Method of erecting a curved bridge

Abstract

The application discloses a curve bridge erecting method, and aims at solving the problem that the operation space of a bridge close to a tunnel is narrow, and the bridge erecting machine is difficult to cross, and further provides a tunnel narrow space precast beam erecting technology. The precast beam erecting difficulty of the bridge at the tunnel can be effectively solved by adopting the application.

Description

Technical Field

[0001] This invention relates to the technical field of bridge construction operations, specifically to a method for erecting a small-radius separated highway bridge adjacent to a tunnel entrance. Background Technology

[0002] Currently, many bridge construction projects involve bridges connected to tunnels, making bridge girder erection through tunnels a major challenge. This is primarily because the height and width of large-tonnage bridge-erecting machines exceed the clearance dimensions of tunnels. Therefore, these machines must be modified to reduce their height and width before being transported by girder transport vehicles. Consequently, solving this construction problem has long been a hot topic both domestically and internationally.

[0003] Patent application CN200610012353.9 discloses a method for erecting a bridge using a temporary bridge at a tunnel exit in conjunction with a bridge erecting machine. The method involves pre-erecting an auxiliary temporary bridge at the desired span location as a working platform, erecting a 64-type temporary bridge using a longitudinal dragging method; dragging the cantilever beams into position and lowering them piece by piece to complete the bridge deck paving; transporting the bridge erecting machine at a low position to the designated location of the temporary bridge at the tunnel exit; lifting the bridge erecting machine to the required bridge erection height using the hydraulic cylinder telescopic sleeve of the transporting vehicle; resetting the upper crossbeam of the rear outrigger and connecting it to the temporary support leg, folding back the front outrigger to form a load-bearing fulcrum, and withdrawing the transporting vehicle so that its hydraulic cylinder and telescopic sleeve align with the bridge erecting machine; lifting the hydraulic cylinder telescopic sleeve, removing the temporary support leg, installing the lower crossbeam of the rear outrigger with a traveling platform; using front and rear overhead cranes to lift and dismantle the temporary bridge, placing it on the transporting vehicle for return beam retrieval; transporting the beam to the feeding position using the transporting vehicle, and then lowering it into place using the front and rear overhead cranes. This tunnel exit erection method solves the problem of erecting prestressed concrete box girders at adjacent tunnel exits without using bridge erecting machines for quasi-high-speed and high-speed railways, and has the advantages of saving project investment and shortening the construction period. However, when this scheme is applied to small-radius curved bridges, there are difficulties in feeding the girders. In addition, this scheme eliminates the bridge erecting machine method, and there is no effective solution for the problem that bridge construction cannot use bridge erecting machines to erect prestressed concrete box girders at adjacent tunnel exits in a whole. Summary of the Invention

[0004] To address the aforementioned problems, this invention discloses a method for erecting curved bridges. It addresses the issue of limited operating space at the entrance of existing bridges near tunnels, which makes it difficult for bridge erecting machines to cross the span. Furthermore, it provides a precast beam erection technology for bridges in confined tunnel spaces. By employing this invention, the problem of difficult precast beam erection at tunnel entrances can be effectively solved.

[0005] The technical solution adopted in this invention is as follows:

[0006] This invention discloses a method for erecting curved bridges. The precast beams are uniformly processed in a prefabrication yard and can only be transported and erected after the strength reaches 100%. The beam erection can only be organized after the substructure of the bridge is completed and the strength reaches 100%.

[0007] Meanwhile, taking into full account the temporary parking platform for the beam transport vehicle, temporary support measures were promptly implemented after the side beam installation was completed to ensure no overturning accidents occurred, and bridge deck construction commenced immediately after the erection was completed. Beams to be erected were transported and fed by beam transport vehicles, and then erected using a bridge erecting machine. The bridge erecting machine assembly site was selected on the already filled roadbed surface.

