High pier bridge side span closure section and straight line section synchronous construction technology and device

Abstract

The invention belongs to the technical field of bridge construction, and particularly relates to a high-pier bridge side span closure section and straight line section synchronous construction technology and device.The high-pier bridge side span closure section and straight line section synchronous construction technology comprises the following steps that a side span hanging basket is pushed forwards to the edge of a pier body bent cap, then a straight line section bottom die system is installed and connected with a hanging basket bottom die, and the hanging basket bottom die is connected with the straight line section bottom die system; synchronous pouring of a straight line section and a side span closure section is achieved; through the effect of improving the welding efficiency of the welding device, during welding operation, the device can effectively conduct position switching among a plurality of pieces of I-shaped steel, meanwhile, high-altitude welding operation is facilitated, the using effect of the device is improved, the manual participation degree is reduced during welding, and therefore potential safety hazards are reduced. The high pier bridge side span closure section and straight line section synchronous construction technology and device have the advantages of being convenient to construct, short in construction period, high in economic benefit, high in welding efficiency, safe and efficient.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a process and apparatus for the simultaneous construction of the side span closure section and straight section of a high-pier bridge. Background Technology

[0002] Bridge construction refers to the process of building a bridge according to its design specifications; it mainly includes bridge construction technology, construction organization, construction management, and construction quality.

[0003] High-pier bridges refer to bridge projects with pier heights of ≥40 meters. Their construction difficulty and risks are significantly higher than those of ordinary bridge piers, especially the construction of straight sections of side spans and closure sections. The construction process is complex and requires special processes and technologies to ensure safety.

[0004] In order to optimize the construction process of the side span closure section and straight section of the high pier bridge, simplify the construction steps, and avoid the erection of scaffolds and brackets; and because the existing high pier bridges require welding operations during construction, and the welding points are located at high altitudes or between multiple I-beams, it is difficult for welding equipment to be moved quickly to the welding points when welding operations are carried out at high altitudes or between multiple I-beams, thus affecting welding efficiency. At the same time, manual welding poses certain safety hazards. Summary of the Invention

[0005] This invention discloses a synchronous construction process and apparatus for the side span closure section and straight section of a high-pier bridge. It aims to solve the problems in the prior art where the construction of the side span and closure section of a high-pier bridge is complex and welding operations are required during construction. The welding points are located at high altitudes or between multiple I-beams, making it difficult for welding equipment to move quickly to the welding points, thus affecting welding efficiency. At the same time, manual welding poses certain safety hazards.

[0006] This invention proposes a simultaneous construction technology for the side span closure section and straight section of a high-pier bridge, which includes the following steps: Construction preparation; Move the basket forward; Sandbox installation is performed in conjunction with permanent support installation; Skateboard support installation; The I-beams are installed under the action of the counterweight, followed by the construction of the hanging basket support. Template connection construction involves installing the templates. Reinforcing steel and prestressed steel installation; Concrete pouring; Prestressed construction; formwork removal.

[0007] Furthermore, the specific steps for construction preparation are as follows: 1) Prepare a special construction plan for the side span closure in advance, and provide written technical instructions to on-site technical and operational personnel; 2) Before the construction of the closure section, measurement and monitoring should be strengthened. Through theoretical calculations, the beam end elevation, plane position and pre-camber should be adjusted two blocks in advance to ensure that the beam size, elevation of each part, plane position and alignment meet the design requirements. 3) Clean up the debris on the hanging basket and the protective bottom, remove the hanging basket feeding platform and the protective bottom, and ensure that the hanging basket can be moved forward into place.

[0008] Furthermore, the specific steps for moving the hanging basket forward are as follows: Operate the control switch to move the hanging basket forward. Stop when the hanging basket is 40 cm away from the cover beam. After the hanging basket moves to the designated position, anchor the three pressure beams with precision-rolled threaded steel to ensure the stability and safety of the hanging basket.

[0009] Furthermore, the specific steps for installing the permanent support are as follows: Before installing the bottom formwork, ensure that the supports have been installed; check the connection status before installation, and do not loosen the bolts; During installation, use concrete wedges to level the surface, adjust it to the design elevation, leave a 20-30mm gap, and install the grouting template to ensure correct positioning and tight contact with the upper and lower structures. After checking the location and elevation, use a non-shrink high-strength grouting material with a compressive strength of not less than 50MPa for gravity grouting, grouting from the center outwards until it is full; According to the construction steps, the connecting bolts should be removed before the concrete reaches the tension strength and before tensioning, and should not be removed before the concrete is poured.

[0010] Furthermore, the specific steps for sand box construction are as follows: To ensure the smooth dismantling of the bottom formwork system, 5 cm angle iron was selected as the sand box enclosure based on the height between the bottom of the beam and the cap beam, so that the height of the sand box was maintained at 5 cm. After the angle iron was installed, the sand and gravel were treated with a watertight method to ensure its compactness. A 12 mm thick wooden board was laid on the surface of the sand and gravel. The cross slope of the gravel surface should match the cross slope of the beam top. During the installation of the angle iron, ensure that the angle iron opening faces inward, and at the same time, set the reinforcing bar ends on the outside of the angle iron at a spacing of 50 cm. The purpose is to prevent the angle iron from deforming outward when the gravel is under pressure, thereby avoiding a reduction in the height of the sand box.

[0011] Furthermore, the specific steps for installing the skateboard support are as follows: Slide bearings are mainly used to reduce the friction coefficient between the formwork system and the cap beam, and to achieve sliding during thermal shrinkage deformation. Slide bearings with a thickness of 25mm are selected according to the space under the beam. The positions of the sliding plate supports are precisely marked on the wooden board of the sand box according to the spacing of the I10 I-beams of the longitudinal main ribs of the bottom mold. Then, the sliding plate supports are installed. The installation of the sliding plate supports needs to ensure that the longitudinal main ribs of the bottom mold remain balanced. Therefore, two sliding plate supports are placed under each I-beam. According to calculations, in order to prevent excessive longitudinal spacing of the sliding plate supports from causing excessive downward deflection of the I-beam and resulting in unevenness at the bottom of the beam, the first row of supports near the edge of the cap beam is placed at the edge of the cap beam, and the distance between the second row of sliding plate supports and the first row is controlled within 90cm.

