A support system and construction method for upper crossbeam of double-deck bridge

Abstract

A support system for the upper crossbeam of a double-deck bridge includes a support frame, which is erected on the lower bridge body; multiple support frames are arranged in the transverse direction, and the tops of adjacent support frames are connected by a transversely arranged first connecting beam, and the tops of the piers are connected to the tops of the inner adjacent support frames by a transversely arranged first connecting beam, and the first connecting beam and the piers are both equipped with a support plate for supporting the upper crossbeam; the construction method includes the conversion of the lower bridge body system, the installation of the support system, the first phase construction of the upper crossbeam, the second phase construction of the upper crossbeam, the conversion of the upper bridge body system, and the removal of the support system. In the embodiment of the present invention, each support frame is connected as a whole by the first connecting beam and is connected to the pier, which reduces the pressure on the lower bridge body; during the construction of the upper crossbeam, concrete pouring and the erection of the upper bridge body are carried out step by step, and the load transferred to the lower bridge body by the support system gradually increases, thereby avoiding excessive load on the lower bridge body in a short period of time, which increases the risk of damage due to pressure.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge construction, and in particular relates to a support system and a construction method for an upper crossbeam of a double-deck bridge. Background Art

[0002] A double-deck bridge is a bridge with two decks, one above and one below. This makes full use of limited ground space, creating more accessible roads and improving traffic efficiency. During the construction of a double-deck bridge, the structure is constructed layer by layer, from top to bottom. After the piers are completed, a lower crossbeam is constructed on the piers. The lower box girder is then attached to the lower crossbeam to form the lower bridge deck. A support system is then installed on the lower deck to construct the upper crossbeam. Finally, a box girder is attached to the upper crossbeam to form the upper bridge deck.

[0003] During the current construction of double-deck bridges, the upper crossbeam support system is only erected on the lower bridge body. Since the bridge deck of a double-deck bridge is not completely straight, it needs to be tilted at turns. Even if the lower bridge body is also tilted, the upper crossbeam support volume is erected on the tilted lower bridge body, which has poor stability. The upper crossbeam transfers all the load to the lower bridge body through the support system. The lower bridge body will bear a larger load in a shorter period of time, increasing the risk of compressive damage. Summary of the Invention

[0004] In response to the shortcomings in the relevant technology, the present invention provides a support system and construction method for the upper crossbeam of a double-deck bridge to solve the problems of insufficient stability and excessive load in a short period of time caused by the current support system being completely erected on the lower bridge body.

[0005] The present invention provides a support system for the upper crossbeam of a double-deck bridge, comprising a support frame, wherein the support frame is erected on the lower bridge body;

[0006] The lower bridge body is erected on the lower crossbeam, which is arranged in the transverse direction and has piers at both ends, and the tops of the piers are higher than the lower bridge body;

[0007] Multiple support frames are arranged in the transverse direction. The tops of adjacent support frames are connected by a transversely arranged first connecting beam. The tops of the piers are connected to the tops of the inner adjacent support frames by a transversely arranged first connecting beam. The first connecting beams and the piers are both equipped with support plates for supporting the upper crossbeam.

[0008] The first connecting beams are all located on the same straight line and are parallel to the bridge deck of the lower bridge body;

[0009] The top end of the support frame protrudes upward from the first connecting beam and is flush with the supporting plate to support the upper crossbeam.

[0010] In some embodiments, the support frame located on one side of the central axis of the lower bridge body is the first support frame, and the support frame located on the other side of the central axis of the lower bridge body is the second support frame. Adjacent first support frames are connected by a transversely arranged second connecting beam, and adjacent second support frames are connected by a transversely arranged second connecting beam.

[0011] In some embodiments, first connecting beams are installed at both ends of the support frame in the longitudinal direction, so that the first connecting beams have two rows in the longitudinal direction;

[0012] The two sides of the support plate in the longitudinal direction are respectively located above the corresponding first connecting beam and are connected thereto through two top screws arranged at intervals in the transverse direction. The four corners of the pier are connected to the corresponding support plate through the top screws.

[0013] In some embodiments, a reinforcing plate is installed between the support frame and the corresponding first connecting beam. The reinforcing plate is triangular and perpendicular to the first connecting beam and the support frame.

[0014] In some embodiments, a steel plate is embedded in the inner side of the pier, and the steel plate is connected to the corresponding first connecting beam by bolts;

[0015] The bottom end of the support frame is provided with a support leg, on which a pad is installed to ensure a gap between the bottom end of the support leg and the lower bridge body. The pad is a concrete component and falls on the lower bridge body.

[0016] In some embodiments, the support frame includes columns, at least two of which are arranged along the longitudinal direction, the tops and bottoms of adjacent columns are connected by a third connecting beam, and reinforcing support members are installed between adjacent columns. The reinforcing support members include two support rods arranged obliquely, and the two support rods are arranged crosswise, and the two ends of the support rods are respectively connected to the two columns.