[0008] This invention discloses a method for erecting a curved bridge, including a prestressed concrete box girder, which is positioned adjacent to the tunnel exit. The prestressed concrete box girder is erected as a whole using a bridge erecting machine, and includes the following steps:

[0009] S1: Including bridge piers and abutments, the first span of the prestressed concrete box girder is assembled by the bridge piers and abutments using a bridge erecting machine. The main beam of the bridge erecting machine is set in 12m sections, and the main beam is assembled to form a 36m main beam. The main beam is then assembled in the area where the bridge and the tunnel are connected, and another 12m is assembled. At this time, the bridge erecting machine has completed the assembly of 48m and extended 4m into the tunnel.

[0010] S2: The prestressed concrete box girder includes the middle beam, the side beams and the rear guide beam. The side beams are hoisted to the front span position of the middle beam using a jack. The outer 12m rear guide beam is removed. The bridge erecting machine carries the beam laterally to the side beam installation position. After adjusting the installation position, it is lowered smoothly.

[0011] S3: After the first span side beam is erected, the 12m outer rear guide beam that was removed is installed. The beam transport vehicle moves the middle beam longitudinally to the front span position and moves it laterally to adjust the erection position before lowering it. The erection of the first span does not require passing through the hole.

[0012] S4: The bridge consists of front legs, middle legs, and rear legs. After the first span of the beam is erected, a crane is used as a counterweight. The main beam is moved longitudinally forward and cantilevered by 12m by the drive mechanism on the middle leg. The upper part of the front leg is firmly connected to the lower chord of the main beam, and the middle leg is firmly connected to the lower chord of the main beam. At this time, the bridge erecting machine installs the remaining 12m section of the main beam. After the bridge erecting machine completes the assembly of all 60m main beams, and the bridge erecting machine is debugged and qualified, it moves longitudinally forward through the span to prepare for the installation of the next span beam.

[0013] Furthermore, the curved bridge adopts a small-radius separated bridge design, and the clearance between the bridge abutment and the adjacent tunnel is 14m.

[0014] Furthermore, the installation of the prestressed concrete box girder proceeds by first erecting the left span, which is located at position 14#→0#. After erection, the girder is dismantled and reassembled once at the roadbed in front of abutment 0#, and then the girder is turned around and erected on the right span, which is located at position 0#→14#. After erection, the bridge erecting machine dismantles the girder at the tunnel exit roadbed.

[0015] When the bridge erecting machine is moving longitudinally, an 80T crane is used as a counterweight at the rear of the bridge erecting machine, wooden wedges are used to stop the traveling wheels, and steel wire ropes are used to connect it to the main beam.

[0016] Furthermore, in step S4, the main beam of the bridge erecting machine is moved forward by the drive mechanism on the middle support leg and the power of the rear beam transport flatcar until the front support leg of the guide beam is located on the front pier cap. The guide beam and the main beam are adjusted to be level by jacking the front support leg of the guide beam. The front support leg of the main beam is moved to the top position of the front pier cap by the hoisting device. The traveling box and the rail are lowered and adjusted to the required height to firmly connect the front support leg to the front pier cap.

[0017] Furthermore, the front outriggers of the guide beam are retracted, and the main beam continues to move forward to the working position by relying on the drive mechanisms on the front and middle outriggers and the power of the beam transport flatcar. The upper part of the front outriggers is firmly connected to the lower chord of the main beam, and the upper part of the middle outriggers is firmly connected to the lower chord of the main beam. At this time, the bridge erecting machine has completed the unloaded forward movement of the main beam.

[0018] After the bridge erecting machine is in longitudinal position, a comprehensive safety inspection must be carried out. Only after the bridge erecting machine is operating normally can the beam installation work begin.

[0019] Furthermore, when feeding beams for a small-radius curved bridge, the last 12m main beam on the inner side of the curve needs to be removed, and the transport flatcar is used to carry the beam to the rear support leg position at the tail of the bridge erecting machine. At this time, the command personnel should pay close attention to the forward movement of the transport flatcar to prevent it from hitting the rear support.

[0020] Furthermore, the tail of the bridge erecting machine is aligned with the transverse track. When feeding the beam, the No. 1 overhead crane vertically lifts the beam, causing the beam to detach from the trolley surface, temporarily supporting the rear outriggers, and at the same time checking the drum rope arrangement and braking.