[0012] Furthermore, the specific steps for installing the I-beam are as follows: I10 I-beams are mainly used as the main load-bearing ribs of the bottom formwork of the cap beam, and also serve as connecting components for the bottom formwork of the cap beam and the hanging basket. According to the stress conditions, double I10 I-beams are installed below the web, and single I10 I-beams are arranged in the hollow areas of the top and bottom plates; the length of the I-beams is 6 meters, of which about 1.75 meters extend into the bottom formwork of the hanging basket; the front end of the I-beam extends 40cm beyond the bottom of the beam to facilitate the installation and reinforcement of the beam end formwork. At the paving stone location, the I-beams are cut. After the I-beams are laid, the straightness of each I-beam surface is checked using the transverse hanging line method to ensure that it meets the specified requirements. After confirming that everything is correct, angle iron or φ22mm steel bars are welded laterally using a welding device to connect the longitudinal I-beams into a unified whole.

[0013] Furthermore, the specific steps for the construction of the hanging basket support are as follows: To reduce the elastic deformation of the hanging basket formwork, φ110 steel bars are installed on the cap beam to assist in supporting the hanging basket. The construction of the hanging basket support system mainly involves setting up inverted channel steel on the steel bars, placing the unloading blocks tightly against the cap beam on the channel steel, and laying double-layered I40b I-beams horizontally on the unloading blocks to assist in supporting the main force transmission components of the hanging basket. I25 short I-beams are arranged diagonally on the double-layered I40b I-beams to directly support the lower front crossbeam of the hanging basket. Two double-span I25a short I-beams are installed at the web position with a spacing of 50cm; two single-span I25a I-beams are installed at the bottom plate position with a spacing of 166cm; to prevent lateral instability of the I-beams, the I25a I-beams are connected by C8 channel steel in a scissor-type connection. In addition, the I25a short I-beams will be spot-welded to the lower crossbeam of the hanging basket and the double-section I40b I-beams respectively.

[0014] Furthermore, the specific steps of the prestressed construction are as follows: Tensioning adopts dual control, namely, dual control of tension force and elongation. It begins after the concrete strength reaches the design tension strength. The prestressing tensioning principle is: first the web, then the top slab, then the bottom slab, and finally the transverse and vertical tensioning, using symmetrical tensioning; first the inside, then the outside; first the longer, then the shorter; first the outer side of the curve, then the inner side of the curve. The dual control principle is used during tensioning. Grouting must be carried out within 48 hours after tensioning. The prestressed duct is grouted using a continuous grouting pump, and special grouting material or grouting agent must be used. The longitudinal prestressing grouting pressure is 0.5MPa to 0.7MPa, and the vertical prestressing grouting pressure is 0.3 to 0.4MPa.

[0015] A welding device is used in the synchronous construction process of the side span closure section and straight section of a high pier bridge as described above. The welding device includes a mounting base plate. Mounting base, wherein the mounting base is disposed at the bottom of the mounting substrate; Adjusting arm two, the adjusting arm two is located below the mounting base, and one end of the adjusting arm two is disposed on the mounting base; Adjusting arm one, one end of which is disposed at the other end of adjusting arm two, and the other end of adjusting arm one is provided with a welding arm; The welding gun body is mounted on the welding arm; A welding adjustment module is provided on both sides of the mounting base plate and includes two flipping motors. The welding adjustment module is used to flip the welding device so that the welding device can directly change its position on the I-beam by flipping, so as to carry out welding operations at high altitude or between multiple I-beams. A fume treatment module is disposed on the mounting base and the welding gun body, and the fume treatment module includes multiple fume suction nozzles and two fume purifiers. The fume treatment module is used to absorb and treat the harmful fumes generated during welding.

[0016] In a preferred embodiment, the welding adjustment module further includes two mounting rings, which are fixedly connected to the outer walls of both sides of the mounting base plate. Annular guide rails are movably connected to the outer walls of both mounting rings, and flip brackets are fixedly connected to one side of the outer walls of both annular guide rails. The two flip brackets are located on the outer sides of both sides of the mounting base plate.

[0017] In a preferred embodiment, servo motors are fixedly connected to both of the flipping brackets. The output shafts of the two servo motors are connected to shaft members via couplings. The two shaft members pass through two annular guide rails and two mounting rings, and one end of each shaft member is fixedly connected to the outer walls of both sides of the mounting base plate.

[0018] In a preferred embodiment, each of the two flipping brackets is movably connected to a mounting rod, and two flipping motors are respectively fixedly connected to one side of the outer wall of the two flipping brackets. The output shafts of the two flipping motors are respectively connected to one end of the two mounting rods through couplings, and the outer walls of the two mounting rods are fixedly connected to a fixing frame, and two electric push rods are fixedly connected to each of the two fixing frames.

[0019] In a preferred embodiment, each of the two fixed rods has two fixed holes, and the inner walls of the four fixed holes are fixedly connected to guide rods. The outer walls of every two adjacent guide rods are movably connected to two adjusting plates. The output ends of the four electric push rods are fixedly connected to one side of the outer wall of the four adjusting plates, and wheel rods are movably connected to the four adjusting plates. Fixed clamping wheels are fixedly connected to the outer walls of the four wheel rods. Drive motors are fixedly connected to two of the adjusting plates, and the output shafts of the two drive motors are connected to one end of two wheel rods respectively through couplings.

[0020] In a preferred embodiment, the fume treatment module further includes a guide rail, which is fixedly connected to the outer wall of the welding gun body. Three fixing members are movably connected to the inner wall of the guide rail, and three fume suction nozzles are respectively disposed on the inner walls of the three fixing members. The same annular frame is fixedly connected to the three fixing members.

