Prestressed floating bridge and construction method thereof

Abstract

The present invention provides a prestressed floating bridge and a construction method thereof, which relate to the technical field of construction of temporary bridges, including a floating bridge body and a floating bridge abutment, and also including a prestressed steel bundle and a tensioning pedestal; the floating bridge body includes a plurality of steel frame beams hinged in sequence head to tail, a plurality of pontoons are arranged at the bottom of the steel frame beams, the floating bridge abutments arranged on both sides are respectively hinged to the two ends of the floating bridge body, there are two tensioning pedestals, the two tensioning pedestals are arranged on both sides, the middle part of the prestressed steel bundle is located below the plurality of pontoons, and the two ends of the prestressed steel bundle are respectively connected to the two tensioning pedestals; adopting this scheme, a cable hoisting system can be provided to replace the arch construction temporary bridge, and the construction of the steel truss arch bridge is transformed into a segmented and ring-shaped manner, which reduces the construction difficulty, saves the project cost, and reduces the construction risk.

Description

Technical Field

[0001] The invention relates to the technical field of temporary bridge construction, and in particular to a prestressed floating temporary bridge and a construction method thereof. Background Art

[0002] When crossing deep valleys in mountainous areas, or when the land and water transportation on both sides of the bridge cannot meet the construction and transportation requirements, a temporary bridge needs to be built. There are many types of temporary bridges. According to their materials and structural forms, they can be mainly divided into circular tube temporary bridges, cover-type temporary bridges, stone arch temporary bridges, log temporary bridges, steel-type temporary bridges, Bailey-type temporary bridges, 64-type temporary bridges, floating temporary bridges, and cable-chain temporary bridges. When deciding the type, span, and pier form of a temporary bridge, it should be based on its own situation and set according to the materials. At the same time, the principle that both the upper and lower projects can be used together, as well as the principles of easy erection and dismantling, and low turnover consumption, should also be considered. In the design of bridges across rivers in cities, the owner requires that the river should be crossed once, and no piers should be set in the river, and the construction process should minimize the impact on the river. A floating bridge is the best solution in this case, but since the deck elevation of a floating bridge is directly determined by the water level, when there is a large height difference between the water surface and the bridge superstructure, it is impossible to use cranes and other equipment to install and construct the superstructure. An arch bridge is also a good choice, but the construction of an arch bridge requires the erection of a bracket or the use of a cable hoisting system. Since the erection of a bracket is not allowed in the river channel, a cable hoisting system can be considered, but the cable hoisting system is difficult to construct, with high costs and risks. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a prestressed floating bridge temporary bridge and a construction method thereof. By adopting this scheme, a temporary bridge for arch construction can be provided to replace the cable hoisting system, and the construction of the steel truss arch bridge is transformed into a partial ring formation, which reduces the construction difficulty, saves the project cost, and reduces the construction risk.

[0004] The technical solution adopted by the present invention is: a prestressed floating bridge, comprising a floating bridge body and a floating bridge abutment, and also comprising a prestressed steel bundle and a tensioning pedestal;

[0005] The floating bridge body includes multiple steel frame beams hinged in sequence head to tail, multiple pontoons are provided at the bottom of the steel frame beams, and the floating bridge abutments arranged on both sides are respectively hinged to the two ends of the floating bridge body. There are two tensioning pedestals, which are arranged on both sides. The middle part of the prestressed steel bundle is located below the multiple pontoons, and the two ends of the prestressed steel bundle are respectively connected to the two tensioning pedestals.

[0006] The floating bridge in the prior art includes a plurality of steel frame beams connected end to end in sequence, and a plurality of pontoons are arranged at the lower ends of the steel frame beams. The pontoons float on the water surface and are used to provide buoyancy for the floating bridge body so that it floats on the water surface. The two ends of the floating bridge are connected to the floating bridge abutments located on both sides to form a floating bridge. In this scheme, prestressed steel bundles and tensioning pedestals are also provided to quickly form an arched temporary bridge, which greatly reduces the difficulty of construction.

