Aerial construction method of low clearance, small curve single guide beam bridge erection machine

Abstract

The present invention discloses a method for overhead construction of a low-headroom, small-curve single-beam bridge erection machine, wherein a single-beam bridge erection machine is used to erect precast beams. The method comprises the following steps: assembling the bridge erection machine and transporting it to the bridgehead where the precast beams are to be erected; performing a bridge erection machine through-hole operation; including the steps of supporting a No. 1 column on the front pier and supporting a No. 2 column on the bridge deck near the pier; during the bridge erection machine through-hole operation, the No. 1 column is set on a No. 1 column transverse track and the No. 2 column is directly placed on the bridge deck; the beam feeding operation; the beam dropping operation; and the precast beam body alignment operation are sequentially performed to complete the erection of the precast beams. By optimizing and adjusting the construction process, the present invention is well suited for beam erection construction operations on high-speed interchange ramps with a headroom of less than 6.29m, and is also suitable for normal construction operations with a relatively small beam erection curve radius, and can effectively ensure safety during the construction operation.

Description

Technical Field

[0001] The invention belongs to the technical field of road and bridge construction, and particularly relates to an overhead construction method of a low-headroom, small-curve single-guide-beam bridge erection machine. Background Art

[0002] Interchanges are commonly used to transfer traffic between highways. One highway interchange project featured a symmetrical double-ring, semi-cloverleaf structure. The interchange's main line and ramps required multiple underpasses of existing highway bridges. The minimum clearance between the ramps and existing bridges was only 6.29 meters, making construction difficult using conventional bridge-erecting machines. Furthermore, the ramp curve radius was limited to just 125 meters, further complicating the construction of the ramp bridges. Summary of the Invention

[0003] The purpose of the present invention is to provide an overhead construction method for a low-headroom, small-curve single-guide-beam bridge erection machine, so as to solve the problems existing in the construction of low-headroom, small-curve ramps in high-speed interchange construction.

[0004] The present invention is achieved through the following technical solutions:

[0005] A low-headroom, small-curve single-beam bridge erection machine overhead construction method uses a single-beam bridge erection machine to erect prefabricated beams. The single-beam bridge erection machine includes a machine arm, a curved beam, column No. 0, column No. 1, column No. 2, column No. 3, a beam crane, and a transverse track for column No. 1 and column No. 2. The curved beam includes a front curved beam and a rear curved beam, and the beam crane includes a front crane and a rear crane.

[0006] The construction method comprises the following steps:

[0007] Assemble the bridge erection machine and transport it to the bridge head where the prefabricated beams are to be erected;

[0008] The bridge-erecting machine's hole-crossing operation includes the steps of supporting the No. 1 column on the front pier and supporting the No. 2 column on the bridge deck near the pier. During the bridge-erecting machine's hole-crossing operation, the No. 1 column is set on the No. 1 column's transverse track, and the No. 2 column is placed directly on the bridge deck.

[0009] Beam feeding operation: flip the No. 3 column horizontally and turn it to the rear, transport the precast beam to be erected to the position behind the No. 2 column, and the front beam crane will lift the precast beam. When lifting the precast beam, the movable tray on the rail beam transport vehicle will be lifted together with the precast beam. The rear rail beam transport vehicle and the front beam crane will feed the beam synchronously. When the other end of the precast beam moves to the position of the rear beam crane, the rear beam crane will lift the precast beam.

[0010] Beam dropping operation: During the beam dropping operation, the prefabricated T-beam is first temporarily placed on the middle beam erection position, and then the second column is placed on the second column transverse track. Through the transverse movement of the first column and the second column on the first column transverse track and the second column transverse track respectively, the entire bridge erection machine can be transversely moved to the beam dropping position, and the prefabricated beam is re-lifted and transversely moved to the erection position before the beam is dropped;

[0011] The precast beams are aligned and the erection of the precast beams is completed in sequence.

[0012] On the other hand, in the construction method of the present invention, the bridge erection machine through-hole operation comprises the following steps:

[0013] a. Connect the front and rear cranes to the front and rear curved beams respectively, release the connection between the curved beam and the boom, and support the No. 1 column on the pier close to the bridge deck;

[0014] b. Lift the third column and drive the arm forward;

[0015] c. Support the third column, retract the second column so that the second column moves horizontally off the ground, drive the second column forward to a position a certain distance from the center of the first column, support the second column, and retract the third column;

[0016] d. The crane drives the boom forward, moving the No. 0 column to the front pier position, and lifts the No. 0 column so that the height difference between the front end of the boom and the No. 1 column is -50 to 150 mm;

[0017] e. Lift the No. 3 column so that the rear end of the boom is 0 to 100 mm higher than the No. 1 column, retract the No. 2 column, drive the No. 2 column to move it to the beam erection position, and support the No. 2 column directly on the bridge deck near the pier;

[0018] f. Retract column No. 1, drive column No. 1 to move column No. 1 to the beam erection position of the front pier, support column No. 1 on the column No. 1 transverse track and firmly support it on the front pier.