[0017] A construction method for the upper crossbeam of a double-deck bridge, using the above-mentioned support system for the upper crossbeam of the double-deck bridge, comprises the following specific steps:

[0018] Construct the lower cross beams between the piers, install the lower box beams on the lower cross beams, construct the transverse and longitudinal wet joints between the lower box beams, and combine the lower box beams into the lower bridge body to complete the system conversion;

[0019] Erect all support frames on the lower bridge body, install the first connecting beam between adjacent support frames and between the support frames and the bridge piers, and install the support plates on the first connecting beams and the bridge piers;

[0020] Install temporary supports on the top of the piers. Pass the corresponding support plates through the temporary supports and make them flush with the support plates. Install the first-phase formwork on the support surface formed by the support plates, support frames and temporary supports.

[0021] Concrete is poured into the first-phase formwork to construct the foundation component, and the first steel strand embedded in the foundation component is prestressed in the first phase;

[0022] Remove the first-phase formwork and pallet, and install the upper box girder of the upper bridge body on the top surface of the foundation structure;

[0023] The second-stage formwork is installed on the top surface of the foundation component, and concrete is poured into the second-stage formwork to form the transverse wet joints between the upper box girders and two edge components located at the two transverse ends. The two edge components are attached to the two upper box girders corresponding to the two transverse ends and integrally connected with the foundation component to form an upper crossbeam. The second steel strand embedded in the upper crossbeam is prestressed for the second stage;

[0024] Construct the longitudinal wet joints between the upper box girders, combine the upper box girders into the upper bridge body, and complete the system conversion;

[0025] The first connecting beam and support frame of the support system were removed, and the third steel strand embedded in the upper beam was prestressed in three stages;

[0026] Remove the temporary supports installed on the top of the pier.

[0027] In some of the embodiments, after the transverse wet joints and the longitudinal wet joints between the upper box girders are constructed, the transverse steel strands embedded in the transverse wet joints and the longitudinal steel strands embedded in the longitudinal wet joints are prestressed.

[0028] In some embodiments, the first steel strand, the second steel strand and the third steel strand are arranged in sequence from bottom to top in the upper crossbeam, and the first steel strand, the second steel strand and the third steel strand are symmetrically arranged relative to the central axis of the upper crossbeam. The first steel strand includes a horizontally arranged first middle section and two first edge sections respectively connected to the two ends of the first middle section, and the first edge sections are both inclined upward; the second steel strand includes a horizontally arranged second middle section and two second edge sections respectively connected to the two ends of the second middle section, and the second edge sections are both inclined upward; the third steel strand includes a horizontally arranged third middle section and two third edge sections respectively connected to the two ends of the third middle section, and the third edge sections are both inclined upward; the lengths of the first middle section, the second middle section and the third middle section increase in sequence; the second edge section is arranged parallel to the corresponding third edge section, and the inclination of both is greater than that of the corresponding first edge section.

[0029] In some embodiments, the bottom end of the support frame of the support system has a concrete pad. When removing the first connecting beam and the support frame of the support system, the pad is first broken and removed from under the support frame.

[0030] Based on the above technical solution, in the embodiment of the present invention, each support frame is connected as a whole through the first connecting beam and is connected to the bridge pier. The support frame is supported in the transverse direction by the bridge pier so that it remains stable when the lower bridge body is tilted, thereby stably supporting the upper crossbeam above. The load of the upper crossbeam is not only transmitted to the lower bridge body through the support frame, but also transmitted to the bridge pier through the first connecting beam, thereby reducing the pressure on the lower bridge body. During the construction of the upper crossbeam, concrete pouring and erection of the upper bridge body are gradually carried out, and the load transmitted to the lower bridge body through the support system gradually increases, thereby avoiding excessive load on the lower bridge body in a short period of time, increasing the risk of compressive damage, and solving the problems of insufficient stability and excessive load of the current support system completely erected on the lower bridge body. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 This is a schematic structural diagram of the upper crossbeam support system of a double-deck bridge according to the present invention;

[0033] Figure 2 for Figure 1 Section 1-1;

[0034] Figure 3 for Figure 1 A partial enlarged view of part A;

[0035] Figure 4 The construction diagram of the upper crossbeam construction method of the double-deck bridge of the present invention is shown in FIG. Figure 1 :

[0036] Figure 5 The construction diagram of the upper crossbeam construction method of the double-deck bridge of the present invention is shown in FIG. Figure 2 :

[0037] Figure 6 The construction diagram of the upper crossbeam construction method of the double-deck bridge of the present invention is shown in FIG. Figure 3 :

[0038] Figure 7 The construction diagram of the upper crossbeam construction method of the double-deck bridge of the present invention is shown in FIG. Figure 4 :