[0021] Furthermore, the No. 1 overhead crane and the rear beam transport flatcar work together to move the beam forward. When the No. 1 overhead crane moves the beam forward to the middle of the front and rear supports at 1 / 2 span, check to prevent the guide beam from deforming. When the No. 2 overhead crane reaches the lifting point, stop the brake and use the No. 2 overhead crane to lift the beam and transport it to the beam erection position.

[0022] Furthermore, a trial lift is performed before each beam lifting operation; when binding the beam, protective iron sheets or rubber pads are used, and the beam is lifted from the bottom; the crane operator slowly raises the hook, and stops raising the hook after the binding rope is slightly stressed, and observes whether the hook is vertical, and adjusts it as needed; after the beam is bound, the hoisting unit is braked 2 to 3 times, and then the beam is lifted slightly to check whether the steel rope jumps out of the groove, whether the hanging bracket pin moves, etc., and formal operation can only be carried out after confirming that it is reliable.

[0023] Furthermore, when the bridge erecting machine erects the first span, the middle support leg is on the bridge abutment, and the foundation under the beam is compacted by the transverse movement of the middle support leg to prevent the bridge erecting machine from sinking during the beam erection process and causing an accident; before the front support leg moves longitudinally, the height of the front support leg is adjusted to meet the installation requirements so that the front support leg can be smoothly positioned.

[0024] The technical effects of this invention are as follows:

[0025] This invention discloses a method for erecting curved bridges, which effectively solves the problem of difficult erection of precast beams for bridges at tunnel entrances.

[0026] The details are as follows:

[0027] 1. This invention utilizes bridge piers and abutments for bridge erection machine assembly technology to complete the erection of the first span of precast beam connecting the bridge and tunnel, thereby improving the efficiency of precast beam erection, accelerating the construction progress, and facilitating the organization of on-site construction.

[0028] 2. The positive effects of the method for assembling the bridge erecting machine at the tunnel entrance and erecting the first span in this invention effectively solve the problem that bridge construction cannot use a bridge erecting machine to erect the prestressed concrete box girder adjacent to the tunnel exit as a whole, thereby saving project investment and shortening the construction period.

[0029] 3. This invention uses a self-balancing double guide beam bridge erecting machine. By utilizing the bridge erecting machine's own mechanism, there is no need to manufacture any new auxiliary special equipment, making it convenient, fast, and very safe and reliable to operate.

[0030] 4. This invention solves the problem of feeding beams on small-radius curved bridges, and is safer and more convenient than dual-crane tower cranes. Attached Figure Description

[0031] Figure 1 This is an elevation view of the first span beam frame of the present invention;

[0032] Figure 2 This is a plan view of the first span side beam erection of the present invention;

[0033] Figure 3 This is an elevation view of the first span of the present invention after its completion;

[0034] Figure 4 This is a plan view of the completed first span of the present invention;

[0035] Figure 5 This is an elevation view of the forward movement of the beam feeding and bridge erecting machine of the present invention;

[0036] Figure 6 This is a plan view of the forward movement of the beam feeding and bridge erecting machine of the present invention;

[0037] Figure 7 This is a plan view of the curved bridge of the present invention;

[0038] Markings in the diagram: 1-Prestressed concrete box girder, 2-Tunnel, 3-Bridge erecting machine, 4-Main girder, 5-Guide beam, 6-Front leg, 7-Middle leg, 8-Rear leg, 9-Abutment, 10-Overhead crane. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings.

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0041] The data used in this embodiment is a preferred solution, but it is not intended to limit the present invention.

