Arched girder system combined bridge construction process

Abstract

The invention discloses a construction process of a combined bridge of an arched girder system. The construction process comprises the following steps: step 1, numerical simulation and process optimization; step 2, pile foundation construction; thirdly, a bearing platform is constructed; step 4, constructing an abutment body; 5, steel box girder construction; sixthly, the prestressed concrete small box girders are erected; seventhly, bridge deck pavement and ancillary facility construction are conducted; eighthly, drainage engineering construction is conducted; step 9, quality control and acceptance inspection; advanced numerical simulation analysis software is adopted, the construction process of the arched girder combined system is subjected to simulation analysis, construction parameters and the technological process are optimized, the optimization strategy based on data driving ensures the reasonability and high efficiency of the construction scheme, reliable theoretical support is provided for actual construction, meanwhile, intelligent construction equipment is introduced, and the construction efficiency is improved. The construction precision and efficiency are improved, errors and uncertainty of manual operation are reduced, and the construction progress is remarkably accelerated through automatic operation.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a construction process for an arch-beam system combined bridge. Background Art

[0002] An arch-beam system combined bridge is a bridge structure that combines the arch ribs that mainly bear pressure and the carriageway beams that mainly bear bending moments to jointly bear the load. The arch-beam combined system bridge combines the advantages of both arch and beam structures. The arch ribs have higher bearing capacity and stiffness and can make full use of materials, while the main beam can balance the thrust of the arch foot and reduce the requirements for the foundation. Through the cooperation of arches and beams, the structural system is mainly composed of tension and compression components, materials are greatly utilized, and the overall stiffness and stability are significantly improved. The arch-beam combined system bridge has a higher spanning capacity and is suitable for the construction of medium and large span bridges.

[0003] The existing construction technology of arch-beam system composite bridge has the following defects: First, there is a lack of systematic construction parameter optimization and process improvement measures. The accurate setting of construction parameters is crucial to ensure the stability and safety of bridge structures. However, the existing construction technology often lacks in-depth research and fine adjustment of these key parameters, and the optimization of the process itself is also insufficient. It fails to make full use of modern scientific and technological technologies to improve construction efficiency and accuracy. The blindness of such parameters and the conservatism of the process not only affect the controllability of construction quality, but also increase engineering costs and time costs; second, due to the complex construction environment, large component sizes and diverse shapes, it is difficult to accurately control the construction accuracy, and it is easy to have problems of error accumulation and excessive deviation. On the other hand, traditional construction technology often relies on manual operation, and the degree of automation and intelligence is low, which makes it difficult to significantly improve construction efficiency. This double bottleneck of accuracy and efficiency not only affects the construction progress, but also increases construction risks and quality hazards; third, traditional construction technology faces great complexity and difficulty in the construction process of arch-beam system composite bridges. Summary of the invention

[0004] The purpose of the present invention is to provide a construction process for an arch-beam system composite bridge to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: a construction process of an arch-beam system composite bridge, comprising step one, numerical simulation and process optimization; step two, pile foundation construction; step three, abutment construction; step four, pier body construction; step five, steel box girder construction; step six, prestressed concrete small box girder erection; step seven, bridge deck pavement and ancillary facilities construction; step eight, drainage engineering construction; step nine, quality control and acceptance;

[0006] In the above step 1, numerical simulation analysis software is used to dynamically simulate the construction process of the arch-beam combination system and optimize the construction process;

[0007] In the above step 2, the bored pile foundation is constructed by a rotary drilling rig, the hole is formed by a mud wall method, underwater concrete is poured by a conduit method, the steel cage is manufactured in sections, and the truck crane is installed, and the foundation pit is backfilled after the pile foundation is poured;

[0008] In the above step 3, the foundation construction is carried out, which involves excavation, protection, drainage, steel bar binding, formwork installation, concrete pouring and backfilling;

[0009] In the above step 4, the pier body is constructed with a standard steel formwork, and the concrete is commercial concrete, which is pumped into the formwork;

[0010] In the above step 5, the method of first beam and then arch is adopted, first the main beam is constructed on the bracket, then the arch rib bracket and arch rib hoisting equipment are installed on the beam, and the steel box arch is erected in sections to form a combined arch beam system;

[0011] In the above step 6, temporary supports are installed, beams are erected and wet joints are constructed, and temporary supports are removed to complete the system conversion;

[0012] In the above step 7, bridge deck materials such as asphalt or cement concrete are laid, and bridge deck drainage systems, lighting facilities, railings and anti-collision facilities are installed to ensure the safety, comfort and beauty of the bridge deck;

[0013] In the above step eight, the laying of rainwater and sewage pipes is carried out in the order of downstream to upstream and deep to shallow. Larsen steel sheet piles are used for foundation pit support. Steel support is set up after trench excavation. After the closed water test is passed, the soil is backfilled and the construction is strengthened with drainage.

[0014] In the above step nine, a systematic inspection and evaluation is carried out, including material quality testing, construction process control, finished product protection, and final acceptance standards and procedures, to ensure that the construction quality and overall performance of the bridge meet the design requirements and relevant standards, thereby ensuring the safety and durability of the bridge.

[0015] As a further technical solution of the present invention, in the step one, advanced numerical simulation and analysis software is used to dynamically simulate the construction process of the arch-beam combination system, predict and analyze the structural response and deformation under different construction parameters, and based on the simulation results, optimize the construction parameters, such as the arch rib hoisting sequence, bracket arrangement and prestressing timing, to ensure the safety and efficiency of the construction process, introduce intelligent hoisting equipment, such as automatically guided cranes and robots, improve the accuracy and efficiency of hoisting operations, reduce human operation errors, and install an intelligent monitoring system at the construction site to monitor key parameters in the construction process, such as stress, deformation and temperature, in real time to ensure construction quality and safety.

[0016] As a further technical solution of the present invention, in the step 2, the bored pile foundation construction adopts different hole-making methods according to the actual geological conditions on site. The crane cooperates with the drilling rig to install the steel cage. The concrete is centrally supplied by the commercial concrete station and transported by the mixing truck. The concrete is pumped by the concrete pump or poured by the hopper. The concrete is moved into position by itself through the self-propelled crawler. After it is in position, the center point of the drill bit is aligned with the center of the pile position. At the same time, the drill mast is adjusted to be vertical, and then drilling is carried out. A mud drill bit is used in the surface soil, and a spiral drill bit plus a rotary bucket are used to form a hole when entering the pebble soil. The rotary drilling rig is suitable for the construction of various soil layers and bedrock with medium hardness or less. Different types of drill bits should be selected according to different geological conditions before construction.

[0017] As a further technical solution of the present invention, in the step three, slope excavation is adopted in general areas, and steel sheet pile protection is adopted for vertical excavation construction when it is restricted by terrain or the geological conditions are poor. The foundation pit of the pedestal is excavated manually with the cooperation of excavators, and centralized drainage or well point dewatering is adopted according to the groundwater level. After excavation, the bottom is manually cleaned and the pile heads are chiseled off by pneumatic picks. Safety protection nets are hung around the top of the foundation pit, the reinforcement of the pedestal is tied on site, the truck crane is used to erect the overall formwork, the concrete is centrally mixed, transported by tank trucks, and poured with the cooperation of cranes or pump trucks. After the construction of the pedestal is completed and accepted, it is immediately taken out Backfilling is carried out manually with the help of a small rammer. Steel sheet piles are driven in for protection and crash piers are set up near the front road of the existing road cap construction. Foundation construction is carried out under safe protection. Rebars are processed in the workshop and transported to the site by flatbed trucks. After the base is inspected and qualified, it is precisely positioned and tied on site. The cap formwork uses large factory-made steel formwork with a panel thickness of 6mm. Vertical and horizontal stiffening ribs are added to the outer wall, as well as annular channel steel stiffening ribs. It is assembled on site in 4 to 6 pieces and connected with bolts. The support method of the cap formwork is external reinforcement, and the support points are placed on the inside of the foundation pit and supporting formwork.