[0007] Specifically, in this solution, prestressed steel bundles are arranged under all pontoons and along the length direction of the floating bridge body. Tensioning pedestals are also provided on both sides. The tensioning pedestals are preferably arranged behind the abutments of the floating bridge, away from the river bank. The ends of the prestressed steel bundles are connected to the positions of the tensioning pedestals, wherein two adjacent steel frame beams are hinged, and the ends of the floating bridge body and the top of the floating bridge pedestals are hinged. In the initial state, the middle of the floating bridge body falls on the water surface, and the two ends are lifted by the floating bridge pedestals to form a concave arc shape. When working, the prestressed steel bundles are stretched to the two ends, and the prestressed steel bundles will gradually lift the floating bridge body upward. The distance between them remains unchanged. In the process of lifting the pontoon body, the pontoon body will gradually be squeezed and bulge upward. After the prestressed steel bundles are stretched to a horizontal position, the pontoon body bulges upward as a whole to form an arch-type temporary bridge. At this time, additional structures such as trusses, web members, and upper chords are installed on the pontoon body to eventually form an arch bridge. Furthermore, two adjacent steel frame beams are connected by expansion joint hinges, and high-strength bolts are provided at the hinge position of the expansion joint hinge. The high-strength bolts are inserted into the oblong holes. While realizing the hinged rotation, a small range of position adjustment can also be achieved through the oblong holes.

[0008] Further optimization also includes a steel member, which is arranged between the pontoon abutment and the tensioning pedestal, one end of the steel member is hinged to the end of the pontoon body, the other end of the steel member is pinned to the tensioning pedestal, and the end of the prestressed steel bundle is connected to the steel member; specifically, in the process of the pontoon body bulging upward, since the two ends of the pontoon are connected by the pontoon abutments and the distance is fixed, the pontoon body will be restricted from continuing to bulge upward, resulting in a smaller amplitude of the formed arched temporary bridge, which may not meet various requirements. This scheme also provides steel members on both banks for lengthening the pontoon body, wherein the steel member is preferably a steel frame beam, one end of which is hinged to the end of the pontoon body, and the other end is pinned to the tensioning pedestal. The pedestal is connected by pins and keys. After the prestressed steel strands are stretched to a horizontal position, the connection between the end of the pontoon body and the pontoon abutment is released, and then the connection between the steel member and the tensioning pedestal is released. At this time, the pontoon body will continue to bulge upward due to the removal of restrictions, and drive one end of the steel structure to lift upward, and the other end of the steel structure will move toward the pontoon abutment. The length of the steel member, that is, the distance between the tensioning pedestal and the pontoon abutment, should be determined according to the length of the arch axis when the temporary bridge is constructed, so that after the pontoon body protrudes upward, the other end of the steel member can just move to the position of the pontoon abutment. At this time, the other end of the steel member is hinged to the pontoon abutment to form an arched temporary bridge.

[0009] Further optimization, the prestressed steel bundle is connected to the other end of the steel member through a prestressed anchor, and the prestressed steel bundle is tensioned by a jack; to facilitate the stretching of the prestressed steel bundle, the prestressed steel bundle in this scheme is installed on the crossbeam of the steel member through a prestressed anchor, and the prestressed anchor enables the prestressed steel bundle to be stretched outward to both sides and cannot be reset. This scheme uses a jack to stretch the prestressed steel bundle.

[0010] Further optimization also includes a winch and a track, wherein the winch is connected to the other end of the steel member, and the track is arranged between the pontoon abutment and the tensioning pedestal, and is used to be slidably connected to the other end of the steel member; in order to accurately control the speed at which the other end of the steel member moves toward the pontoon abutment to avoid damage caused by excessive speed, the present scheme is also provided with a winch and a track, wherein the winch is connected to the other end of the steel member, and the track is arranged between the pontoon abutment and the tensioning pedestal. During specific operation, the tensioning force in the winch is first adjusted to be equal to the tensioning force in the prestressing force, and then the connection between the end of the pontoon body and the pontoon abutment is released, and the connection between the steel member and the tensioning pedestal is released, so that the other end of the steel member is slidably connected to the track, and the tension in the prestressed steel bundle and the winch is adjusted according to the tensioning force and the stress conditions in the winch, so that the steel frame beam slowly rolls along the track toward the abutment support, and finally the steel frame beam is hinged to the abutment to form a construction temporary bridge arch frame.

[0011] Further optimization also includes a tensioning guide frame, wherein a tensioning guide frame is installed at the hinge position of two adjacent steel frame beams, one end of the tensioning guide frame is connected to the bottom of the steel frame beam, and the other end of the tensioning guide frame extends beyond the bottom of the pontoon and cooperates with the prestressed steel bundle. In order to enable the floating bridge body as a whole to better protrude upward into a curve, the present scheme also provides a tensioning guide frame at the hinge position of two adjacent steel frame beams, wherein the tensioning guide frame is preferably arranged perpendicular to the steel frame beam, one end of which is connected to the lower end of the steel frame beam, and the other end extends toward the bottom of the pontoon and exceeds the bottom of the pontoon, corresponding to the prestressed steel bundle, and during the stretching process of the prestressed steel bundle, the floating bridge body will be lifted by contacting the tensioning guide frame.