[0019] On the other hand, in the construction method of the present invention, during the bridge-building machine's hole-passing operation, the horizontality of the machine arm is adjusted so that the horizontality of the machine arm is always no more than 0.5%; when the No. 0 column and the No. 1 column are supporting, the verticality of the No. 0 column and the No. 1 column is adjusted so that the verticality is always no more than 0.5%.

[0020] On the other hand, in the construction method of the present invention, in the bridge construction of a small radius curved ramp, when setting the No. 1 column and the No. 2 column during the bridge-building machine's through-hole operation, the No. 1 column, the No. 2 column and the center line of the cap beam of the corresponding pier form an angle of 3° to 5°.

[0021] On the other hand, in the construction method of the present invention, the cap beam of each span of the pier is set to a fan-shaped structure, so that the center line of the cap beam and the end face of the precast beam form an angle of 3° to 5°.

[0022] On the other hand, in the construction method of the present invention, in the beam feeding operation step, the front beam crane lifts the precast beam, maintaining the inclination angle of the precast beam no greater than 20 degrees, and the front bridge crane and the rear rail beam transport vehicle advance synchronously, and during the advancement process, the lateral movement of the entire machine is synchronously adjusted to adjust the position of the precast beam;

[0023] When the rear rail beam transport vehicle reaches the position of the rear beam crane, the rear beam crane lifts the prefabricated beam to make it horizontal. The beam crane lifts the beam forward at the same time and adjusts the No. 2 column laterally during the movement so that the prefabricated beam can pass through the No. 2 column smoothly.

[0024] On the other hand, in the construction method of the present invention, during the process of adjusting the lateral movement of the entire machine, the verticality of column No. 1 is always ensured to be no more than 0.5%. When column No. 1 tilts, the longitudinal movement cylinder located above the curved beam of column No. 1 is adjusted in time to adjust the verticality of column No. 1.

[0025] On the other hand, in the construction method of the present invention, in the bridge construction of a small radius curve ramp, the order of beam erection is inner side beam, secondary inner side beam, outer side beam, secondary outer side beam and middle beam, and the erection operation of a single-span bridge is completed in sequence.

[0026] On the other hand, in the construction method of the present invention, during the beam dropping operation, when erecting the inner side beam, the center points of column No. 1 and column No. 2 on the corresponding transverse track do not exceed the corresponding pier cap beam block and the outermost edge of the bridge deck; during the beam dropping process, the transverse track of column No. 1 and column No. 2 are first moved into place, the transverse track wheels of column No. 1 and column No. 2 are locked, and then the hoisted prefabricated beam is adjusted to the beam erection position by adjusting the curved beam transverse cylinder before the beam is dropped.

[0027] On the other hand, in the construction method of the present invention, during the beam dropping operation, when erecting the outer side beam, the transverse track wheel of column No. 1 is moved to the outermost edge of the cap beam, and then the prefabricated beam near one end of column No. 1 is temporarily dropped on the support pad stone of the corresponding pier, and a transverse track is set on the pier close to the bridge deck, and the prefabricated beam near one end of column No. 2 is dropped on the transverse track, and then the prefabricated beam is pushed and moved transversely to the beam erection position before the beam is dropped.

[0028] The present invention optimizes and adjusts the construction process, and optimizes the structure of the bridge erection machine on the basis of the existing single-guide beam bridge erection machine, which effectively solves the impact of low clearance construction height on the bridge erection machine's construction operations of passing through holes, feeding beams, and dropping beams, making the bridge erection machine well suitable for beam erection construction operations of high-speed interchange ramps with a clearance of less than 6.29m, ensuring the normal construction of the bridge erection machine's operations of passing through holes, feeding beams, and dropping beams.

[0029] The construction process of the present invention is not only applicable to the beam erection construction of low-clearance high-speed interchange ramps, but also solves the problem that the bridge erection machine is difficult to perform beam erection construction due to the small curve radius of the interchange ramp by adjusting the setting position of the bridge erection machine when dropping the beam and the construction steps. It makes it applicable to normal construction operations with a small beam erection curve radius and can effectively ensure safety during the construction operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 It is a schematic diagram of the bridge construction structure of a single guide beam bridge erecting machine according to the construction method of the present invention.

[0032] Figure 2 This is a schematic diagram of step a in the hole-passing operation of the bridge-building machine in the construction method of the present invention.

[0033] Figure 3 This is a schematic diagram of step b in the bridge-building machine through-hole operation in the construction method of the present invention.

[0034] Figure 4 This is a schematic diagram of step c in the bridge-building machine through-hole operation in the construction method of the present invention.

[0035] Figure 5 This is a schematic diagram of step d in the through-hole operation of the bridge-building machine in the construction method of the present invention.

[0036] Figure 6 This is a schematic diagram of step e in the through-hole operation of the bridge-building machine in the construction method of the present invention.

[0037] Figure 7 This is a schematic diagram of step f in the bridge-building machine through-hole operation in the construction method of the present invention.

[0038] Figure 8 This is a diagram showing the sequence of erecting precast beams in the construction method of the present invention.

[0039] Figure 9 This is a schematic diagram of the bridge erection machine in position during the through-hole operation of the small curve beam erection and bridge erection machine in the construction method of the present invention.