[0018] As a further technical solution of the present invention, in the fourth step, the pier body is constructed by the bracket method, a steel pipe scaffold is set up around the pier body as a construction platform, the factory-made steel mold is erected by a car crane, and the pier with a pier column height of less than 10m adopts an integral steel template to erect the mold at one time, and the whole is cast in one time. After the construction of the pier is completed, the surveying team will carry out the layout of the pier construction section according to the pier body design drawings, and the cooperative team will chisel the top surface of the pier according to the layout position to expose fresh aggregate. In order to make the pier body template have sufficient strength and rigidity and ensure the appearance quality of the pier body, the pier body template is to be adopted Use steel formwork, the steel formwork panel is made of 6mm thick steel plate, the inner surface of the formwork is required to be smooth and rust-free, the joints are tight and leak-proof, and before the formwork is erected, a layer of release agent is applied on the inner side of the formwork. The release agent should be of the same type to ensure the uniform color of the concrete surface, and then the formwork is erected to the designed pier height according to the released pier body center line and pier bottom elevation. After the pier body formwork is erected, the designed size of the pier body and the vertical verticality of the pier body should be ensured. To ensure the vertical stability of the formwork, 3 to 4 wind cables are pulled on the outside of the steel formwork to fix the formwork to prevent the formwork from tilting when pouring concrete. There should be a gap between the formwork and the scaffolding. They are independent of each other to avoid deformation of the formwork during manual operation on the scaffolding. The pier body formwork is reinforced with homemade light trusses around it. The trusses are bolted and Φ32 tie rods are used to form a whole. The steel bars are centrally cut, classified by model, specification, and numbered in the processing workshop according to the design drawings. They are transported to the site by flatbed trucks and tied on the steel skeleton positioning mold. The pier body steel bars must be tied and formed in one time, and their quality should meet relevant regulations. The main reinforcement joints of the structure are connected by straight tube threads. The main reinforcement and stirrups are tied with wire. The tied or welded steel mesh and steel skeleton shall not be deformed or loose. The soil pads are made of high polyester UPVC pads. In order to prevent the performance indicators of concrete mixture from declining, all of them are transported by concrete tankers, pumped into the mold, poured in layers, and continuously, and vibrated with an inserted vibrator. Before pouring concrete, sprinkle a proper amount of water to wet the concrete surface on the top of the pile. The concrete pouring is guided by a conduit. The free fall of concrete does not exceed 2m. The stacking height of the conduit discharge should not exceed 0.5m each time. Use an inserted vibrator to vibrate and compact it. When pouring concrete, check and measure the support of the bracket and the formwork at the same time. If there is deformation, displacement or subsidence, it should be corrected in time.

[0019] As a further technical solution of the present invention, in the step 4, the concrete is cast once or twice according to the height of the pier body. When a continuous casting process needs to be temporarily interrupted due to special circumstances, the allowed interruption time shall not exceed 90 minutes. When casting twice, before the second concrete casting, the top surface of the first concrete must be fully roughened before it can be cast. After the pier body concrete is initially set, watering and curing begin. The pier body is cured by wrapping it in the form of clothes and hats, and an automatic sprinkler system is installed. The curing time of the pier body concrete is more than 14 days, and the number of watering times per day is controlled according to the ambient humidity and temperature. The degree of watering is to ensure that the concrete surface is always in a moist state. During the curing period, the concrete shall not be subjected to external loads before the specified strength is reached. When the concrete strength meets the demolding requirements, and the temperature difference between the core concrete and the surface concrete, and the temperature difference between the surface concrete and the environment The formwork can be removed only when the temperature difference between the pier and the pier body is ≤20℃. When removing the formwork, avoid heavy prying and hard smashing to avoid damaging the concrete surface layer of the pier body. After removing the formwork, cover it tightly with plastic film and keep it moist for more than 14 days. During the curing period, arrange special personnel to supervise and inspect, and replenish water in time if it is insufficient to ensure that the pier body is in a moist curing state. Check the working status of the spray system to ensure the normal operation of the automatic spray curing system. To improve the durability of concrete, concrete components should be poured in one time as much as possible. Emergency measures for water and power outages must be taken before construction. Construction joints caused by construction reasons should be avoided as much as possible during the concrete pouring process. When construction joints are unavoidable, enter the concrete construction joint processing procedure according to the requirements of the specifications. When the design requires the setting of construction joints due to changes in the size of the structure, the location of the construction joints should be set at the part of the structure with less stress. When the structure is located in water, the construction joints should avoid the parts that are in alternating dry and wet changes all year round.

[0020] As a further technical solution of the present invention, in the step five, the steel box girder is produced and formed in pieces and groups by a steel structure processing plant with corresponding qualifications according to the requirements of the drawings, and then transported to the vicinity of the bridge for assembly and hoisting. The manufacturing of steel box girders can be divided into four major stages: unit manufacturing stage, segment assembly and pre-assembly stage, and site connection stage. The overall process flow is as follows: unit manufacturing, unit component transportation, unit assembly, multi-segment continuous matching pre-assembly, segment painting, segment storage, segment transportation, bridge connection, and final painting. The production of steel box girder components is mainly divided into the production of top plates, bottom plates, webs, partitions, wing plates and stiffening components. The steel box girder should be assembled and welded on a sturdy and reliable tire frame assembly line. The processing of components is mainly carried out by CNC equipment to maximize the use of mechanical operations and use tooling fixtures to reduce the randomness and instability of manual operations, improve the accuracy and production efficiency of components, and steel After the overall welding of the beam is completed, the surface is sandblasted to remove rust, and the painting operation is carried out using a high-pressure airless spray pump. The last coat of topcoat should be applied continuously once the entire bridge is built. Before the steel box girder segment leaves the factory, it should be assembled in three dimensions in the factory. It can only be transported to the construction site for assembly after the trial assembly meets the accuracy requirements. The finished product storage site should be solid, flat, ventilated and have drainage facilities. It should be numbered according to the assembly sequence and the storage location should be arranged according to the lifting sequence. It is advisable to stack it in a single layer. The stacking fulcrum must be located under the web, diaphragm and longitudinal diaphragm. The force at each point should be uniform as much as possible. The seesaw situation is not allowed, and uneven settlement of the stacking foundation is not allowed. During the stacking, transportation and erection process, in order to prevent local deformation and instability of the steel beam, a transverse frame or longitudinal frame can be added between the transverse diaphragm or web of the steel beam. The packaging of the steel structure must be carried out after the paint is dry. Tipping and collision should be prevented during transportation to avoid damaging the paint surface.