[0012] Further optimization is carried out, the lengths of the multiple tensioning guide frames gradually decrease from the midpoint of the floating bridge body toward the two ends of the floating bridge body; in order to avoid the situation where the floating bridge body has irregular protrusion curves, in this scheme, the length of the tensioning guide frame gradually decreases from the midpoint of the floating bridge body toward the two ends, and the tensioning guide frame located at the center of the floating bridge body is the longest. At this time, the middle part of the floating bridge body protrudes upward first, and then protrudes from the middle to the two ends in turn, forming a regular curve, which can avoid the situation where the two sides protrude first, resulting in failure of arch bridge construction.

[0013] Further optimization also includes a limit device, a limit device is installed at the hinge position of two adjacent steel frame beams, the limit device includes two upper limit steel plates, one end of the two upper limit steel plates is respectively connected to the upper ends of the two adjacent steel frame beams, the other ends of the two upper limit steel plates extend toward the direction of the hinge position of the two adjacent steel frame beams, and the other ends of the two upper limit steel plates contact each other; to prevent the steel frame beam from protruding upward at the hinge position and then rotating downward and falling, when the floating bridge steel frame forms an upward protruding curve, the present scheme sets a limit device at the hinge position of two adjacent steel frame beams, wherein the limit device includes two upper limit steel plates, the two upper limit plates are respectively located on both sides of the hinge, one end of the upper limit steel plate is connected to the upper end of the steel frame beam, the other end of the upper limit steel plate extends toward the hinge position, and the ends of the two upper limit steel plates contact and resist each other, which can prevent the hinge position from rotating downward when there is a protruding curve protruding upward.

[0014] According to further optimization, the limit device also includes two lower limit steel plates, one end of the two lower limit steel plates are respectively connected to the lower ends of two adjacent steel frame beams, the other ends of the two lower limit steel plates extend toward the direction of the hinge position of the two adjacent steel frame beams, and a gap is left between the other ends of the two lower limit steel plates; in order to make the floating bridge body achieve the required protruding curve, in this scheme, the limit device also includes two lower limit steel plates, the two lower limit steel plates are arranged on both sides of the hinge position, one end of the lower limit steel plate is connected to the lower end of the steel frame beam, and the other end extends toward the hinge position, and a certain distance is left between the two lower limit steel plates, and the length of the distance can be determined according to needs to ensure that during the tensioning process, each segment can only rotate in the direction of the lower limit steel plate, and the rotation angle at each hinge can reach the designed angle.

[0015] Further optimized, a construction method of a prestressed floating bridge temporary bridge comprises the following steps:

[0016] Determine the segment length and span of the floating bridge body according to the design elevation and span of the temporary bridge;

[0017] Then the floating bridge body and the floating bridge abutment are constructed according to conventional methods, and prestressed steel strands are set at the bottom of the pontoon;

[0018] Construct the tensioning pedestal and the steel structure between the tensioning pedestal and the end of the floating bridge body, so that the prestressed steel strands are installed on the steel structure through the prestressed anchors;

[0019] The prestressed steel strands are tensioned by jacks to make the floating bridge body protrude upward to a predetermined position;

[0020] Then, the constraints between the steel member and the tensioning pedestal and between the floating bridge body and the floating bridge abutment are released, so that the other end of the steel member moves toward the floating bridge abutment, and finally the steel member and the floating bridge abutment are hinged to form a temporary bridge arch frame;

[0021] Finally, trusses and other facilities are constructed on the temporary bridge arch to form a truss arch bridge.

[0022] For further optimization, when the prestressed steel strands are tensioned by the jacks so that the floating bridge body forms an upwardly protruding curve, a limiting device is installed at the hinged positions of two adjacent steel frame beams.

