Pier-beam-cap beam integrated road-rail double-deck viaduct and construction method

Abstract

The present invention relates to a pier-beam-capping integrated public-rail double-deck viaduct and a construction method, and the construction method comprises the following steps: pre-embedded adjustment bracket installation; hoisting of the first section of the steel cage of the pier; foundation casting; casting of the lower pier; integrated casting of the lower pier and the track beam; casting of the upper pier; integrated casting of the upper pier and the capping beam. The beneficial effects of the present invention are: the installation accuracy of the bottom of the first section of the steel cage of the pier is improved by pre-embedded adjustment brackets, #-shaped steel fixing frames and positioning steel plates; the leakage of concrete during the pouring of the pier is reduced by sponge strips; the steel clamp is installed on the steel pipe column by bolts, which improves the efficiency of the diagonal bracing connection between the column steel pipes and reduces the damage to the steel pipe caused by welding; the formwork system consisting of steel pipe columns + Bailey beams + formwork trusses + templates is used to support the track beams and capping beams, thereby avoiding the impact on the traffic of existing roads; the piers, beams and capping beams are integrally cast without joints and are durable.

Description

Technical Field

[0001] The present invention relates to a pier-crossbeam-cap beam integrated road-rail double-deck viaduct and a construction method, which is mainly suitable for the construction of a road-rail double-deck viaduct with complex terrain at the project site, high piers, some piers and cap beam cantilever ends adjacent to or located on existing roads, large traffic flow, great difficulty in traffic diversion and organization during the construction period, large span and variation of structural dimensions, and high safety risks. Background Art

[0002] With the rapid development of my country's economy, bridge construction has developed rapidly. In particular, in the past 20 years, my country has built nearly 100 bridges, pushing my country's bridge construction level to the forefront of the world. Among them, urban viaducts, especially double-deck bridges for road and rail (rail), have developed rapidly as an effective way to solve urban traffic congestion caused by urbanization.

[0003] A double-deck bridge is not a simple superposition of single-deck bridges. The increasing demand for double-deck bridges has brought new challenges to the structure's construction organization, construction measures, construction methods, and construction machinery and equipment.

[0004] At present, the casting height of the piers of my country's double-deck elevated bridges is relatively high, the types of lower structures are diverse, the styles are complex, and the span and variation of structural dimensions are large, which leads to the following problems during the construction process: 1) The self-weight of the first section of the steel cage of the pier column affects the pre-embedded installation accuracy of the first section of the steel cage; 2) During the pouring of the pedestal concrete, the first section of the steel cage of the pier column is easy to deform under the action of gravity due to its large size, and the verticality and inclination of the main reinforcement of the steel cage are difficult to accurately limit; 3) Due to the high height of the pier column, the contact surface between the flip mold system and the pedestal is not tight, which is easy to leak; 4) The cross-section steel connection between the steel pipe columns of the crossbeam and cap beam formwork system is welded. Type connection not only destroys standard steel pipe fittings and shortens their service life, but also has low welding construction efficiency, high cost, and great difficulty in later demolition; 5) When piers, beams and cap beams are adjacent to or located on existing roads, they have a great impact on traffic. The styles of piers, beams and cap beams are complex, the span and variation of structural dimensions are large, the construction is complex and the cycle is long; 6) When the piers are high, the construction of piers, beams and cap beams is high-altitude operation, which is very dangerous and difficult to control in quality; when cast separately, the piers and beams, cap beams and other components are independent structures, the integrity of the connection is poor, and the quality requirements for joint treatment are high. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a pier-beam-cap beam integrated road-rail double-deck viaduct and a construction method.

[0006] The pier-beam-capping beam integrated road-rail double-deck viaduct comprises a cap, a lower pier, an upper pier, a track beam, a capping beam and a pre-buried adjustment bracket; the lower pier and the upper pier are connected up and down, and a pier steel cage and an upper pier steel cage are respectively arranged in the lower pier and the upper pier, the bottom section of the pier steel cage is the first section steel cage of the pier, and the bottom of the first section steel cage of the pier is connected to the pre-buried adjustment bracket in the cap; a #-shaped steel fixing frame is arranged around the first section steel cage of the pier, and a main reinforcement positioning steel plate is arranged between the #-shaped steel fixing frame and the first section steel cage of the pier;

