Transport bridge for prefabricating box girder and construction method thereof

Abstract

The invention relates to the technical field of bridge engineering, in particular to a transport bridge for prefabricating box girders and a construction method thereof.The transport bridge for prefabricating the box girders comprises a steel bridge, the steel bridge is located on the side, away from an existing line, of a line to be built, the steel bridge comprises three bridge sections, and the three bridge sections are the starting section, the middle section and the merging section. The starting section is connected to a storage field of the prefabricated box girder, the merging section is connected with a to-be-built line, and the middle section is located between the starting section and the merging section. The transportation channel is formed between the storage field of the prefabricated box girders and the to-be-built line through the steel bridge, and the problem that when a bridge construction project adjacent to an existing high-speed rail line is faced, the prefabricated box girders cannot be directly hoisted to the bridge deck of the to-be-built bridge through a gantry crane can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, and in particular to a transport bridge for prefabricated box beams and a construction method thereof. Background Art

[0002] In the field of bridge construction, especially in bridge erection operations in complex environments, traditional methods usually rely on gantry crane systems to efficiently lift prefabricated box girders from the ground or temporary storage areas to the partially built bridge deck. As a large-scale lifting equipment, the gantry crane has a unique double-column structure that can be stably erected on both sides of the bridge. Through the lifting mechanism on its crossbeam, the heavy box girders are accurately and safely lifted and placed on the beam transporter preset on the bridge deck, and then transported by the beam transporter along the bridge deck to the designated location for splicing and installation. This process greatly improves the efficiency and safety of bridge construction.

[0003] However, in actual engineering projects, some special challenges are encountered, especially when the bridge to be built is close to the operating high-speed railway line, the situation becomes particularly complicated. Due to the particularity of the high-speed railway line and its strict requirements for safe operation, any construction activities that may affect its normal operation must be strictly restricted. Under such conditions, the traditional gantry crane erection scheme faces severe tests: on the one hand, the erection height, span and operating radius of the gantry crane must be strictly controlled within the range that does not affect the safe operation of the high-speed train; on the other hand, the existence of the high-speed railway line itself greatly limits the installation space of the gantry crane, making it difficult to implement the traditional method.

[0004] Therefore, when faced with a bridge construction project adjacent to an existing high-speed rail line, the gantry crane cannot be used to directly hoist the prefabricated box beam onto the bridge deck to be built, which undoubtedly poses a huge challenge to the entire bridge construction plan. In this context, an innovative technical solution is urgently needed to ensure the efficient advancement of bridge construction while strictly complying with the safety protection requirements of the high-speed rail line and achieving safe and accurate hoisting of prefabricated box beams. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem in the prior art that when facing a bridge construction project adjacent to an existing high-speed railway line, a gantry crane cannot be used to directly lift prefabricated box girders onto the bridge deck of the bridge to be built, and to provide a transport bridge for prefabricated box girders and a construction method thereof.

[0006] In a first aspect, the present invention provides a transport bridge for prefabricated box girders, comprising:

[0007] The steel bridge is located on a side of the line to be built away from the existing line. The steel bridge includes three bridge sections, which are a starting section, a middle section and a merging section.

[0008] The starting section is connected to a storage yard of prefabricated box girders, the merging section is connected to the line to be built, and the middle section is located between the starting section and the merging section.

[0009] The present invention provides a transport bridge for prefabricated box girders, wherein the steel bridge is located on a side of the line to be built away from the existing line, so as to avoid the influence of the construction of the steel bridge and the transportation of the prefabricated box girders on the normal and safe operation of the existing line. The starting section is connected to the storage yard of the prefabricated box girders, so as to facilitate the hoisting of the prefabricated box girders onto the steel bridge. The merging section is connected to the line to be built, so that the prefabricated box girders can be transported to the line to be built via the steel bridge. The steel bridge forms a transport channel between the storage yard of the prefabricated box girders and the line to be built, thereby solving the problem that when facing a bridge construction project adjacent to an existing high-speed railway line, the prefabricated box girders cannot be directly hoisted onto the bridge deck of the bridge to be built using a gantry crane.