[0023] The specific working principle of this solution is:

[0024] First, determine the segment length and span of the floating bridge according to the design elevation and span of the temporary bridge. Then, construct the floating bridge body and the floating bridge abutment according to the conventional method, so that the end of the floating bridge body and the floating bridge abutment are hinged, and prestressed steel bundles are set at the bottom of the pontoon. Then, construct the tensioning pedestal on both sides. When constructing the tensioning pedestal, it is necessary to determine the distance between the tensioning pedestal and the floating bridge abutment according to the length of the arch axis when the temporary bridge is completed, and set a winch behind the tensioning pedestal. Set a track between the tensioning pedestal and the floating bridge abutment. Assemble a steel member between the tensioning pedestal and the floating bridge abutment. One end of the steel member is connected to the end of the floating bridge by a hinged joint, and the other end is connected to the tensioning pedestal by a pin. The steel member is preferably a steel frame beam. Connect the prestressed steel bundle under the pontoon to the steel member beam at the tensioning pedestal, and install a prestressed anchor to limit the prestressed steel bundle. Then, a tensioning guide frame is placed at each expansion joint hinge of the floating bridge. One end of the tensioning guide frame is connected to the floating bridge steel frame, and the other end corresponds to the position of the prestressed steel bundle. The size of the tensioning guide frame is set according to the principle that during the prestressing process, the middle of the floating bridge will first protrude, and then protrude from the middle to both sides in sequence; the prestress is tensioned with a jack; when the floating bridge steel frame forms an upward protruding curve, the upper and lower limit steel plates are installed at the expansion joint hinge to ensure that each segment can only rotate in the direction of the limit steel plate downward during the tensioning process, and the rotation angle at each hinge can reach the designed angle. The winch is connected to the steel frame crossbeam, and the tensioning force in the winch is adjusted to be equal to the tensioning force in the prestressing force, and the constraint between the steel frame crossbeam and the tensioning pedestal is released. According to the tensioning force and the force in the winch, the prestressed steel bundle and the tension in the winch are adjusted, so that the steel frame crossbeam slowly rolls along the track toward the abutment support, and finally the steel frame crossbeam is hinged with the abutment to form a construction temporary bridge arch frame. Continue to set up rods on the arch frame to form an arch truss.

[0025] The present invention has the following beneficial effects:

[0026] The present invention provides a prestressed floating bridge and a construction method thereof. By adopting the present invention, an arch-type construction bridge can be provided to replace the cable hoisting system, and the construction of the steel truss arch bridge can be transformed into a segmented ring-shaped construction method, thereby reducing the construction difficulty, saving the project cost, and reducing the construction risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A front view of the prestressed floating bridge provided by the present invention;

[0028] Figure 2 A partial top view of the prestressed floating bridge provided by the present invention;

[0029] Figure 3 A partial view of the prestressed floating bridge provided by the present invention;

[0030] Figure 4 b is a partial view of the prestressed floating bridge provided by the present invention;

[0031] Figure 5 A partial view c of the prestressed floating bridge provided by the present invention.

[0032] The reference numerals in the figure are: 1- floating bridge body, 11- steel frame beam, 12- pontoon, 2- floating bridge abutment, 3- prestressed steel bundle, 4- tensioning pedestal, 5- steel member, 6- tensioning guide frame, 7- upper limit steel plate, 8- lower limit steel plate, 9- winch, 10- track, 13- bolt, 14- oblong hole. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0034] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details are not necessarily employed to practice the present invention. In other instances, well-known structures, circuits, materials, or methods are not specifically described in order to avoid obscuring the present invention.

[0035] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] In the description of the present invention, it should be understood that the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the scope of protection of the present invention.

[0037] Example: Figures 1 to 5As shown, a prestressed floating bridge temporary bridge comprises a floating bridge body 1 and a floating bridge abutment 2, and also comprises a prestressed steel bundle 3 and a tensioning pedestal 4;

[0038] The floating bridge body 1 includes a plurality of steel frame beams 11 hinged end to end in sequence, a plurality of pontoons 12 are provided at the bottom of the steel frame beams 11, and the floating bridge abutments 2 arranged on both sides are respectively hinged to the two ends of the floating bridge body 1. There are two tensioning pedestals 4, and the two tensioning pedestals 4 are arranged on both sides. The middle part of the prestressed steel bundle 3 is located below the plurality of pontoons 12, and the two ends of the prestressed steel bundle 3 are respectively connected to the two tensioning pedestals 4.

[0039] The floating bridge in the prior art includes a plurality of steel frame beams 11 connected end to end in sequence, and a plurality of pontoons 12 are arranged at the lower end of the steel frame beams 11. The pontoons 12 float on the water surface and are used to provide buoyancy for the floating bridge body 1 so that it floats on the water surface. The two ends of the floating bridge are connected to the floating bridge abutments 2 located on both sides to form a floating bridge. In this solution, prestressed steel bundles 3 and tensioning pedestals 4 are also provided to quickly form an arched temporary bridge, which greatly reduces the difficulty of construction.

