Demolition construction method of tied-arch bridge

Abstract

The invention provides a dismantling construction method for a tied-arch bridge, and relates to the field of bridge dismantling construction. According to the method, a first target wind brace in the middle of a main span of the tied-arch bridge is removed, then a target bridge deck and a target middle cross beam in the middle of the main span of the tied-arch bridge are removed, and then temporary cross beams are installed on the two longitudinal sides of a bridge in a target middle cross beam removing area correspondingly; after the remaining bridge deck slabs and the remaining middle cross beams are removed, temporary supporting structures used for supporting arch ribs and tie bars are installed on the two end cross beams of the tied-arch bridge correspondingly, then the remaining wind braces are removed, and temporary wind braces are installed on the sides, facing the bridge end, of the first target wind braces; and finally, the arch ribs, the tie bars, the suspenders, the temporary cross beams, the temporary supporting structures and the temporary wind braces on the outer side and the inner side are integrally dismantled. According to the technical scheme, no temporary support needs to be arranged when the tied-arch bridge is dismantled, the bridge dismantling construction period is greatly shortened, dismantling of the tied-arch bridge can be safely and rapidly completed, and the channel passing influence is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bridge demolition construction, in particular to a method for demolishing a tied-arch bridge. BACKGROUND

[0002] With the gradual development of social economy, some of the previous roads have been unable to meet the existing traffic flow demand, and reconstruction and expansion projects are increasing, and bridge demolition is also gradually increasing. At present, the temporary support method is used for the demolition of most cross-channel tied-arch bridges, which not only occupies the channel during the demolition period, but also causes the construction period of the whole bridge demolition to be long and has a greater impact on the channel. SUMMARY

[0003] An object of the present application is to provide a method for demolishing a tied-arch bridge, which solves the technical problem of long overall construction period and channel occupation caused by the temporary support method used in the prior art to demolish the bridge.

[0004] In particular, the present application provides a method for demolishing a tied-arch bridge, comprising the following steps: demolishing a first target wind brace located in the middle of the main span of the tied-arch bridge; demolishing a preset number of target bridge decks and target mid-beams located in the middle of the main span of the tied-arch bridge; installing temporary crossbeams on both sides of the bridge in the target mid-beam demolition area in the longitudinal direction; demolishing the remaining bridge decks and the remaining mid-beams; installing temporary support structures for supporting arch ribs and tie bars at both end crossbeams of the tied-arch bridge; demolishing the remaining wind braces and installing temporary wind braces on the side of the first target wind brace facing the bridge end; cutting at the connection between the end crossbeam and the arch foot, and integrally lifting and demolishing the arch ribs, tie bars, suspenders, temporary crossbeams, temporary support structures and temporary wind braces on the outside and inside.

[0005] Optionally, the step of demolishing the target bridge deck and the target mid-beam located in the middle of the main span of the tied-arch bridge comprises the following steps: cutting and demolishing the first target bridge deck located in the middle of the main span of the tied-arch bridge; cutting and demolishing the first target mid-beam arranged below the first target bridge deck; According to the order of alternately demolishing the bridge deck and the mid-beam, the preset number of target bridge decks and target mid-beams are sequentially demolished from the middle of the main span to the bridge end.

[0006] Optionally, in the step of cutting and removing the first target bridge deck slab located in the middle of the main span of the tied-arch bridge, the target bridge deck slab is cut into a plurality of bridge deck slab blocks; the widths of the plurality of bridge deck slab blocks are different or the same.

[0007] Optionally, in the step of cutting and removing the first target mid-beam arranged below the first target bridge deck slab, the first target mid-beam is cut into a plurality of beam segments; the lengths of the plurality of beam segments are different or the same.

[0008] Optionally, in the step of installing temporary beams on both sides of the bridge in the longitudinal direction of the target mid-beam removal area, the following steps are performed: placing an I-beam as the temporary beam on the tie rod and arranging a limiting plate on the inner side of the tie rod; fixing the limiting plate and the tie rod with wooden wedges to limit and support the I-beam.

[0009] Optionally, in the step of installing temporary support structures for supporting arch ribs and tie rods at the two end beams of the tied-arch bridge, the following steps are performed: installing a counter-force seat at each of the two end beams of the tied-arch bridge and fixing the counter-force seat and the end beam with steel bars; installing a temporary diagonal brace at each of the two end beams and welding one side of the temporary diagonal brace to the counter-force seat and the other side to the top of the suspender closest to the end beam.