[0040] Figure 10 This is a schematic diagram of the front crane hoisting the beam during the small curve beam erection and feeding operation of the construction method of the present invention.

[0041] Figure 11 This is a schematic diagram of the rear beam crane hoisting during the small curve beam erection and feeding operation of the construction method of the present invention.

[0042] Figure 12 It is a schematic diagram of the inner side beam dropping structure in the small curve beam erection and dropping operation of the construction method of the present invention.

[0043] Figure 13 It is a schematic diagram of the outer beam dropping structure in the small curve beam erection and dropping operation of the construction method of the present invention.

[0044] Figure 14 It is a schematic diagram of the transverse track structure of the construction method of the present invention.

[0045] Figure 15 It is a schematic diagram of the rolling structure in the transverse track of the construction method of the present invention.

[0046] Figure 16 It is a schematic diagram of the structure of prefabricated T-beams erected on piers in the construction method of the present invention.

[0047] in:

[0048] 11. Arm, 12. Column 0, 13. Column 1, 14. Column 2, 15. Column 3, 16. Front curved beam, 17. Rear curved beam;

[0049] 21. Pier, 22. Front pier, 23. Precast T-beam, 231. Inner side beam, 232. Secondary inner side beam, 233. Middle beam, 234. Secondary outer side beam, 235. Outer side beam, 24. Support, 25. Support pad stone, 26. Cap beam;

[0050] 31. Rail, 32. Roller, 33. Slide;

[0051] 41. Front rail beam transport vehicle, 42. Rear rail beam transport vehicle. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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, not all of the embodiments.

[0053] In view of the characteristics of the project and the problem of limited construction space, the DJ180 bridge-building machine is used for construction in this embodiment. This type of bridge-building machine is a single-arm simply supported type, which can realize full-width mechanical transverse movement of beams and drop the beams into place in one go. It has the characteristics of simple structure.

[0054] Reference Figure 1 This type of bridge-building machine includes an arm assembly, a curved beam and a transverse movement mechanism, a No. 0 column 12, a No. 1 column 13, a No. 2 column 14, a No. 3 column 15, a No. 1 column transverse movement track, a No. 2 column transverse movement track, a beam crane and an electric hydraulic control system for controlling the movement of each component.

[0055] Among them, the arm assembly includes the arm 11, which is the main load-bearing structural component of the bridge-building machine; it adopts a box-type section, with upper and lower ear beams on both sides of the section; a rack is provided at the bottom, and the arm is usually made of five-section unit beams assembled and connected by pins.

[0056] The curved beams and their traverse mechanisms are the primary components supporting and driving the boom. They comprise a front curved beam 16 and a rear curved beam 17, mounted on the upper crossbeams of the No. 1 and No. 2 columns, respectively, and connected to the boom via balancing wheels. The traverse mechanism is bolted to the top of the curved beam at one end and bolted to the upper crossbeams of the No. 1 and No. 2 columns, respectively, at the other end. The traverse mechanisms of the front and rear curved beams have identical connection directions and can achieve a traverse range of up to 750mm in both the left and right directions, driving the No. 1 and No. 2 columns laterally on the No. 1 and No. 2 traverse tracks.

[0057] During the curved beam feeding operation, it is necessary to separately adjust the transverse cylinder on the curved beam at column No. 2 to prevent the prefabricated T-beam piece from colliding with the column No. 2; but this will cause column No. 1 to deflect, so it is also necessary to adjust the longitudinal adjustment cylinder at column No. 1 to adjust column No. 1 to a vertical state.

[0058] The zero column is installed at the front end of the machine arm and adopts a two-stage telescopic and narrow door frame structure; it can be flipped in the horizontal direction, and the zero column can be easily flipped to a horizontal position during transportation.

[0059] The No. 1 column is connected to the front curved beam via its upper crossbeam. Its shaft utilizes two telescopic columns, each with a 3000mm adjustment range. Conventional structures typically feature two adjustment sections: a 3400mm adjustment for flat bridges and an 1100mm adjustment for downhill bridges. The No. 1 column is mounted on a lateral track and equipped with a traveling mechanism, enabling it to move horizontally along the track at a speed of 1.6m / min.

[0060] The No. 2 column is connected to the rear curved beam through its upper crossbeam; the column body of the No. 2 column adopts four two-stage retractable columns with an adjustable height of 3000m; the No. 2 column is set on the No. 2 column transverse track, and the No. 2 column is also equipped with a walking mechanism, so that the No. 2 column can move laterally on the No. 2 column transverse track with a transverse speed of 1.6m / min. There are two No. 2 column transverse tracks.

[0061] The third column is mounted at the rear end of the boom and connected to the boom via a frame-shaped connecting bracket. Its body features two telescopic columns, with an adjustable height of 3150m. The conventional structure includes a 400mm adjustment joint, which is useful when erecting uphill bridges. To accommodate beam feeding operations on small curves, the third column is connected to the boom using a flip connection, allowing it to flip backward. A hydraulic cylinder is installed between the boom and the third column to power its rotation.