[0040] Specifically, in this solution, the prestressed steel bundle 3 is arranged under all the pontoons 12 and along the length direction of the floating bridge body 1. Tensioning pedestals 4 are also provided on both sides. The tensioning pedestals 4 are preferably arranged behind the floating bridge abutments 2, away from the river bank. The ends of the prestressed steel bundle 3 are connected to the positions of the tensioning pedestals 4, wherein two adjacent steel frame cross beams 11 are hinged, and the ends of the floating bridge body 1 are hinged to the top of the floating bridge pedestals. In the initial state, the middle of the floating bridge body 1 falls on the water surface, and the two ends are lifted by the floating bridge pedestals to form a concave arc shape. When working, the prestressed steel bundle 3 is stretched to the two ends, and the prestressed steel bundle 3 will gradually lift the floating bridge body 1 upward. The distance between the two ends remains unchanged. During the process of lifting the floating bridge body 1 upward, the floating bridge body 1 will be gradually squeezed and bulged upward. After the prestressed steel bundle 3 is stretched to a horizontal position, the floating bridge body 1 bulges upward as a whole to form an arch-type temporary bridge. At this time, additional structures such as trusses, web members, and upper chords are installed on the floating bridge body 1 to eventually form an arch bridge. Furthermore, two adjacent steel frame beams 11 are connected by an expansion joint hinge, and a high-strength bolt 13 is provided at the hinge position of the expansion joint hinge. The high-strength bolt 13 is inserted into the oblong hole 14. While realizing the hinged rotation, the oblong hole 14 can also realize a small range of position adjustment.

[0041] In this embodiment, a steel member 5 is also included, and the steel member 5 is arranged between the pontoon abutment 2 and the tensioning pedestal 4. One end of the steel member 5 is hinged to the end of the pontoon body 1, and the other end of the steel member 5 is pinned to the tensioning pedestal 4. The end of the prestressed steel bundle 3 is connected to the steel member 5. Specifically, in the process of the pontoon body 1 protruding upward, since the two ends of the pontoon are connected by the pontoon abutments 2 and the distance is fixed, the pontoon body 1 will be restricted from continuing to protrude upward, resulting in a smaller amplitude of the arched temporary bridge formed, which may not meet various requirements. In this scheme, steel members 5 are respectively arranged on both sides to lengthen the pontoon body 1, wherein the steel member 5 is preferably a steel frame beam 11, one end of which is hinged to the end of the pontoon body 1, and the other end is hinged to the The tensioning pedestal 4 is connected by pins and keys. After the prestressed steel bundle 3 is stretched to a horizontal position, the connection between the end of the floating bridge body 1 and the floating bridge abutment 2 is released, and then the connection between the steel member 5 and the tensioning pedestal 4 is released. At this time, the floating bridge body 1 will continue to bulge upward due to the release of restrictions, and drive one end of the steel structure to lift upward, and the other end of the steel structure will move toward the floating bridge abutment 2. The length of the steel member 5, that is, the distance between the tensioning pedestal 4 and the floating bridge abutment, should be determined according to the length of the arch axis when the temporary bridge is constructed, so that after the floating bridge body 1 protrudes upward, the other end of the steel member 5 can just move to the position of the floating bridge abutment 2. At this time, the other end of the steel member 5 is hinged to the floating bridge abutment 2 to form an arched temporary bridge.

[0042] In this embodiment, the prestressed steel bundle 3 is connected to the other end of the steel component 5 through a prestressed anchor, and the prestressed steel bundle 3 is tensioned by a jack. In order to facilitate the stretching of the prestressed steel bundle 3, the prestressed steel bundle 3 in this solution is installed on the crossbeam of the steel component 5 through a prestressed anchor. The prestressed anchor allows the prestressed steel bundle 3 to be stretched outward on both sides and cannot be reset. This solution uses a jack to stretch the prestressed steel bundle 3.