[0021] In a preferred embodiment, the annular frame is located inside the guide rail component, a cutting tooth ring is fixedly connected to the outer wall of the annular frame, and a support frame is fixedly connected to the bottom of the welding gun body, with a reciprocating motor fixedly connected to the support frame.

[0022] In a preferred embodiment, the output shaft of the reciprocating motor is connected to a drive gear via a coupling. The drive gear meshes with a cutting gear ring, and each of the three dust suction nozzles is fixedly connected to a connecting pipe. One end of each of the three connecting pipes is fixedly connected to the same annular through pipe.

[0023] In a preferred embodiment, the mounting base plate has two mounting openings at its top, and two dust purifiers are respectively disposed on the inner walls of the two mounting openings. A negative pressure pump is fixedly connected to the bottom of each of the two dust purifiers, and a delivery pipe is fixedly connected to the input end of each of the two negative pressure pumps. The input end of each of the two delivery pipes is connected to the inside of an annular pipe, and an exhaust pipe is fixedly connected to the top of each of the two dust purifiers.

[0024] As can be seen from the above, the synchronous construction technology and device for the side span closure section and straight section of the high pier bridge provided by the present invention can improve welding efficiency. During welding operations, the device can effectively switch positions between multiple I-beams, and facilitate high-altitude welding operations, thereby increasing the effectiveness of the device and reducing manual intervention during welding, thus reducing safety hazards. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the synchronous construction process of the side span closure section and straight section of a high-pier bridge proposed in this invention. Figure 2 This is a schematic diagram illustrating the principle of simultaneous casting of the straight section and the closure section of the side span in this invention; Figure 3 This is a schematic diagram illustrating the installation of I-beams under the action of a counterweight according to the present invention. Figure 4 This is a schematic diagram of the overall structure of a welding device proposed in this invention; Figure 5 This is a schematic diagram of the overall bottom view of a welding device proposed in this invention; Figure 6 This is a schematic diagram of the welding adjustment module structure of a welding device proposed in this invention; Figure 7 This is a schematic diagram of the combined structure of the flipping bracket and mounting rod of the welding device proposed in this invention; Figure 8 This is a schematic diagram of the fume treatment module structure of a welding device proposed in this invention; Figure 9 This is a schematic diagram of the combined structure of the support frame and welding gun body of a welding device proposed in this invention; Figure 10 This is a schematic diagram of the combined structure of the cutting tooth ring and the drive gear of a welding device proposed in this invention.

[0026] In the diagram: 1. Welding adjustment module; 101. Mounting ring; 102. Guide rod; 103. Tilting bracket; 104. Tilting motor; 105. Mounting rod; 106. Circular guide rail; 107. Electric push rod; 108. Drive motor; 109. Fixed clamping wheel; 110. Fixed rod frame; 111. Adjusting plate; 112. Servo motor; 2. Mounting base plate; 3. Adjusting arm one; 4. Fume and dust treatment module; 40 1. Exhaust pipe; 402. Smoke and dust purifier; 403. Delivery pipe; 404. Negative pressure pump; 405. Support frame; 406. Annular through pipe; 407. Smoke and dust suction nozzle; 408. Guide rail; 409. Annular frame; 410. Cutting gear ring; 411. Drive gear; 412. Reciprocating motor; 413. Fixing component; 414. Connecting pipe; 5. Mounting base; 6. Adjusting arm II; 7. Welding arm; 8. Welding gun body. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0028] The present invention discloses a synchronous construction technology and device for the closure section of the side span and the straight section of a high-pier bridge. It is mainly used in scenarios where welding equipment is difficult to move quickly to the welding point when welding operations are carried out at high altitudes or between multiple I-beams, thus affecting welding efficiency. At the same time, manual welding poses certain safety hazards.

[0029] Reference Figures 1-3 The present invention proposes a synchronous construction technology for the side span closure section and straight section of a high-pier bridge, which includes the following steps: Construction preparation; Move the basket forward; Sandbox installation is performed in conjunction with permanent support installation; Skateboard support installation; The I-beams are installed under the action of the counterweight, followed by the construction of the hanging basket support. Template connection construction involves installing the templates. Reinforcing steel and prestressed steel installation; Concrete pouring; Prestressed construction; formwork removal.

[0030] Furthermore, the specific steps for construction preparation are as follows: 1) Prepare a special construction plan for the side span closure in advance, and provide written technical instructions to on-site technical and operational personnel; 2) Before the construction of the closure section, measurement and monitoring should be strengthened. Through theoretical calculations, the beam end elevation, plane position and pre-camber should be adjusted two blocks in advance to ensure that the beam size, elevation of each part, plane position and alignment meet the design requirements. 3) Clean up the debris on the hanging basket and the protective bottom, remove the hanging basket feeding platform and the protective bottom, and ensure that the hanging basket can be moved forward into place.

[0031] Furthermore, the specific steps for moving the hanging basket forward are as follows: Operate the control switch to move the hanging basket forward. Stop when the hanging basket is 40 cm away from the cover beam. After the hanging basket moves to the designated position, anchor the three pressure beams with precision-rolled threaded steel to ensure the stability and safety of the hanging basket.

[0032] Furthermore, the specific steps for installing the permanent support are as follows: Before installing the bottom formwork, ensure that the supports have been installed; check the connection status before installation, and do not loosen the bolts; During installation, use concrete wedges to level the surface, adjust it to the design elevation, leave a 20-30mm gap, and install the grouting template to ensure correct positioning and tight contact with the upper and lower structures. After checking the location and elevation, use a non-shrink high-strength grouting material with a compressive strength of not less than 50MPa for gravity grouting, grouting from the center outwards until it is full; According to the construction steps, the connecting bolts should be removed before the concrete reaches the tension strength and before tensioning, and should not be removed before the concrete is poured.