[0039] Figure 8 The construction diagram of the upper crossbeam construction method of the double-deck bridge of the present invention is shown in FIG. Figure 5 :

[0040] Figure 9 The construction diagram of the upper crossbeam construction method of the double-deck bridge of the present invention is shown in FIG. Figure 6 :

[0041] Figure 10 The construction diagram of the upper crossbeam construction method of the double-deck bridge of the present invention is shown in FIG. Figure 7 :

[0042] Figure 11 This is a construction diagram after installing the second-phase formwork and pouring concrete in the construction method of the upper crossbeam of a double-deck bridge of the present invention:

[0043] Figure 12 This is a schematic diagram of the structure of the upper crossbeam and steel strands in the construction method of the upper crossbeam of a double-deck bridge according to the present invention:

[0044] In the picture:

[0045] 1. Support frame; 1A, first support frame; 1B, second support frame; 101, column; 102, support rod;

[0046] 2. Lower bridge body; 21. Lower box girder

[0047] 3. Lower beam; 4. Bridge pier;

[0048] 51. First connecting beam; 52. Second connecting beam; 53. Third connecting beam;

[0049] 6. Pallet;

[0050] 7. Upper beam; 71. Foundation member; 72. Edge member;

[0051] 8. Upper bridge body; 81. Upper box girder;

[0052] 9. Top screw; 10. Steel plate; 11. Reinforcement plate; 12. Support legs; 13. Foot pads;

[0053] 14. Temporary support; 20. Longitudinal wet joint; 30. Horizontal wet joint; 40. Second phase formwork; 50. Temporary support;

[0054] 41. First steel strand; 41a. First middle section; 41b. First edge section; 42. Second steel strand; 42a. Second middle section; 42b. Second edge section; 43. Third steel strand; 43a. Third middle section; 43b. Third edge section. DETAILED DESCRIPTION

[0055] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0056] In the description of the present invention, it should be understood that the terms "center", "transverse", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship 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 orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0057] The terms "first," "second," and "third" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first," "second," or "third" may explicitly or implicitly include one or more of such features.

[0058] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0059] like Figures 1 to 3 As shown, in an illustrative embodiment of the support system for the upper cross beam of a double-deck bridge of the present invention, the support system for the upper cross beam of the double-deck bridge includes a support frame 1, which is erected on the lower bridge body 2.

[0060] The lower bridge body 2 is erected on the lower crossbeam 3, which is arranged horizontally and has piers 4 at both ends. The bottom ends of the piers 4 touch the ground, thereby supporting the lower crossbeam 3 and supporting the lower bridge body 2 through the lower crossbeam 3. The top ends of the piers 4 are higher than the lower bridge body 2.

[0061] Multiple support frames 1 are arranged transversely, arranged one after another from one pier 4 to the next. The tops of two adjacent support frames 1 are connected by a transverse first connecting beam 51. The tops of each pier 4 are connected to the tops of the innermost adjacent support frames 1 via a transverse first connecting beam 51. Support plates 6 are mounted on the first connecting beams 51 and the piers 4. Upper crossbeams 7 are constructed on these support plates 6, which contact and directly support the upper crossbeams 7 above.

[0062] The first connecting beams 51 are all located on the same straight line and are parallel to the bridge deck of the lower bridge body 2. The top end of the support frame 1 protrudes upward from the first connecting beam 51 and is flush with the support plate 6 to support the upper crossbeam.

[0063] The piers 4 support the support frames 1 laterally via the first connecting beams 51. Each support frame 1 supports each other laterally via the first connecting beams 51. The support frames 1 will not fall over due to the tilted setting of the lower bridge body 2, thus maintaining the support system's laterally stability. The load of the upper beam 7 is transferred to the first connecting beam 51 via the support plate 6, and then transferred from the first connecting beam 51 to each support frame 1 and the two piers 4. This distributes part of the load of the upper beam 7 to the piers 4, preventing the entire load of the upper beam 7 from acting on the lower bridge body 2, causing damage to the lower bridge body 2. The first connecting beams 51 are all located at the top to maximize their straightening effect on the support frames 1 and maintain the stability of the support frames 1 to the greatest extent possible.

[0064] The first connecting beams 51 are all located on the same straight line, so that the load transferred from the upper cross beam 7 to the first connecting beam 51 through the support plate 6 can be transferred to the pier 4 more smoothly, reducing the pressure on the support frame 1 and the load on the lower bridge body 2.

[0065] The straight line on which the first connecting beam 51 is located is parallel to the bridge deck of the lower bridge body 2, so that the arrangement direction of the first connecting beam 51 can be tilted as the lower bridge body 2 is tilted, transferring more load to the pier 4, further reducing the pressure on the support frame 1, reducing the load on the lower bridge body 2, and also enabling the upper crossbeam 7 made above to be tilted, so that the inclination of the upper bridge body 8 erected on the upper crossbeam 7 can be more easily matched with the inclination of the lower bridge body 2.