[0007] The pier column reinforcement cages on the top of the lower pier columns on both sides are connected to the track beam reinforcement cages in the track beam, and a formwork system is provided between the track beam and the pedestal; the formwork system includes steel pipe columns, transverse Bailey beams and track beam formworks, and the steel pipe columns are vertically connected to the pedestal and the lower top beam; the steel pipe columns are vertically connected to a plurality of steel hoops through bolts, and a transverse diagonal bracing structure is provided between the steel hoops; the lower top beam is connected to the transverse Bailey beam through the upper top beam and the sand cylinder in turn, and the track beam formwork is connected to the track beam formwork through the distribution beam and the track beam formwork truss above the transverse Bailey beam;

[0008] The top of the upper pier column steel cage in the upper pier column is connected to the cap beam steel cage in the cap beam; a formwork system is also provided under the cap beam, but a double-layer extended transverse Bailey beam is connected above the sand cylinder in the formwork system of the cap beam, and the distribution beam, cap beam formwork truss and cap beam formwork are connected in sequence above the double-layer extended transverse Bailey beam.

[0009] As a preferred embodiment: a circle of sponge strips is provided around the #-shaped steel fixed frame on the upper edge of the pedestal, the outer side formwork of the first section of the steel cage of the pier column is supported on the sponge strips, the width of the sponge strips is at least 10 cm larger than the thickness of the lower pier column mold; the main reinforcement positioning steel plate is provided with main reinforcement positioning grooves, the main reinforcement positioning grooves match the main reinforcement positions of the first section of the steel cage of the pier column; the outer formwork of the lower pier column is connected to the ground by a wind cable.

[0010] Preferably: the embedded adjustment bracket is square in shape, the size of the embedded adjustment bracket matches that of the first section of the steel cage of the pier column, the embedded adjustment bracket comprises an enclosing limiting steel plate, a supporting steel plate and a main reinforcement positioning sleeve; the supporting steel plate is arranged on the inner side of the enclosing limiting steel plate, the top surface height of the supporting steel plate is lower than that of the top surface height of the enclosing limiting steel plate, the supporting steel plate is provided with a main reinforcement positioning sleeve, and the main reinforcement positioning sleeve matches the main reinforcement position of the first section of the steel cage of the pier column.

[0011] Preferably, a lower plate is provided between the lower top beam and the upper top beam in the formwork system, an upper plate is provided between the lower plate and the sand cylinder, a shock-absorbing rubber sheet and a limiter are provided between the sand cylinder and the lower chord of the transverse Bailey beam; a shock-absorbing rubber sheet and a limiter are also provided between the sand cylinder and the double-layer extended transverse Bailey beam.

[0012] Preferably, the double-layered extended transverse Bailey beam is a two-layer structure of upper and lower layers, and the upper and lower layers of the double-layered extended transverse Bailey beam are connected by reinforcing vertical rods.

[0013] The construction method of the pier-beam-cap beam integrated road-rail double-deck viaduct comprises the following steps:

[0014] S1. Installation of embedded adjustment bracket: Customize the embedded adjustment bracket, tie the steel cage of the cap and then support the cap template, and weld the embedded adjustment bracket to the steel cage of the cap;

[0015] S2. Hoisting of the first section of the steel cage of the pier column: tie and hoist the first section of the steel cage of the pier column, insert the main reinforcement of the first section of the steel cage of the pier column into the main reinforcement positioning sleeve, assemble the steel cage of the pier column and the steel cage of the upper pier column, and install the #-shaped steel fixing frame;

[0016] S3, foundation pouring: pouring concrete on the foundation and roughening it;

[0017] S4. Casting of lower pier column: glue a circle of sponge strips around the #-shaped steel fixing frame at the top of the cap, remove the main reinforcement positioning steel plate and the #-shaped steel fixing frame, install the template of the lower pier column and cast concrete, and keep the top section of the lower pier column without casting;

[0018] S5. Integral casting of lower pier column and track beam: set up the formwork system of track beam on the cap, tie the track beam steel cage to the track beam formwork and the pier steel cage of the uncast section at the top of the lower pier column respectively; then integrally cast the uncast section at the top of the lower pier column and the track beam;

[0019] S6. Casting of upper pier columns: The upper pier columns are molded in sections and concrete is poured to a certain distance below the cap beam;

[0020] S7. Integrated casting of upper pier and cap beam: dismantle the formwork system of the track beam, and set up the formwork system of the cap beam. Tie the cap beam reinforcement cage to the cap beam formwork and the upper pier reinforcement cage of the uncast section of the upper pier respectively; then, cast the uncast section at the top of the upper pier and the cap beam in an integrated manner.