[0062] The crane is divided into a front crane and a rear crane, depending on its location on the boom. Both cranes are mounted on the lower boom ears via wheels. The crane travels on the boom at a speed of 5 m / min. The crane hoists utilize electric winches at a speed of 0.6 m / min. Each electric winch is equipped with a 7.5 kW brake motor and an electromagnetic brake for bipolar braking.

[0063] The overhead construction method of erecting beams using a single-beam bridge-erecting machine usually includes: loading and transporting beams - feeding beams - dropping beams - and horizontal movement operations.

[0064] The existing ordinary bridge-building machine generally has a height of 9.8m-10.5m, which cannot meet the requirements of the low-headroom construction conditions in this construction project; the current DJ180 dual-purpose road-rail bridge-building machine has a total machine height of 8.8m during beam erection operation, which is greater than the minimum headroom height of the construction of this project (6.29m). Therefore, in order to meet the requirements of low-headroom construction, the structure of the single-beam bridge-building machine needs to be further optimized.

[0065] 1) Bridge erection machine structure optimization and through-hole operation

[0066] First, the height of the adjustment section of the No. 1 column of the bridge-building machine was optimized, and the original design size of the adjustment section with a size of 3.4m was improved to a combined structure of 2.8m+0.65m; when erecting beams under the trough-type beam, only the 2.8m adjustment section was used. When erecting beams, the No. 1 and No. 2 columns could be lowered by 1.5m at the same time to meet the requirement of lowering the height of the entire machine.

[0067] During the through-hole operation of the bridge erection machine, the horizontality of the machine arm and the verticality of the column should be controlled. The through-hole operation process of the bridge erection machine includes:

[0068] a. Connect the front and rear beam cranes to the front and rear curved beam pin shafts, connect the front end of the beam crane to the rear end of the curved beam, and release the connection between the curved beam and the arm. Fix the No. 1 column on the pier 21. Figure 2 ;

[0069] b. Lift the third column and drive the arm forward, such as Figure 3 ;

[0070] c. Support the third column, keep the arm horizontal, retract the second column so that the second column moves horizontally off the ground; drive the second column forward to a position 16.4m away from the center of the first column, such as Figure 4 ; Support the second pillar and close the third pillar;

[0071] d. The front and rear cranes drive the arms forward 15m, moving the zero column to the predetermined position of the front pier 22. Figure 5 Lift the zero column so that the height difference between the front end of the arm and the first column is -50 to 150 mm, and adjust the verticality of the zero column to ≤5‰;

[0072] e. Lift the No.3 column so that the rear end of the arm is 0 to 100 mm higher than the No.1 column, retract the No.2 column, move the No.2 column forward 13.6 m to the beam erection position, and then lower the No.2 column to support it firmly. Figure 6 ;

[0073] f. Retract the No.1 column and drive it forward 30m to the front pier beam mounting position. Connect the curved beam to the machine arm, level it and support it firmly. Insert the column pin. Figure 7 ;

[0074] g. Release the connection between the curved beam and the beam crane, retract the No. 0 column to ensure that the bottom is higher than the No. 1 column travel motor; the beam crane moves back to the tail end of the arm to prepare for beam erection operations.

[0075] When the bridge-erecting machine is operating at low clearance through a hole, adjust the height of the bridge-erecting machine and lower the stroke of the oil cylinder of the second column by 1.3m. At this time, the height of the whole machine can reach 6.0m, enabling the bridge-erecting machine to pass through the hole and meet the requirements of low clearance bridge-erecting.

[0076] After the bridge-erecting machine passes through the hole, the height of the second column will not meet the size requirements of the beam feeding operation; usually the height of the prefabricated T-beam is 2.5m, the height of the beam transport trolley is 0.65m, and the total height needs to meet 3.2m. Further considering that the installation height required for the hanging beam wire rope and other pads is 40cm, in order to facilitate the removal and hanging of the wire rope, the prefabricated T-beam feeding operation requires the beam feeding clearance height of the second column to be above 3.6m; therefore, the beam feeding clearance height of the second column needs to be adjusted after the bridge-erecting machine passes through the hole. Due to the limited clearance height, if the second column of the bridge-erecting machine is set on the horizontal track of the second column (the height of the horizontal track of the second column is 39cm), the beam feeding clearance height requirement will not be met at this time.

[0077] Therefore, in the actual operation process, it is necessary to place the No. 2 column directly on the bridge deck after the bridge-building machine passes through the hole, and firmly support it with wooden wedges and sleepers, and adjust the No. 2 column cylinder stroke to the maximum to meet the beam feeding clearance of 3.6m to realize the beam feeding operation.

[0078] 2) Loading and transporting beams

[0079] The precast T-beam 23 is transported using a four-axle rail-mounted beam transporter, including a front rail-mounted beam transporter 41 and a rear rail-mounted beam transporter 42. During beam transport, the two ends of the precast T-beam are placed on the movable pallets of the two rail-mounted beam transporters, respectively, so that the precast T-beam can rotate relative to the rail-mounted beam transporter during transport. The precast T-beam is transported to 100m from the front of the bridge crane, and a double-row beam-lifting gantry is set up 100m in front of the bridge crane. Tracks are laid 50m from the bridge crane, and rail-mounted beam transporters are set up above the tracks. The rail-mounted beam transporters also need to meet the requirement of lowering the height of the bridge crane feeding beams during beam erection construction. Usually, two rail-mounted beam transporters are used, both with a height of 0.65m.

