Fabricated prestressed concrete hollow slab bridge capable of being rapidly constructed and construction method of fabricated prestressed concrete hollow slab bridge

Abstract

The invention relates to a quickly constructed fabricated prestressed concrete hollow slab bridge and a construction method thereof. The construction method comprises the following steps: constructing concrete pile foundations, bottom straining beams and concrete upright posts; a cover beam hoop is installed, an I-shaped steel beam and a bottom formwork are installed and erected on the top in the transverse bridge direction, a formwork operation platform is laid, reinforcing steel bars are bound, and a concrete abutment cover beam is poured; fabricated prestressed concrete hollow slabs are manufactured, the fabricated prestressed concrete hollow slabs are hoisted to the position above a concrete pier and abutment cover beam one by one and fall to the designated position, the fabricated prestressed concrete hollow slabs are arranged in parallel in the transverse bridge direction, the width of longitudinal wet joints between the slabs is reserved, and after a reinforcing mesh is installed in the longitudinal wet joints between the slabs, the concrete wet joints are poured to form a hollow slab layer; and a reinforcing mesh is installed at the top of the hollow slab layer, then concrete pouring is conducted to form an integrated layer, and finally the bridge deck pavement layer is completed. The prestressed concrete hollow slabs with the inner cavities manufactured by thin-wall steel pipe hole forming are additionally arranged in the structure, and the beneficial effects of being good in forming effect, high in construction efficiency and short in construction period are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of the manufacture and construction of highway bridges at all levels, and particularly relates to a precast prestressed concrete hollow slab bridge for rapid construction and its construction method. Background Art

[0002] When newly built or rebuilt highways at all levels intersect with existing roads in a three-dimensional manner, in order to reduce congestion and improve traffic efficiency, it is often necessary to construct in the form of a newly built overpass bridge. At present, with the rapid development of the construction of highways at all levels, the number of overpass bridges spanning existing roads is increasing day by day. However, due to factors such as construction time, construction site, and under-bridge clearance restrictions, when cast-in-place beam slabs are used for bridges, a large amount of construction temporary measure costs need to be invested in construction, resulting in defects such as long construction periods, high costs, and high safety risks, and it cannot meet the construction needs of specific environments and construction progress requirements.

[0003] In some current engineering practices, precast beam slabs can be used for bridges, and prefabricated construction means can be applied. Compared with cast-in-place construction, it can effectively save construction measures and improve construction efficiency. Among them, precast hollow slabs are widely used beam types, which can simultaneously meet the characteristics and requirements of larger spans and smaller beam slab construction heights. However, in the production process of existing precast hollow slabs, it is difficult to demold the inner cavity, the top and bottom plates and the middle webs are thin, and it is easy to leak steel bars. The PVC pipes used for hole forming are easy to deform, be crushed and are not easy to fix. In addition, when the hollow slabs are connected by hinge joints, cracks and leaks are likely to occur, and the hinge joints are easy to be damaged after long-term use, resulting in the situation of single slab stress.

[0004] Therefore, it is necessary to propose new measures to overcome the above technical defects. Summary of the Invention

[0005] The purpose of the present invention is to provide a precast prestressed concrete hollow slab bridge for rapid construction and its construction method to solve the problems of poor durability of existing precast hollow slabs and easy occurrence of insufficient single slab stress.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] The construction method of a precast prestressed concrete hollow slab bridge for rapid construction, the construction method includes:

[0008] Construct concrete pile foundations;

[0009] Construct bottom tie beams and concrete columns on the top of the concrete pile foundations;

[0010] Install cap beam hoops, horizontally install and erect I-shaped steel beams and bottom formwork on the top of the cap beam hoops of multiple concrete columns, perform preloading treatment on the bottom formwork, then lay a formwork operation platform, bind steel bars and pour concrete pier cap beams;

[0011] For the inner cavity, thin-walled steel pipes are used to form holes for fabricating precast prestressed concrete hollow slabs. The precast prestressed concrete hollow slabs are hoisted one by one above the concrete pier cap beams, lowered to the designated positions, arranged horizontally in the transverse bridge direction, and a longitudinal wet joint width between the slabs is reserved. After installing a steel mesh in the longitudinal wet joint between the slabs, concrete wet joints are poured to form a hollow slab layer.