[0042] like Figure 1-7 As shown, this embodiment provides a method for erecting a curved bridge, including a prestressed concrete box girder. The prestressed concrete box girder is positioned adjacent to the tunnel exit, and a bridge erecting machine is used to erect the prestressed concrete box girder as a whole across the entire span. The method includes the following steps:

[0043] S1: Including bridge piers and abutments, the first span of the prestressed concrete box girder is assembled by the bridge piers and abutments using a bridge erecting machine. The main beam of the bridge erecting machine is set in 12m sections, and the main beam is assembled to form a 36m main beam. The main beam is then assembled in the area where the bridge and the tunnel are connected, and another 12m is assembled. At this time, the bridge erecting machine has completed the assembly of 48m and extended 4m into the tunnel.

[0044] S2: The prestressed concrete box girder includes the middle beam, the side beams and the rear guide beam. The side beams are hoisted to the front span position of the middle beam using a jack. The outer 12m rear guide beam is removed. The bridge erecting machine carries the beam laterally to the side beam installation position. After adjusting the installation position, it is lowered smoothly.

[0045] S3: After the first span side beam is erected, the 12m outer rear guide beam that was removed is installed. The beam transport vehicle moves the middle beam longitudinally to the front span position and moves it laterally to adjust the erection position before lowering it. The erection of the first span does not require passing through the hole.

[0046] S4: The bridge consists of front legs, middle legs, and rear legs. After the first span of the beam is erected, a crane is used as a counterweight. The main beam is moved longitudinally forward and cantilevered by 12m by the drive mechanism on the middle leg. The upper part of the front leg is firmly connected to the lower chord of the main beam, and the middle leg is firmly connected to the lower chord of the main beam. At this time, the bridge erecting machine installs the remaining 12m section of the main beam. After the bridge erecting machine completes the assembly of all 60m main beams, and the bridge erecting machine is debugged and qualified, it moves longitudinally forward through the span to prepare for the installation of the next span beam.

[0047] Unlike conventional bridge erecting machines that assemble precast beams, in normal construction environments, a 60m main beam of the bridge erecting machine is assembled in the roadbed section, and then the bridge erecting machine lifts and erects the beam. In this embodiment, the bridge is adjacent to a tunnel structure, and the bridge-tunnel roadbed is only 14m long, making it impossible to assemble using conventional bridge erecting machine methods.

[0048] In this embodiment, the first span is directly assembled by the bridge erecting machine using the bridge piers and abutments, with a span of 30m. The main beam of the bridge erecting machine is in 12m sections. The main beam is first assembled to a length of 36m, and then another 12m is assembled in the area where the bridge connects to the tunnel. At this point, the bridge erecting machine has assembled 48m and extended 4m into the tunnel. The jacking vehicle lifts the side beams to the front span position of the middle beam, and the outer rear guide beam is removed for 12m. The entire machine carries the beam and moves laterally to the side beam installation position. The accuracy of the position is checked, and after confirmation, it is lowered smoothly. After the side beams of the first span are erected, the previously removed outer rear 12m main beam is installed. The beam transport vehicle moves the middle beam longitudinally to the front span position, then laterally to the erection position, and then lowers it. The erection of the first span does not require crossing the span.

[0049] In this embodiment, because the outer 12m main beam will block the lateral movement, preventing the beam from moving laterally, the outer 12m rear guide beam needs to be removed after the bridge erecting machine raises the side beam to the middle position.

[0050] In this embodiment, after the first span of the beam is erected, an 80T crane is used as a counterweight. The main beam is moved longitudinally forward and cantilevered by 12m by the drive mechanism on the middle support leg. Then, the upper part of the front support leg is firmly connected to the lower chord of the main beam, and the middle support leg is firmly connected to the lower chord of the main beam. At this time, the bridge erecting machine installs the remaining 12m section of the main beam. At this time, the assembly of all 60m main beams of the bridge erecting machine is completed. In this embodiment, each span is erected in 30m sections to meet the crossing conditions. After the debugging is qualified, the bridge erecting machine moves longitudinally forward through the hole to prepare for the installation of the next span beam.