[0021] As a further technical solution of the present invention, in the step five, the steel box girder is prefabricated and assembled in a steel structure factory in a longitudinal segmented and transversely divided manner. Except for the last coat of topcoat, all painting is completed in the factory. After the steel beam is transported to the construction site, the geometric dimensions of each part and the welding quality of the connection parts are inspected, and the beams are classified and numbered according to the beam sections and the order of erection. They are stacked in the temporary beam storage yard on the construction site according to the order of erection. An assembly platform is set up at the original position of the steel box girder bridge. A combination of Type 83 railway military piers and Type 64 railway military beams is used. A concrete strip foundation is set under the military pier or it is directly placed on the bridge pedestal. The transverse blocks are connected to each other. The bridge is welded on the ground in sections, and the welded components are lifted by crane to the assembly platform for longitudinal splicing and welding between the sections. The steel beams are hoisted and erected in sections by two large crawler cranes in a single-end flow order. After the whole steel beam is assembled and welded and tested to be qualified, a hydraulic cylinder is used to lift the whole pier top, and the gap between the support and the bottom of the beam and the support reaction force are adjusted. Finally, the support system is dismantled, and the beams are dropped into place to realize the conversion of the entire bridge system. After the construction of the steel beam deck system is completed, the surface of the steel beams of the entire bridge is thoroughly cleaned, the concrete residue is removed, and the final outer surface topcoat is applied as a whole. At this time, special attention should be paid to ensure that the color of the coating is uniform and the appearance is exquisite.

[0022] As a further technical solution of the present invention, in the step six, the temporary support has sufficient strength and rigidity, is easy to assemble and disassemble, and the beam is evenly dropped. The temporary support adopts sulfur mortar with embedded electric thermal resistance wire. In a beam, the relative height difference of the top surface of the temporary support should not be greater than 2mm. Effective measures should be taken to close the horizontal gap between the permanent support and the bottom mold to prevent leakage. The elevation of the top surface of the temporary support should be flush with the elevation of the top surface of the permanent support. The top surface of the permanent support is directly poured together with the bottom of the joint concrete. Before pouring the joint concrete, the working status of the permanent support should be carefully checked. If any problems are found, they should be corrected in time to prevent the support from working with defects. The prefabricated small box beam adopts the lifting method of setting lifting holes, passing the bottom of the bundle bag and adding a shoulder pole. When the concrete strength of the beam body reaches the design strength and is qualified after inspection, it is lifted with a prefabricated The gantry crane in the manufacturing yard moves and lifts the beams, and the special beam transporter transports the beams to the bridge deck via the ground road. The automobile crane is used for erection. Before the beam is erected, the dimensions of the finished beam and the platform cap are checked, the elevation of the support point and the centerline of the beam span are remeasured, and the beam ends are left with the gap specified in the design. When erecting the bridge, the method of erecting the two sides first and then the middle is followed, and the beams are placed on temporary supports hole by hole to become simply supported. After the erection of each beam body, the end cross beams, diaphragms and bridge deck wet joints should be constructed in time. In order to prevent the precast beams from arching too much and the precast beams and the integral layer of the bridge deck from shrinking too much due to the age difference, the time from the prefabrication of the beams to the pouring of the cast-in-place concrete on the pier top should not exceed three months. After the erection of each beam piece, the cast-in-place end cross beams and the mid-span diaphragms are poured first, and then the bridge deck wet joints are poured. The cast-in-place section on the pier top is constructed Before construction, the ends of the beams are roughened, the steel bars of the continuous joint section at the top of the pier are connected, the cast-in-place crossbeam steel bars are tied, the joint plate bundle corrugated pipes are set and the bundles are threaded. When the daily temperature is lowest, the continuous joint concrete and the middle crossbeam and the bridge deck concrete on both sides of the top plate within the same length range of the negative bending moment bundle are poured. After the concrete strength reaches the strength specified in the design, the prestressed steel bundles in the negative bending moment area of ​​the top plate are tensioned and cement slurry is injected. The remaining wet joint concrete of the bridge deck should be poured from the mid-span to the support, the annular steel bars of the wet joint of the top plate should be aligned and welded, micro-expansive cement can be used for wet joint concrete, and hanging formwork can be used for pouring. The formwork should be steel formwork and should have sufficient rigidity and strength. After the formwork is firmly installed, rinse the roughened concrete surface, and brush the construction joint before pouring the secondary layer of concrete. A layer of cement slurry, concrete pouring and vibration requirements are the same as those for the pouring of the precast beam top plate. It is advisable to use a flat vibrator in combination with an insertion rod, and the designed thickness must be ensured. When pouring wet joints, it is advisable to do so under low temperature conditions and perform maintenance to prevent cracks. All new and old concrete bonding surfaces must be strictly roughened. Before pouring the cast-in-place concrete layer of the bridge deck, the floating slurry and oil stains on the top of the beam must be cleaned to ensure a good bond between the new and old concrete. After the wet joint concrete strength reaches the designed strength, the temporary sulfur mortar supports in a unit are removed symmetrically, evenly, synchronously and smoothly in the order and steps required by the design, and the electric heating method is used to remove the temporary supports of the internal sulfur mortar to complete the system conversion. Starting from the inner side piers of a unit, the temporary supports are symmetrically removed, and the same pier position is removed from the middle to both sides to carry out the system conversion.

[0023] As a further technical solution of the present invention, in the step eight, the laying of rainwater and sewage pipes is carried out in the order of downstream first and upstream later, deep first and shallow later. Larsen steel sheet piles are used for enclosure of foundation pits with deeper pipeline burial depths. The Larsen steel sheet piles are guided by double-sided purlin guide frames and driven by crawler crane hydraulic vibratory hammer screen-type driving method. After the foundation pit is backfilled with soil, the steel sheet piles are pulled out by hydraulic vibratory hammers. After removal, the pile holes are backfilled and compacted with cement mortar. Under the protection of foundation pit enclosures, manual labor and excavators are used to excavate pipeline trenches in layers and sections, and steel supports are erected in sequence. Automobile cranes are used to lower the pipe body. After the water-tightness test is passed, small machines are used to compact the backfill soil. Drainage measures are strengthened during construction to ensure that the bottom of the trench is not soaked in water.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention adopts advanced numerical simulation analysis software to simulate and analyze the construction process of the arch-beam combination system, optimizes the construction parameters and process flow, and this data-driven optimization strategy ensures the rationality and efficiency of the construction plan, provides reliable theoretical support for actual construction, and introduces intelligent construction equipment to improve the construction accuracy and efficiency, which not only reduces the error and uncertainty of manual operation, but also significantly speeds up the construction progress through automated operations. The integration of this technology and equipment enables every detail in the construction process to be accurately controlled, thereby ensuring the safety and stability of the bridge structure, and proposes a construction method of beam first and arch later, breaking the constraints of the traditional construction sequence, and providing solid support for the subsequent installation of the arch rib by first completing the construction of the main beam on the bracket, and then installing the arch rib bracket and hoisting equipment on the completed main beam, erecting the steel box arch in sections, and finally forming a complete combined arch-beam system. The adoption of this construction method not only simplifies the construction process and reduces the construction difficulty, but also significantly improves the construction efficiency. Through phased implementation, each construction link can be fully managed and optimized, thereby ensuring the smooth progress of the entire construction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a process flow chart of the present invention;