[0033] Furthermore, the specific steps for sand box construction are as follows: To ensure the smooth dismantling of the bottom formwork system, 5 cm angle iron was selected as the sand box enclosure based on the height between the bottom of the beam and the cap beam, so that the height of the sand box was maintained at 5 cm. After the angle iron was installed, the sand and gravel were treated with a watertight method to ensure its compactness. A 12 mm thick wooden board was laid on the surface of the sand and gravel. The cross slope of the gravel surface should match the cross slope of the beam top. During the installation of the angle iron, ensure that the angle iron opening faces inward, and at the same time, set the reinforcing bar ends on the outside of the angle iron at a spacing of 50 cm. The purpose is to prevent the angle iron from deforming outward when the gravel is under pressure, thereby avoiding a reduction in the height of the sand box.

[0034] Furthermore, the specific steps for installing the skateboard support are as follows: Slide bearings are mainly used to reduce the friction coefficient between the formwork system and the cap beam, and to achieve sliding during thermal shrinkage deformation. Slide bearings with a thickness of 25mm are selected according to the space under the beam. The positions of the sliding plate supports are precisely marked on the wooden board of the sand box according to the spacing of the I10 I-beams of the longitudinal main ribs of the bottom mold. Then, the sliding plate supports are installed. The installation of the sliding plate supports needs to ensure that the longitudinal main ribs of the bottom mold remain balanced. Therefore, two sliding plate supports are placed under each I-beam. According to calculations, in order to prevent excessive longitudinal spacing of the sliding plate supports from causing excessive downward deflection of the I-beam and resulting in unevenness at the bottom of the beam, the first row of supports near the edge of the cap beam is placed at the edge of the cap beam, and the distance between the second row of sliding plate supports and the first row is controlled within 90cm.

[0035] The specific steps for balancing the counterweights are as follows: The counterweight uses a water tank method. The weight of the counterweight, calculated based on the stress model, is mainly half the weight of the reinforced concrete excluding the top of the cap beam. The counterweight is installed all at once and then gradually unloaded according to the construction progress. After the formwork is in place, counterweighting begins simultaneously at both ends of the T-shaped cantilever. During the counterweighting process, the height difference between the two ends of the cantilever must be monitored and controlled within 10mm. During the reinforcement installation, water is gradually poured from the side span water tank to unload the weight of the synchronously installed reinforcement, ensuring torque balance at both ends of the T-shaped structure. During concrete pouring, the counterweight in the side span water tank is unloaded simultaneously, and the deviation between the poured weight and the unloaded water volume is monitored to ensure the deviation does not exceed 5%, while the counterweight in the secondary span remains stable. After all the side span closure bundles are tensioned, the water in the secondary span water tank is unloaded in stages, while the beam rebound is monitored. When unloading the secondary span side, a reserve weight should be left for the secondary span closure to facilitate subsequent secondary span closure construction.

[0036] Furthermore, the specific steps for installing the I-beam are as follows: I10 I-beams are mainly used as the main load-bearing ribs of the bottom formwork of the cap beam, and also serve as connecting components for the bottom formwork of the cap beam and the hanging basket. According to the stress conditions, double I10 I-beams are installed below the web, and single I10 I-beams are arranged in the hollow areas of the top and bottom plates; the length of the I-beams is 6 meters, of which about 1.75 meters extend into the bottom formwork of the hanging basket; the front end of the I-beam extends 40cm beyond the bottom of the beam to facilitate the installation and reinforcement of the beam end formwork. At the paving stone location, the I-beams are cut. After the I-beams are laid, the straightness of each I-beam surface is checked using the transverse hanging line method to ensure that it meets the specified requirements. After confirming that everything is correct, angle iron or φ22mm steel bars are welded laterally using a welding device to connect the longitudinal I-beams into a unified whole.

[0037] Furthermore, the specific steps for the construction of the hanging basket support are as follows: To reduce the elastic deformation of the hanging basket formwork, φ110 steel bars are installed on the cap beam to assist in supporting the hanging basket. The construction of the hanging basket support system mainly involves setting up inverted channel steel on the steel bars, placing the unloading blocks tightly against the cap beam on the channel steel, and laying double-layered I40b I-beams horizontally on the unloading blocks to assist in supporting the main force transmission components of the hanging basket. I25 short I-beams are arranged diagonally on the double-layered I40b I-beams to directly support the lower front crossbeam of the hanging basket. Two double-span I25a short I-beams are installed at the web position with a spacing of 50cm; two single-span I25a I-beams are installed at the bottom plate position with a spacing of 166cm; to prevent lateral instability of the I-beams, the I25a I-beams are connected by C8 channel steel in a scissor-type connection. In addition, the I25a short I-beams will be spot-welded to the lower crossbeam of the hanging basket and the double-section I40b I-beams respectively.

[0038] The specific steps for template installation are as follows: The formwork for the 2-meter straight section on the outer side of the cap beam and the closure section of the side span adopts a hanging basket formwork system. Approximately 1 meter from the bottom formwork of the hanging basket to the front lower crossbeam is not covered by formwork; this area is covered by wooden formwork. At the junction of the hanging basket longitudinal beam end and the pier top formwork, square timber is used to fix the wooden formwork to improve its structural rigidity. Pre-drilled holes are also provided at the lifting strap locations to facilitate subsequent hanging basket dismantling operations. The outer formwork at the pier top uses #0 steel blocks to connect and install with the outer formwork of the hanging basket. The inner formwork is installed using disc-lock brackets and wooden formwork. The inner and outer formwork are connected and fixed by φ20 tie rods. Leveling blocks are installed on top of the permanent supports. The leveling block formwork and the top and bottom formwork of the cap beam are installed simultaneously using wooden formwork. Double-sided tape is used to fill the gaps in the formwork assembly to prevent grout leakage during concrete pouring.