[0080] During the operation of loading and transporting beams, when the prefabricated T-beam is transported to the bottom of the beam-lifting gantry, the beam-lifting gantry will lift the prefabricated T-beam onto the rail beam transport vehicle. The center of gravity of the prefabricated T-beam should fall on the longitudinal center line of the rail beam transport vehicle, with a deviation of no more than 20mm; when the prefabricated T-beam falls on the rail beam transport vehicle, the front end of the prefabricated T-beam shall not exceed 2.5m of the supporting crossbeam of the rail beam transport vehicle, and the upper end of the inclined support of the rail beam transport vehicle shall be padded with hard miscellaneous wood or rubber belts to ensure complete contact with the beam piece, and the diagonal support shall be firmly supported and locked to protect the concrete of the beam piece; before transporting the beam, ensure that the steel wire ropes binding the beam piece are tightened and locked, and the contact points between the steel wire ropes and the beam piece are padded with rubber to protect the concrete of the beam body and the steel wire ropes binding the beam piece, so as to ensure the safe transportation of the prefabricated T-beam.

[0081] 3) Feeding beams

[0082] Hang steel wire ropes on the beam cranes respectively. The front beam crane lifts one end of the prefabricated T-beam, and the rear rail beam transport vehicle feeds the beam synchronously with the front beam crane. When the other end of the prefabricated T-beam moves to the position of the rear beam crane, the rear beam crane lifts the prefabricated T-beam to realize synchronous beam feeding.

[0083] During the beam feeding operation, since the boom is in a horizontal state, the bridge has a certain slope during the erection of the hub interchange. At this time, during the beam feeding operation, the distance between the bottom surface of the prefabricated T-beam and the top surface of the rail beam transport vehicle will gradually decrease; to ensure the smooth progress of the beam feeding operation, when the front crane lifts the prefabricated T-beam beam, the movable pallet on the rail beam transport vehicle will be lifted together with the prefabricated T-beam, thereby lowering the height of the front rail beam transport vehicle, so as to meet the requirements of the uphill bridge erection, the bottom of the prefabricated T-beam can pass through the rail beam transport vehicle smoothly without interfering with the rail beam transport vehicle, and meet the low clearance construction requirements.

[0084] 4) Falling beams

[0085] During the erection of the prefabricated T-beam 23, taking the erection of 5 prefabricated T-beams in one span as an example, the erection order of the prefabricated T-beam is: inner side beam 231 - second inner side beam 232 - outer side beam 235 - second outer side beam 234 - middle beam 233, refer to Figure 8 .

[0086] During the beam dropping operation, since the size of the feed beam for the second column is limited by the clearance height, when erecting the prefabricated T-beam, the prefabricated T-beam must be temporarily placed at the erection position of the middle beam. After the beam is dropped at this position, the bridge erection machine is unloaded.

[0087] Then, raise the No. 1 column, retract the No. 2 column, and reposition it on the No. 2 column transverse track. Adjust the height of the bridge erection machine to ensure that the entire machine height does not exceed 6.2 meters. After the No. 2 column transverse track is installed, move the entire machine transversely to the beam drop position, re-lift the prefabricated T-beam, and move it transversely to the erection position. The beam drop and alignment operations are then carried out in sequence to complete the erection of the prefabricated T-beam.

[0088] 5) Beam in place

[0089] When the bridge-erecting machine is about to drop the beam into place, install the rubber bearing. According to the center line of the bearing plate led out from the end of the prefabricated T-beam, use a hanging hammer to align with the cross line of the pad stone to align the prefabricated T-beam. When there is a conflict between the alignment of the longitudinal center line and the end line of the prefabricated T-beam, the center line of the bearing shall be used as the standard. After the beam is dropped, the rubber bearing shall be in close contact with the steel plate at the bottom of the beam.

[0090] After the entire span of prefabricated T-beams is in place, all wet joints of the beam body are welded and connected transversely with steel bars to ensure the safety and stability of subsequent hole-passing and beam transportation operations.

[0091] In the high-speed hub interchange of this project, the ramp bridge radius is 125m, and the ramp curve radius is relatively small. When erecting the outer beam, the bridge-erecting machine will not be able to move the prefabricated T-beam into place horizontally. In this construction plan, a single-beam bridge-erecting machine is used to drop the beam. When erecting the outer beam, in order to ensure the safety of the entire bridge-erecting machine and prevent the bridge-erecting machine from overturning, one end of the outer beam is placed on the pier, and the other end is dropped on the transverse track slide. Then, a jack is used to move the other end of the outer beam into place horizontally. The prefabricated T-beams in other locations can be erected using a single-beam bridge-erecting machine according to normal construction operations.