[0026] Figure 2 It is a schematic diagram of the construction of the cap foundation of the present invention. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] Please see attached Figure 1 -Attached Figure 2 The present invention provides an embodiment: a construction process of an arch-beam system composite bridge, comprising step one, numerical simulation and process optimization; step two, pile foundation construction; step three, abutment construction; step four, pier body construction; step five, steel box girder construction; step six, prestressed concrete small box girder erection; step seven, bridge deck pavement and ancillary facilities construction; step eight, drainage engineering construction; step nine, quality control and acceptance;

[0029] In the above step 1, advanced numerical simulation analysis software is used to dynamically simulate the construction process of the arch-beam combination system, predict and analyze the structural response and deformation under different construction parameters, and based on the simulation results, optimize the construction parameters, such as the arch rib hoisting sequence, bracket arrangement and prestressing timing, to ensure the safety and efficiency of the construction process, introduce intelligent hoisting equipment, such as automatic guided cranes and robots, to improve the accuracy and efficiency of hoisting operations, reduce human operation errors, and install intelligent monitoring systems at the construction site to monitor key parameters in the construction process, such as stress, deformation and temperature, in real time to ensure construction quality and safety;

[0030] In the above step 2, the bored pile foundation construction adopts different hole-making methods according to the actual geological conditions on site. The crane cooperates with the drilling rig to install the steel cage. The concrete is centrally supplied by the commercial concrete station and transported by the mixing truck. The concrete is pumped by the concrete pump or poured by the hopper. The concrete is moved into position by the self-propelled crawler. After the position is in position, the center point of the drill bit is aligned with the center of the pile position. At the same time, the drill mast is adjusted to be vertical, and then the drilling is carried out. The mud drill bit is used in the surface soil, and the spiral drill bit plus the rotary bucket are used to form holes in the pebble soil. The rotary drilling rig is suitable for the construction of various soil layers and bedrock with a hardness below medium. Different types of drill bits should be selected according to different geological conditions before construction;

[0031] Among them, in the above step three, slope excavation is adopted in general areas. When restricted by terrain or poor geological conditions, steel sheet pile protection is adopted for vertical excavation construction. The foundation pit of the pedestal is excavated manually with the help of excavators. Centralized drainage or well point dewatering is adopted according to the groundwater level. After excavation, the bottom is cleaned manually and the pile heads are chiseled off with pneumatic picks. Safety nets are hung around the top of the foundation pit. The reinforcement of the pedestal is tied on site. The truck crane is used to erect the overall formwork. Concrete is mixed centrally and transported by tank trucks. It is poured with the help of cranes or pump trucks. After the construction of the pedestal is completed and accepted, manual work is immediately adopted. Backfilling is done with a small tamping machine. Steel sheet piles and crash piers are installed near the front road of the existing road cap construction. Foundation construction is carried out under safety protection. Steel bars are processed in the processing workshop and transported to the site by flatbed trucks. After the base is inspected and qualified, it is precisely positioned and tied on site. The cap template uses a factory-made large steel template with a panel thickness of 6mm. The outer wall is added with vertical and horizontal stiffening ribs, and annular channel steel stiffening ribs are added. It is assembled on site in 4 to 6 pieces and connected with bolts. The support method of the cap template is external reinforcement, and the support points are placed on the inside of the foundation pit and the supporting template.

[0032] In the above step 4, the pier body is constructed by the bracket method, and a steel pipe scaffold is set up around the pier body as a construction platform. The factory-made steel formwork is erected by a car crane. The pier with a pier column height of less than 10m adopts an integral steel formwork for one-time formwork and is cast in one step. After the construction of the pier, the surveying team will carry out the layout of the pier construction section according to the pier body design drawings, and the cooperative team will roughen the top surface of the pier according to the layout position, requiring fresh aggregate to be exposed, so that the pier body formwork has sufficient strength and rigidity to ensure the appearance quality of the pier body. The pier formwork is planned to use steel formwork, and the steel formwork panel is made of 6mm thick steel plate. The inner surface of the formwork is required to be smooth and rust-free, and the joints are tight and leak-proof. Before the formwork is erected, a layer of release agent is applied on the inside of the formwork. The release agent should be of the same type to ensure the uniform color of the concrete surface. Then, the formwork is erected to the designed pier height according to the released pier center line and pier bottom elevation. After the pier formwork is erected, the designed size of the pier and the vertical verticality of the pier should be ensured. To ensure the vertical stability of the formwork, 3 to 4 wind cables are pulled on the outside of the steel formwork to fix the formwork. To prevent the formwork from tilting when pouring concrete, the formwork and scaffolding should be independent of each other to avoid deformation of the formwork during manual operation on the scaffolding. The pier body formwork is reinforced with homemade light trusses around it, and the trusses are bolted and Φ32 tie rods are used to form a whole. The steel bars are centrally cut, classified by model, specification, and numbered in the processing workshop according to the design drawings, and transported to the site by flatbed trucks. They are tied on the steel skeleton positioning mold. The pier body steel bars should be tied and formed at one time, and their quality should meet relevant regulations. The main structural reinforcement joints are connected by straight tube threads, and the main The reinforcement and stirrups are tied with wires. The tied or welded steel mesh and steel skeleton shall not be deformed or loose. The concrete pads are made of high-polyester UPVC pads. In order to prevent the performance index of the concrete mixture from decreasing, all concrete is transported by concrete transport tankers, pumped into the mold, poured in layers, and continuously, and vibrated by an inserted vibrator. Before pouring concrete, a proper amount of water should be sprinkled to wet the concrete surface on the top of the pile. The concrete pouring is guided by a conduit. The free fall of concrete does not exceed 2m, and the stacking height of the conduit discharge should not exceed 0.5m, use an inserted vibrator to vibrate and compact. When pouring concrete, the support and formwork should be checked and measured at the same time. If there is deformation, displacement or subsidence, it should be corrected in time. According to the height of the pier body, the concrete is poured in one time or in two times. When a continuous pouring process is required, if it is temporarily interrupted due to special circumstances, the allowed interruption time shall not exceed 90 minutes. When pouring in two times, before the second concrete pouring, the top surface of the first concrete must be fully roughened before it can be poured. After the pier body concrete has initially set, watering and curing can begin. The pier body is cured by wrapping it in the form of clothes and hats, and an automatic sprinkler system is installed for curing. The pier body concrete is cured by watering for more than 14 days. The number of watering times per day depends on the ambient humidity and temperature. The degree of watering should be such that the concrete surface is always in a moist state. During the curing period, the concrete shall not be subjected to external loads before the specified strength is reached. When the concrete strength meets the requirements for demolding and the core concrete and the surface The formwork can be removed only when the temperature difference between the layers of concrete and the temperature difference between the surface concrete and the environment are both ≤20℃. When removing the formwork, avoid heavy prying and hard smashing to damage the concrete surface layer of the pier body. After removing the formwork, cover it tightly with plastic film and keep it moist for more than 14 days. During the curing period, arrange special personnel to supervise and inspect, replenish water in time if it is insufficient, and ensure that the pier body is in a moist curing state. Check the working status of the spray system to ensure that the automatic spray curing system works normally. In order to improve the durability of concrete, concrete components should be poured in one time as much as possible. Before construction, emergency measures must be taken to stop water and power outages. Try to avoid construction joints caused by construction reasons during the concrete pouring process. When construction joints are unavoidable, enter the concrete construction joint processing procedure according to the requirements of the specifications. When the design requires the setting of construction joints due to changes in the size of the structure, the location of the construction joints should be set at the part of the structure with less stress. When the structure is located in water, the construction joints should avoid the parts that are in alternating dry and wet changes all year round.