[0039] The specific steps for formwork connection construction are as follows: The formwork connection system primarily connects the top formwork of the cap beam with the hanging basket formwork into a unified whole, forming a cohesive load-bearing system that expands and contracts synchronously with the concrete during temperature changes, ensuring the quality of the concrete structure. The I10 H-beam of the cap beam's bottom formwork is placed on the front crossbeam of the hanging basket. When the I10 H-beam conflicts with the I36b longitudinal beam of the hanging basket's bottom formwork, its lateral position is adjusted appropriately. There is a height difference between the I10 H-beam and the lower front crossbeam of the hanging basket; this is adjusted using the H-beam and steel plate supports to ensure the I10 H-beam can be placed on the lower front crossbeam. To ensure a stable connection between the I10 H-beam longitudinal beam of the side span's cast-in-place section's bottom formwork and the lower front crossbeam of the hanging basket, and to prevent deformation of the I10 longitudinal beam due to downward deflection of the lower front crossbeam, the I10 longitudinal beam should maintain a 3 cm gap from the bottom formwork of the hanging basket and should not contact it. During installation, the longitudinal beam is placed directly on the adjusting steel above the bottom crossbeam without welding or forming a rigid connection. The straight section bottom formwork system and the hanging basket bottom formwork utilize the friction between the wooden formwork and the I10 I-beams in contact with the hanging basket to cause the top formwork of the cap beam to slide and expand. Subsequently, 10×10cm square timbers are laid horizontally on top of the I10 I-beams, with a center-to-center spacing of 30cm. Finally, 18mm thick bamboo plywood is laid, connected to the square timbers with nails. The laid bamboo plywood should smoothly connect with the hanging basket bottom steel formwork, and its surface flatness should not exceed 3mm.

[0040] The specific steps for installing reinforcing bars and prestressing are as follows: Steel bars processed centrally at the steel bar factory are transported to the site by handcarts. Steel bar processing utilizes CNC bending centers; the surface of the steel bars must be clean, and any adhering oil, dirt, or rust must be thoroughly cleaned before use.

[0041] The reinforcement of the closure section is tied in two stages. First, the bottom web reinforcement is completed, then the vertical and longitudinal bottom slab prestressing ducts are installed. After installation, the prestressing tendons are threaded in time, and the inner formwork is erected. Then, the top slab and wing plate reinforcements are installed, and finally, the longitudinal top slab tendons and transverse bridge prestressing tendons are installed. The reinforcement joints between the side span closure section and the cantilever section are not tied or welded temporarily, allowing them to move freely. The reinforcement joints will be restored after the closure time is determined to reduce the impact of temperature difference on the large-segment reinforcement. The longitudinal prestressing tendons are tensioned at both ends according to the design, and the prestressing tendons are threaded in later. Therefore, care must be taken to protect the ducts from weld slag damage during reinforcement construction.

[0042] The specific steps for concrete pouring are as follows: Before pouring concrete, the formwork system and hanging basket must be strictly inspected, with a focus on checking the connections and reinforcement parts of the formwork to ensure construction safety. Check the firmness of the formwork support to prevent bulging, strictly check the formwork dimensions to ensure the dimensions of the continuous beam structure, pay attention to the quantity and location of embedded parts, check the corrugated pipes for burns or cracks, and check whether the joints are tightly sealed. HDPE lining pipes should be placed inside the corrugated pipes in advance to prevent grout leakage.

[0043] Concrete is pumped onto the approach bridge using a truck-mounted pump, simultaneously poured from both ends of the junction between the side span closure section and the side span cast-in-place section (prioritizing the area with the greatest deformation). Pouring begins from the middle of the base slab and proceeds outwards to the chamfered corners of the web. After a 20-30 minute interval, the middle of the web, the remaining portion, and the top slab concrete are poured sequentially. During vibration, extra vibration is applied near the transverse diaphragms, the web chamfers, and the tensioning slots to ensure compaction. The slump is adjusted according to temperature, transportation, and pouring speed to control the unbalanced moments on both sides of the cantilever construction. The side span cast-in-place section and the side span closure section are generally poured during the coldest part of the day. The closure section uses micro-expansion concrete or concrete of a higher grade, and counterweights are added to the cantilever end before pouring.

[0044] During the concrete pouring of the beam segment, a designated person supervises the process, promptly adjusting any damaged or displaced corrugated pipes to prevent grout leakage, pipe blockage, misalignment, and tension cracking. After tensioning the vertical prestressing tendons, grouting is performed immediately, protecting the grouting ports and PVC pipes. Vibration and early curing are emphasized. To stabilize the stress on the closure segment and the end sections and reduce the impact of settlement, a water-pressure counterweight pouring method is used for the closure segment. Water is simultaneously unloaded from the water tank during pouring to maintain a stable total load, with the unloading weight and pouring speed kept as close as possible. During the curing period after pouring, water is sprayed throughout the entire span of the closure segment's top slab and inside the box girder to cool it down and prevent excessive heat of hydration at the beam ends from causing cracks.

[0045] Furthermore, the specific steps of the prestressed construction are as follows: Tensioning adopts dual control, namely, dual control of tension force and elongation. It begins after the concrete strength reaches the design tension strength. The prestressing tensioning principle is: first the web, then the top slab, then the bottom slab, and finally the transverse and vertical tensioning, using symmetrical tensioning; first the inside, then the outside; first the longer, then the shorter; first the outer side of the curve, then the inner side of the curve. The dual control principle is used during tensioning. Grouting must be carried out within 48 hours after tensioning. The prestressed duct is grouted using a continuous grouting pump, and special grouting material or grouting agent must be used. The longitudinal prestressing grouting pressure is 0.5MPa to 0.7MPa, and the vertical prestressing grouting pressure is 0.3 to 0.4MPa.

[0046] The specific steps for removing the formwork are as follows: After the side span closure section is poured and the concrete reaches a certain strength, the inner formwork and the outer formwork of the web are removed first. The bottom formwork and hanging basket formwork can only be removed after tensioning and grouting are completed. When removing the bottom formwork, a high-pressure water gun is used to remove the sand on top of the cap beam, and the bottom formwork of the hanging basket is lowered by 5cm. The bamboo plywood, square timber, and I-beams are gradually removed, and finally, a special jack lifting device is used to remove the hanging basket.