[0092] Specifically, in this embodiment, for the construction condition where the radius of the high-speed interchange ramp is small, the construction scheme adopted is as follows:

[0093] 1) Curved hole-passing and positioning operation of bridge erection machine

[0094] Due to the small radius of the ramp curve, the cap beam of each span of the pier is set to a fan-shaped structure, and the angle between the center line of the cap beam and the end face of the precast beam is 5°; during the beam erection process, the horizontal track of the first column and the horizontal track of the second column of the bridge erection machine should be kept balanced. In order to meet the needs of the horizontal movement of the inner and outer side beams, when setting the first and second columns, the horizontal track of the first column and the horizontal track of the second column are at a 5° angle to the center line of the cap beam. Figure 9 Schematic diagram of the bridge-building machine through-hole in place.

[0095] 2) Prefabricated T-beam transportation and beam erection operations

[0096] According to the order of beam erection, the inner side beam, the secondary inner side beam, the outer side beam, the secondary outer side beam are erected in sequence, and finally the middle beam is erected to complete the erection operation of a single-span bridge.

[0097] Precast T-beams are hoisted using a bottom-of-beam hoisting method with lifting holes installed. Using this hoisting method, wire ropes are passed through the bottom plate of the precast T-beam from the lifting points at both ends of the beam, around the precast T-beam flanges, and then snapped into the clamping ring at the top of the hoist. Due to the small radius of the ramp curve, the dimensional deviations of the flanges on both sides of the precast T-beam are large. To ensure the stability of the side beam hoisting, lifting holes are reserved on both sides of the side beam web during prefabrication to ensure the stability of the side beam hoisting.

[0098] 3) Beam feeding and beam dropping operations

[0099] a. Front crane beam;

[0100] Reference Figure 10 , flip the No.3 column horizontally to the rear, and the rail-mounted beam transporter transports the prefabricated T-beam to the rear of the No.2 column. Adjust the bridge-erecting machine to achieve horizontal movement of the entire machine, so that the front beam crane is directly above one end of the prefabricated T-beam. At this time, the distance between the front beam crane and the No.2 column horizontal movement track is about 3.5m;

[0101] The front crane hoisted the beam, maintaining an inclination angle of no more than 20°. The crane then advanced simultaneously with the rear rail-mounted beam transporter, coordinating the vehicle's speed. During this advancement, the crane's arm tracked the precast T-beam, while the rear rail-mounted beam transporter tracked the precast T-beam. Therefore, the crane's lateral movement was adjusted to adjust the position of the precast T-beam and prevent any scraping between the precast T-beam and the No. 2 column. During this adjustment process, the verticality of the No. 1 column was maintained (no more than 0.5%). If tilting occurred, the longitudinal displacement cylinder above the No. 1 curved beam was promptly adjusted to maintain the column's verticality.

[0102] b. Rear crane beam;

[0103] Reference Figure 11 When the rear rail beam transport vehicle reaches the lifting position of the rear beam crane, the other end of the prefabricated T-beam is lifted by the rear beam crane and raised so that the prefabricated T-beam is in a horizontal state. At this time, the front and rear beam cranes lift the beam forward at the same time, and adjust the position of the No. 2 column laterally during the movement so that the prefabricated T-beam can pass through the No. 2 column smoothly.

[0104] c. Erection of inner side beams and secondary inner side beams;

[0105] Reference Figure 12When erecting the inner side beam, in order to ensure the stability of the entire bridge erection machine and prevent the bridge erection machine from overturning, the center points of the No. 1 and No. 2 columns of the bridge erection machine on the corresponding transverse track must not exceed the cap beam block and the outermost edge of the bridge deck to avoid the bridge erection machine from tipping over due to the outward extension of the bridge erection machine. Therefore, during the beam lowering process, the No. 1 column transverse track and the No. 2 column transverse track should be moved into place first, and after locking the transverse track wheels of the No. 1 and No. 2 columns, they should be accurately positioned by adjusting the curved beam transverse cylinder to ensure the safety of beam erection.

[0106] When the transverse track wheel of column No. 1 reaches the outermost edge of the cap beam, the transverse track wheel of column No. 2 is 22 cm away from the outermost edge of the bridge deck, and the position of the center line of the curved beam and the center line of the support meet the requirements for beam dropping. At this time, the inner side beam can be directly moved into place by the bridge erection machine.

[0107] After the inner side beam is erected, the secondary inner side beam is erected, and then the cross-partition steel bars between the two prefabricated T-beams are welded to ensure the stability of the beam.

[0108] e. Erection of outer beams and secondary outer beams

[0109] Reference Figure 13 When erecting the outer edge beam, the transverse track wheel of the bridge erection machine's No. 1 column moves to the outermost edge of the cap beam 26. At this time, the distance between the centerline of the curved beam at the No. 2 column and the centerline of the cap beam support is 49 cm, making it impossible to drop the precast T-beam piece on the support pad. To ensure the safety of the bridge erection machine, the precast T-beam at the end of the No. 1 column is temporarily dropped on the support pad, and the precast T-beam at the end of the No. 2 column is dropped on the transverse track and moved into place using a jack.