[0010] The two ends of the middle section are connected to the starting section and the merging section respectively. The middle section serves to connect the starting section and the merging section. The path and length of the middle section can be set according to the actual situation of the construction site.

[0011] The steel bridge is a steel structure bridge, which is convenient for erection, dismantling and reuse at the construction site. Compared with the concrete structure bridge, it can shorten the construction period and reduce the construction cost. The steel bridge can be a steel structure bridge made of steel sections, or a modified steel trestle. The overall plane layout of the steel bridge can be a straight line, or an arc or a broken line. The bridge deck of the steel bridge is used for traveling beam transport vehicles, and the beam transport vehicles are used to transport prefabricated box beams.

[0012] Preferably, the three bridge sections each include a plurality of bridge piers and Bailey beams, the two ends of the Bailey beams are respectively connected to the tops of two adjacent bridge piers, and a bridge deck is provided above the Bailey beams. The Bailey beams are easy to install and remove, which can improve the construction efficiency of the steel bridge, and the Bailey beams are easy to reuse, further saving construction costs.

[0013] Preferably, each of the bridge piers comprises a plurality of steel columns, which are arranged in a single row in the transverse direction of the bridge, and a main crossbeam is provided on the top of the steel column, which is arranged in the transverse direction of the bridge, and the Bailey beam is connected to the top surface of the main crossbeam. The steel columns are responsible for supporting and bearing the vertical load of the steel bridge. The main crossbeam can connect the plurality of steel columns together to improve the integrity of the bridge pier, and the main crossbeam serves as a supporting table at both ends of the Bailey beam.

[0014] Preferably, a first distribution beam is provided between the Bailey beam and the bridge deck, and the first distribution beam is arranged transversely to the bridge. The first distribution beam is used to disperse the load transmitted from the bridge deck, and disperse the load to the Bailey beam, thereby improving the safety of the entire steel bridge.

[0015] Preferably, a V-shaped clip is provided at the intersection of the Bailey beam and the first distribution beam, and the V-shaped clip is a steel plate with a V-shaped groove, and the two edges of the V-shaped groove are respectively connected to the upper chord of the Bailey beam and the bottom of the first distribution beam. The V-shaped clip is used to connect the Bailey beam and the first distribution beam together. When the Bailey beams are arranged in a high-density manner, when the spacing between two adjacent Bailey frames in the Bailey beam is less than the width of the limiting channel steel, the V-shaped clip also plays a role in limiting the Bailey frames. The V-shaped clip is not only easy to install, but also can effectively limit the displacement of the first distribution beam through the mutual connection between the Bailey beam and the first distribution beam, and also solves the installation problem of the Bailey beam under high-density conditions.

[0016] Preferably, the starting section, the middle section and the merged section are all straight sections, and there is an angle between two adjacent bridge sections. This solution makes the overall plan layout of the steel bridge present a broken line shape, which has higher flexibility than a single straight line shape; and is more convenient to construct and has lower cost than an arc shape.

[0017] Preferably, the steel columns of the bridge piers below the connecting area of ​​two adjacent bridge sections are arranged in double rows, each row of the steel columns is arranged along the transverse direction of the bridge, and the tops of the corresponding steel columns between the two rows are provided with a main crossbeam along the bridge direction, and the main crossbeam is provided with two crossbeams in the transverse direction of the bridge, and the top surfaces of the two crossbeams are respectively connected to the Bailey beams of the two adjacent bridge sections. This solution can better handle the connection between the two adjacent bridge sections and improve the reliability of the connection.

[0018] Preferably, a second distribution beam along the bridge direction is connected between two adjacent bridge sections, and both ends of the second distribution beam are respectively connected to the Bailey beams of the two adjacent bridge sections. When the span of the second distribution beam is greater than or equal to 800 mm, a support portion is provided between the second distribution beam and the main cross beam. This solution can better deal with the problem that the first distribution beam in the cross direction cannot be arranged between two adjacent bridge sections, thereby ensuring that the turning point of the two adjacent bridge sections has sufficient bearing capacity.