[0033] Among them, in the above step five, the steel box girder is produced in pieces and groups by the steel structure processing factory with corresponding qualifications according to the requirements of the drawings, and then transported to the vicinity of the bridge for assembly and hoisting. The manufacturing of steel box girders can be divided into four major stages: unit manufacturing stage, segment assembly and pre-assembly stage, and site connection stage. The overall process flow is as follows: unit manufacturing, unit component transportation, unit assembly, multi-segment continuous matching pre-assembly, segment painting, segment storage, segment transportation, bridge connection, and final painting. The production of steel box girder components is mainly divided into the production of top plates, bottom plates, webs, partitions, wing plates and stiffening parts. Steel box girders should be assembled and welded on a sturdy and reliable tire frame assembly line. The processing of parts is mainly carried out by CNC equipment to maximize the use of machine tools. Mechanical operation and the use of fixtures and fixtures can reduce the randomness and instability of manual operation, improve the accuracy and production efficiency of components. After the overall welding of the steel beam is completed, the surface is sandblasted to remove rust, and the painting operation is carried out using a high-pressure airless spray pump. The last coat of topcoat should be applied continuously once the entire bridge is built. Before the steel box girder segment leaves the factory, it should be assembled in three dimensions in the factory. Only after the trial assembly meets the accuracy requirements can it be transported to the construction site for assembly. The finished product storage site should be solid, flat, ventilated and have drainage facilities. It should be numbered in the order of assembly and the storage location should be arranged in the order of lifting. It is advisable to stack it in a single layer. The stacking fulcrum must be located under the web, transverse diaphragm and longitudinal diaphragm. The force at each point should be even as much as possible. The seesaw situation is not allowed, and uneven settlement of the stacking foundation is not allowed During stacking, transportation and erection, in order to prevent local deformation and instability of steel beams, a transverse frame or longitudinal frame can be added between the cross diaphragms or webs of the steel beams. The packaging of the steel structure must be carried out after the coating is dried. Tipping and collision should be prevented during transportation to avoid damaging the paint surface. The steel box beam is prefabricated and assembled in the steel structure factory in the form of longitudinal sections and transverse blocks. Except for the last coat of topcoat, all the painting is completed in the factory. After the steel beam is transported to the construction site, the geometric dimensions of each part and the welding quality of the connection parts are checked, and they are classified and numbered according to the beam sections and the order of erection. They are stacked in the temporary beam storage yard on the construction site according to the order of erection. An assembly platform is set up at the original position of the steel box beam bridge, and the Type 83 railway military pier is used. Combined with the Type 64 railway military beam, the military pier is equipped with a concrete strip foundation or directly placed on the bridge pedestal. The horizontal blocks are welded on the ground to form sections. The welded components are lifted by crane to the assembly platform for longitudinal splicing and welding between the sections. The steel beams are hoisted and erected in sections by two large crawler cranes. They are erected in a single-end flow order. After the whole steel beam is assembled and welded and tested to be qualified, the hydraulic cylinder is used to lift the whole pier top, adjust the gap between the support and the bottom of the beam and the support reaction force, and finally remove the support system, drop the beam into place, and realize the conversion of the whole bridge system. After the construction of the steel beam deck system is completed, the surface of the steel beam of the whole bridge is thoroughly cleaned, the concrete residue is removed, and the final outer surface topcoat is applied as a whole. At this time, special attention should be paid to ensure the uniform color and exquisite appearance of the coating.

[0034] Among them, in the above step six, the temporary support has sufficient strength and rigidity, is easy to assemble and disassemble, and the beam is dropped evenly. The temporary support adopts sulfur mortar with embedded electric thermal resistance wire. In a beam, the relative height difference of the top surface of the temporary support should not be greater than 2mm. Effective measures should be taken to prevent leakage of mortar in the horizontal gap between the permanent support and the bottom mold. The elevation of the top surface of the temporary support should be flush with the elevation of the top surface of the permanent support. The top surface of the permanent support is directly poured together with the bottom of the joint concrete. Before pouring the joint concrete, the working status of the permanent support should be carefully checked. If any problems are found, they should be corrected in time to prevent the support from working with defects. The prefabricated small box beam adopts the lifting method of setting lifting holes, passing the bottom of the bundle bag and adding a shoulder pole. When the concrete strength of the beam reaches the design strength and is qualified after inspection, the beam is moved with a gantry crane in the prefabrication yard. Lifting the beam, a special beam transporter transports the beam to the bridge deck via the ground road, and the beam is erected by a car crane. Before the beam is erected, the size of the finished beam and the platform cap are checked, the elevation of the support point and the center line of the beam span are re-measured, and the beam end is left with the gap specified in the design. When erecting the bridge, the method of erecting the two sides first and then the middle is followed, and the beam body is placed on the temporary support hole by hole to become a simply supported state. After the erection of each beam body, the end beam, diaphragm and bridge deck wet joint construction should be carried out in time. In order to prevent the precast beam from arching too much and the precast beam and the integral layer of the bridge deck from shrinking too much due to the age difference, the time from the prefabrication of the beam body to the pouring of the cast-in-place concrete on the pier top should not exceed three months. After the erection of each beam piece, the cast-in-place end beam and the mid-span diaphragm are poured first, and then the bridge deck wet joint is poured. Before the construction of the cast-in-place section on the pier top, the beam piece is first The ends are roughened, the reserved steel bars of the continuous joint section of the pier top are connected, the cast-in-place beam steel bars are tied, the joint plate bundle corrugated pipe is set and the bundle is passed through. When the daily temperature is the lowest, the continuous joint concrete and the middle crossbeam and the bridge deck concrete on both sides of the top plate within the same length range of the negative bending moment bundle are poured. After the concrete strength reaches the strength specified in the design, the prestressed steel bundles in the negative bending moment area of ​​the top plate are tensioned and cement slurry is injected. The remaining bridge deck wet joint concrete should be poured from the mid-span to the support. The top plate wet joint annular steel bars should be aligned and welded. Micro-expansive cement can be used for wet joint concrete. The pouring can be carried out by hanging formwork. The formwork should be steel formwork and should have sufficient rigidity and strength. After the formwork is firmly installed, rinse the roughened concrete surface, and brush a layer of cement on the construction joint before pouring the second layer of concrete The same requirements are applied to the pouring and vibration of the clean slurry, concrete and the pouring of the top plate of the precast beam. It is advisable to use a flat vibrator and an insert rod to ensure the designed thickness. When pouring the wet joint, it is advisable to do so under relatively low temperature conditions and to maintain it properly to prevent cracks. All the bonding surfaces between new and old concrete should be strictly roughened. Before pouring the cast-in-place concrete of the bridge deck, the floating slurry and oil stains on the top of the beam should be cleaned to ensure a good combination of new and old concrete. After the strength of the wet joint concrete reaches the design strength, the temporary sulfur mortar support in one joint should be removed symmetrically, evenly, synchronously and smoothly according to the design sequence and steps. The temporary support should be removed symmetrically from the inner side pier of one joint. The same pier position should be removed from the middle to both sides to carry out the system conversion.