[0012] A steel mesh is installed on the top of the hollow slab layer, and then concrete is poured to form an integral layer, and finally the bridge deck pavement layer is completed.

[0013] Furthermore, construct concrete pile foundations, including:

[0014] Drive the protective piles into the soil layer, then bury the steel casing, drill the hole, hoist the steel reinforcement cage, and pour the concrete pile foundation.

[0015] Furthermore, construct a bottom tie beam and concrete columns on the top of the concrete pile foundation, including:

[0016] Chisel off the pile head at the top of the concrete pile foundation, bind the steel bars, and erect the formwork to pour the bottom tie beam;

[0017] Hoist the steel bar skeleton of the column and then erect the formwork to pour the concrete column.

[0018] Furthermore, before pouring the concrete of the integral layer, construct the end cross beam, including:

[0019] Bind and weld the steel bars of the end cross beam, and pour the concrete of the end cross beam after erecting the formwork.

[0020] On the other hand, provide a precast prestressed concrete hollow slab bridge constructed by the construction method as described above. The precast prestressed concrete hollow slab bridge includes a bridge body and the piers below it;

[0021] The piers include, from bottom to top, two concrete pile foundations, two bottom tie beams arranged horizontally in the transverse bridge direction at the tops of the two concrete pile foundations, two concrete columns, and two concrete pier cap beams arranged horizontally in the transverse bridge direction at the tops of the two concrete columns;

[0022] The bridge body includes, from bottom to top, precast prestressed concrete hollow slabs, an integral layer, and a bridge deck pavement layer. The precast prestressed concrete hollow slabs are laid longitudinally in the bridge direction on the tops of the concrete pier cap beams and are arranged horizontally and at intervals in the transverse bridge direction. The integral layer is constructed on the tops of the precast prestressed concrete hollow slabs.

[0023] Furthermore, a longitudinal wet joint is reserved between adjacent precast prestressed concrete hollow slabs in the transverse bridge direction. A steel mesh is arranged on the top of the precast prestressed concrete hollow slab and inside the longitudinal wet joint between the slabs. The integral layer is cast on the top of the precast prestressed hollow slab and the longitudinal wet joint between the slabs, forming a concrete wet joint between adjacent precast prestressed concrete hollow slabs in the transverse bridge direction.

[0024] Furthermore, the cross-section of the precast prestressed hollow slab is rectangular, and through holes are arranged longitudinally in the bridge direction inside the slab.

[0025] Furthermore, thin steel pipes are embedded inside the through holes. Studs are arranged at intervals with the stirrups inside the slab on the outer side of the thin steel plate of the thin steel pipe, and the ends of the thin steel pipes are sealed with steel plates.

[0026] Furthermore, prestressed steel tendons are arranged inside the webs of the precast prestressed concrete hollow slabs.

[0027] Furthermore, end cross beams are arranged at the ends of adjacent precast prestressed concrete hollow slabs in the longitudinal bridge direction and are connected through concrete wet joints.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] The present invention provides a precast prestressed concrete hollow slab bridge and its construction method with rapid construction, which optimizes the precast structure constructed by the existing precast and installation process of hollow slabs. The cross-section form adopts a rectangle, increasing the width of the hollow slab and reducing the number of hollow slabs arranged transversely. At the same time, two circular steel pipes are longitudinally formed inside the slab to avoid the situation that the hollow slab is difficult to demold. At the same time, studs are arranged on the outer side of the steel pipe to ensure the effective connection between the steel pipe and the concrete. The steel pipe serves as a bearing capacity reserve and can improve the service performance of the hollow slab.

[0030] The present invention not only improves the structural performance and mechanical performance of the precast prestressed concrete hollow slab, but also has the advantages of high construction efficiency and short construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is the transverse elevation view of the precast prestressed concrete hollow slab bridge in the embodiment of the present invention.