[0019] In a second aspect, the present invention provides a construction method for a transport bridge of prefabricated box girders, comprising the following steps:

[0020] S1: constructing a pile foundation in the foundation below the corresponding installation position of the steel column, constructing a tie beam on the top of the pile foundation, and simultaneously constructing embedded parts on the tie beam;

[0021] S2: hoisting the steel column onto the tie beam and connecting it to the corresponding embedded parts;

[0022] S3: hoisting the main cross beam to the top of the corresponding steel column, installing the main cross beam in the transverse direction of the bridge; the main cross beam below the connecting area of ​​two adjacent bridge sections is installed in the longitudinal direction of the bridge, and the cross beam in the transverse direction of the bridge is installed above the main cross beam installed in the longitudinal direction of the bridge;

[0023] S4: hoisting the assembled Bailey beam onto the main beam or the beam for installation and fixing;

[0024] S5: hoisting the first distribution beam onto the Bailey beam for installation and fixing, welding a steel connector between two adjacent first distribution beams, and installing a V-shaped clip at the intersection of the Bailey beam and the first distribution beam;

[0025] S6: below the predetermined installation position of the second distribution beam, when the span of the second distribution beam is greater than or equal to 800 mm, a support portion is installed on the main cross beam installed along the bridge below the second distribution beam, and then the second distribution beam is hoisted to the predetermined position, and both ends of the second distribution beam are connected to the Bailey beam, and the bottom of the second distribution beam is connected to the support portion;

[0026] S7: Laying a bridge deck above the first distribution beam and the second distribution beam to complete the construction of the transport bridge.

[0027] The present invention provides a construction method for a transport bridge of prefabricated box girders, wherein the vertical support system of the steel bridge is formed by the steel columns and the main cross beams, and the horizontal support system of the steel bridge is formed by the Bailey beams, the first distribution beams, the second distribution beams and the bridge deck. Both the vertical support system and the horizontal support system use prefabricated steel structural components and are spliced ​​and constructed on site. This method can not only achieve rapid advancement of the construction of the steel bridge, but also ensure the high load-bearing performance of the steel bridge, so as to be used for transporting the prefabricated box girders to the line to be built.

[0028] Preferably, in step S3, the main crossbeam installed in the transverse direction of the bridge is divided into a plurality of sections. After the main crossbeam sections are hoisted to the top of the steel column, the sections of the steel column are welded on-site. The lower part of the sections of the main crossbeam must be located at the top of the steel column, and the sections of the main crossbeam must not be located directly below the walking track of the wheels of the beam transport vehicle.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention provides a transport bridge for prefabricated box girders. By arranging the steel bridge on the side of the line to be built away from the existing line, the steel bridge forms a transport channel between the storage yard of the prefabricated box girders and the line to be built, which can solve the problem that when facing a bridge construction project adjacent to an existing high-speed railway line, the prefabricated box girders cannot be directly hoisted onto the bridge deck of the bridge to be built using a gantry crane.

[0031] 2. The present invention provides a construction method for a transport bridge for prefabricated box girders, wherein the vertical support system of the steel bridge is formed by the steel columns and the main cross beams, and the horizontal support system of the steel bridge is formed by the Bailey beams, the first distribution beams, the second distribution beams and the bridge deck. Both the vertical support system and the horizontal support system use prefabricated steel structural components and are spliced ​​on site. This method can not only achieve rapid advancement of the construction of the steel bridge, but also ensure the high load-bearing performance of the steel bridge, so as to be used for transporting prefabricated box girders to the line to be built. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The diagram is a plan view of a transport bridge with prefabricated box girders.

[0033] Figure 2 for Figure 1 Schematic diagram of the AA section.

[0034] Figure 3 for Figure 1 Schematic diagram of the BB section.

[0035] Figure 4 This is the first schematic diagram of the turning point of the transport bridge.

[0036] Figure 5 This is the second schematic diagram of the turning point of the transport bridge.