[0066] The support frame 1 extending upward relative to the first connecting beam 51 directly supports the upper crossbeam 7, preventing the entire load from being transmitted to the support frame 1 through the first connecting beam 51, thereby reducing the load on the first connecting beam 51 and preventing it from being deformed due to excessive load. The pier 4 can stably support the support frame 1 laterally through the first connecting beam 51, thereby maintaining the stability of the support system.

[0067] In the above-mentioned schematic embodiment, in the support system of the upper crossbeam of the double-deck bridge, each support frame is connected as a whole through the first connecting beam and is connected to the piers. The support frame is supported in the transverse direction by the piers so that it remains stable when the lower bridge body is tilted, thereby stably supporting the upper crossbeam above. The load of the upper crossbeam is not only transmitted to the lower bridge body through the support frame, but also transmitted to the piers through the first connecting beam, thereby reducing the pressure on the lower bridge body and reducing the load transmitted to the lower bridge body; the first connecting beam is connected in a straight line and is parallel to the bridge deck, so that when the lower bridge body is in an inclined state, the first connecting beam is smoothly transmitted to the piers, reducing the pressure on the support frame 1 and reducing the load on the lower bridge body; the support frame and the first connecting beam jointly support the upper crossbeam, avoiding the load concentration causing the first connecting beam to be compressed and deformed, and avoiding the instability of the support system caused by deformation, thereby solving the problems of insufficient stability and excessive load of the current support system that is completely erected on the lower bridge body.

[0068] The construction method using the above-mentioned support system for the upper crossbeam of a double-deck bridge comprises the following steps:

[0069] Two bridge piers 4 are constructed on both sides, and a lower crossbeam 3 is constructed in the middle between the two bridge piers 4. Each lower box beam 21 is installed on the lower crossbeam 3, and concrete is poured between the transversely arranged lower box beams 21, and concrete is poured between the longitudinally arranged lower box beams 21, thereby constructing the longitudinal wet joints 20 and transverse wet joints 30 between the lower box beams 21, and the various lower box beams 21 are combined into the lower bridge body 2 to complete the system conversion.

[0070] like Figure 4 As shown, the support frames 1 are all erected on the lower bridge body 2, the first connecting beams 51 are installed between adjacent support frames 1 and between the support frames 1 and the piers 4, and the support plates 6 are installed on the first connecting beams 51 and the piers 4, thereby completing the construction of the support system for the upper crossbeams of the double-deck bridge.

[0071] A temporary support 14 is installed on the top of the pier 4. The pallet 6 mounted on the pier 4 has an assembly window. The temporary support 14 is inserted into the assembly window, allowing it to pass into the pallet 6 and align its top surface with the top surface of the pallet 6. The primary formwork is then installed on the support surface formed by the pallet 6, the support frame 1, and the temporary support 14. Multiple primary formworks are combined into a primary mold, in which rebar is tied and the first, second, and third steel strands 41, 42, 43, which serve as prestressing strands, are installed.

[0072] like Figure 5 As shown, concrete is poured into the first-phase mold formed by the first-phase template assembly to construct the foundation component 71, and the first steel strand 41 embedded in the foundation component 71 is prestressed for a period of time. After the prestressing is completed, the first steel strand 41 is grouting and fixed.

[0073] like Figure 6 As shown, remove the first phase template and all the pallets 6. Figure 7 As shown, the upper box girder 81 of the upper bridge body 8 is installed on the top surface of the foundation member 71 .

[0074] like Figure 11 As shown, a second-stage formwork 40 is installed on the top surface of the foundation component 71. Multiple second-stage formwork 40 are arranged along the edge of the top surface of the foundation component 71. That is, the portion of the edge of the top surface of the foundation component 71 not covered by the upper box beam 81 is installed with a second-stage formwork 40. The second-stage formwork 40 is located between adjacent upper box beams 81 in the transverse direction and at both ends of the top surface of the foundation component 71. The second-stage formwork 40 is combined into a second-stage mold, which, together with the upper box beam 81, completely surrounds the space above the top surface of the foundation component 71. Rebar is tied in the second-stage mold, and concrete is poured into the second-stage mold, as shown in FIG. Figure 8 As shown, a transverse wet joint 30 is constructed between the upper box girders 81, along with two edge members 72 at each transverse end. Because the second-stage formwork 40, installed along the edge, connects the upper box girders 81, completely enclosing the space above the foundation members 71, the edge members 72 are affixed to the adjacent corresponding upper box girders 81. The two edge members 72 are integrally connected to the foundation member 71 to form the upper crossbeam 7. The second steel strand 42 undergoes a second-stage prestressing. After the prestressing is completed, the second steel strand is grout-secured.

[0075] like Figure 9 As shown, concrete is poured between the transversely arranged upper box girders 81 to construct the longitudinal wet joints 20 between the upper box girders 81 , and the upper box girders 81 are combined into the upper bridge body 8 to complete the system conversion.