[0033] Figure 2 It is the longitudinal elevation view of the precast prestressed concrete hollow slab bridge in the embodiment of the present invention.

[0034] Figure 3 It is the general structure elevation view of the precast prestressed concrete hollow slab in the embodiment of the present invention.

[0035] Figure 4 It is the general structure plan view of the precast prestressed concrete hollow slab in the embodiment of the present invention.

[0036] Figure 5 It is the schematic diagram of the internal steel pipe and stud weld in the precast prestressed concrete hollow slab in the embodiment of the present invention.

[0037] Figure 6 It is the schematic diagram of the pier and abutment capping beam construction in the embodiment of the present invention.

[0038] The identifications in the figure are as follows:

[0039] 1 - Bridge body, 2 - Bridge pier, 3 - Capping beam hoop, 4 - Z-shaped climbing ladder, 5 - I-shaped steel beam, 6 - Bottom formwork, 7 - Formwork operation platform, 8 - End cross beam, 9 - Concrete wet joint, 10 - Bridge deck pavement layer, 11 - Integral layer, 12 - Precast prestressed concrete hollow slab, 13 - Thin steel pipe, 14 - Stud weld;

[0040] 21 - Concrete pier and abutment capping beam, 22 - Concrete column, 23 - Bottom tie beam, 24 - Concrete pile foundation. Specific embodiments

[0041] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0042] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "longitudinal", "transverse", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is 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 operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0043] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, terms such as "installation" and "setting" should be understood in a broad sense. For example, it can be fixedly connected and set, or detachably connected and set, or integrally connected and set. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] It should also be noted that although the order of steps is involved in the method description, in some cases, it can be executed in a different order from here and should not be understood as a limitation on the order of steps.

[0045] In the specific implementation manner, the length direction of the bridge is defined as the "longitudinal bridge direction", and the direction perpendicular to it is defined as the "transverse bridge direction". Figure 1 The direction from left to right in the figure is the "transverse bridge direction", and other drawings are consistent with this.

[0046] When newly built highways of all levels intersect with existing roads in a three-dimensional manner, a flyover can be used to cross the existing road. Considering the construction cost, when the clearance under the bridge is satisfied, the smaller the height of the superstructure of the newly built flyover, the shorter the section of the highway crossing the existing road, and the lower the construction cost. Therefore, the hollow slab is a widely used form. However, the construction of the existing hollow slab using hinge joints is relatively complex, and it is prone to poor durability and single-slab stress.

[0047] The present invention optimizes the body structure of the existing hollow slab. It adopts a rectangular cross-section, and the width of the beam slab is relatively wide, which can effectively reduce the number of beam slabs in the transverse bridge direction. Two longitudinally arranged circular steel pipes are provided inside the slab, and studs are arranged outside the steel pipes. During the precast stage, they are used as internal formwork to avoid demoulding. During the operation stage, they act as steel-concrete composite members and bear force together with the concrete structure of the hollow slab, improving the bearing capacity of the hollow slab. The transverse connection is made by wet joints, which can effectively improve the construction efficiency and shorten the precast cycle and construction cycle of the hollow slab. Specifically, the present invention provides a precast prestressed concrete hollow slab bridge for rapid construction, and the precast prestressed concrete hollow slab bridge includes a bridge body 1 and piers 2 below it.

[0048] The pier 2 includes, from bottom to top, two concrete pile foundations 24, a bottom tie beam 23 arranged transversely at the top of the two concrete pile foundations 24, two concrete columns 22, and a concrete pier cap beam 21 arranged transversely at the top of the two concrete columns 22.

[0049] The bridge body 1 includes, from bottom to top, precast prestressed hollow slabs 12, an integral layer 11, and a bridge deck paving layer 10. The precast prestressed hollow slabs 12 are longitudinally laid on the top of the concrete pier cap 21 and are arranged in parallel at intervals transversely across the bridge and connected by concrete wet joints 9. Reinforcement meshes are arranged on the top of the precast prestressed hollow slabs 12 and in the longitudinal expansion joints between the slabs. The integral layer 11 is cast on the top of the precast prestressed hollow slabs 12 and the longitudinal wet joints between the slabs, and the bridge deck paving layer 10 is paved on the top of the integral layer 11.