[0037] Markings in the figure:

[0038] 1- Steel bridge,

[0039] 101-starting segment, 102-middle segment, 103-merging segment,

[0040] 2- Lines to be built,

[0041] 201-cast-in-place section, 202-prefabricated erection section,

[0042] 3- Existing lines,

[0043] 4- Bridge deck,

[0044] 5- First distribution beam,

[0045] 6- Bailey beam,

[0046] 7- Main beam,

[0047] 8-Steel columns,

[0048] 9- Tie beam,

[0049] 10- Pile foundation,

[0050] 11- beam,

[0051] 12- Bridge piers to be built,

[0052] 13- Second distribution beam,

[0053] 14- Pad. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below in conjunction with specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0055] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0056] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0057] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0058] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0059] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0060] Example 1

[0061] like Figure 1-Figure 5 As shown, a transport bridge for prefabricated box girders comprises a steel bridge 1.

[0062] The steel bridge 1 is located on a side of the line 2 to be built away from the existing line 3 . The steel bridge 1 includes three bridge sections, namely a starting section 101 , a middle section 102 and a merging section 103 .

[0063] The starting section 101 is connected to the storage yard of the prefabricated box beam, the merging section 103 is connected to the line 2 to be built, and the middle section 102 is located between the starting section 101 and the merging section 103. The two ends of the middle section 102 are respectively connected to the starting section 101 and the merging section 103. One end of the merging section 103 is connected to the cast-in-place section 201 of the line 2 to be built, and the other end thereof is forked into two branches, one branch is connected to the cast-in-place section 201 on the other side of the line 2 to be built, and the other branch is connected to the middle section 102.

[0064] The length direction of the starting section 101 is parallel to the direction of the gantry crane moving track of the prefabricated box girder storage yard, which facilitates the gantry crane to lift the prefabricated box girder from the storage yard to the beam transport vehicle on the starting section 101 of the steel bridge 1, and then transport the prefabricated box girder along the bridge deck of the steel bridge 1 to the prefabricated erection section 202 on the line 2 to be built by the beam transport vehicle.

[0065] In an optional embodiment, each of the three bridge sections may include a plurality of bridge piers and Bailey beams 6, the two ends of the Bailey beam 6 are respectively connected to the tops of two adjacent bridge piers, and a bridge deck 4 is provided above the Bailey beam 6. The Bailey beam 6 is composed of a plurality of Bailey frames, and the Bailey frames are spliced ​​by a plurality of Bailey sheets according to the span requirements. The net distance between two adjacent Bailey frames is 48mm-60mm to meet the bearing capacity requirements, and the specific net distance may be 48mm, 49mm, 50mm, 52mm, 55mm, 58mm, 60mm. The bridge deck 4 may be a patterned steel plate, and pedestrian walkways and guardrails may be provided on both sides of the bridge deck 4.

[0066] In an optional implementation manner, each of the bridge piers may include a plurality of steel columns 8, which are arranged in a single row in the transverse direction of the bridge. The number of steel columns 8 in a single row may be 4, 5 or 6. A main crossbeam 7 is provided on the top of the steel column 8, and the main crossbeam 7 is arranged in the transverse direction of the bridge. The Bailey beam 6 is connected to the top surface of the main crossbeam 7. Figure 2 The bridge piers of the merged section 103 also include the line piers 12 to be built, and the main cross beam 7 is supported by the steel columns 8 and the line piers 12 to be built. Figure 3 As shown. When the top elevations of the steel column 8 and the bridge pier 12 to be built are inconsistent, a cushion block 14 can be set between the top surface of the steel column 8 and the main beam 7, and between the top surface of the bridge pier 12 to be built and the main beam 7, so as to effectively support the main beam 7. The main beam 7 can be composed of two 700mm high I-beams, and a stiffening plate is welded at the waist of the 700mm high I-beam. The spacing between the stiffening plates can be equal to the spacing of the Bailey plates above the main beam 7 to strengthen the structural strength of the main beam 7. The center spacing between two adjacent Bailey plates can be 200mm-240mm, and the specific center spacing can be 200mm, 210mm, 220mm, 225mm, 230mm, 240mm. The steel column 8 is a Φ820×12mm steel pipe, and end plates are welded at the upper and lower ends of the steel column 8, and a stiffening plate is welded between the end plate and the steel pipe. The main cross beam 7 is made of HN700*300*13*24 steel, and the Bailey beam 6 is made of "321" type steel.