[0047] Reference Figures 4-10 A welding device is used in a synchronous construction process for the side span closure section and straight section of a high pier bridge as described above, including the installation of a base plate 2; Mounting base 5 is disposed at the bottom of mounting base 2; Adjusting arm 2 6 is located below the mounting base 5, and one end of adjusting arm 2 6 is mounted on the mounting base 5; Adjusting arm 3, one end of which is located at the other end of adjusting arm 6, and the other end of adjusting arm 3 is provided with welding arm 7; The welding gun body 8 is mounted on the welding arm 7; Welding adjustment module 1 is disposed on both sides of mounting base plate 2, and welding adjustment module 1 includes two flipping motors 104. Welding adjustment module 1 is used to flip the welding device so that the welding device can directly change its position on the I-beam by flipping, so as to carry out welding operations at high altitude or between multiple I-beams. The fume treatment module 4 is mounted on the mounting base plate 2 and the welding gun body 8, and includes multiple fume suction nozzles 407 and two fume purifiers 402. The fume treatment module 4 is used to absorb and treat the harmful fumes generated during welding.

[0048] Reference Figures 4-7In a preferred embodiment, the welding adjustment module 1 further includes two mounting rings 101, which are fixedly connected to the outer walls of both sides of the mounting base plate 2. Annular guide rails 106 are movably connected to the outer walls of both mounting rings 101. A flip bracket 103 is fixedly connected to one side of each of the two annular guide rails 106, and the two flip brackets 103 are located on the outer sides of both sides of the mounting base plate 2. Servo motors 112 are fixedly connected to each of the two flip brackets 103. The output shafts of the two servo motors 112 are connected to shaft members via couplings. The two shaft members pass through the two annular guide rails 106 and the two mounting rings 101, and one end of each shaft member is fixedly connected to the outer walls of both sides of the mounting base plate 2. Mounting rods 105 are movably connected to each of the two flip brackets 103, and two flip motors 104 are fixedly connected to one side of each of the two flip brackets 103. On the outer side wall, the output shafts of two tilting motors 104 are connected to one end of two mounting rods 105 via couplings. Each mounting rod 105 has a fixed mounting bracket 110 on its outer wall, and each fixed mounting bracket 110 has two electric push rods 107 fixedly connected to it. Each fixed mounting bracket 110 has two fixing holes, and the inner walls of each of the four fixing holes are fixedly connected to guide rods 102. Each pair of adjacent guide rods 102 has two adjusting plates 111 movably connected to its outer wall. The output ends of the four electric push rods 107 are fixedly connected to one side of the outer wall of each of the four adjusting plates 111. Each of the four adjusting plates 111 has a movably connected wheel rod, and each of the four wheel rods has a fixed clamping wheel 109 fixedly connected to its outer wall. Each of the two adjusting plates 111 has a drive motor 108 fixedly connected to it, and the output shafts of the two drive motors 108 are connected to one end of each of the two wheel rods via couplings.

[0049] Specifically, during welding adjustment, the electric push rod 107 drives two adjusting plates 111 to move to both sides, causing them to move on the guide rod 102. This causes the two adjusting plates 111 to separate the fixed clamping wheel 109 from the I-beam, thus separating this end of the device from the original I-beam. Then, the flipping motor 104 at the other end of the device operates. Since this end is fixed to the I-beam, the flipping motor 104 causes the flipping bracket 103 to rotate the mounting base 2. When the mounting base 2 rotates to a vertical position, the servo motor 112 at this end operates. The servo motor 112 can drive the mounting base 2 to rotate itself, so that the mounting base 2 drives the welding gun body 8 to flip. Then, the flipping bracket 103 continues to drive the mounting base 2 to move until it reaches a horizontal position. At this time, the electric push rod 107 at the other end operates again and drives the adjusting plate 111 to move closer until the fixed clamping wheel 109 contacts another I-beam, thus completing the flipping adjustment. During welding operations, the drive motor 108 can drive the fixed clamping wheel 109 to rotate, so that the device can move along the direction of the I-beam to perform welding operations. In specific application scenarios, the welding adjustment module 1 is suitable for the welding process in the construction of high-pier bridges. When in use, the welding adjustment module 1 can flip the welding device, allowing it to directly change its position on the I-beam, thereby changing the position of the welding gun body 8. This allows for rapid adjustment based on the welding point, facilitating welding operations between multiple I-beams. Furthermore, the device can be pre-set on the I-beam, placing it in a suspended state at high altitude, further facilitating welding operations at height, improving welding efficiency, and reducing manual intervention during welding, thus lowering safety hazards.

[0050] Reference Figure 1 , Figure 8 , Figure 9 and Figure 10 In a preferred embodiment, the fume treatment module 4 further includes a guide rail 408, which is fixedly connected to the outer wall of the welding gun body 8. Three fixing members 413 are movably connected to the inner wall of the guide rail 408. Three fume suction nozzles 407 are respectively disposed on the inner walls of the three fixing members 413, and the same ring frame 409 is fixedly connected to the three fixing members 413. The ring frame 409 is located inside the guide rail 408. A cutting tooth ring 410 is fixedly connected to the outer wall of the ring frame 409, and a support frame 405 is fixedly connected to the bottom of the welding gun body 8. A reciprocating motor 412 is fixedly connected to the support frame 405. The output shaft of the reciprocating motor 412 is connected to a drive gear 411 through a coupling. The drive gear 411 meshes with the cutting tooth ring 410. Connecting pipes 414 are fixedly connected to each of the three dust suction nozzles 407. One end of each of the three connecting pipes 414 is fixedly connected to the ring frame 409. The two dust collectors 402 are fixedly connected to the same annular pipe 406. The top of the mounting base 2 has two mounting ports, and the two dust collectors 402 are respectively set on the inner walls of the two mounting ports. The bottom of each dust collector 402 is fixedly connected to a negative pressure pump 404. The input end of each negative pressure pump 404 is fixedly connected to a delivery pipe 403. The input end of each delivery pipe 403 is connected to the inside of the annular pipe 406. The top of each dust collector 402 is fixedly connected to an exhaust pipe 401.