[0021] Preferably, in step S2: after the main reinforcement positioning sleeve is inserted into the bottom of the first section of the steel cage of the pier column, an #-shaped steel fixing frame is installed around the first section of the steel cage of the pier column on the top of the base formwork, the main reinforcement positioning steel plate is fixed on the #-shaped steel fixing frame, the main reinforcement of the first section of the steel cage of the pier column is embedded into the main reinforcement positioning groove of the main reinforcement positioning steel plate, and the verticality of the first section of the steel cage of the pier column is corrected; after the verticality correction of the first section of the steel cage of the pier column is completed, the hook on the top of the first section of the steel cage of the pier column is released to completely unload.

[0022] Preferably, step S3 specifically includes: reviewing the position of the reinforcement cage and formwork of the cap, casting the cap, and when the concrete strength of the cap reaches 2.5 MPa, roughening the concrete within the pier body range of the cap top surface.

[0023] Preferably, in step S4: the formwork structure of the lower pier column adopts a flip mold system, and the flip mold system is supported on a sponge strip; external tie rods are used for the tie rods between the formworks, and the standard segment flip mold system of the lower pier column is installed by a car crane flip cycle; after the first section of the lower pier column formwork is assembled, it is stabilized by evenly and symmetrically arranging wind cables and rope tighteners around the pier body formwork; then the first flip mold concrete of the lower pier column is poured, and after the first concrete strength reaches the requirement, the formwork is removed from bottom to top, and the formwork is installed again in the next pouring section and poured, and the above steps are repeated, and finally the formwork is installed at the topmost section of the lower pier column, but no pouring is done.

[0024] The beneficial effects of the present invention are:

[0025] 1) The present invention improves the installation accuracy of the bottom of the first section of the pier column steel cage by pre-embedded adjustment brackets, #-shaped steel fixing frames and positioning steel plates, ensures the accurate positioning of the first section of the pier column steel cage above the pedestal during the pouring process of the pedestal, and reduces its deformation.

[0026] 2) The present invention reduces the leakage of concrete during the pouring of pier column concrete by arranging a sponge strip between the pier column bottom section overmolding system and the cap.

[0027] 3) The present invention improves the connection efficiency of the diagonal braces between the column steel pipes by installing steel hoops on the steel pipe columns and fixing the transverse diagonal brace structure through the steel hoops; the steel hoops are fixed to the steel pipe columns by bolts, which reduces the damage to the steel pipes caused by welding and prolongs the cycle service life of the steel pipes.

[0028] 4) The present invention adopts a formwork system consisting of steel pipe columns + Bailey beams + formwork trusses + formwork to support the track beams and cap beams, avoiding the impact of setting up full-floor supports on the traffic of existing roads. The formwork system has a simple structure, a short construction period and low safety risks.

[0029] 5) The piers, cross beams and cap beams of the present invention are integrally cast, and the three form a whole without any joint processing links, with good appearance quality, strong bridge integrity, large bearing capacity and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall formation of the pier column-crossbeam-cap beam integrated road rail double-deck viaduct of the present invention;

[0031] Figure 2 It is an overall schematic diagram of the first section of the steel cage of the pier column of the present invention being placed on the pre-embedded adjustment bracket in the cap;

[0032] Figure 3 It is a plane schematic diagram of the embedded adjustment bracket of the present invention;

[0033] Figure 4 It is a schematic diagram of the connection between the first section of the steel cage of the pier column of the present invention and the embedded adjustment bracket;

[0034] Figure 5 It is a schematic diagram of the connection between the first section of the steel cage of the pier column of the present invention and the embedded adjustment bracket;

[0035] Figure 6 This is a simplified diagram of the #-shaped steel fixed frame structure of the present invention;

[0036] Figure 7 It is a top view of the connection between the #-shaped steel fixed frame structure and the main reinforcement positioning steel plate of the present invention;

[0037] Figure 8 This is a structural diagram of the main reinforcement positioning steel plate of the present invention;

[0038] Fig. 9 This is a front structural diagram of the connection between the #-shaped steel fixed frame structure and the main reinforcement positioning steel plate of the present invention;

[0039] Fig.10 This is a structural diagram of the #-shaped steel fixed frame structure of the present invention being sleeved around the first section of the steel cage of the pier column;

[0040] Fig.11 It is a schematic diagram of the track beam formwork system structure of the present invention;

[0041] Fig.12 It is an enlarged view of the local structure of the track beam formwork system of the present invention;

[0042] Fig.13 This is a schematic diagram of the cap beam formwork system structure of the present invention;

[0043] Fig.14 It is a construction process flow chart of the present invention.