[0067] In an optional embodiment, a first distribution beam 5 may be provided between the Bailey beam 6 and the bridge deck 4, and the first distribution beam 5 is arranged transversely to the bridge. The spacing between two adjacent first distribution beams 5 is 250 mm-350 mm, and the specific spacing may be 250 mm, 280 mm, 300 mm, 320 mm, 340 mm, 350 mm. Specifically, the first distribution beam 5 may be a 20# I-beam.

[0068] In an optional embodiment, a V-shaped clip may be provided at the intersection of the Bailey beam 6 and the first distribution beam 5. The V-shaped clip is a steel plate with a V-shaped groove, and the two edges of the V-shaped groove are respectively connected to the upper chord of the Bailey beam 6 and the bottom of the first distribution beam 5. Specifically, the opening of the V-shaped groove of the V-shaped clip faces the horizontal direction, the upper edge of the V-shaped groove is welded to the lower flange of the first distribution beam 5, and the welding point is on the side of the lower flange of the first distribution beam 5 facing upward; the lower edge of the V-shaped groove is welded to the upper chord of the Bailey frame constituting the Bailey beam 6, and the welding point is on the side of the upper chord facing downward. The V-shaped clip is connected to the intersection at an angle of 45°, and the side of the V-shaped clip opposite to the V-shaped groove contacts another adjacent Bailey frame constituting the Bailey beam 6, which plays a role in limiting the position of the Bailey frames with respect to each other.

[0069] In an optional implementation, the starting section 101, the middle section 102 and the merging section 103 can all be straight line sections, and there is an angle between two adjacent bridge sections. Specifically, the middle section 102 can be divided into three broken line sections, the starting section 101 is parallel to the line 2 to be built, the distance between the starting section 101 and the line 2 to be built is 30 meters to 33 meters, the three broken line sections of the middle section 102 gradually deviate to the line 2 to be built, the deflection angle of each broken line section increases by 5° successively, and finally the third broken line end is connected to the merging section 103. The plane of the merging section 103 is a step-shaped, and the lateral width of each span gradually decreases from one end close to the middle section 102 to the other end, and the final width is consistent with the width of the line 2 to be built. The width of the starting section 101 and the middle section 102 is 11 meters, and the maximum width of the merging section 103 is 23.9 meters, and the minimum width is 12.2 meters.

[0070] In an optional embodiment, the steel columns 8 of the bridge piers below the connecting area of ​​two adjacent bridge sections may be arranged in double rows, such as Figure 4 As shown, each row of steel columns 8 is arranged along the transverse direction of the bridge, and the tops of the corresponding steel columns 8 between two rows are provided with main crossbeams 7 along the bridge direction, and two crossbeams 11 are provided on the main crossbeam 7 in the transverse direction of the bridge, and the top surfaces of the two crossbeams 11 are respectively connected to the Bailey beams 6 of the two adjacent bridge sections.

[0071] In an optional embodiment, a second distribution beam 13 along the bridge direction may be connected between two adjacent bridge sections, such as Figure 5 As shown, both ends of the second distribution beam 13 are respectively connected to the Bailey beams 6 of the two adjacent bridge sections. When the span of the second distribution beam 13 is greater than or equal to 800 mm, a support portion is provided between the second distribution beam 13 and the main cross beam 7. The support portion may be a combination of a steel pipe column and a steel section.

[0072] Example 2

[0073] The following is a detailed description of a construction method for a transport bridge for prefabricated box girders in Example 1. The specific construction steps are as follows:

[0074] S1: constructing a pile foundation 10 in the foundation below the corresponding installation position of the steel column 8, constructing a tie beam 9 on the top of the pile foundation 10, and simultaneously constructing embedded parts on the tie beam 9.

[0075] Pile foundation construction: The drilling of pile foundation 10 adopts rotary drilling construction. The diameter of pile foundation 10 is 100cm, and the drilling rig uses ZSD200 casing rotary drilling rig. The verticality of the active drill rod should be checked regularly during the drilling process, and the deviation should be adjusted immediately. The hole mouth is backfilled flat and dense to prevent the hole mouth from collapsing and the casing from sinking, so as to ensure the quality of the hole. After the pile foundation 10 is drilled, the steel cage is immediately lowered. After the steel cage is installed, the catheter method is immediately used for underwater concrete pouring. After the pouring is completed, the casing is pulled out and the hole mouth is backfilled after the initial setting of the concrete and before the final setting.