[0051] Specifically, during welding, the negative pressure pump 404 operates, and the negative pressure pump 404 discharges the gas inside the annular pipe 406 through the delivery pipe 403 to make its interior a negative pressure state. Then, the gas generated during welding is absorbed through the connecting pipe 414 and the fume suction nozzle 407. At the same time, the reciprocating motor 412 operates, and the reciprocating motor 412 drives the drive gear 411 to rotate back and forth. Since the drive gear 411 meshes with the cutting tooth ring 410, it can drive the cutting tooth ring 410 to move, and further cause the cutting tooth ring 410 to drive the annular frame 409 and the fixing member 413 to rotate back and forth inside the guide rail member 408. This changes the position of the fume suction nozzle 407 when absorbing the fume, thereby increasing the fume absorption range. Afterwards, the fume enters the fume purifier 402 through the negative pressure pump 404, and is discharged through the exhaust pipe 401 after purification treatment, thus performing fume treatment until the welding is completed. In specific application scenarios, the fume treatment module 4 is suitable for the welding fume treatment process. When in use, the fume treatment module 4 can absorb the harmful fumes generated during welding and treat them after absorption, thereby reducing the amount of harmful welding fumes emitted and preventing personnel in the vicinity or above the welding device from inhaling the fumes, thus increasing the safety effect during use. At the same time, when absorbing fumes, the device can absorb the fumes around the welding gun body 8 over a large area, increasing the fume treatment effect.

[0052] Working principle: During welding adjustment, the electric push rod 107 drives two adjusting plates 111 to move to both sides, causing them to move on the guide rod 102. This causes the two adjusting plates 111 to separate the fixed clamping wheel 109 from the I-beam, thus separating this end of the device from the original I-beam. Then, the flipping motor 104 at the other end of the device runs. Since this end is fixed to the I-beam, the flipping motor 104 causes the flipping bracket 103 to rotate the mounting base 2. When the mounting base 2 rotates to a vertical position, the servo motor 112 at this end runs. The servo motor 112 can drive the mounting base 2 to rotate itself, so that the mounting base 2 drives the welding gun body 8 to flip. Then, the flipping bracket 103 continues to drive the mounting base 2 to move until it reaches a horizontal position. At this time, the electric push rod 107 at the other end runs again and drives the adjusting plate 111 to move closer until the fixed clamping wheel 109 contacts another I-beam, thus completing the flipping adjustment. During welding, the negative pressure pump 404 operates, and the negative pressure pump 404 discharges the gas inside the annular pipe 406 through the delivery pipe 403 to make its interior a negative pressure state. Then, the gas generated during welding is absorbed through the connecting pipe 414 and the fume suction nozzle 407. At the same time, the reciprocating motor 412 operates, and the reciprocating motor 412 drives the drive gear 411 to rotate back and forth. Since the drive gear 411 meshes with the cutting tooth ring 410, it can drive the cutting tooth ring 410 to move, and further cause the cutting tooth ring 410 to drive the annular frame 409 and the fixing member 413 to rotate back and forth inside the guide rail member 408. This changes the position of the fume suction nozzle 407 when absorbing fume, thereby increasing the fume absorption range. Afterwards, the fume enters the fume purifier 402 through the negative pressure pump 404, and is discharged through the exhaust pipe 401 after purification treatment, thus treating the fume until the welding is completed.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A synchronous construction technique for the side span closure section and straight section of a high-pier bridge, characterized in that, The construction process includes the following steps: Construction preparation; Move the basket forward; Sandbox installation is performed in conjunction with permanent support installation; Skateboard support installation; The I-beams are installed under the action of the counterweight, followed by the construction of the hanging basket support. Template connection construction involves installing the templates. Reinforcing steel and prestressed steel installation; Concrete pouring; Prestressed construction; formwork removal.

2. The synchronous construction technology for the side span closure section and straight section of a high-pier bridge according to claim 1, characterized in that, The specific steps for construction preparation are as follows: 1) Prepare a special construction plan for the side span closure in advance, and provide written technical instructions to on-site technical and operational personnel; 2) Before the construction of the closure section, measurement and monitoring should be strengthened. Through theoretical calculations, the beam end elevation, plane position and pre-camber should be adjusted two blocks in advance to ensure that the beam size, elevation of each part, plane position and alignment meet the design requirements. 3) Clean up the debris on the hanging basket and the protective bottom, remove the hanging basket feeding platform and the protective bottom, and ensure that the hanging basket can be moved forward into place.

3. The synchronous construction technology for the side span closure section and straight section of a high-pier bridge according to claim 1, characterized in that, The specific steps for moving the basket forward are as follows: Operate the control switch to move the hanging basket forward. Stop when the hanging basket is 40 cm away from the cover beam. After the hanging basket moves to the designated position, anchor the three pressure beams with precision-rolled threaded steel to ensure the stability and safety of the hanging basket.

4. The synchronous construction technology for the side span closure section and straight section of a high-pier bridge according to claim 1, characterized in that, The specific steps for installing the permanent support are as follows: Before installing the bottom formwork, ensure that the supports have been installed; check the connection status before installation, and do not loosen the bolts; During installation, use concrete wedges to level the surface, adjust it to the design elevation, leave a 20-30mm gap, and install the grouting template to ensure correct positioning and tight contact with the upper and lower structures. After checking the location and elevation, use a non-shrink high-strength grouting material with a compressive strength of not less than 50MPa for gravity grouting, grouting from the center outwards until it is full; According to the construction steps, the connecting bolts should be removed before the concrete reaches the tension strength and before tensioning, and should not be removed before the concrete is poured.