[0010] Optionally, before the step of removing the first target wind brace located in the middle of the main span of the tied-arch bridge, the following step is performed: milling the bridge deck of the tied-arch bridge with a milling thickness in the range of 5 cm to 15 cm.

[0011] Optionally, in the step of removing the remaining bridge deck slab and the remaining mid-beam, the following steps are performed: alternately removing the remaining bridge deck slab and the remaining mid-beam from the middle of the main span to the bridge end in sequence.

[0012] Optionally, in the step of cutting the connection between the end beam and the arch foot and integrally lifting and removing the outer and inner arch ribs, tie rods, suspenders, temporary beams, temporary support structures, and temporary wind braces, the following steps are performed: using multiple floating cranes to hold the outer arch ribs and cutting the connection between the outer end beam and the arch foot with a rope saw, so that the floating cranes integrally lift and remove the outer arch ribs, tie rods, suspenders, temporary beams, and temporary wind braces; Multiple floating cranes are used to clamp the inner arch rib, and the connection between the inner end beam and the arch foot is cut with a wire saw, so that the floating cranes can lift and dismantle the inner arch rib, the tie rod, the lifting rod and the temporary diagonal brace as a whole.

[0013] This invention first removes the first target wind brace located in the middle of the main span of the tied arch bridge. Then, it removes a predetermined number of target bridge panels and target central crossbeams located in the middle of the main span. Next, temporary crossbeams are installed on both sides of the bridge's longitudinal direction in the area where the target central crossbeams were removed. The remaining bridge panels and remaining central crossbeams are then removed. Temporary support structures for supporting the arch ribs and tie rods are then installed at the two end crossbeams of the tied arch bridge. The remaining wind braces are then removed, and temporary wind braces are installed on the side of the first target wind brace facing the bridge end. Finally, the connection between the end crossbeam and the arch foot is cut, and the outer and inner arch ribs, tie rods, hangers, temporary crossbeams, temporary support structures, and temporary wind braces are lifted and removed as a whole. Compared to using temporary supports to dismantle tied arch bridges, this technical solution eliminates the need for temporary supports, significantly shortening the overall construction period for bridge dismantling, enabling safe and rapid completion of the tied arch bridge dismantling, and greatly reducing the impact on waterway traffic.

[0014] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0015] The following sections will describe some specific embodiments of the invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic flowchart of a method for dismantling a tied-arch bridge according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of a method for dismantling a tied-arch bridge according to another embodiment of the present invention; Figure 3 This is a schematic side view of a tied-arch bridge according to an embodiment of the present invention; Figure 4 This is a schematic front view of a tied-arch bridge according to an embodiment of the present invention; Figure 5 This is a schematic diagram of removing the target bridge deck according to an embodiment of the present invention; Figure 6 This is a schematic diagram of an angle at which a temporary crossbeam is installed according to an embodiment of the present invention; Figure 7This is a schematic diagram of another angle of the installation of a temporary crossbeam according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the installation of the reaction seat and temporary diagonal brace at an angle according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the installation reaction seat and temporary diagonal brace from another angle according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the removal of the outer integral structure according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the removal of the inner integral structure according to an embodiment of the present invention.

[0016] Figure label: 100-Tie-arch bridge, 200-Floating crane, 10-First target wind brace, 11-Temporary wind brace, 20-Arch rib, 30-Tie rod, 31-Hanging rod, 40-End crossbeam, 50-Target bridge deck, 51-Bridge deck block, 60-Temporary crossbeam, 70-Temporary diagonal brace, 80-Reaction seat, 90-Target middle crossbeam. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0018] Figure 1 This is a schematic flowchart illustrating a method for dismantling a tied-arch bridge 100 according to an embodiment of the present invention. Figure 1 As shown, in a specific embodiment, the dismantling method of the tied-arch bridge 100 includes the following steps: Step S100: Remove the first target wind brace 10 located in the middle of the main span of the tied arch bridge 100; Step S200: Remove the predetermined number of target bridge deck panels 50 and target middle crossbeams 90 located in the middle of the main span of the tied arch bridge 100. Step S300: Install temporary crossbeams 60 on both sides of the bridge longitudinally in the area where the crossbeam 90 is removed in the target; Step S400: Remove the remaining bridge deck and the remaining middle crossbeam; Step S500: Install temporary support structures for supporting the arch rib 20 and tie rod 30 at the two end crossbeams 40 of the tied arch bridge 100 respectively. Step S600: Remove the remaining wind braces and install temporary wind braces 11 on the side of the first target wind brace 10 facing the bridge end; In step S700, the connection between the end beam 40 and the arch foot is cut, and the outer and inner arch ribs 20, tie rods 30, hangers 31, temporary beams 60, temporary support structures and temporary wind braces 11 are lifted and dismantled as a whole.