[0110] like Figure 14 and 15 As shown, the transverse track here adopts No. 43 steel rail 31, and rollers 32 and slides 33 are arranged in sequence on the steel rail 31. The rollers 32 are made of 50cm round steel and 2cm steel plate; one end of the prefabricated T-beam to be erected is placed on the slide 33; the prefabricated T-beam is stably fixed on the slide, and a 15t jack is used to perform the transverse operation of the prefabricated T-beam. After the transverse movement is into place, two QYL32-ton jacks are used to synchronously unload the prefabricated T-beam to the beam erection position.

[0111] The specific steps of the jacking construction operation are as follows: place the prefabricated T-beam on the slide. During the jacking process, the pads need to be followed up in time. The size of the horizontal jacking is estimated based on the support reaction force calculated according to the center beam of the prefabricated T-beam. The jacking force is gradually increased according to the required jacking force until the beam starts to move forward. After the beam starts to move, the jacking force of the jack is appropriately reduced to allow the beam to move forward in a balanced manner.

[0112] During the jacking process of the beam, as the beam advances, the lateral limit controls the deviation of its center line within 10mm. During the jacking process of the T-beam, the deviation of each pier and the center line position of the beam are tracked and measured, and the jacking speed is controlled. A limit device is set between the slide of the transverse track and the pier top to prevent large movement during jacking. Hard wooden blocks are used to fill the space between the limit device and the pier top to prevent the lateral movement distance from exceeding the center line position of the pier support.

[0113] The specific steps of the beam drop construction operation are as follows: After the prefabricated T-beam is pushed into place horizontally, the prefabricated T-beam is lifted by a jack, and the transverse track is pulled out. After the beam body is lifted into place, the jack oil valve is locked, and the longitudinal and transverse position deviations of the prefabricated T-beam are checked. The support 24 is installed on the support pad 25, and the jack is slowly depressurized to slowly drop the prefabricated T-beam onto the support. Figure 16 Schematic diagram of the structure of prefabricated T-beam erected on the pier.

[0114] After the erection of the outer beam is completed, the secondary outer beam is erected and the cross-partition steel bars of the two prefabricated beams are welded to ensure the stability of the beam body.

[0115] f. Middle beam installation

[0116] During the installation of the middle beam, the speed of beam dropping is slowed down to prevent the middle beam from colliding with other beams and causing the beam to overturn.

[0117] After the middle beam is erected, the bridge deck system is installed in time, and then the erection of the next beam is carried out.

[0118] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. used to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0119] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of the present invention does not necessarily imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical" and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0120] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0121] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for overhead construction of a low-headroom, small-curve single-beam bridge erection machine, characterized in that: A single-beam bridge erection machine is used to erect precast beams. The single-beam bridge erection machine includes a machine arm, a curved beam, a No. 0 column, a No. 1 column, a No. 2 column, a No. 3 column, a beam crane, and a No. 1 column transverse track and a No. 2 column transverse track. The curved beam includes a front curved beam and a rear curved beam, and the beam crane includes a front crane and a rear crane. The construction method comprises the following steps: Assemble the bridge erection machine and transport it to the bridge head where the prefabricated beams are to be erected; The bridge-erecting machine's hole-crossing operation includes the steps of supporting the No. 1 column on the front pier and supporting the No. 2 column on the bridge deck near the pier. During the bridge-erecting machine's hole-crossing operation, the No. 1 column is set on the No. 1 column's transverse track, and the No. 2 column is placed directly on the bridge deck. Beam feeding operation: flip the No. 3 column horizontally and turn it to the rear, transport the precast beam to be erected to the position behind the No. 2 column, and the front beam crane will lift the precast beam. When lifting the precast beam, the movable tray on the rail beam transport vehicle will be lifted together with the precast beam. The rear rail beam transport vehicle and the front beam crane will feed the beam synchronously. When the other end of the precast beam moves to the position of the rear beam crane, the rear beam crane will lift the precast beam. Beam dropping operation: During the beam dropping operation, the prefabricated T-beam is first temporarily placed on the middle beam erection position, and then the second column is placed on the second column transverse track. Through the transverse movement of the first column and the second column on the first column transverse track and the second column transverse track respectively, the entire bridge erection machine can be transversely moved to the beam dropping position, and the prefabricated beam is re-lifted and transversely moved to the erection position before the beam is dropped; The precast beam body is aligned and the erection of the precast beams is completed in sequence; To meet the requirements of low clearance construction, the structure of the single-beam bridge erection machine is optimized, including: The height of the adjustment section of the No. 1 column of the bridge erection machine was optimized, with the original design size of 3.4m being improved to a combined structure of 2.8m + 0.65m. When erecting beams under channel beams, only the 2.8m adjustment section is used. During the process, both No. 1 and No. 2 columns can be lowered by 1.5m simultaneously, achieving the required height reduction for the entire machine. During the through-hole operation of the bridge erection machine, the horizontality of the machine arm and the verticality of the column are controlled. The through-hole operation process of the bridge erection machine includes: a. Connect the front and rear cranes to the front and rear curved beams respectively, release the connection between the curved beam and the boom, and support the No. 1 column on the pier close to the bridge deck; b. Lift the No. 3 column and drive the arm forward; c. Support the third column, retract the second column so that the second column moves horizontally off the ground, drive the second column forward to a position a certain distance from the center of the first column, support the second column, and retract the third column; d. The crane drives the arm forward to move the No. 0 column to the front pier position, lift the No. 0 column so that the height difference between the front end of the arm and the No. 1 column is -50 to 150 mm, and adjust the verticality of the No. 0 column to ≤5‰; e. Lift the No. 3 column so that the rear end of the boom is 0 to 100 mm higher than the No. 1 column, retract the No. 2 column, drive the No. 2 column to move it to the beam erection position, and support the No. 2 column directly on the bridge deck near the pier; f. Retract column No. 1, drive column No. 1 to move it to the beam-erecting position on the front pier, support column No. 1 on its transverse track and secure it on the front pier; g. Release the connection between the curved beam and the beam crane, retract the zero column to ensure that the bottom is higher than the travel motor of the first column; the beam crane moves back to the tail of the boom to prepare for beam erection operations; When the bridge erection machine is operating at low clearance, adjust the height of the bridge erection machine and lower the stroke of the second column cylinder by 1.3m. At this time, the height of the whole machine can reach 6.0m, realizing the bridge erection machine passing through the hole; After the bridge erection machine passes through the hole, place the No. 2 column directly on the bridge deck and support it firmly with wooden wedges and sleepers. Adjust the stroke of the No. 2 column cylinder to the maximum to meet the 3.6m clearance requirement for beam feeding to realize the beam feeding operation.