[0044] Explanation of reference numerals: 1-cap; 2-lower pier; 3-upper pier; 4-track crossbeam; 5-cap beam; 6-embedded adjustment bracket; 7-first section steel cage of pier; 8-wind cable; 9-enclosed limiting steel plate; 10-supporting steel plate; 11-main reinforcement positioning sleeve; 12-#-shaped steel fixing frame; 13-main reinforcement positioning steel plate; 14-main reinforcement positioning groove; 15-sponge strip; 16-steel pipe column; 17-steel hoop; 18-cross-connecting diagonal bracing structure; 19-lower top beam; 20 -Upper top beam; 21-Sand cylinder; 22-Transverse Bailey beam; 23-Distribution beam; 24-Pier column reinforcement cage; 25-Track beam reinforcement cage; 26-Lower plate; 27-Upper plate; 28-Shock-absorbing rubber sheet; 29-Bailey beam lower chord; 30-Track beam formwork truss; 31-Track beam formwork; 32-Double-layer extended transverse Bailey beam; 33-Reinforced vertical bar; 34-Cap beam formwork truss; 35-Cap beam formwork; 36-Upper pier column reinforcement cage, 37-Cap beam reinforcement cage. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0046] Embodiment 1

[0047] As an example, Figures 1 to 13 As shown, a pier-beam-capping beam integrated road-rail double-deck viaduct comprises a cap 1, a lower pier 2, an upper pier 3, a track beam 4, a capping beam 5 and a pre-embedded adjustment bracket 6; the lower pier 2 and the upper pier 3 are connected up and down, and a pier steel cage 24 and an upper pier steel cage 36 are respectively arranged in the lower pier 2 and the upper pier 3, the bottommost section of the pier steel cage 24 is the pier first section steel cage 7, and the bottom of the pier first section steel cage 7 is connected to the pre-embedded adjustment bracket 6 in the cap 1; the bottom of the pier first section steel cage 7 is accurately positioned and fixed by the pre-embedded adjustment bracket 6, and the The embedded adjustment bracket 6 is embedded in the process of pouring the pedestal 1. Its size is customized according to the size of the first section of the steel cage 7 of the pier column. It is square in shape as a whole and mainly consists of three parts: an enclosing limiting steel plate 9, a supporting steel plate 10, and a main reinforcement positioning sleeve 11. The supporting steel plate 10 is on the inner side of the enclosing limiting steel plate 9, and its top surface height is lower than the top surface height of the enclosing limiting steel plate 9, presenting a "groove" structure. The main reinforcement positioning sleeve 11 is evenly fixed on the supporting steel plate 10 at a designed interval. The main reinforcement of the first section of the steel cage 7 of the pier column is inserted into the main reinforcement positioning sleeve 11 for precise positioning.

[0048] A #-shaped steel fixing frame 12 is arranged around the first section steel cage 7 of the pier column. The #-shaped steel fixing frame 12 is made of I-beams, and its height is determined according to the height of the first section steel cage 7 of the pier column. Multiple horizontal cross-connections are arranged in the middle to enhance the integrity.

[0049] A main reinforcement positioning steel plate 13 is provided between the #-shaped steel fixing frame 12 and the first section reinforcement cage 7 of the pier column; a plurality of main reinforcement positioning grooves 14 are provided in the main reinforcement positioning steel plate 13, and the size and spacing of the main reinforcement positioning grooves 14 are processed and manufactured according to the main reinforcement profile of the first section reinforcement cage 7 of the pier column. The main reinforcement of the first section reinforcement cage 7 of the pier column is embedded in the main reinforcement positioning groove 14 to accurately limit the first section reinforcement cage 7 of the pier column.

[0050] Mortar is used to level the base 1 and the pier formwork, and a layer of sponge strip 15 is bonded around the #-shaped steel fixed frame 12. The outer formwork of the first section of the pier steel cage 7 is supported on the sponge strip 15, and the width of the sponge strip 15 is at least 10 cm thicker than the thickness of the lower pier 2 mold.