5. The synchronous construction technology for the side span closure section and straight section of a high-pier bridge according to claim 1, characterized in that, The specific steps for sand box construction are as follows: To ensure the smooth dismantling of the bottom formwork system, 5 cm angle iron was selected as the sand box enclosure based on the height between the bottom of the beam and the cap beam, so that the height of the sand box was maintained at 5 cm. After the angle iron was installed, the sand and gravel were treated with a watertight method to ensure its compactness. A 12 mm thick wooden board was laid on the surface of the sand and gravel. The cross slope of the gravel surface should match the cross slope of the beam top. During the installation of the angle iron, ensure that the angle iron opening faces inward, and at the same time, set the reinforcing bar ends on the outside of the angle iron at a spacing of 50 cm. The purpose is to prevent the angle iron from deforming outward when the gravel is under pressure, thereby avoiding a reduction in the height of the sand box.

6. The synchronous construction technology for the side span closure section and straight section of a high-pier bridge according to claim 1, characterized in that, The specific steps for installing the skateboard support are as follows: Slide bearings are mainly used to reduce the friction coefficient between the formwork system and the cap beam, and to achieve sliding during thermal shrinkage deformation. Slide bearings with a thickness of 25mm are selected according to the space under the beam. The positions of the sliding plate supports are precisely marked on the wooden board of the sand box according to the spacing of the I10 I-beams of the longitudinal main ribs of the bottom mold. Then, the sliding plate supports are installed. The installation of the sliding plate supports needs to ensure that the longitudinal main ribs of the bottom mold remain balanced. Therefore, two sliding plate supports are placed under each I-beam. According to calculations, in order to prevent excessive longitudinal spacing of the sliding plate supports from causing excessive downward deflection of the I-beam and resulting in unevenness at the bottom of the beam, the first row of supports near the edge of the cap beam is placed at the edge of the cap beam, and the distance between the second row of sliding plate supports and the first row is controlled within 90cm.

7. The synchronous construction technology for the side span closure section and straight section of a high-pier bridge according to claim 1, characterized in that, The specific steps for installing the I-beam are as follows: I10 I-beams are mainly used as the main load-bearing ribs of the bottom formwork of the cap beam, and also serve as connecting components for the bottom formwork of the cap beam and the hanging basket. According to the stress conditions, double I10 I-beams are installed below the web, and single I10 I-beams are arranged in the hollow areas of the top and bottom plates; the length of the I-beams is 6 meters, of which about 1.75 meters extend into the bottom formwork of the hanging basket; the front end of the I-beam extends 40cm beyond the bottom of the beam to facilitate the installation and reinforcement of the beam end formwork. At the paving stone location, the I-beams are cut. After the I-beams are laid, the straightness of each I-beam surface is checked using the transverse hanging line method to ensure that it meets the specified requirements. After confirming that everything is correct, angle iron or φ22mm steel bars are welded laterally using a welding device to connect the longitudinal I-beams into a unified whole.

8. The synchronous construction technology for the side span closure section and straight section of a high-pier bridge according to claim 1, characterized in that, The specific steps for the construction of the hanging basket support are as follows: To reduce the elastic deformation of the hanging basket formwork, φ110 steel bars are installed on the cap beam to assist in supporting the hanging basket. The construction of the hanging basket support system mainly involves setting up inverted channel steel on the steel bars, placing the unloading blocks tightly against the cap beam on the channel steel, and laying double-layered I40b I-beams horizontally on the unloading blocks to assist in supporting the main force transmission components of the hanging basket. I25 short I-beams are arranged diagonally on the double-layered I40b I-beams to directly support the lower front crossbeam of the hanging basket. Two double-span I25a short I-beams are installed at the web position with a spacing of 50cm; two single-span I25a I-beams are installed at the bottom plate position with a spacing of 166cm; to prevent lateral instability of the I-beams, the I25a I-beams are connected by C8 channel steel in a scissor-type connection. In addition, the I25a short I-beams will be spot-welded to the lower crossbeam of the hanging basket and the double-section I40b I-beams respectively.

9. The synchronous construction technology for the side span closure section and straight section of a high-pier bridge according to claim 1, characterized in that, The specific steps of the prestressed construction are as follows: Tensioning employs dual control, namely, controlling both tension force and elongation. It begins after the concrete strength reaches the design tension strength. The prestressing tensioning principle is: first the web, then the top slab, then the bottom slab, and finally the transverse and vertical sections, using symmetrical tensioning; first the inside, then the outside; first the longer sections, then the shorter sections; first the outer side of the curve, then the inner side of the curve, using the dual control principle during tensioning. Grouting must be carried out within 48 hours after tensioning. The prestressed duct is grouted using a continuous grouting pump, and special grouting material or grouting agent must be used. The longitudinal prestressing grouting pressure is 0.5MPa to 0.7MPa, and the vertical prestressing grouting pressure is 0.3 to 0.4MPa.

10. A welding device, applied to a synchronous construction process for the side span closure section and straight section of a high-pier bridge as described in claim 7, characterized in that, Including mounting base plate; Mounting base, wherein the mounting base is disposed at the bottom of the mounting substrate; Adjusting arm two, the adjusting arm two is located below the mounting base, and one end of the adjusting arm two is disposed on the mounting base; Adjusting arm one, one end of which is disposed at the other end of adjusting arm two, and the other end of adjusting arm one is provided with a welding arm; The welding gun body is mounted on the welding arm; A welding adjustment module is provided on both sides of the mounting base plate and includes two flipping motors. The welding adjustment module is used to flip the welding device so that the welding device can directly change its position on the I-beam by flipping, so as to carry out welding operations at high altitude or between multiple I-beams. A fume treatment module is disposed on the mounting base and the welding gun body, and the fume treatment module includes multiple fume suction nozzles and two fume purifiers. The fume treatment module is used to absorb and treat the harmful fumes generated during welding.

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