2. The overhead construction method of a low-headroom, small-curve single-beam bridge erection machine according to claim 1 is characterized in that: During the bridge-building machine's hole-passing operation, adjust the horizontality of the machine arm so that the horizontality of the machine arm is always no greater than 0.5%; when supporting the No. 0 column and the No. 1 column, adjust the verticality of the No. 0 column and the No. 1 column so that the verticality is always no greater than 0.5%.

3. The overhead construction method of a low-headroom, small-curve single-beam bridge erection machine according to claim 1, characterized in that: During the bridge construction of a small radius curved ramp, when setting the No. 1 and No. 2 columns during the bridge-building machine's through-hole operation, an angle of 3° to 5° is formed between the No. 1 and No. 2 columns and the center line of the cap beam of the corresponding pier.

4. The overhead construction method of a low-headroom, small-curve single-beam bridge erection machine according to claim 3 is characterized in that: The cap beam of each span of the pier is set to a fan-shaped structure, so that the center line of the cap beam and the end face of the precast beam form an angle of 3° to 5°.

5. The overhead construction method of a low-headroom, small-curve single-beam bridge erection machine according to claim 1, characterized in that: During the beam feeding operation, the front beam crane lifts the precast beam, keeping the inclination angle of the precast beam no greater than 20°. The front bridge crane and the rear rail beam transport vehicle move forward synchronously, and during the forward movement, the lateral movement of the entire machine is adjusted to adjust the position of the precast beam. When the rear rail beam transport vehicle reaches the lifting position of the rear beam crane, the rear beam crane lifts the prefabricated beam to make it horizontal. The beam crane moves the beam forward at the same time and adjusts the No. 2 column laterally during the movement so that the prefabricated beam can pass through the No. 2 column smoothly.

6. The overhead construction method of a low-headroom, small-curve single-beam bridge erection machine according to claim 5, characterized in that: During the lateral movement adjustment of the entire machine, ensure that the verticality of the No. 1 column is always no more than 0.5%. When the No. 1 column tilts, promptly adjust the longitudinal movement cylinder located above the curved beam of the No. 1 column to adjust the verticality of the No. 1 column.

7. The overhead construction method of a low-headroom, small-curve single-beam bridge erection machine according to claim 1, characterized in that: In the bridge construction of a small radius curved ramp, the order of beam erection is inner side beam, secondary inner side beam, outer side beam, secondary outer side beam and middle beam, and the erection operation of a single-span bridge is completed in sequence.

8. The overhead construction method of a low-headroom, small-curve single-guide-beam bridge erection machine according to claim 7, characterized in that: During the beam lowering operation, when erecting the inner side beam, the center points of column No. 1 and column No. 2 on the corresponding transverse track do not exceed the corresponding pier cap beam block and the outermost edge of the bridge deck; during the beam lowering process, first move the transverse track of column No. 1 and column No. 2 into position, lock the transverse track wheels of column No. 1 and column No. 2, and then adjust the hoisted prefabricated beam to the beam erection position by adjusting the curved beam transverse cylinder before lowering the beam.

9. The low headroom, small curve single guide beam according to claim 7 The overhead construction method of the bridge erection machine is characterized in that: During the beam dropping operation, when erecting the outer beam, move the transverse track wheel of column No. 1 to the outermost edge of the cap beam, and then temporarily drop the precast beam near the end of column No. 1 on the support pad stone of the corresponding pier. Set a transverse track on the pier close to the bridge deck, drop the precast beam near the end of column No. 2 on the transverse track, and then push the precast beam to the beam erection position and drop the beam.

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