[0051] The pier column reinforcement cage 24 on the top of the lower pier columns 2 on both sides is connected to the track beam reinforcement cage 25 in the track beam 4, and a formwork system is provided between the track beam 4 and the pedestal 1; the formwork system includes steel pipe columns 16, transverse Bailey beams 22 and track beam templates 31, and the steel pipe columns 16 are vertically connected to the pedestal 1 and the lower top beam 19; the steel pipe columns 16 are provided with steel hoops 17 at uniform vertical intervals, and the steel hoops 17 are detachable arc-shaped steel hoops, and the steel hoops 17 are tightened with bolts after tightening the steel pipe columns 16, and a plurality of high-strength bolt connection holes are provided on the steel hoops 17, and the transverse diagonal bracing structures 18 are fixed between the steel hoops 17 by high-strength bolts. Lower plates 26 are welded to the upper parts of both ends of the lower top beam 19, upper top beams 20 are evenly arranged on the lower plates 26, upper plates 27 are welded to the upper top beams 20, sand cylinders 21 are fixed on the upper plates 27, shock-absorbing rubber sheets 28 are placed on the top of the sand cylinders 21, lower chords 29 of the Bailey beams are placed on the shock-absorbing rubber sheets 28, and limiters are welded, and the transverse Bailey beams 22 are connected by scissor struts. After the elevation of the transverse Bailey beams 22 is accurately adjusted by the sand cylinders 21, I32a steel distribution beams 23 are evenly arranged on the top of the transverse Bailey beams 22, and the track beam formwork trusses 30 made in advance in the factory are hoisted and placed on the distribution beams 23 and fixed, and the track beam formwork 31 is laid on the top of the track beam formwork trusses 30.

[0052] The intersection section of the lower pier 2 and the track cross beam 4 is cast into one piece by using the integral integrated casting technology.

[0053] The top of the upper pier column reinforcement cage 36 in the upper pier column 3 is connected to the cap beam reinforcement cage 37 in the cap beam 5; the cap beam 5 is also provided with a formwork system below, but the double-layered extended transverse Bailey beam 32 is connected above the sand cylinder 21 in the formwork system of the cap beam 5. The double-layered extended transverse Bailey beam 32 is an upper and lower two-layer structure, which is placed on the sand cylinder 21 and connected by a reinforcing vertical rod 33. The distribution beam 23, the cap beam formwork truss 34 and the cap beam template 35 are connected in sequence above the double-layered extended transverse Bailey beam 32.

[0054] The uncast section at the top of the upper pier 3 and the cap beam 5 are integrally cast and formed.

[0055] Embodiment 2

[0056] According to the pier column-cross beam-cap beam integrated road rail double-deck viaduct proposed in the first embodiment, the present embodiment proposes a construction method of the pier column-cross beam-cap beam integrated road rail double-deck viaduct, such as Fig.14 As shown, the following steps are included:

[0057] S1. Installation of embedded adjustment bracket: Before construction, measurements and layout shall be carried out according to multiple factors such as site conditions, tower crane operating range, vehicle transportation channel, etc., and the flatness, strength and rigidity of the template shall be tested. The embedded adjustment bracket 6 shall be customized in advance in the factory according to the size of the first section of the steel cage 7 of the pier column, the steel cage of the pedestal 1 shall be tied, the template of the pedestal 1 shall be supported, and the embedded adjustment bracket 6 shall be welded to the steel cage of the pedestal 1 according to the designed position.

[0058] S2. Hoisting of the first section of the steel cage of the pier column:

[0059] The first section of the steel cage 7 of the pier column is tied in advance according to the designed diameter and length. The first section of the steel cage 7 of the pier column is hoisted by a special hanger for the steel cage, and is hoisted to the pre-embedded adjustment bracket 6 on the cap 1. It is kept vertical, gently and slowly placed. The position of the steel cage is adjusted manually with the help of a truck crane, so that all the main bars of the steel cage are inserted into the main bar positioning sleeve 11 of the pre-embedded adjustment bracket 6, and the sleeve is tightened;

[0060] After the bottom of the first section of the pier column steel cage 7 is tightened, the #-shaped steel fixing frame 12 is installed on the top of the cap 1 template. The #-shaped steel fixing frame 12 surrounds the first section of the pier column steel cage 7. The main reinforcement positioning steel plate 13 is fixed on the #-shaped steel fixing frame 12 in time, and the verticality of the first section of the pier column steel cage 7 is corrected, so that the main reinforcement of the first section of the pier column steel cage 7 is embedded in the main reinforcement positioning groove 14 of the main reinforcement positioning steel plate 13, so as to accurately limit the first section of the pier column steel cage 7 before the cap 1 concrete is poured; and the pier column steel cage 24 and the upper pier column steel cage 36 are assembled;

[0061] After the bottom and the top of the first section of the steel cage 7 of the pier column are accurately limited, the automobile hook on the top of the first section of the steel cage 7 of the pier column is released to completely unload.