[0050] Among them, there are two through holes arranged longitudinally in the bridge direction in the precast prestressed hollow slab 12. Steel pipes are embedded inside the through holes, stud welds 14 are arranged on the outer side of the steel pipes, and the ends are sealed with steel plates. Prestressed steel bundles are arranged in the webs of the precast prestressed hollow slabs 12.

[0051] In addition, end cross beams 8 are provided between adjacent precast prestressed hollow slabs 12 longitudinally in the bridge direction and are connected by concrete wet joints 9.

[0052] Embodiment 1:

[0053] As Figure 1 and Figure 2 shown, this embodiment provides a precast prestressed concrete hollow slab bridge for rapid construction, specifically including a bridge body 1. On both sides below the bridge body 1, there are piers 2.

[0054] The bridge body 1 includes a hollow slab layer, an integral layer 11, and a bridge deck paving layer 10 arranged in sequence from bottom to top. The hollow slab layer is obtained by arranging multiple precast prestressed hollow slabs 12 in parallel transversely across the bridge and connecting them with longitudinal wet joints 9.

[0055] The pier 2 includes, from bottom to top, two concrete pile foundations 24, a bottom tie beam 23 arranged transversely across the bridge on the top of the two concrete pile foundations 24, two concrete columns 22, and a concrete pier cap 21 arranged transversely across the bridge on the top of the two concrete columns 22. The bottom of the precast prestressed hollow slab 12 is provided with a bearing and placed on the top of the concrete pier cap 21.

[0056] In this embodiment, the precast prestressed concrete hollow slab is applicable to a span of 20 m, the applicable bridge width is 9 m, the width of each precast prestressed concrete hollow slab 12 is 1.8 cm, the height is 0.96 m, the number of transverse arrangements is 4, and the thicknesses of the top plate, bottom plate, side web and middle web of the precast prestressed concrete hollow slab 12 are 21 cm, 15 cm, 20 cm and 20 cm respectively. Prestressed steel bundles are arranged inside the side web and the middle web, and the number of internal steel bundles is 9. In the specific design of this embodiment, considering that the inner cavity of the precast prestressed concrete hollow slab 12 cannot be demoulded, and the top plate, bottom plate and middle web are thin and prone to steel bar leakage, and when the precast prestressed concrete hollow slab 12 is precast, the PVC pipe is prone to deformation, crushing and difficult to fix, making it difficult to accurately control the originally thin slab thickness of the precast prestressed concrete hollow slab 12, so a steel pipe with a wall thickness of 6 mm is used to replace the PVC pipe, and the end is blocked with a round steel plate with a thickness of 10 mm.

[0057] In this embodiment, two through holes are provided on the precast prestressed concrete hollow slab 12. The longitudinal bridge direction through hole is 1.2 m away from the beam end of the hollow slab, the diameter of the through hole is 0.6 m, and the distance between the two through holes is 0.8 m. A steel pipe is embedded inside the through hole, the outer diameter of the steel pipe is 0.6 m, and the wall thickness of the steel pipe is 6 mm. At the same time, 8 studs are evenly arranged around the steel pipe, and the longitudinal bridge direction setting spacing is 300 mm to enhance the connection between the steel pipe and the concrete.

[0058] Embodiment 2:

[0059] This embodiment provides a construction method for the overpass described in Embodiment 1, which specifically includes:

[0060] S1: Construction of the pier 2, which specifically includes the following steps:

[0061] S11: Construction of the concrete pile foundation 24:

[0062] Drive the guide piles into the soil layer, then bury the steel casing, excavate the mud pit and sedimentation tank, then drill and clean the hole, hoist the steel reinforcement cage, and then clean the hole for the second time and pour the concrete to complete the construction of the concrete pile foundation 24, which specifically includes the following steps:

[0063] (1) Construction layout

[0064] Before excavating the foundation pit and burying the casing, 4 guide piles are led out from the center of the pile position, and the center of the pile foundation is accurately determined by pulling lines from the 4 guide piles, which is also convenient for rechecking during the drilling process and the positioning of the steel reinforcement cage. The guide piles are driven into the soil layer with steel bars and firmly wrapped with mortar.