[0076] Tie beam construction: After the pile foundation 10 is completed and the pile body integrity test is passed, the tie beam 9 construction begins. The steel bars of tie beam 9 are tied and formed on site. The formwork of tie beam 9 is all made of large-block formed steel formwork, and the concrete is poured in horizontal layers in one go. In order to ensure the compactness of the concrete at the bottom of the embedded steel plate, a φ150mm pouring hole is reserved in the center of the embedded steel plate; the RTK measuring instrument is used to locate the four corners of the embedded steel plate, and the level is used to locate the flatness of the embedded steel plate, and the embedded steel plate is welded to the main reinforcement of tie beam 9. After verification, concrete pouring is carried out. During the pouring process, vibration is strengthened and the vibrating rod is prevented from touching the embedded steel plate.

[0077] S2: The steel columns 8 are processed and manufactured in a centralized manner in the processing plant, and then transported to the construction site by dump trucks through the beam yard transportation channel. After the coordinates of the steel columns 8 are determined by the surveyors, they are hoisted by the fishing method, and the steel columns 8 are slowly hooked to make the wire rope bear force, and are manually positioned on the embedded parts of the corresponding tie beams 9. Four-point electric welding positioning is first performed, and after the position and verticality of the steel columns 8 are re-measured, repair welding is performed in time. After the construction of the steel columns 8 is completed, the connection system of the steel columns 8 is installed and constructed. The connection system is a Φ426×6mm steel pipe. Because the connection system is installed between the steel columns 8, it cannot be placed in the designed position as a whole due to the influence of the mutual structural dimensions. 1 / 2 of the arc at one end of the connection system is cut off. After the connection system is in place, the cut part is welded to the original position again.

[0078] S3: The main crossbeam 7 and the crossbeam 11 are processed and manufactured in a centralized manner in a processing plant, transported to the construction site by a flatbed truck, and hoisted using a lifting device using a two-point binding method. The main crossbeam 7 is connected to the top of the corresponding steel column 8, and the main crossbeam 7 is installed in the transverse direction of the bridge; the main crossbeam 7 below the connecting area of ​​the two adjacent bridge sections is installed in the longitudinal direction of the bridge, and the crossbeam 11 in the transverse direction of the bridge is installed above the main crossbeam 7 installed in the longitudinal direction of the bridge.

[0079] S4: First, assemble the single-piece Bailey sheet into a single-span Bailey sheet according to the length of each span, and then assemble the single-piece Bailey sheet into a single-span Bailey frame through the support frame. After the assembly is completed, the Bailey frame is hoisted to the main beam 7 or beam 11 in sequence by a car crane. In order to ensure that the main beam 7 and beam 11 are well stressed, each Bailey sheet is installed at the position of the stiffening plate corresponding to the main beam 7 or beam 11. When installing the Bailey sheet of the merged section 103, in order to solve the problem that the spacing between the Bailey sheets is extremely small and the pin shaft cannot be installed when the span is installed, a segmented stepped installation method is adopted. When the first segment is installed, each group of adjacent Bailey frames is staggered with the connection position of the second segment in a stepped manner. After the first segment is installed, the second segment is installed in sequence. Two groups of full-length Bailey frames are reserved for overall hoisting and closing. The length of the full-length Bailey frame is 57m. Two sets of full-length Bailey plates were installed in place using two 80-meter truck cranes and two-point lifting method. This method can ensure that the installation pins of each set of Bailey plates are not disturbed.