[0019] Compared to using temporary supports for dismantling the tied-arch bridge 100, this embodiment eliminates the need for temporary supports, significantly shortening the overall dismantling period and enabling the safe and rapid completion of the dismantling of the tied-arch bridge 100, greatly minimizing the impact on waterway traffic. Using this dismantling method, the bridge dismantling was completed approximately 20 days earlier than using temporary supports, significantly reducing waterway closure time and saving approximately 1 million yuan in costs.

[0020] Figure 2 This is a schematic flowchart of a demolition construction method for a tied-arch bridge 100 according to another embodiment of the present invention. Figure 2 As shown, in some embodiments, the following steps are included before step S100: Step S10: Mill the bridge deck of the tied arch bridge 100, with a milling thickness ranging from 5cm to 15cm.

[0021] In step S10, traffic is diverted, traffic is closed, 10cm of asphalt surface layer on the bridge deck is milled, and 10cm of concrete pavement layer is retained.

[0022] Figure 3 This is a schematic side view of a tied-arch bridge 100 according to an embodiment of the present invention. Figure 4 This is a schematic front view of a tied-arch bridge 100 according to an embodiment of the present invention.

[0023] like Figure 3 and Figure 4 As shown, in step S100, a 100t truck crane is used to lift the first target wind support 10, which is then cut and removed using a wire saw. The first target wind support 10 is a φ60cm, 1cm thick steel pipe concrete structure. A ladder truck is used for the aerial work; safety belts and non-slip shoes are worn. After cutting, the support is hoisted onto the bridge deck, loaded onto a truck, and transported away. The two middle wind supports are removed, while the two side wind supports are retained. The removed first target wind support 10 is... Figure 3 Wind bracing #2 and wind bracing #3.

[0024] Figure 5 This is a schematic diagram of removing the target bridge deck 50 according to an embodiment of the present invention. Figure 5 As shown, and see Figure 2 In some embodiments, step S200 specifically includes the following steps: Step S210: Cut and remove the first target bridge deck 50 located in the middle of the main span of the tied arch bridge 100; Step S220: Cut and remove the first target crossbeam 90 located below the first target bridge deck 50; In step S230, following the alternating sequence of bridge deck removal and middle crossbeam removal, a predetermined number of target bridge decks 50 and target middle crossbeams 90 are removed sequentially from the middle of the main span toward the bridge end.

[0025] In some embodiments, in step S210, the target bridge deck 50 is cut to form a plurality of bridge deck blocks 51, the plurality of bridge deck blocks 51 having different or the same width.

[0026] In some embodiments, in step S220, the crossbeam 90 in the first target is cut into multiple crossbeam segments; the multiple crossbeam segments may have different or the same length.

[0027] Specifically, the target bridge deck 50 was dismantled using a circular saw and a 100t truck crane. The target bridge deck 50 was cut into multiple bridge deck panels 51, with widths of 2m and 3m. After cutting, the panels were hoisted to the positioning piles on a vessel and transported away. The target middle crossbeam 90 was dismantled using a wire saw and a 100t truck crane. The target middle crossbeam 90 was cut into multiple segments with lengths of 2.3m, 8.4m, and 2.3m. After cutting, the segments were hoisted to the positioning piles on a vessel and transported away. The target bridge deck 50 and the target middle crossbeam 90 were dismantled alternately; that is, one span of bridge deck was dismantled, followed by one middle crossbeam, proceeding from the mid-span towards the arch foot while simultaneously retracting. Dismantling was paused at crossbeams #5 and #9, where temporary crossbeams 60 were installed.

[0028] In some embodiments, step S400 specifically includes the following steps: In step S400', following the alternating sequence of bridge deck removal and central crossbeam removal, the remaining bridge deck panels and central crossbeams are dismantled sequentially from the middle of the main span towards the bridge end. That is, one span of bridge deck panel is removed, followed by one central crossbeam, dismantling and backing away from the middle of the span towards the arch foot.

[0029] Figure 6 This is a schematic diagram of the installation of a temporary crossbeam 60 according to an embodiment of the present invention. Figure 7 This is a schematic diagram of the installation of a temporary crossbeam 60 from another angle according to an embodiment of the present invention. Figure 6 and Figure 7 As shown, in some embodiments, step S300 specifically includes the following steps: Step S310: Place the I-beam, which serves as a temporary crossbeam 60, on the tie rod 30, and set limiting plates inside both sides of the tie rod 30 respectively. In step S320, wooden wedges are used to fix the limiting plate and the tie rod 30 to limit and support the I-beam.