[0051] like Figure 7 As shown, the installation of the prestressed concrete box girder proceeds by first erecting the left span, which is located at position 14#→0#. After erection, the girder is disassembled and reassembled once at the roadbed in front of pier 0#, and then the girder is turned around and erected for the right span, which is located at position 0#→14#. After erection, the bridge erecting machine disassembles the girder at the tunnel exit roadbed. Preferably, in this embodiment, the bridge erecting machine does not pass through the span and directly assembles the girder using piers 13# and 14#. Therefore, the bridge erecting machine can erect the first span before it has been assembled to 60m.

[0052] Conventional bridge erecting machines assemble a 60m main beam in one go. In this embodiment, the bridge erecting machine can be suspended by 2 / 3L to pass through the span. The erection method in this embodiment can erect a 30m bridge and assemble a 50m bridge to meet the specifications.

[0053] The conventional method of feeding beams is to transport the beam to the bottom of the bridge erecting machine using a jacking vehicle. The bridge erecting machine then uses jacking vehicles at the front and rear to lift the beam, move it to the predetermined position in the front span, and lower it into place. This conventional method is suitable for bridges with straight sections or large curves.

[0054] In this embodiment, the curved bridge adopts a small-radius, separated bridge design, and the clearance between the bridge abutment and the adjacent tunnel is 14m. The application of the small-radius, narrow-span curved beam feeding technology in bridge construction involves removing the 12m main beam on one side behind the bridge erecting machine, and then loading the beam onto a flatbed transport vehicle near the rear support leg of the bridge erecting machine. At this time, the command personnel must pay close attention to the forward movement of the flatbed transport vehicle to prevent it from hitting the rear support. First, the rear of the bridge erecting machine is aligned with the transverse track. During beam feeding, the No. 1 overhead crane vertically lifts the beam, causing it to detach from the trolley surface, temporarily supporting the rear support leg, while simultaneously checking the drum rope arrangement and brakes.

[0055] Furthermore, the No. 1 overhead crane and the rear beam transport flatcar work together to move the beam forward. When the No. 1 overhead crane moves the beam forward to the midpoint of the front and rear supports, close attention should be paid to the deformation of the guide beam. When the No. 2 overhead crane reaches the lifting point, stop and brake. Use the No. 2 overhead crane to lift the beam and transport it to the beam erection position. After each span of beam is erected, the 12m main beam is spliced ​​and moved forward through the span.