[0080] S5: Several first distribution beams 5 are placed side by side at intervals of 300mm, with a side-by-side width of 2.1 meters as a group, and each group is 3 meters to 4 meters long. Two adjacent first distribution beams 5 are welded together by steel sections, and each group of first distribution beams 5 is hoisted to the designated position of Bailey beam 6 by a 25t crane. The designated position takes into account the passing position of the tires of the beam transporter to ensure that the tires of the beam transporter do not pass through the joint of the first distribution beam 5. Another 30cm is reserved between two adjacent groups of first distribution beams 5, and 14cm long steel sections are welded on site to ensure the overall stability of the distribution beam. Due to the extremely high density of Bailey plates, the spacing between each group of Bailey frames is 49mm, but the width of the limiting channel steel is 63mm, and it is impossible to limit the Bailey plates with conventional limiting steel plates. Therefore, V-type clips are used here to limit the Bailey plates at the intersection of the Bailey plates and the first distribution beams 5 by using the upper and lower structures to limit the Bailey plates. This method is not only easy to install, but also can effectively limit the displacement of the distribution beam by connecting the Bailey plates and the distribution beams.

[0081] S6: Since the triangular area formed at the turning point between two adjacent bridge sections cannot be installed with the Bailey beam 6, the second distribution beam 13 is used to cross the triangular area in this area, and a support part is installed on the main cross beam 7 installed along the bridge below the second distribution beam 13, below the predetermined installation position of the second distribution beam 13, and when the span of the second distribution beam 13 is greater than or equal to 800 mm. Then the second distribution beam 13 is hoisted to the predetermined position, the two ends of the second distribution beam 13 are connected to the Bailey beam 6, and the bottom of the second distribution beam 13 is connected to the support part.

[0082] S7: Lay the bridge deck 4 above the first distribution beam 5 and the second distribution beam 13 to complete the construction of the transport bridge.

[0083] In an optional implementation, in step S3, the main crossbeam 7 installed in the transverse direction of the bridge can be divided into multiple sections, each section is separately manufactured in a processing plant and then transported to the construction site. After the main crossbeam 7 sections are hoisted to the top of the steel column 8, the sections of the steel column 8 are welded on-site, and the lower part of the sections of the main crossbeam 7 must be located at the top of the steel column 8, and the sections of the main crossbeam 7 must not be directly below the walking track of the wheels of the beam transport vehicle.

[0084] The transport bridge for prefabricated box girders of the present invention meets the technical requirements for transporting large-tonnage prefabricated box girders, can solve the problem of transporting large-tonnage prefabricated box girders on the lateral steel trestle of the main line, and by designing a curved steel trestle in a folding manner instead of a curved manner, solves the construction problem of steel trestle lifting and transporting beams in the case of being close to the existing line 3. This steel trestle has also been proven in practice to be effective in transporting large-tonnage prefabricated box girders, safe to use, simple to install and dismantle, and cost-saving, providing a safe and reliable practical proof for the application of heavy-load curved steel trestles. The steel trestle has the characteristics of adapting to various terrains, reliable structure, small footprint, easy installation and dismantling, high safety, simple maintenance, and can be reused after dismantling.

[0085] A transport bridge for prefabricated box girders of the present invention is assembled and constructed using steel structure components such as Bailey beams and steel pipes, which can achieve the effect of rapid assembly installation, thereby improving the construction efficiency of the transport bridge and shortening the project construction period. The steel structure components are reusable and can be recycled in multiple projects, thereby greatly reducing construction costs.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A transport bridge for prefabricated box girders, characterized in that: include: A steel bridge (1), the steel bridge (1) being located on a side of a line to be built (2) away from an existing line (3), the steel bridge (1) comprising three bridge sections, the three bridge sections being a starting section (101), a middle section (102) and a merging section (103); The starting section (101) is connected to a storage yard for prefabricated box beams, the merging section (103) is connected to the line to be built (2), and the middle section (102) is located between the starting section (101) and the merging section (103).

2. A transport bridge for prefabricated box girders according to claim 1, characterized in that: The three bridge sections all include a plurality of bridge piers and Bailey beams (6), the two ends of the Bailey beams (6) are respectively connected to the tops of two adjacent bridge piers, and a bridge deck (4) is provided above the Bailey beams (6).

3. A transport bridge for prefabricated box girders according to claim 2, characterized in that: Each of the bridge piers comprises a plurality of steel columns (8), wherein the plurality of steel columns (8) are arranged in a single row in the transverse direction of the bridge, a main crossbeam (7) is provided on the top of the steel columns (8), the main crossbeam (7) is arranged in the transverse direction of the bridge, and the Bailey beam (6) is connected to the top surface of the main crossbeam (7).