[0076] like Figure 10 As shown, the first connecting beam 51 and the support frame 1 are removed, thereby completely dismantling the support system. The third steel strand 43 is subjected to three-stage prestressing. After the prestressing is completed, the third steel strand is grouting and fixed. The temporary support installed on the top of the pier is removed.

[0077] During the construction of the upper crossbeam of a double-deck bridge, after the foundation components are constructed, only the load of the foundation components 71 is transferred to the piers 4 and the lower bridge body 2. The lower bridge body 2 bears the initial load, which is the first increase in the load borne by the lower bridge body 2. Because the foundation components 71 are part of the upper crossbeam 7 and are relatively light, the initial load borne by the lower bridge body 2 is small and will not be damaged by pressure. After the upper box girder 81 is installed and the transverse wet joints 30 between the edge components 72 and the upper box girder 81 are constructed, the load of the upper box girder 81, its transverse wet joints 30, and the entire upper crossbeam 7 are transferred to the piers 4 and the lower bridge body 2, increasing the load borne by the lower bridge body 2. This is the second increase in the load borne by the lower bridge body 2. After all the wet joints of the upper box girder 81 are completed, the load borne by the lower bridge body 2 is further increased, which is the third increase in the load borne by the lower bridge body 2. The load borne by the lower bridge body 2 is gradually increased in three steps, thereby avoiding the risk of damage to the lower bridge body 2 caused by a rapid increase in the load in a short period of time.

[0078] In addition, before installing the upper box girder 81 and constructing the edge member 72, not only the first-phase formwork was removed, but also all the support plates 6 in the support system were removed, eliminating the load transmitted to the lower bridge body 2 by all the support plates 6. The support frame 1 and the pier 4 of the support system can stably support the upper structure, reducing the amount of the second load increase on the lower bridge body 2, reducing the amplitude and speed of the load increase on the lower bridge body 2, and further reducing the risk of compression damage to the lower bridge body 2.

[0079] The construction of foundation member 71, installation of upper box girder 81, construction of edge member 72, and construction of wet joints in upper box girder 81 not only increased the load on lower bridge body 2 three times, but also on upper crossbeam 7. The three steel strands of upper crossbeam 7 were prestressed three times, gradually increasing their rigidity as the load increased. Ultimately, upon completion, upper crossbeam 7 possessed sufficient rigidity to provide stable support for itself and upper bridge body 8 above.

[0080] The second-phase formwork 40 installed along the edge is connected to the upper box girder 81, completely surrounding the space above the foundation component 71. The constructed edge component 72 completely covers the end of the upper box girder 81, so that the edge component 72 can support and limit the upper box girder 81 laterally, making the upper bridge body 8 more stable. The load of the upper bridge body 8 can be transmitted to the middle and edge of the upper beam 7 laterally and vertically, so that the load borne by the upper beam 7 is more dispersed, thereby improving the life of the upper beam 7.

[0081] In some embodiments, after the transverse wet joints 30 between the upper box girders 81 are constructed, the transverse steel strands embedded in the transverse wet joints 30 are prestressed. More specifically, the second-phase formwork 40 is installed to form a second-phase mold, rebar is tied into the second-phase mold, and transverse steel strands serving as prestressing bundles are transversely installed in the second-phase mold. Concrete is poured into the second-phase mold, and the concrete flows between the longitudinally arranged upper box girders 81 to form the transverse wet joints 30 of the upper box girders 81. The transverse steel strands are embedded in the transverse wet joints 30 and prestressed. After the prestressing is completed, the transverse steel strands are fixed by grouting.

[0082] After the longitudinal wet joints 20 between the upper box girders 81 are constructed, the longitudinal steel strands embedded in the longitudinal wet joints 20 are prestressed. More specifically, the longitudinal steel strands are installed between the transversely arranged upper box girders 81, and then concrete is poured to construct the longitudinal wet joints 20 between the upper box girders. The longitudinal steel strands are embedded in the longitudinal wet joints 20 and prestressed. After the prestressing is completed, the longitudinal steel strands are fixed by grouting.

[0083] After the transverse wet joints 30 and longitudinal wet joints 20 of the upper box girder 81 are constructed, they are both prestressed, which not only improves the transverse and longitudinal rigidity of the upper bridge body 8, but also reduces the deformation of the upper bridge body 8 caused by compression, thereby avoiding longitudinal pulling of the upper box girder 81 due to deformation, and maintaining a stable connection between the upper box girder 81 and the upper crossbeam 7.

[0084] In some embodiments, as Figure 12As shown, the first steel strand 41 , the second steel strand 42 and the third steel strand 43 are arranged in sequence from bottom to top in the upper crossbeam, and the first steel strand 41 , the second steel strand 42 and the third steel strand 43 are all symmetrically arranged relative to the central axis of the upper crossbeam 7 .