[0065] (2) Burying the steel casing

[0066] The steel casing is adopted and made of steel plates with a thickness of not less than 12 mm. Its inner diameter is 30 cm larger than the pile diameter, and the inner diameter of the steel casing must be 30 cm larger than the pile diameter. The central axis of the casing is located at the center of the pile position, and the verticality of the steel casing is strictly controlled. The top of the steel casing should be not less than 0.3 m above the original ground surface, and it should be firmly buried and not leak. A slurry outlet with a height of 300 mm and a width of 200 mm is reserved at the upper part of the top section of the steel casing. The steel casing is buried by digging a hole to ensure that the top of the steel casing is 1.5 - 2.0 m above the groundwater level. The buried depth of the bottom of the steel casing: in water and where the riverbed is soft soil, silt, or sand, the buried depth of the bottom of the steel casing should be not less than 3 m. When the soft soil and silt layer is relatively thick, it should be buried into the impermeable soft soil layer by 1.0 - 1.5 m as much as possible. In general geology, the buried depth is not less than 2 m. The slurry level in the hole should be kept more than 1 m above the groundwater level.

[0067] (3) Excavate the slurry pit and sedimentation tank

[0068] For the pile foundation using an impact drill, a steel box for drilling and hole cleaning slurry pit and sedimentation tank should be placed nearby within not less than 2 m from the pile position. The capacity of the slurry pit is not less than 30 m3, and the sedimentation tank is not less than 12 m 3 . A filter screen is set between the slurry pit and the sedimentation tank. To fully improve the utilization rate of the slurry and prevent slurry from polluting the environment, the extracted slurry is reused after sedimentation and slag removal.

[0069] (4) Drilling and hole cleaning

[0070] When the drill is within 1 m above and below the foot of the steel casing, the stroke is controlled within 1 m. When it is below 1 m in the sand layer, the stroke is controlled between 1 - 2 m, and the slurry specific gravity is controlled between 1.35 - 1.40. After the drilling is completed, the slurry in the hole is removed.

[0071] (5) Hoist the steel reinforcement cage

[0072] The fabrication and installation process of the pile foundation steel reinforcement cage mainly includes the following links: material inspection upon arrival, semi-finished product processing, assembly and inspection of the steel reinforcement cage (including acoustic logging tubes), transportation of the steel reinforcement cage to the hole position, hoisting and sectional connection of the steel reinforcement cage, alignment and fixation, etc. Each link is constructed in sequence according to the technological requirements.

[0073] (6) Secondary hole cleaning and concrete pouring

[0074] The secondary hole cleaning adopts the slurry replacement method. Continuously input low-concentration slurry to the bottom of the hole through the conduit to replace the slurry in the hole, and continuously reduce the sand content rate and relative density of the slurry in the hole. Before pouring concrete, detect the five major indicators of the slurry: relative density, viscosity, sand content rate, colloid rate, and pH value. The slurry indicators after secondary hole cleaning are: relative density: 1.03 - 1.10; viscosity: 17 - 20 pa·s; sand content rate: < 2%. Before pouring concrete, the thickness of the sediment at the bottom of the hole should meet the requirements that for rock-socketed piles, it should not be greater than 5 cm, and for friction piles, it should not be greater than 10 cm. Finally, pour the pile foundation concrete to complete the construction of the concrete pile foundation 24.