[0035] In the above step 7, bridge deck materials such as asphalt or cement concrete are laid, and bridge deck drainage systems, lighting facilities, railings and anti-collision facilities are installed to ensure the safety, comfort and beauty of the bridge deck;

[0036] Among them, in the above step eight, the laying of rainwater and sewage pipes is carried out in the order of downstream first and upstream later, deep first and shallow later. Larsen steel sheet piles are used for the foundation pit with a deeper buried depth of the pipeline. The Larsen steel sheet piles are guided by a double-sided purlin guide frame and driven by a crawler crane hydraulic vibration hammer screen-type driving method. After the foundation pit is backfilled, the steel sheet piles are pulled out by hydraulic vibration hammers. After the piles are pulled out, the pile holes are backfilled with cement mortar. Under the protection of the foundation pit enclosure, manual labor and excavators are used to excavate the pipeline trench in layers and sections, and steel supports are erected in sequence. The car crane cooperates to lower the pipe body. After the closed water test is qualified, the backfill soil is compacted by small machines. During construction, drainage measures are strengthened to ensure that the bottom of the trench is not soaked by water;

[0037] In the above step nine, a systematic inspection and evaluation is carried out, including material quality testing, construction process control, finished product protection, and final acceptance standards and procedures, to ensure that the construction quality and overall performance of the bridge meet the design requirements and relevant standards, thereby ensuring the safety and durability of the bridge.

[0038] Based on the above, the advantages of the present invention are: the present invention uses advanced numerical simulation analysis software to dynamically simulate the construction process of the arch-beam combination system, and can accurately predict and analyze the structural response and deformation under different construction parameters. This data-based prediction and analysis provides a scientific basis for the optimization of construction parameters, such as the optimization of the arch rib hoisting sequence, bracket arrangement and prestressing timing, ensuring the rationality and efficiency of the construction plan. Through simulation analysis, the risks and problems that may exist in the construction can be discovered in advance, so that corresponding preventive measures can be taken to reduce construction risks. At the same time, the construction parameters and process flow are optimized, unnecessary material consumption and labor input are reduced, and the construction cost is reduced. By introducing intelligent hoisting equipment, such as automatically guided cranes and robots, the accuracy and efficiency of hoisting operations are significantly improved. These equipment can reduce human operation errors and ensure accurate control of the construction process, thereby improving the safety and stability of the bridge structure. The automated operation capability of intelligent construction equipment significantly speeds up the construction progress. Compared with traditional construction methods, intelligent construction can reduce the construction period and improve construction efficiency, providing a strong guarantee for the early completion of the bridge project. The construction method of first beam and then arch breaks the traditional construction sequence. The main beam is first constructed on the support frame, which provides a solid support for the subsequent installation of the arch ribs. This construction method simplifies the construction process, reduces the construction difficulty, and makes the entire construction process smoother. The construction method of first beam and then arch can implement the construction task in stages, so that each construction link can be fully managed and optimized, which not only improves the construction efficiency, but also ensures the smooth progress of the entire construction process. At the same time, the main beam completed first can provide a stable support platform for the subsequent installation of the arch ribs, which is conducive to speeding up the construction progress. Through systematic inspection and evaluation work, including material quality inspection, construction process control, finished product protection and final acceptance standards and procedures, it is ensured that the construction quality and overall performance of the bridge meet the design requirements and relevant standards. This comprehensive quality control measure provides a strong guarantee for the safety and durability of the bridge. In summary, the arch-beam system combined bridge construction process adopted by the present invention has shown significant beneficial effects in numerical simulation optimization, introduction of intelligent construction equipment, first beam and then arch construction method, quality control and safety assurance, environmental protection and sustainability, etc. These beneficial effects not only improve the efficiency and quality of bridge construction, but also reduce construction risks and costs, providing a strong guarantee for the smooth construction of bridge projects.

[0039] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A construction process for an arch-beam system composite bridge, comprising step 1, numerical simulation and process optimization; step 2, pile foundation construction; step 3, cap construction; step 4, pier body construction; step 5, steel box girder construction; step 6, prestressed concrete small box girder erection; step 7, bridge deck pavement and ancillary facilities construction; step 8, drainage engineering construction; step 9, quality control and acceptance; characterized in that: In the above step 1, numerical simulation analysis software is used to dynamically simulate the construction process of the arch-beam combination system and optimize the construction process; In the above step 2, the bored pile foundation is constructed by a rotary drilling rig, the hole is formed by a mud wall method, underwater concrete is poured by a conduit method, the steel cage is manufactured in sections, and the truck crane is installed, and the foundation pit is backfilled after the pile foundation is poured; In the above step 3, the foundation construction is carried out, which involves excavation, protection, drainage, steel bar binding, formwork installation, concrete pouring and backfilling; In the above step 4, the pier body is constructed with a standard steel formwork, and the concrete is commercial concrete, which is pumped into the formwork; In the above step 5, the method of first beam and then arch is adopted, first the main beam is constructed on the bracket, then the arch rib bracket and arch rib hoisting equipment are installed on the beam, and the steel box arch is erected in sections to form a combined arch beam system; In the above step 6, temporary supports are installed, beams are erected and wet joints are constructed, and temporary supports are removed to complete the system conversion; In the above step 7, bridge deck materials such as asphalt or cement concrete are laid, and bridge deck drainage systems, lighting facilities, railings and anti-collision facilities are installed to ensure the safety, comfort and beauty of the bridge deck; In the above step eight, the laying of rainwater and sewage pipes is carried out in the order of downstream to upstream and deep to shallow. Larsen steel sheet piles are used for foundation pit support. Steel support is set up after trench excavation. After the closed water test is passed, the soil is backfilled and the construction is strengthened with drainage. In the above step nine, a systematic inspection and evaluation is carried out, including material quality testing, construction process control, finished product protection, and final acceptance standards and procedures, to ensure that the construction quality and overall performance of the bridge meet the design requirements and relevant standards, thereby ensuring the safety and durability of the bridge.

2. The construction process of an arch-beam system composite bridge according to claim 1, characterized in that: In the step one, advanced numerical simulation and analysis software is used to dynamically simulate the construction process of the arch-beam combination system, predict and analyze the structural response and deformation under different construction parameters, and based on the simulation results, optimize the construction parameters, such as the arch rib hoisting sequence, bracket arrangement and prestressing timing, to ensure the safety and efficiency of the construction process, introduce intelligent hoisting equipment, such as automatically guided cranes and robots, improve the accuracy and efficiency of hoisting operations, reduce human operation errors, and install an intelligent monitoring system at the construction site to monitor key parameters in the construction process, such as stress, deformation and temperature, in real time to ensure construction quality and safety.

3. The construction process of an arch-beam system composite bridge according to claim 1, characterized in that: In the step 2, the bored pile foundation construction adopts different hole-making methods according to the actual geological conditions on site. The crane cooperates with the drilling rig to install the steel cage. The concrete is centrally supplied by the commercial concrete station and transported by the mixing truck. The concrete is pumped by the concrete pump or poured by the hopper into the underwater concrete. The pile is moved into position by itself through the self-propelled crawler. After the position is in position, the center point of the drill bit is aligned with the center of the pile position. At the same time, the drill mast is adjusted to be vertical, and then drilling is carried out. A mud drill bit is used in the surface soil, and a spiral drill bit plus a rotary bucket are used to form holes in the pebble soil. The rotary drilling rig is suitable for the construction of various soil layers and bedrock with medium hardness or less. Different types of drill bits should be selected according to different geological conditions before construction.