[0085] The first steel strand 41 includes a horizontally arranged first middle section 41a and two first edge sections 41b respectively connected at both ends of the first middle section 41a, and the first edge sections 41b are both inclined upward; the second steel strand 42 includes a horizontally arranged second middle section 42a and two second edge sections 42b respectively connected at both ends of the second middle section 42a, and the second edge sections 42b are both inclined upward; the third steel strand 43 includes a horizontally arranged third middle section 43a and two third edge sections 43b respectively connected at both ends of the third middle section 43a, and the third edge sections 43b are both inclined upward.

[0086] The lengths of the first middle section 41a, the second middle section 42a and the third middle section 43a increase in sequence; the second edge section 42b is arranged parallel to the corresponding third edge section 43b, and the inclination is greater than the corresponding first edge section 41b.

[0087] The upper crossbeam 7 is constructed in two phases from top to bottom. The wet joints of the upper bridge body 8 are constructed during the second phase of construction of the upper crossbeam 7 and after the construction of the upper crossbeam 7 is completed. The center of gravity of the structure gradually rises, and the height settings of the three steel strands that undergo three-stage prestressing are gradually increased to match the rising center of gravity, so that the longer steel strands can better bear the weight of the structure and improve the strength of the structure.

[0088] The lengths of the three horizontal parts of the steel strands increase gradually as the height position increases. The first middle section 41a at the bottom layer is the longest, the second middle section 42a above it is the second longest, and the third middle section 43a at the top is the shortest, forming a support structure that is wide at the bottom and narrow at the top. The structure is stable, thereby improving the structural strength of the upper beam.

[0089] The inclinations of the two upper edge portions are greater than that of the first edge segment 41b, so that both ends of the second and third steel strands can extend into the edge member 72 of the upper beam 7, more fully supporting the upper beam 7 and improving the rigidity of the upper beam 7 structure.

[0090] Since both ends of the second and third steel strands extend to the edge member 72, when constructing the foundation member 71, two support tubes containing steel strands can be buried in the foundation member 71, and the two ends of the support tubes extend out from the top surfaces of the foundation member 71 at both ends. When casting the edge member 72, the ends of the support tubes are buried in the edge member 72. Finally, when the concrete is not completely solidified, the support tubes are pulled out, and the steel strands can be buried in the upper crossbeam 7.

[0091] In some embodiments, the bottom end of the support frame 1 of the support system has a concrete foot 13. When removing the first connecting beam 51 and the support frame 1 of the support system, the foot 13 is first broken and removed from under the support frame 1. The destructible foot 13 increases the convenience of dismantling the support system and facilitates the recycling of the support system.

[0092] In some embodiments, when constructing the transverse wet joints 30 and the longitudinal wet joints 20 between the lower box girders 21, temporary supports 50 are provided under the wet joints of the lower box girders; when removing the first connecting beam 51 and the support frame 1 of the support system, the temporary supports 50 under the wet joints of the lower box girders 21 are removed.

[0093] Before the support system is erected, the temporary supports 50 installed can increase the stability of the lower bridge body 2 and improve the support system's stability for the upper crossbeam 7 and upper bridge body 8. After the support system is dismantled, the temporary supports 50 are removed to ensure the stability of the lower bridge body 2 and reduce the load on the lower crossbeam 3.

[0094] In some embodiments, the support frame 1 located on one side of the central axis of the lower bridge body 2 is the first support frame 1A, and the support frame 1 located on the other side of the central axis of the lower bridge body 2 is the second support frame 1B. Adjacent first support frames 1A are connected by a transversely arranged second connecting beam 52, and adjacent second support frames 1B are connected by a transversely arranged second connecting beam 52.

[0095] The support frame 1 is divided into two units on either side of the lower bridge body 2. The top and bottom of each unit are connected by a connecting beam, resulting in high structural strength and stability. The two units can evenly distribute the load of the upper crossbeam 7 to both sides of the lower bridge body 2, preventing load concentration and damage to the lower bridge body 2. In addition, the bridge deck of the lower bridge body between the two units can form a traffic lane, facilitating the movement of construction machinery and improving construction convenience.

[0096] In some embodiments, first connecting beams 51 are installed at both ends of the support frame 1 in the longitudinal direction, so that the first connecting beams 51 have two rows in the longitudinal direction.

[0097] The two sides of the support plate 6 in the longitudinal direction are respectively located above the corresponding first connecting beam 51 and are connected thereto via two top screws 9 arranged at intervals in the transverse direction. The four corners of the pier 4 are connected to the corresponding support plate 6 via the top screws 9 .