[0062] S3. Pouring of cap concrete: Check the position of the steel cage and formwork of cap 1, pour concrete, and after the construction of cap 1 is completed and the concrete strength reaches 2.5MPa, roughen the concrete within the pier body range of the top surface of cap 1.

[0063] S4. Concrete pouring of lower pier column:

[0064] The mortar is used to level the mold support range of the lower pier 2 at the top of the cap 1, and the sponge strip 15 is bonded. The sponge strip 15 surrounds the #-shaped steel fixed frame 12 in one circle. The width of the sponge strip 15 is at least 10 cm greater than the thickness of the mold of the lower pier 2;

[0065] After the concrete strength of the cap 1 reaches the design requirements, take protective measures for the sponge strip 15, and remove the main reinforcement positioning steel plate 13 and the #-shaped steel fixing frame 12 in sequence;

[0066] The formwork structure of the lower pier column 2 adopts a flip mold system, which is supported on a sponge strip 15. The tie rods between the templates are external tie rods. The installation of the standard segment flip mold system of the lower pier column 2 adopts a car crane flip cycle. After the first section of the lower pier column 2 template is assembled, four wind cables 8 are evenly and symmetrically arranged around the pier body template, and a rope tightener is set on the wind cable 8 to ensure the stability of the pier body;

[0067] Pour the first formwork concrete for the lower pier 2, and the pouring height is consistent with the design drawing. After the first concrete strength reaches the requirement, remove and install the formwork from bottom to top, pour the concrete for the second time or more, and finally reserve the top section of the formwork without pouring, as the fixed end for the support system of the formwork for pouring concrete in the next section.

[0068] S5. Integrated casting of lower pier and track beam:

[0069] A steel pipe column 16 is erected on the cap 1, and steel hoops 17 are installed at uniform vertical intervals on the steel pipe column 16. A transverse diagonal bracing structure 18 is fixed between the steel hoops 17 by high-strength bolts. A 45# steel lower top beam 19 is welded on the top of the steel pipe column 16, and a lower plate 26 is welded on the top of the lower top beam 19. A 22# steel upper top beam 20 is evenly placed on the lower plate 26. An upper plate 27 is welded on the upper part of the upper top beam 20. A sand cylinder 21 is placed on the upper plate 27. A shock-absorbing rubber sheet 28 is placed on the top of the sand cylinder 21. The transverse Bailey beam 22 assembled in advance is hoisted and placed on the shock-absorbing rubber sheet. 28, weld the limiter, connect the transverse Bailey beams 22 with scissors struts, accurately adjust the elevation of the transverse Bailey beam 22 with the sand cylinder 21, evenly arrange the I32a steel distribution beam 23 on the top of the transverse Bailey beam 22, lift the track beam formwork truss 30 made in the factory in advance, place it on the distribution beam 23, and fix it, lay the track beam formwork 31 on the top of the track beam formwork truss 30, pre-arch the track beam formwork truss 30 and the track beam formwork 31, and pre-press them to test whether their bearing capacity and deformation meet the design requirements.

[0070] Tie the track beam reinforcement cage 25 on the track beam template 31, tie the track beam reinforcement cage 25 and the pier reinforcement cage 24 of the uncast section of the lower pier 2 together, and check the elevation and position of the reinforcement cage.

[0071] The uncast section of the lower pier column 2 is cast integrally with the track cross beam 4. During the casting process, the lower pier column 2 and the track cross beam 4 are cast integrally by vibrating in layers without leaving a construction joint.

[0072] S6. Upper pier column construction: After the concrete of the track beam 4 reaches a certain strength, the upper pier column 3 is turned over and the concrete is poured in sections until a certain distance from the bottom of the cap beam 5 is reached.

[0073] S7. Integrated casting of upper pier column and cap beam:

[0074] The formwork system of the track beam 4 is dismantled from top to bottom, and the formwork system of the cap beam 5 is re-erected on the cap 1 according to the designed position, and the cap beam formwork system is preloaded.

