing plates and is connected to the upper and lower wing plates through the limiter.

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