[0043] In this embodiment, a winch 9 and a track 10 are also included. The winch 9 is connected to the other end of the steel member 5, and the track 10 is arranged between the pontoon abutment 2 and the tensioning pedestal 4, and is used to be slidably connected to the other end of the steel member 5. In order to accurately control the speed at which the other end of the steel member 5 moves toward the pontoon abutment 2 to avoid damage caused by excessive speed, the present solution is also provided with a winch 9 and a track 10, wherein the winch 9 is connected to the other end of the steel member 5, and the track 10 is arranged between the pontoon abutment 2 and the tensioning pedestal 4. Specifically During operation, the tensioning force in the winch 9 is first adjusted to be equal to the tensioning force in the prestressing force, and then the connection between the end of the floating bridge body 1 and the floating bridge abutment 2 is released, and the connection between the steel member 5 and the tensioning pedestal 4 is released, so that the other end of the steel member 5 is slidably connected to the track 10, and the tension in the prestressed steel bundle 3 and the winch 9 is adjusted according to the tensioning force and the force conditions in the winch 9, so that the steel frame crossbeam 11 slowly rolls along the track 10 toward the abutment support, and finally the steel frame crossbeam 11 is hinged to the abutment to form a construction temporary bridge arch frame.

[0044] In this embodiment, a tensioning guide frame 6 is also included. A tensioning guide frame 6 is installed at the hinge position of two adjacent steel frame beams 11, one end of the tensioning guide frame 6 is connected to the bottom of the steel frame beam 11, and the other end of the tensioning guide frame 6 extends beyond the bottom of the pontoon 12 and cooperates with the prestressed steel bundle 3. In order to enable the floating bridge body 1 to better protrude upward into a curve as a whole, this scheme also provides a tensioning guide frame 6 at the hinge position of two adjacent steel frame beams 11, wherein the tensioning guide frame 6 is preferably arranged perpendicular to the steel frame beam 11, one end of which is connected to the lower end of the steel frame beam 11, and the other end extends toward the bottom of the pontoon 12 and exceeds the bottom of the pontoon 12, corresponding to the prestressed steel bundle 3, and during the stretching process of the prestressed steel bundle 3, the floating bridge body 1 will be lifted by contacting the tensioning guide frame 6.

[0045] In the present embodiment, the lengths of the plurality of tensioning guide frames 6 gradually decrease from the midpoint of the floating bridge body 1 toward the two ends of the floating bridge body 1. In order to avoid irregular protrusion curves on the floating bridge body 1, in the present embodiment, the lengths of the tensioning guide frames 6 gradually decrease from the midpoint of the floating bridge body 1 toward the two ends. The tensioning guide frame 6 located at the center of the floating bridge body 1 is the longest. At this time, the middle part of the floating bridge body 1 first protrudes upward, and then protrudes from the middle to the two ends in sequence, forming a regular curve, which can avoid the situation where the two sides protrude first, resulting in failure of the arch bridge construction.

[0046] In the present embodiment, a limiting device is also included. The limiting device is installed at the hinge positions of two adjacent steel frame beams 11. The limiting device includes two upper limit steel plates 7. One end of the two upper limit steel plates 7 is respectively connected to the upper ends of the two adjacent steel frame beams 11. The other ends of the two upper limit steel plates 7 extend toward the direction of the hinge positions of the two adjacent steel frame beams 11, and the other ends of the two upper limit steel plates 7 contact each other. In order to prevent the steel frame beam 11 from protruding upward at the hinge position and then rotating downward and falling, when the floating bridge steel frame forms an upward protruding curve, the limiting device is set at the hinge positions of the two adjacent steel frame beams 11. The limiting device includes two upper limit steel plates 7. The two upper limit plates are respectively located on both sides of the hinge, one end of the upper limit steel plate 7 is connected to the upper end of the steel frame beam 11, and the other end of the upper limit steel plate 7 extends toward the hinge position. The ends of the two upper limit steel plates 7 contact and resist each other, which can prevent the hinge position from rotating downward when there is a protruding curve protruding upward.

[0047] In this embodiment, the limiting device also includes two lower limiting steel plates 8, one end of the two lower limiting steel plates 8 is respectively connected to the lower ends of two adjacent steel frame beams 11, and the other ends of the two lower limiting steel plates 8 extend toward the hinge positions of the two adjacent steel frame beams 11, and a gap is left between the other ends of the two lower limiting steel plates 8; in order to make the floating bridge body 1 achieve the required protruding curve, in this scheme, the limiting device also includes two lower limiting steel plates 8, the two lower limiting steel plates 8 are arranged on both sides of the hinge position, one end of the lower limiting steel plates 8 is connected to the lower end of the steel frame beam 11, and the other end extends toward the hinge position, and a certain distance is left between the two lower limiting steel plates 8, and the length of the distance can be determined according to needs to ensure that each segment can only rotate in the direction of the lower limiting steel plate 8 during the tensioning process, and the rotation angle at each hinge can reach the designed angle.