4. A transport bridge for prefabricated box girders according to claim 3, characterized in that: A first distribution beam (5) is provided between the Bailey beam (6) and the bridge deck (4), and the first distribution beam (5) is arranged transversely to the bridge.

5. A transport bridge for prefabricated box girders according to claim 4, characterized in that: A V-shaped clip is provided at the intersection of the Bailey beam (6) and the first distribution beam (5), wherein the V-shaped clip is a steel plate with a V-shaped groove, and two edges of the V-shaped groove are respectively connected to the upper chord of the Bailey beam (6) and the bottom of the first distribution beam (5).

6. A transport bridge for prefabricated box girders according to any one of claims 3 to 5, characterized in that: The starting section (101), the middle section (102) and the merging section (103) are all straight line sections, and there is an angle between two adjacent bridge sections.

7. A transport bridge for prefabricated box girders according to claim 6, characterized in that: The steel columns (8) of the piers below the connection area of ​​two adjacent bridge sections are arranged in double rows, and each row of the steel columns (8) is arranged along the transverse direction of the bridge. The tops of the corresponding steel columns (8) between the two rows are provided with a main crossbeam (7) along the direction of the bridge, and the main crossbeam (7) is provided with two crossbeams (11) in the transverse direction of the bridge. The top surfaces of the two crossbeams (11) are respectively connected to the Bailey beams (6) of the two adjacent bridge sections.

8. A transport bridge for prefabricated box girders according to claim 7, characterized in that: A second distribution beam (13) along the bridge direction is connected between two adjacent bridge sections, and two ends of the second distribution beam (13) are respectively connected to the Bailey beams (6) of the two adjacent bridge sections. When the span of the second distribution beam (13) is greater than or equal to 800 mm, a support portion is provided between the second distribution beam (13) and the main cross beam (7).

9. A construction method for a transport bridge of prefabricated box girders, characterized in that: A transport bridge for prefabricated box girders as claimed in claim 8, comprising the following steps: S1: constructing a pile foundation (10) in the foundation below the corresponding installation position of the steel column (8), constructing a tie beam (9) on the top of the pile foundation (10), and simultaneously constructing embedded parts on the tie beam (9); S2: hoisting the steel column (8) onto the tie beam (9) and connecting it with the corresponding embedded parts; S3: hoisting the main cross beam (7) to the top of the corresponding steel column (8), and installing the main cross beam (7) in the transverse direction of the bridge; the main cross beam (7) below the connecting area of ​​two adjacent bridge sections is installed in the longitudinal direction of the bridge, and the cross beam (11) in the transverse direction of the bridge is installed above the main cross beam (7) installed in the longitudinal direction of the bridge; S4: hoisting the assembled Bailey beam (6) onto the main crossbeam (7) or the crossbeam (11) for installation and fixing; S5: hoisting the first distribution beam (5) onto the Bailey beam (6) for installation and fixing, welding a steel connection piece between two adjacent first distribution beams (5), and installing a V-shaped clip at the intersection of the Bailey beam (6) and the first distribution beam (5); S6: below the predetermined installation position of the second distribution beam (13), and when the span of the second distribution beam (13) is greater than or equal to 800 mm, a support portion is installed on the main cross beam (7) installed along the bridge below the second distribution beam (13), and then the second distribution beam (13) is hoisted to the predetermined position, and the two ends of the second distribution beam (13) are connected to the Bailey beam (6), and the bottom of the second distribution beam (13) is connected to the support portion; S7: Laying the bridge deck (4) above the first distribution beam (5) and the second distribution beam (13) to complete the construction of the transport bridge.

10. A construction method for a transport bridge for prefabricated box girders according to claim 9, characterized in that: In step S3, the main cross beam (7) installed in the transverse direction of the bridge is divided into a plurality of sections. After the main cross beam (7) is hoisted in sections to the top of the steel column (8), the sections of the steel column (8) are welded on site. The lower part of the sections of the main cross beam (7) must be located at the top of the steel column (8), and the sections of the main cross beam (7) must not be located directly below the walking track of the wheels of the beam transport vehicle.

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