4. The construction process of an arch-beam system composite bridge according to claim 1, characterized in that: In the step 3, slope excavation is generally adopted in general areas. When the terrain is restricted or the geological conditions are poor, steel sheet pile protection vertical excavation construction is adopted. The foundation pit of the pedestal is excavated manually with the help of an excavator. Centralized drainage or well point dewatering is adopted according to the groundwater level. After excavation, the bottom is manually cleaned and the pile heads are chiseled off by a pneumatic pick. A safety net is hung around the top of the foundation pit. The reinforcement of the pedestal is tied on site. The truck crane is used to form the entire form. Concrete is centrally mixed and transported by tank trucks. It is poured with the help of cranes or pump trucks. After the construction of the pedestal is completed and accepted, manual and small-scale concrete grouting is adopted immediately. Backfill is carried out with a tamping machine, steel sheet piles are driven in for protection and crash piers are set up near the front road of the existing road cap construction, and foundation construction is carried out under safe protection. The steel bars are processed in the processing workshop and transported to the site by a flatbed truck. After the base is inspected and qualified, it is precisely positioned and tied on site. The cap formwork uses large factory-made steel formwork with a panel thickness of 6mm. Vertical and horizontal stiffening ribs are added to the outer wall, as well as annular channel steel stiffening ribs. It is assembled on site in 4 to 6 pieces and connected with bolts. The support method of the cap formwork is external reinforcement, and the support points are placed on the inside of the foundation pit and supporting formwork.

5. The construction process of an arch-beam system composite bridge according to claim 1, characterized in that: In the fourth step, the pier body is constructed by the bracket method, and a steel pipe scaffold is set up around the pier body as a construction platform. The factory-made steel formwork is erected by a car crane. The pier with a pier column height of less than 10m adopts an integral steel formwork to erect the formwork at one time, and the whole is cast in one time. After the construction of the pier is completed, the surveying team will carry out the layout of the pier construction section according to the pier body design drawings, and the cooperation team will chisel the top surface of the pier according to the layout position to expose fresh aggregate. In order to make the pier body formwork have sufficient strength and rigidity and ensure the appearance quality of the pier body, the pier body formwork is planned to adopt a steel formwork, and the steel formwork panel is adopted. The formwork is made of 6mm thick steel plate. The inner surface of the formwork is required to be smooth and rust-free, and the joints are tight and leak-proof. Before the formwork is erected, a layer of release agent is applied on the inner side of the formwork. The release agent should be of the same type to ensure the uniform color of the concrete surface. Then, the formwork is erected to the designed pier height according to the released pier body center line and pier bottom elevation. After the pier body formwork is erected, the designed size of the pier body and the vertical verticality of the pier body should be ensured. To ensure the vertical stability of the formwork, 3 to 4 wind cables are pulled on the outside of the steel formwork to fix the formwork to prevent the formwork from tilting during concrete pouring. The formwork and the scaffolding should be independent of each other to avoid Manual operation on the scaffolding causes the formwork to deform. The pier body formwork is reinforced with homemade light trusses around it. The trusses are bolted and Φ32 tie rods are used to form a whole. The steel bars are cut, classified, stacked and numbered in the processing workshop according to the design drawings. They are transported to the site by flatbed trucks and tied on the steel skeleton positioning mold. The pier body steel bars must be tied and formed in one time, and their quality should meet relevant regulations. The main reinforcement joints of the structure are connected with straight tube threads. The main reinforcement and stirrups are tied with wire. The tied or welded steel mesh and steel skeleton shall not be deformed or loose. The concrete pads are made of Use high polyester UPVC pads. In order to prevent the performance indicators of concrete mixture from declining, all concrete tankers are used for transportation, pumped into the mold, poured in layers, and continuously, and vibrated with an inserted vibrator. Before pouring concrete, sprinkle a proper amount of water to wet the concrete surface on the top of the pile. The concrete pouring is guided by a conduit. The free fall of concrete should not exceed 2m. The stacking height of the conduit discharge should not exceed 0.5m each time. Use an inserted vibrator to vibrate and compact it. When pouring concrete, check and measure the support and formwork at the same time. If there is deformation, displacement or subsidence, it should be corrected in time.

6. The construction process of an arch-beam system composite bridge according to claim 5, characterized in that: In the step 4, the concrete is cast once or twice according to the height of the pier body. When a continuous casting process needs to be temporarily interrupted due to special circumstances, the allowed interruption time shall not exceed 90 minutes. When casting twice, the top surface of the first concrete shall be fully roughened before the second concrete casting. After the pier body concrete is initially set, watering and curing begin. The pier body is cured by wrapping it with clothes and hats, and an automatic sprinkler system is installed. The curing time of the pier body concrete is more than 14 days. The number of watering times per day depends on the ambient humidity and temperature. The watering is to ensure that the concrete surface is always in a moist state. During the curing period, the concrete shall not be subjected to external loads before the specified strength is reached. When the concrete strength meets the demoulding requirements, and the temperature difference between the core concrete and the surface concrete, and the temperature difference between the surface concrete and the environment are both ≦2 The formwork can be removed only when the temperature reaches 0℃. When removing the formwork, avoid heavy prying and hard smashing to avoid damaging the concrete surface layer of the pier body. After removing the formwork, cover it tightly with plastic film and keep it moist for more than 14 days. During the curing period, arrange special personnel to supervise and inspect, and replenish water in time if it is insufficient to ensure that the pier body is in a moist curing state. Check the working status of the spray system to ensure that the automatic spray curing system works normally. To improve the durability of concrete, concrete components should be poured in one time as much as possible. Emergency measures for water and power outages must be taken before construction. Construction joints caused by construction reasons should be avoided as much as possible during the concrete pouring process. When construction joints are unavoidable, enter the concrete construction joint processing procedure according to the requirements of the specifications. When the design requires the setting of construction joints due to changes in the size of the structure, the location of the construction joints should be set at the part of the structure with less stress. When the structure is located in water, the construction joints should avoid the parts that are in alternating dry and wet changes all year round.