[0048] In this embodiment, a construction method of a prestressed floating bridge comprises the following steps:

[0049] Determine the segment length and span of the floating bridge body 1 according to the design elevation and span of the temporary bridge for construction;

[0050] Then, the floating bridge body 1 and the floating bridge abutment 2 are constructed according to conventional methods, and a prestressed steel strand 3 is arranged at the bottom of the pontoon 12;

[0051] Construct a tensioning pedestal 4, and construct a steel member 5 between the tensioning pedestal 4 and the end of the floating bridge body 1, so that the prestressed steel strand 3 is installed on the steel member 5 through a prestressed anchor;

[0052] The prestressed steel strands 3 are tensioned by the jacks to make the floating bridge body 1 protrude upward to a predetermined position;

[0053] Then, the constraints between the steel member 5 and the tensioning pedestal 4 and between the floating bridge body 1 and the floating bridge abutment 2 are released, so that the other end of the steel member 5 moves toward the floating bridge abutment 2, and finally the steel member 5 and the floating bridge abutment 2 are hinged to form a temporary bridge arch frame;

[0054] Finally, trusses and other facilities are constructed on the temporary bridge arch to form a truss arch bridge.

[0055] In this embodiment, when the prestressed steel strands 3 are tensioned by the jacks to form an upwardly protruding curve in the floating bridge body 1, a limiting device is installed at the hinged positions of two adjacent steel frame beams 11.

[0056] The specific working principle of this solution is:

[0057] First, the segment length and span of the floating bridge are determined according to the design elevation and span of the temporary bridge. Then, the floating bridge body 1 and the floating bridge abutment 2 are constructed according to the conventional method, so that the end of the floating bridge body 1 and the floating bridge abutment 2 are hinged, and the prestressed steel bundle 3 is set at the bottom of the pontoon 12; then, the tensioning pedestal 4 is constructed on both sides. When constructing the tensioning pedestal 4, the distance between the tensioning pedestal 4 and the floating bridge abutment 2 needs to be determined according to the length of the arch axis when the temporary bridge is completed, and a winch 9 is set behind the tensioning pedestal 4. A track 10 is set between the tensioning pedestal 4 and the floating bridge abutment 2; a steel member 5 is assembled between the tensioning pedestal 4 and the floating bridge abutment 2, one end of the steel member 5 is connected to the end of the floating bridge by a hinged joint, and the other end is connected to the tensioning pedestal 4 by a pin shaft, wherein the steel member 5 is preferably a steel frame crossbeam 11. The prestressed steel bundle 3 under the pontoon 12 is connected to the crossbeam of the steel member 5 at the tensioning pedestal 4, and a prestressed anchor is installed to limit the prestressed steel bundle 3. Then, a tensioning guide frame 6 is placed at each expansion joint hinge of the floating bridge. One end of the tensioning guide frame 6 is connected to the floating bridge steel frame, and the other end corresponds to the position of the prestressed steel bundle 3. The size of the tensioning guide frame 6 is set according to the principle that during the prestressing process, the middle of the floating bridge will first protrude, and then protrude from the middle to both sides in sequence; the prestress is tensioned with a jack; when the floating bridge steel frame forms an upward protruding curve, the upper and lower limit steel plates 8 are installed at the expansion joint hinge to ensure that during the tensioning process, each segment can only rotate in the direction of the lower limit steel plate 8, and the rotation angle at each hinge can reach the designed angle. The winch 9 is connected to the steel frame crossbeam 11, and the tensioning force in the winch 9 is adjusted to be equal to the tensioning force in the prestressing force, and the constraint between the steel frame crossbeam 11 and the tensioning pedestal 4 is released. According to the tension and the stress in the winch 9, the tension in the prestressed steel strand 3 and the winch 9 is adjusted, so that the steel frame beam 11 slowly rolls along the track 10 toward the abutment support, and finally the steel frame beam 11 is hinged with the abutment to form a temporary bridge arch frame. Rods are continuously erected on the arch frame to form an arch truss.