[0030] Specifically, in theFigure 6 After the central crossbeams at locations #5 and #9 are removed, temporary crossbeams 60 are installed in their original positions. Double-section 20mm I-beams are placed on tie rods 30, with limiting plates installed inside the tie rods 30 on both sides. Wooden wedges are used for reinforcement and support. In this embodiment, the temporary crossbeams 60 connect the inner and outer arch ribs 20 and the tie rods 30, increasing overall stability. The temporary crossbeams 60 are removed when the outer arch ribs 20 and tie rods 30 are dismantled.

[0031] Figure 8 This is a schematic diagram of the installation reaction seat 80 and temporary diagonal brace 70 at an angle according to an embodiment of the present invention. Figure 9 This is a schematic diagram of the installation reaction seat 80 and temporary diagonal brace 70 from another angle according to an embodiment of the present invention.

[0032] like Figure 8 and Figure 9 As shown, in some embodiments, step S500 specifically includes the following steps: Step S510: Install reaction seats 80 at the two end crossbeams 40 of the tied arch bridge 100 respectively, and fix the reaction seats 80 and the end crossbeams 40 with steel bars. In step S520, temporary diagonal braces 70 are installed at the two end beams 40 respectively, and one side of the temporary diagonal brace 70 is welded to the reaction seat 80, and the other side is welded to the top of the hanger 31 closest to the end beam 40.

[0033] Specifically, in step S510, the reaction seat 80 is... The steel plate is anchored to the end beam with φ20 steel bars to form a whole.

[0034] In step S520, the temporary diagonal brace 70 is made of φ426 steel pipe. One side is welded to the top of the No. 1 and No. 13 hangers 31 on the inner side of the bridge, and the bottom of the steel pipe is welded to the reaction seat 80 on the top of the end crossbeam 40 for temporary support. In this embodiment, the temporary diagonal brace 70 can provide temporary support to prevent the inner arch rib 20 and tie rod 30 from becoming unstable and overturning after the outer arch rib 20 and tie rod 30 are completely removed.

[0035] In some embodiments, in step S600, a 600t floating crane with 200 lifting supports is used to lift the arch ribs, and wire saw cutting is employed for dismantling. Supports #4 and #10 are dismantled, and temporary supports 11 are installed in their original locations. These temporary supports 11 are made of φ426 steel pipe and, after cutting, are hoisted to the crushing site for further crushing and dismantling. This embodiment uses temporary supports 11 to provide temporary lateral connection constraints between the arch ribs 20, enhancing lateral stability during dismantling and overall lifting, preventing instability, torsion, or relative displacement of the arch ribs 20, and improving the safety and reliability of the dismantling work.

[0036] Figure 10This is a schematic diagram illustrating the removal of the outer integral structure according to an embodiment of the present invention. Figure 11 This is a schematic diagram of the removal of the inner integral structure according to an embodiment of the present invention.

[0037] like Figure 10 and Figure 11 As shown, in some embodiments, step S700 specifically includes the following steps: In step S710, multiple floating cranes 200 are used to clamp the outer arch rib 20, and the connection between the outer end beam 40 and the arch foot is cut by wire saw, so that the floating cranes 200 can lift and dismantle the outer arch rib 20, tie rod 30, lifting rod 31, temporary beam 60 and temporary wind brace 11 as a whole. In step S720, multiple floating cranes 200 are used to clamp the inner arch rib 20, and the connection between the inner end beam 40 and the arch foot is cut by wire saw, so that the floating cranes 200 can lift and dismantle the inner arch rib 20, tie rod 30, lifting rod 31 and temporary diagonal brace 70 as a whole.

[0038] In step S710, the outer arch rib 20, tie rod 30, suspender rod 31, temporary crossbeam 60, and temporary wind brace 11 are hoisted and dismantled as a whole. Two 600t floating cranes 200 are used for lifting. The crossbeam 40 and the arch foot are cut off by wire saw and then hoisted to the crushing site for dismantling.

[0039] In step S720, the inner arch rib 20, tie rod 30, suspender rod 31, and temporary diagonal brace 70 are hoisted and dismantled as a whole using two 600t floating cranes 200. The crossbeam 40 at the end of the wire saw is cut off from the arch foot connection and then hoisted to the crushing site for dismantling.

[0040] In steps S710 and S720, a traction rope is set at each of the four corners of each floating crane 200. During the lifting process, the floating crane 200 can be moved backward and turned by adjusting different traction ropes and using auxiliary boats for propulsion.