[0098] Two longitudinal first connecting beams 51 connect adjacent support frames 1, further enhancing the structural strength of the support system, increasing the three-dimensionality of the support system in the longitudinal direction, and improving the longitudinal stability of the support system. The two longitudinal first connecting beams 51 support the same support plate 6 via four top screws 9, further improving the stability of the support plate 6 and thus enhancing the stability of the support for the upper crossbeam 7 above. In addition, the four top screws 9 can adjust the height of the four corners of the support plate 6, increasing the flexibility of the adjustment of the support plate 6, allowing it to tilt in any direction and flexibly match the upper crossbeam 7 above.

[0099] In some embodiments, a reinforcing plate 11 is installed between the support frame 1 and the corresponding first connecting beam 51 . The reinforcing plate 11 is triangular and perpendicular to the first connecting beam 51 and the support frame 1 .

[0100] Since most of the load of the upper crossbeam 7 first acts on the first connecting beam 51 through the support plate 6 and is then transmitted to the pier 4 and the support frame 1 by the first connecting beam 51, the support frame 1 can support the first connecting beam 51 through the reinforcement plate 11, thereby improving the stability of the first connecting beam 51 and preventing the first connecting beam 51 from being deformed due to excessive load, so that the pier 4 can stably support the support frame 1 laterally through the first connecting beam 51, and the reinforcement plate 11 can provide more channels for load transfer, reduce the pressure at the connection point between the support frame 1 and the first connecting beam 51, and maintain the stability of the support system.

[0101] In some embodiments, a steel plate 10 is embedded inside the pier 4 and connected to the corresponding first connecting beam 51 via bolts. The connecting beam is mounted on the pier 4 via the steel plate 10, which is easy to install and disassemble, facilitating the recycling of the support system.

[0102] The bottom end of the support frame 1 has a leg 12, and a pad 13 is installed on the leg 12. The pad 13 falls on the lower bridge body 2, so that the lower bridge body 2 supports the support frame 1 through the pad 13 and the leg 12. The pad 13 raises the leg 12 so that there is a gap between its bottom end and the lower bridge body 2. Since the upper crossbeam 7 above tightly presses the support frame 1 down on the lower bridge body 2, it is difficult to directly withdraw the support frame 1 from between the upper crossbeam 7 and the lower bridge body 2. The pad 13 is a concrete component. When the support system is dismantled, the pad 13 is broken to form a gap between the bottom end of the support frame 1 and the lower bridge body 2, so that the support frame 1 can be withdrawn from between the upper crossbeam 7 and the lower bridge body 2, which increases the convenience of dismantling the support system and facilitates the recycling of the support system.

[0103] In some embodiments, the support frame 1 includes columns 101, with at least two columns 101 provided longitudinally. The tops and bottoms of adjacent columns 101 are connected by a third connecting beam 53, thereby forming a single structure connected by the upper and lower connecting beams. Piers 4 are connected to the support frame 1 via the connecting beams, but the longitudinal support provided by piers 4 is limited. The support frame 1 has multiple columns 101 longitudinally, providing multiple support points and ensuring the longitudinal stability of the support frame 1.

[0104] To further enhance the longitudinal stability of the support frame 1 and prevent longitudinal deformation under pressure, a reinforcing support member is installed between adjacent columns. The reinforcing support member includes two inclined support rods 102, which are intersectingly arranged between the columns 101, with each end of the support rod 102 connected to the two columns 101. The intersecting support rods 102 of the reinforcing support member enable the columns 101 to support each other in the longitudinal direction, thereby enhancing the structural strength of the support frame 1 in the longitudinal direction. Furthermore, the two support rods 102 enable stress to be transmitted longitudinally, thereby enabling the support frame 1 to evenly transfer the load to the lower bridge body 2 in the longitudinal direction, thereby preventing load concentration and damage to the lower bridge body.

[0105] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0106] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to preferred embodiments, persons skilled in the art should understand that the specific implementation methods of the present invention may still be modified or some technical features may be replaced by equivalents without departing from the spirit of the technical solutions of the present invention, and all of these should fall within the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A support system for the upper crossbeam of a double-deck bridge, characterized in that: It includes a support frame, which is set up on the lower bridge body; The lower bridge body is erected on the lower crossbeam, which is arranged in a transverse direction and has piers at both ends, and the tops of the piers are higher than the lower bridge body; Multiple support frames are arranged in a transverse direction, and the tops of adjacent support frames are connected by a transversely arranged first connecting beam. The tops of the piers are connected to the tops of the inner adjacent support frames by a transversely arranged first connecting beam. The first connecting beams and the piers are both equipped with support plates for supporting the upper crossbeam. The first connecting beams are all located on the same straight line and are parallel to the bridge deck of the lower bridge body; The top end of the support frame protrudes upward from the first connecting beam and is flush with the supporting plate to support the upper crossbeam.

2. The support system for the upper crossbeam of a double-deck bridge according to claim 1, characterized in that: The support frame located on one side of the central axis of the lower bridge body is the first support frame, and the support frame located on the other side of the central axis of the lower bridge body is the second support frame. Adjacent first support frames are connected by a transversely arranged second connecting beam, and adjacent second support frames are connected by a transversely arranged second connecting beam.