[0075] Tie the upper pier column reinforcement cage and the cap beam reinforcement cage: tie the cap beam reinforcement cage 37 on the top of the cap beam formwork 35, tie the cap beam reinforcement cage 37 and the upper pier column reinforcement cage 36 of the uncast section of the upper pier column together, and check the elevation and position of the reinforcement cage;

[0076] The uncast section at the top of the upper pier column 3 is cast integrally with the cap beam 5. The casting process is vibrated layer by layer without leaving a construction joint, so that the upper pier column 3 and the cap beam 5 are cast into one piece.

Claims

1. A pier-beam-cap beam integrated road-rail double-deck viaduct, characterized in that: include: A cap (1), a lower pier column (2), an upper pier column (3), a track cross beam (4), a cap beam (5) and a pre-buried adjustment bracket (6); the lower pier column (2) and the upper pier column (3) are connected up and down, and a pier column steel cage (24) and an upper pier column steel cage (36) are respectively provided in the lower pier column (2) and the upper pier column (3); the bottom section of the pier column steel cage (24) is the first section steel cage (7) of the pier column, and the bottom of the first section steel cage (7) of the pier column is connected to the pre-buried adjustment bracket (6) in the cap (1); a #-shaped steel fixed frame (12) is provided around the first section steel cage (7) of the pier column, and the #-shaped steel fixed frame (12) and the first section steel cage of the pier column are connected to the pre-buried adjustment bracket (6) in the cap (1); (7); the embedded adjustment bracket (6) is square in shape, the embedded adjustment bracket (6) matches the size of the first section of the pier column reinforcement cage (7), the embedded adjustment bracket (6) comprises an enclosing limit steel plate (9), a supporting steel plate (10) and a main reinforcement positioning sleeve (11); the supporting steel plate (10) is arranged on the inner side of the enclosing limit steel plate (9), the top surface height of the supporting steel plate (10) is lower than the top surface height of the enclosing limit steel plate (9), the supporting steel plate (10) is provided with a main reinforcement positioning sleeve (11), and the main reinforcement positioning sleeve (11) matches the main reinforcement position of the first section of the pier column reinforcement cage (7); The pier column reinforcement cages (24) at the tops of the lower pier columns (2) on both sides are connected to the track beam reinforcement cages (25) in the track beam (4), and a formwork system is provided between the track beam (4) and the pedestal (1); the formwork system includes steel pipe columns (16), transverse Bailey beams (22) and track beam templates (31), and the steel pipe columns (16) are vertically connected to the pedestal (1) and the lower top beam (19); the steel pipe columns (16) are vertically connected to a plurality of steel hoops (17) by bolts, and a transverse bracing structure (18) is provided between the steel hoops (17); the lower top beam (19) is connected to the transverse Bailey beam (22) in turn through the upper top beam (20) and the sand cylinder (21), The track cross beam formwork (31) is connected to the top of the transverse Bailey beam (22) through a distribution beam (23) and a track cross beam formwork truss (30); a circle of sponge strips (15) are arranged around the #-shaped steel fixed frame (12) on the upper edge of the pedestal (1), and the outer template of the first section of the pier column steel cage (7) is supported on the sponge strips (15), and the width of the sponge strips (15) is at least 10 cm greater than the thickness of the lower pier column (2) mold; the main reinforcement positioning steel plate (13) is provided with a main reinforcement positioning groove (14), and the main reinforcement positioning groove (14) matches the main reinforcement position of the first section of the pier column steel cage (7); the outer template of the lower pier column (2) is connected to the ground through a wind cable (8); The top end of the upper pier column reinforcement cage (36) in the upper pier column (3) is connected to the cap beam reinforcement cage (37) in the cap beam (5); a formwork system is also provided below the cap beam (5), except that a double-layered extended transverse Bailey beam (32) is connected above the sand cylinder (21) in the formwork system of the cap beam (5), and a distribution beam (23), a cap beam formwork truss (34) and a cap beam formwork (35) are connected in sequence above the double-layered extended transverse Bailey beam (32).

2. The pier-beam-cap beam integrated road-rail double-deck viaduct according to claim 1, characterized in that: In the formwork system, a lower plate (26) is provided between a lower top beam (19) and an upper top beam (20); an upper plate (27) is provided between the lower plate (26) and a sand cylinder (21); a shock-absorbing rubber sheet (28) and a stopper are provided between the sand cylinder (21) and a Bailey beam lower chord (29) of a transverse Bailey beam (22); and a shock-absorbing rubber sheet (28) and a stopper are also provided between the sand cylinder (21) and a double-layered extended transverse Bailey beam (32).