7. The construction process of an arch-beam system composite bridge according to claim 1, characterized in that: In the step five, the steel box girder is produced in pieces and groups by a steel structure processing plant with corresponding qualifications according to the requirements of the drawings, and then transported to the vicinity of the bridge for assembly and hoisting. The manufacturing of steel box girders can be divided into four major stages: unit manufacturing stage, segment assembly and pre-assembly stage, and site connection stage. The overall process flow is as follows: unit manufacturing, unit component transportation, unit component assembly, multi-segment continuous matching pre-assembly, segment painting, segment storage, segment transportation, bridge connection, and final painting. The production of steel box girder components is mainly divided into the production of top plates, bottom plates, webs, partitions, wing plates and stiffening components. Steel box girders should be assembled and welded on a sturdy and reliable tire frame assembly line. Component processing is mainly carried out by CNC equipment to maximize the use of mechanical operations and use fixtures to reduce the randomness and instability of manual operations, improve the accuracy and production efficiency of components, and complete the overall welding of steel beams. After that, the surface is sandblasted for rust removal and the painting operation is constructed using a high-pressure airless spray pump. The last coat of topcoat should be applied continuously once the entire bridge is built. Before the steel box girder segments leave the factory, they should be assembled in three dimensions in the factory. Only after the trial assembly meets the accuracy requirements can they be transported to the construction site for assembly. The finished product storage site should be solid, flat, ventilated and have drainage facilities. They are numbered in the order of assembly and arranged in the order of lifting. They should be stacked in a single layer. The stacking fulcrum must be located under the web, diaphragm and longitudinal diaphragm. The force at each point should be as uniform as possible. The seesaw situation is not allowed, and uneven settlement of the stacking foundation is not allowed. During the stacking, transportation and erection process, in order to prevent local deformation and instability of the steel beam, a transverse frame or longitudinal frame can be added between the cross diaphragm or web of the steel beam. The packaging of the steel structure must be carried out after the coating is dry. Dumping and collision should be prevented during transportation to avoid damage to the coating surface.

8. The construction process of an arch-beam system composite bridge according to claim 7, characterized in that: In the step 5, the steel box girder is prefabricated and assembled in a steel structure factory in a longitudinal segmentation and transverse block manner. Except for the last coat of topcoat, all painting is completed in the factory. After the steel beam is transported to the construction site, the geometric dimensions of each part and the welding quality of the connection parts are inspected, and the beam is classified and numbered according to the beam section and the erection sequence. It is stacked in the construction site's temporary beam storage yard according to the erection sequence. An assembly platform is set up at the original position of the steel box girder bridge. A combination of Type 83 railway military piers and Type 64 railway military beams is used. The military piers are provided with concrete strip foundations or are directly placed on the bridge pedestal. The transverse blocks are welded on the ground to form sections. The welded components are lifted by crane to the assembly platform for longitudinal splicing and welding between sections. The steel beams are hoisted and erected in sections by two large crawler cranes in a single-end flow order. After the entire steel beam is assembled and welded and tested to be qualified, a hydraulic cylinder is used to lift the entire pier top to adjust the gap between the support and the bottom of the beam and the support reaction force. Finally, the support system is dismantled and the beam is dropped into place to realize the conversion of the entire bridge system. After the construction of the steel beam deck system is completed, the surface of the steel beams of the entire bridge is thoroughly cleaned, the concrete residue is removed, and the final outer surface topcoat is applied as a whole. At this time, special attention should be paid to ensure that the color of the coating is uniform and the appearance is exquisite.

9. The construction process of an arch-beam system composite bridge according to claim 1, characterized in that: In the step six, the temporary support has sufficient strength and rigidity, is easy to assemble and disassemble, and the beam is dropped evenly. The temporary support adopts sulfur mortar with embedded electric thermal resistance wire. In a beam, the relative height difference of the top surface of the temporary support should not be greater than 2mm. Effective measures should be taken to prevent leakage of mortar in the horizontal gap between the permanent support and the bottom mold. The elevation of the top surface of the temporary support should be flush with the elevation of the top surface of the permanent support. The top surface of the permanent support is directly poured together with the bottom of the joint concrete. Before pouring the joint concrete, the working status of the permanent support should be carefully checked. If any problems are found, they should be corrected in time to prevent the support from working with defects. The prefabricated small box beam adopts the lifting method of setting lifting holes, passing the bottom of the bundle bag and adding a shoulder pole. When the concrete strength of the beam reaches the design strength and is qualified after inspection, the gantry crane in the prefabrication yard is used to move and lift the beam. , a special beam transporter transports the beam to the bridge deck via the ground road, and the beam is erected by a car crane. Before the beam is erected, the size of the finished beam and the platform cap are checked, the elevation of the support point and the centerline of the beam span are remeasured, and the beam ends are left with the gap specified in the design. When erecting the bridge, the method of erecting the two sides first and then the middle is followed, and the beam body is placed on the temporary support hole by hole to become a simply supported state. After the erection of each beam body, the end cross beam, cross diaphragm and bridge deck wet joint construction should be carried out in time. In order to prevent the precast beam from arching too much and the precast beam and the integral layer of the bridge deck from shrinking too much due to the age difference, the time from the prefabrication of the beam body to the pouring of the cast-in-place concrete on the pier top should not exceed three months. After the erection of each beam piece, the cast-in-place end cross beam and the mid-span cross diaphragm are poured first, and then the bridge deck wet joint is poured. Before the construction of the cast-in-place section on the pier top, the end of the beam piece should be Roughen the head, connect the reserved steel bars of the continuous joint section on the pier top, tie the cast-in-place beam steel bars, set the joint plate bundle corrugated pipe and pass the bundle. When the daily temperature is lowest, pour the continuous joint concrete and the middle beam and the bridge deck concrete on both sides of the top plate within the same length range of the negative bending moment bundle. After the concrete strength reaches the strength specified in the design, tension the prestressed steel bundle in the negative bending moment area of ​​the top plate, and inject cement slurry. The remaining bridge deck wet joint concrete should be poured from the mid-span to the support. The top plate wet joint annular steel bars should be aligned and welded. Micro-expansive cement can be used for wet joint concrete. Hanging formwork can be used for pouring. The formwork should be steel formwork and should have sufficient rigidity and strength. After the formwork is firmly installed, rinse the roughened concrete surface. Before pouring the second layer of concrete, a layer of cement cleaner should be brushed on the construction joint. The same requirements are met for pouring slurry, concrete pouring and vibration as for pouring precast beam top plates. It is advisable to use a flat vibrator in combination with an insert rod and ensure the designed thickness. When pouring wet joints, it is advisable to do so under relatively low temperatures and perform maintenance to prevent cracks. All new and old concrete bonding surfaces should be strictly roughened. Before pouring the cast-in-place concrete layer of the bridge deck, the floating slurry and oil stains on the beam top should be cleaned to ensure a good bond between the new and old concrete. After the wet joint concrete strength reaches the designed strength, the temporary sulfur mortar supports in a unit should be removed symmetrically, evenly, synchronously and smoothly from hole to hole in the order and steps required by the design to complete the system conversion. The temporary supports should be removed symmetrically starting from the inner side piers of a unit, and the same pier position should be removed from the middle to both sides to carry out the system conversion.

10. The construction process of an arch-beam system composite bridge according to claim 1, characterized in that: In the step eight, the laying of rainwater and sewage pipes is carried out in the order of downstream first and upstream later, deep first and shallow later. Larsen steel sheet piles are used for enclosure of foundation pits with deeper buried pipes. The Larsen steel sheet piles are guided by double-sided purlin guide frames and driven by crawler crane hydraulic vibratory hammer screen-type driving method. After the foundation pit is backfilled with soil, the steel sheet piles are pulled out by hydraulic vibratory hammer. After being pulled out, the pile holes are backfilled and compacted with cement mortar. Under the protection of foundation pit enclosure, manual labor and excavators are used to excavate pipeline trenches in layers and sections, and steel supports are erected in sequence. Automobile cranes are used to lower the pipe body. After the closed water test is passed, small machines are used to compact the backfill soil. Drainage measures are strengthened during construction to ensure that the bottom of the trench is not soaked in water.

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