3. The support system for the upper crossbeam of a double-deck bridge according to claim 1, characterized in that: The first connecting beams are installed at both ends of the support frame in the longitudinal direction, so that the first connecting beams have two rows in the longitudinal direction; The two sides of the supporting plate in the longitudinal direction are respectively located above the corresponding first connecting beam and are connected thereto through two top screws arranged at intervals in the transverse direction. The four corners of the pier are connected to the corresponding supporting plate through top screws.

4. The support system for the upper crossbeam of a double-deck bridge according to claim 1, characterized in that: A reinforcing plate is installed between the support frame and the corresponding first connecting beam. The reinforcing plate is triangular and perpendicular to the first connecting beam and the support frame.

5. The support system for the upper cross beam of a double-deck bridge according to claim 1, characterized in that: A steel plate is pre-embedded inside the pier, and the steel plate is connected to the corresponding first connecting beam via bolts; The bottom end of the support frame has a support leg, and the support leg is equipped with a pad foot to ensure a gap between the bottom end of the support leg and the lower bridge body. The pad foot is a concrete component and falls on the lower bridge body.

6. The support system for the upper cross beam of a double-deck bridge according to claim 1, characterized in that: The support frame includes columns, and at least two columns are arranged in the longitudinal direction. The tops and bottoms of adjacent columns are connected by a third connecting beam. Reinforced support members are installed between adjacent columns, and the reinforced support members include two support rods arranged obliquely, and the two support rods are arranged crosswise, and the two ends of the support rods are respectively connected to the two columns.

7. A construction method for the upper crossbeam of a double-deck bridge, using the support system for the upper crossbeam of a double-deck bridge as claimed in any one of claims 1 to 6, characterized in that: The specific steps are as follows: Construct the lower cross beams between the piers, install the lower box beams on the lower cross beams, construct the transverse and longitudinal wet joints between the lower box beams, and combine the lower box beams into the lower bridge body to complete the system conversion; Erect all support frames on the lower bridge body, install the first connecting beam between adjacent support frames and between the support frames and the bridge piers, and install the support plates on the first connecting beams and the bridge piers; Install temporary supports on the top of the piers. Pass the corresponding support plates through the temporary supports and make them flush with the support plates. Install the first-phase formwork on the support surface formed by the support plates, support frames and temporary supports. Concrete is poured into the first-phase formwork to construct the foundation component, and the first steel strand embedded in the foundation component is prestressed in the first phase; Remove the first-phase formwork and pallet, and install the upper box girder of the upper bridge body on the top surface of the foundation structure; The second-stage formwork is installed on the top surface of the foundation component, and concrete is poured into the second-stage formwork to form the transverse wet joints between the upper box girders and two edge components located at the two transverse ends. The two edge components are attached to the two upper box girders corresponding to the two transverse ends and integrally connected with the foundation component to form an upper crossbeam. The second steel strand embedded in the upper crossbeam is prestressed for the second stage; Construct the longitudinal wet joints between the upper box girders, combine the upper box girders into the upper bridge body, and complete the system conversion; The first connecting beam and support frame of the support system were removed, and the third steel strand embedded in the upper beam was prestressed in three stages; Remove the temporary supports installed on the top of the pier.

8. The construction method of the upper cross beam of a double-deck bridge according to claim 7, characterized in that: After constructing the transverse wet joints and longitudinal wet joints between the upper box girders, the transverse steel strands embedded in the transverse wet joints and the longitudinal steel strands embedded in the longitudinal wet joints are prestressed.

9. The construction method of the upper cross beam of a double-deck bridge according to claim 7, characterized in that: The first steel strand, the second steel strand and the third steel strand are arranged in sequence from bottom to top in the upper crossbeam, and the first steel strand, the second steel strand and the third steel strand are symmetrically arranged relative to the central axis of the upper crossbeam. The first steel strand includes a horizontally arranged first middle section and two first edge sections respectively connected to the two ends of the first middle section, and the first edge sections are both inclined upward; the second steel strand includes a horizontally arranged second middle section and two second edge sections respectively connected to the two ends of the second middle section, and the second edge sections are both inclined upward; the third steel strand includes a horizontally arranged third middle section and two third edge sections respectively connected to the two ends of the third middle section, and the third edge sections are both inclined upward; the lengths of the first middle section, the second middle section and the third middle section decrease in sequence; the second edge section is arranged parallel to the corresponding third edge section, and the inclination of both is greater than that of the corresponding first edge section.

10. The construction method of the upper cross beam of a double-deck bridge according to claim 7, characterized in that: The bottom end of the support frame of the support system is provided with a concrete pad. When dismantling the first connecting beam and the support frame of the support system, the pad is first broken and removed from under the support frame.

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