3. The pier-beam-cap beam integrated road-rail double-deck viaduct according to claim 1, characterized in that: The double-layered elongated transverse Bailey beam (32) is a two-layer structure of upper and lower layers, and the upper and lower layers of the double-layered elongated transverse Bailey beam (32) are connected by a reinforcing vertical rod (33).

4. The construction method of the pier-beam-cap beam integrated road-rail double-deck viaduct as claimed in claim 1, characterized in that: The following steps are involved: S1. Installation of the embedded adjustment bracket: customizing the embedded adjustment bracket (6), tying the steel cage of the cap (1), and then supporting the template of the cap (1), and welding the embedded adjustment bracket (6) to the steel cage of the cap (1); S2, hoisting of the first section of the pier column reinforcement cage: tying and hoisting the first section of the pier column reinforcement cage (7), inserting the main reinforcement of the first section of the pier column reinforcement cage (7) into the main reinforcement positioning sleeve (11), assembling the pier column reinforcement cage (24) and the upper pier column reinforcement cage (36), and installing the #-shaped steel fixing frame (12); S3, pouring the cap: pouring concrete on the cap (1) and roughening it; S4, casting of the lower pier column: a circle of sponge strips (15) is bonded around the #-shaped steel fixing frame (12) at the top of the cap (1), and the main reinforcement positioning steel plate (13) and the #-shaped steel fixing frame (12) are removed, and the template of the lower pier column (2) is installed and concrete is poured, and the top section of the lower pier column (2) is retained without pouring; S5, integral casting of the lower pier column and the track beam: a formwork system for the track beam (4) is set up on the cap (1), and the track beam reinforcement cage (25) is respectively tied to the track beam template (31) and the pier column reinforcement cage (24) of the uncast section at the top of the lower pier column (2); then, the uncast section at the top of the lower pier column (2) and the track beam (4) are integrally cast; S6, casting of the upper pier column: the upper pier column (3) is molded in sections and concrete is poured to a certain distance below the cap beam (5); S7. Integral casting of the upper pier column and the cap beam: dismantle the formwork system of the track cross beam (4), and set up the formwork system of the cap beam (5), and tie the cap beam reinforcement cage (37) to the cap beam formwork (35) and the upper pier column reinforcement cage (36) of the uncast section of the upper pier column (3) respectively; then, integrally cast the uncast section at the top of the upper pier column (3) and the cap beam (5).

5. The construction method of the pier-beam-cap beam integrated road-rail double-deck viaduct according to claim 4 is characterized in that: In step S2: after the main reinforcement positioning sleeve (11) is inserted into the bottom of the first section of the pier column reinforcement cage (7), a #-shaped steel fixing frame (12) is installed around the first section of the pier column reinforcement cage (7) on the top of the foundation (1) template, the main reinforcement positioning steel plate (13) is fixed on the #-shaped steel fixing frame (12), and the main reinforcement of the first section of the pier column reinforcement cage (7) is embedded in the main reinforcement positioning groove (14) of the main reinforcement positioning steel plate (13) to correct the verticality of the first section of the pier column reinforcement cage (7); after the verticality correction of the first section of the pier column reinforcement cage (7) is completed, the hook on the top of the first section of the pier column reinforcement cage (7) is released to completely unload.

6. The construction method of the pier-beam-cap beam integrated road-rail double-deck viaduct according to claim 4, characterized in that: Step S3 specifically includes: checking the position of the steel cage and formwork of the cap (1), casting the cap (1), and when the concrete strength of the cap (1) reaches 2.5 MPa, roughening the concrete within the pier body range of the top surface of the cap (1).

7. The construction method of the pier-beam-cap beam integrated road-rail double-deck viaduct according to claim 4, characterized in that: In step S4: the formwork structure of the lower pier column (2) adopts a flip mold system, the flip mold system is supported on a sponge strip (15), the tie rods between the templates adopt external tie rods, and the standard segment flip mold system of the lower pier column (2) is installed by a car crane flip cycle; after the first section of the lower pier column (2) is assembled, it is stabilized by evenly and symmetrically arranging wind cables (8) and rope tighteners around the pier body template; then the first flip mold concrete of the lower pier column (2) is poured, and after the first concrete strength reaches the requirement, the template is removed from bottom to top, and the template is installed again in the next pouring section and poured, and the above steps are repeated. Finally, the template is installed at the topmost section of the lower pier column (2), but no pouring is done.

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