[0075] S12. Construction of the bottom tie beam 23:

[0076] After the concrete pile foundation 24 passes the inspection, level and clean the surrounding site, and excavate the foundation pit with a slope of 1:1. Generally, the bottom of the foundation should be widened by 0.5 - 1 m compared to the size of the tie beam foundation. The construction of the bottom tie beam 23 adopts manual cooperation with an excavator to excavate the foundation pit. When excavation is difficult, pneumatic picks can be used for operation. After excavating to 20 cm above the designed elevation of the bottom, manually excavate to the bottom and level it. Use the circumcision method to break the pile head, and use an air compressor pneumatic pick to clean the cut pile head. After the foundation pit is excavated in place and the drainage work is done well, first lay a layer of C20 concrete cushion with a thickness of 10 cm at the bottom for leveling. After leveling, accurately set out the position of the tie beam. Make the steel bars into semi-finished products at the steel bar processing site, do a good job in numbering and hanging signs, and stack them neatly in categories. After passing the acceptance, use a crane and a flatbed truck to transport them to the corresponding pier positions. Install the tie beam steel bars on the cushion according to the set-out points and the protective layer thickness shown in the drawings. After the steel bar installation is completed, install the tie beam formwork, pour concrete and carry out maintenance, and then complete the construction of the bottom tie beam 23.

[0077] S13. Construction of the concrete column 22:

[0078] Chisel the top of the concrete pile foundation 24 and clean it. Then, use a total station to determine the center of the column, and use a ink line to pop the corresponding longitudinal and transverse axes of the column on the top of the concrete pile foundation 24, and leave corresponding leads for positioning when installing the formwork. Install the construction ladder.

[0079] Carry out steel bar processing and installation.

[0080] (1) The lap welding method is adopted for the steel bar connection of the pile-column joint. Before the steel bar welding construction, the rust, oil stains, sundries, etc. on the surface of the steel bar welding part and the contact surface between the steel bar and the electrode should be removed. When there are bends and twists at the end of the steel bar, it should be straightened. During the welding process, slag should be removed in time, the weld surface should be smooth, and the weld pit should be filled. When lap welding, the axes of the two connected steel bars should be consistent. The length of the double-sided weld should not be less than 5d, and the length of the single-sided weld should not be less than 10d.

[0081] (2) The steel bars are cut, fabricated, and welded into shape in the steel bar processing yard to form a steel cage. The surface of the steel bars should be clean, and before use, the oil stains, paint skins, scale rust, etc. on the surface should be removed. The steel bars should be straight and without local bends.

[0082] (3) The connection of the steel cage adopts straight thread sleeve connection.

[0083] (4) After the steel cage is processed and formed, it is transported to the site and installed by a crane. The steel cage should be lifted and lowered gently. During transportation, it is necessary to ensure that the steel cage does not deform and that the verticality of the steel cage meets the specification requirements. The steel bar spacing, quantity, and welds should all meet the design and specification requirements. The protective layer pads should be standard and firmly tied.

[0084] Install the column formwork. The column formwork adopts a composite formwork integrally rolled with a stainless steel panel and uses a water-based release agent. After the formwork installation is completed, pour the column concrete and promptly cover and sprinkle water for curing to complete the construction of the concrete column 22.

[0085] S14. Construction of the concrete pier and abutment cap beam 21:

[0086] After the construction of the concrete column 22 is completed, install the cap beam hoop 3, I-beam 5, and bottom formwork 6. After the installation is completed, preload the bottom formwork 6, then lay the formwork operation platform 7, carry out steel bar installation and concrete pouring. After the cap beam concrete is poured and reaches final setting, before the side formwork is removed, cover the top surface with geotextile and sprinkle water for curing; after removal, wrap it with geotextile and carry out drip irrigation curing. The concrete curing time is generally 7 days, and it can be appropriately extended according to the temperature to complete the construction of the concrete pier and abutment cap beam 21.

[0087] S2. Construction of the bridge body 1, specifically including the following steps:

[0088] S21. Construction of the hollow slab layer:

[0089] The hollow slab layer is obtained by arranging four precast prestressed concrete hollow slabs 12 in parallel in the transverse direction of the bridge. Specifically, lift the precast prestressed concrete hollow slabs 12 to the corresponding positions above the concrete pier and abutment cap beam 21 and number them. Then lower the precast prestressed concrete hollow slabs 12 to a position 10 - 15 cm above the concrete pier and abutment cap beam 21. After the shims are corrected, release the precast prestressed concrete hollow slabs 12, and then repeat the above steps to erect the remaining precast prestressed concrete hollow slabs 12. The steel bar processing of the concrete wet joint 9 and end cross beam 8 is carried out in the steel bar processing yard, transported by vehicle to the construction area, and the steel bars are tied and welded. After the formwork is installed, concrete is poured. After the pouring is completed, it is promptly covered with geotextile and sprinkled with water for curing until the construction of the hollow slab layer is completed.