[0041] In addition, the demolition method of the tied arch bridge 100 in this embodiment was analyzed using MIDIS software. The bearing capacity of the bridge deck and the stability of the bridge section to be demolished met the specifications under various working conditions during the demolition process.

[0042] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A method for dismantling a tied-arch bridge, characterized in that, Includes the following steps: Remove the first target wind brace located in the middle of the main span of the tied arch bridge; Remove a predetermined number of target bridge panels and target crossbeams located in the middle of the main span of the tied arch bridge; Temporary crossbeams were installed on both longitudinal sides of the bridge in the area where the crossbeams were removed within the target area. Remove the remaining bridge deck panels and the remaining central crossbeams; Temporary support structures for supporting the arch ribs and tie rods are installed at the two end crossbeams of the tied arch bridge. Remove the remaining wind bracing and install temporary wind bracing on the side of the first target wind bracing facing the bridge end; Cut at the connection between the end beam and the arch foot, and lift and dismantle the outer and inner arch ribs, tie rods, hangers, temporary beams, temporary support structures and temporary wind braces as a whole.

2. The demolition construction method according to claim 1, characterized in that, The steps for removing the target bridge deck and target crossbeam located in the middle of the main span of the tied arch bridge specifically include the following steps: The first target bridge deck located in the middle of the main span of the tied arch bridge was cut and removed. The crossbeam of the first target, located below the first target bridge deck, was cut and removed. Following the alternating process of bridge deck removal and central crossbeam removal, a predetermined number of target bridge decks and target central crossbeams are sequentially removed from the middle of the main span toward the bridge end.

3. The demolition construction method according to claim 2, characterized in that, In the step of cutting and dismantling the first target bridge panel located in the middle of the main span of the tied arch bridge, the target bridge panel is cut into multiple bridge panel blocks; the widths of the multiple bridge panel blocks are different or the same.

4. The demolition construction method according to claim 3, characterized in that, In the step of cutting and dismantling the first target crossbeam located below the first target bridge deck, the first target crossbeam is cut into multiple crossbeam segments; the multiple crossbeam segments may have different or the same length.

5. The demolition construction method according to any one of claims 1-4, characterized in that, The steps for installing temporary crossbeams on both sides of the bridge longitudinally in the area where the crossbeams are removed in the target are as follows: The I-beam serving as the temporary crossbeam is placed on the tie rod, and limiting plates are respectively installed inside both sides of the tie rod; Wooden wedges are used to fix the limiting plate to the tie rod in order to limit and support the I-beam.

6. The demolition construction method according to any one of claims 1-4, characterized in that, The steps of installing temporary support structures for supporting the arch ribs and tie rods at the two end crossbeams of the tied arch bridge specifically include the following steps: Reaction seats are installed at the two end crossbeams of the tied arch bridge, and the reaction seats and the end crossbeams are fixed with steel bars. Temporary diagonal braces are installed at each of the two end beams, and one side of the temporary diagonal brace is welded to the reaction seat, and the other side is welded to the top of the hanger closest to the end beam.

7. The demolition construction method according to any one of claims 1-4, characterized in that, Before the step of removing the first target wind brace located in the middle of the main span of the tied arch bridge, the following steps are also included: The bridge deck of the tied arch bridge is milled, with a milling thickness ranging from 5cm to 15cm.

8. The demolition construction method according to any one of claims 1-4, characterized in that, The steps for removing the remaining bridge deck panels and the remaining crossbeams specifically include the following: Following the alternating process of dismantling the bridge deck and the central crossbeam, the remaining bridge deck and the remaining central crossbeam were dismantled sequentially from the middle of the main span toward the bridge end.

9. The demolition construction method according to claim 6, characterized in that, The steps of cutting at the connection between the end beam and the arch foot, and then lifting and dismantling the outer and inner arch ribs, tie rods, hangers, temporary beams, temporary support structures, and temporary wind braces as a whole, specifically include the following steps: Multiple floating cranes are used to clamp the outer arch rib, and the connection between the outer end beam and the arch foot is cut with a wire saw, so that the floating cranes can lift and dismantle the outer arch rib, the tie rod, the lifting rod, the temporary beam and the temporary wind brace as a whole; Multiple floating cranes are used to clamp the inner arch rib, and the connection between the inner end beam and the arch foot is cut with a wire saw, so that the floating cranes can lift and dismantle the inner arch rib, the tie rod, the lifting rod and the temporary diagonal brace as a whole.

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