[0056] In this embodiment, the bridge erecting machine includes a 60m beam erection length and the beam carriage includes a 30m beam erection length. At this point, the length has reached more than 90m, and the projected area is already outside the curve of the bridge, making normal construction impossible and posing too great a safety hazard. Therefore, 12m of the main beam on the rear side of the bridge erecting machine is removed to meet the beam feeding conditions.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of erecting a curved bridge, characterized by, The project includes a prestressed concrete box girder (1), which is located adjacent to the tunnel (2) exit. The prestressed concrete box girder (1) is erected as a whole using a bridge erecting machine (3). The curved bridge adopts a small curve radius separated bridge, and the abutment (9) of the bridge is 14m away from the tunnel (2). The project includes the following steps: S1: Including bridge piers, the first span of the prestressed concrete box girder (1) is assembled by the bridge pier using the bridge erecting machine (3). The main beam (4) of the bridge erecting machine (3) is set to be 12m pieces, and assembled to form a 36m main beam (4). The main beam (4) is then assembled for 12m in the area connecting the bridge and the tunnel (2). At this time, the bridge erecting machine (3) is assembled to 48m and extends into the tunnel (2) by 4m. The installation of the prestressed concrete box girder (1) is carried out by first erecting the left span, which is the position from 14# to 0#. After the erection is completed, the left span is dismantled and reassembled once in front of the 0# abutment roadbed, and then the right span is erected after turning around. The right span is the position from 0# to 14#. After the erection is completed, the bridge erecting machine (3) completes the dismantling of the roadbed at the tunnel (2) exit. S2: The prestressed concrete box girder (1) includes the middle beam, the side beam and the rear guide beam (5). The side beam is hoisted to the front span position of the middle beam using a gun vehicle. The outer 12m rear guide beam (5) is removed. The bridge erecting machine (3) carries the beam and moves it laterally to the side beam installation position. After adjusting the installation position, it is dropped smoothly. S3: After the first span side beam is erected, the 12m outer rear guide beam (5) that was removed is installed. The beam transport vehicle moves the middle beam longitudinally to the front span position and moves laterally to adjust the erection position. Then it is lowered. The erection of the first span does not require passing through the hole. S4: The bridge consists of a front leg (6), a middle leg (7) and a rear leg (8). After the first span of the beam is erected, a crane is used as a counterweight. The main beam (4) is driven to move longitudinally forward and cantilever by 12m by the drive mechanism on the middle leg (7). The upper part of the front leg (6) is firmly connected to the lower chord of the main beam (4), and the middle leg (7) is firmly connected to the lower chord of the main beam (4). At this time, the bridge erecting machine (3) installs the remaining 12m main beam (4). The bridge erecting machine (3) completes the assembly of all 60m main beams (4) of the bridge erecting machine (3). After the bridge erecting machine (3) is qualified, it moves longitudinally forward through the hole to prepare for the installation of the next span of beam. Using the drive mechanism on the middle support leg (7) and the power of the rear beam flatcar, the main beam (4) of the bridge erecting machine (3) is moved forward to the guide beam (5). The front support leg (6) is located on the front pier cap. The guide beam (5) and the front support leg (6) are lifted by jacks. The guide beam (5) and the main beam (4) are adjusted to be horizontal. The front support leg (6) of the main beam (4) is moved to the top position of the front pier cap through the hoisting device. The traveling box and rail are lowered and adjusted to the required height. The front support leg (6) is firmly connected to the front pier cap. Retract the front support leg (6) of the guide beam (5), and continue to drive the main beam (4) forward to the working position by relying on the drive mechanism on the front support leg (6) and the middle support leg (7) and the power of the beam transport flatcar. Securely connect the upper part of the front support leg (6) to the lower chord of the main beam (4), and securely connect the upper part of the middle support leg (7) to the lower chord of the main beam (4). At this time, the bridge erecting machine (3) has completed the unloaded forward movement of the main beam (4).

2. The curve bridge erecting method according to claim 1, characterized by, When feeding beams for a small-radius, separate bridge, the last 12m main beam (4) on the inner side of the curve needs to be removed, and the beam is transported by flatcar to the rear support leg (8) of the bridge erecting machine.

3. The method for erecting a curved bridge according to claim 2, characterized in that, The tail of the bridge erecting machine (3) is aligned with the transverse track. When feeding the beam, the No. 1 overhead crane (10) lifts the beam vertically, so that the beam is removed from the trolley surface. The rear support leg (8) is temporarily supported, and the drum rope arrangement and braking are checked at the same time.

4. The curved bridge erecting method according to claim 3, characterized by, The No. 1 overhead crane (10) and the rear beam transport flatcar work together to move the beam forward. When the No. 1 overhead crane (10) moves the beam forward to the middle of the front and rear supports at 1 / 2 span, check to prevent the guide beam (5) from deforming. When the No. 2 overhead crane (10) reaches the lifting point, stop the brake and use the No. 2 overhead crane (10) to lift the beam and transport it to the beam erection position.

5. The curved bridge erecting method according to claim 4, characterized by, Before lifting the beam, a trial lift should be performed. When binding the beam, use protective iron sheets or rubber pads and adopt a bottom-lifting method. The crane operator should slowly lift the hook and stop lifting after the binding rope is slightly stressed. Observe whether the hook is vertical and adjust it as needed. After binding the beam, first perform a braking test on the hoisting unit 2 to 3 times, and then lift the beam slightly to check whether the steel rope jumps out of the groove and whether the hanging bracket pin moves. Only after confirming that it is reliable can the formal operation begin.

6. The curved bridge erecting method according to claim 1, characterized by, When the bridge erecting machine (3) erects the first span, the middle support leg (7) is on the bridge abutment (9). The foundation under the middle support leg (7) is compacted by moving it laterally. Before the front support leg (6) moves longitudinally, the height of the front support leg (6) is adjusted to meet the installation requirements.

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