[0058] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A prestressed floating bridge, comprising a floating bridge body (1) and a floating bridge abutment (2), characterized in that: It also includes a prestressed steel strand (3) and a tensioning pedestal (4); The floating bridge body (1) comprises a plurality of steel frame beams (11) hinged in sequence head to tail, a plurality of pontoons (12) are provided at the bottom of the steel frame beams (11), the floating bridge abutments (2) arranged on both sides are respectively hinged to the two ends of the floating bridge body (1), there are two tensioning pedestals (4), the two tensioning pedestals (4) are arranged on both sides, the middle part of the prestressed steel bundle (3) is located below the plurality of pontoons (12), and the two ends of the prestressed steel bundle (3) are respectively connected to the two tensioning pedestals (4); It also includes a steel component (5), which is arranged between the floating bridge abutment (2) and the tensioning pedestal (4), one end of the steel component (5) is hinged to the end of the floating bridge body (1), the other end of the steel component (5) is pin-connected to the tensioning pedestal (4), and the end of the prestressed steel bundle (3) is connected to the steel component (5).

2. The prestressed floating bridge according to claim 1, characterized in that: The prestressed steel bundle (3) is connected to the other end of the steel member (5) via a prestressed anchor, and the prestressed steel bundle (3) is tensioned via a jack.

3. The prestressed floating bridge according to claim 1, characterized in that: It also includes a winch (9) and a track (10), wherein the winch (9) is connected to the other end of the steel member (5), and the track (10) is provided between the floating bridge abutment (2) and the tensioning pedestal (4), and is used for being slidably connected to the other end of the steel member (5).

4. The prestressed floating bridge according to claim 1, characterized in that: It also includes a tensioning guide frame (6), each of which is installed at the hinged position of two adjacent steel frame cross beams (11), one end of the tensioning guide frame (6) is connected to the bottom of the steel frame cross beam (11), and the other end of the tensioning guide frame (6) extends beyond the bottom of the pontoon and cooperates with the prestressed steel bundle (3).

5. The prestressed floating bridge according to claim 4 is characterized in that: From the midpoint of the floating bridge body (1) towards the two ends of the floating bridge body (1), the lengths of the plurality of tensioning guide frames (6) gradually decrease.

6. The prestressed floating bridge according to claim 1, characterized in that: It also includes a limiting device, wherein the limiting device is installed at the hinge position of two adjacent steel frame beams (11), and the limiting device includes two upper limit steel plates (7), one end of the two upper limit steel plates (7) is respectively connected to the upper ends of two adjacent steel frame beams (11), and the other ends of the two upper limit steel plates (7) extend in the direction of the hinge position of the two adjacent steel frame beams (11), and the other ends of the two upper limit steel plates (7) are in contact with each other.

7. The prestressed floating bridge according to claim 6, characterized in that: The limiting device further comprises two lower limiting steel plates (8), one end of the two lower limiting steel plates (8) being respectively connected to the lower ends of two adjacent steel frame cross beams (11), the other ends of the two lower limiting steel plates (8) extending towards the direction of the hinged positions of the two adjacent steel frame cross beams (11), and a gap being left between the other ends of the two lower limiting steel plates (8).

8. A construction method for a prestressed floating bridge according to any one of claims 1 to 7, characterized in that: The following steps are involved: Determine the segment length and span of the floating bridge body (1) according to the design elevation and span of the temporary bridge for construction; Then, the floating bridge body (1) and the floating bridge abutment (2) are constructed according to conventional methods, and a prestressed steel bundle (3) is arranged at the bottom of the pontoon; Constructing a tensioning pedestal (4), and constructing a steel member (5) between the tensioning pedestal (4) and the end of the floating bridge body (1), so that the prestressed steel strand (3) is installed on the steel member (5) through a prestressed anchor; Starting to tension the prestressed steel strands (3) by means of a jack, so that the floating bridge body (1) protrudes upward to a predetermined position; Then, the constraints between the steel member (5) and the tensioning pedestal (4) and between the floating bridge body (1) and the floating bridge abutment (2) are released, so that the other end of the steel member (5) moves toward the floating bridge abutment (2), and finally the steel member (5) and the floating bridge abutment (2) are hinged to form a temporary bridge arch frame; Finally, trusses and other facilities are constructed on the temporary bridge arch to form a truss arch bridge.

9. The construction method of a prestressed floating bridge according to claim 8, characterized in that: When the prestressed steel strands (3) are tensioned by the jacks so that the floating bridge body (1) forms a curve protruding upward, a limiting device is installed at the hinged positions of two adjacent steel frame cross beams (11).

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