[0090] S22. Construction of the integral layer 11:

[0091] The integral layer is constructed using a four-roller concrete screed. The four-roller concrete screed should travel at a uniform and slow speed to facilitate the formation of smooth and dense concrete. If local lack of material is found during the construction process, the material should be replenished in a timely manner and re-vibrated to ensure the one-time formation of the cast-in-place bridge deck, and then manually finish and level the surface. The specific construction sequence is the joint measurement of the beam surface elevation → chiseling off the floating slag and cleaning the top surface of the beam slab → laying the bridge deck steel mesh → pouring the bridge deck concrete → roughening and curing.

[0092] In this embodiment, the integral layer 11 includes a steel mesh binding layer and a concrete pouring layer. The steel mesh is arranged above the hollow slab layer. The steel mesh binding layer includes a plurality of longitudinal steel bars and a plurality of transverse steel bars, and the plurality of longitudinal steel bars and the plurality of transverse steel bars are arranged crosswise.

[0093] S23. Construction of the bridge deck pavement layer 10:

[0094] Clean the bridge deck, remove debris and dust, check the flatness of the base layer, and make necessary repairs and leveling.

[0095] Apply waterproof coating to ensure that the waterproof layer is uniform, without missed coating and air bubbles. Apply adhesive to enhance the bonding force between the pavement layer and the base layer. Use a paver to pave asphalt concrete, control the paving thickness and speed, and let the asphalt concrete cool naturally after paving to complete the construction of the bridge deck pavement layer.

[0096] The method of the present invention speeds up the construction progress and shortens the construction period. The beam slab has a rectangular cross-section, the beam slab width is relatively wide, and 2 longitudinal circular steel pipes arranged longitudinally along the bridge are provided inside the slab. During the precast stage, it is used as an inner mold to avoid demolding. During the operation stage, it serves as a steel-concrete composite member to bear force together with the hollow slab concrete structure, improving the bearing capacity of the hollow slab. The transverse connection uses wet joints. This kind of hollow slab structure is simple and the construction is convenient, avoiding the relatively complex construction of the conventional hollow slab using hinge joints, and it is easy to cause poor durability and single-slab loading.

[0097] The above uses specific examples to elaborate on the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the technical field to which the present invention belongs, according to the idea of the present invention, several simple deductions, deformations or substitutions can also be made.

Claims

1. Construction method of precast prestressed concrete hollow slab bridge for rapid construction, characterized in that: The construction method includes: Constructing concrete pile foundations (24); Constructing bottom tie beams (23) and concrete columns (22) on the top of the concrete pile foundations (24); Installing cap beam hoops (3), horizontally installing and erecting I-shaped steel beams (5) and bottom formworks (6) on the top of the cap beam hoops (3) of multiple concrete columns (22), preloading the bottom formworks (6), then laying formwork operation platforms (7), tying steel bars and pouring concrete pier and abutment cap beams (21); Making precast prestressed concrete hollow slabs (12) by forming holes with thin-walled steel pipes in the inner cavity, lifting the precast prestressed concrete hollow slabs (12) one by one above the concrete pier and abutment cap beams (21), lowering them to the designated positions, arranging them horizontally and parallel in the cross-bridge direction and reserving the longitudinal wet joint width between the slabs, installing steel bar meshes in the longitudinal wet joints between the slabs and then pouring concrete wet joints (9) to form a hollow slab layer; Installing steel bar meshes on the top of the hollow slab layer, then pouring concrete to form an integral layer (11), and finally completing the bridge deck pavement layer (10).

2. The construction method of precast prestressed concrete hollow slab bridge for rapid construction according to claim 1, characterized in that: Constructing the concrete pile foundations (24) includes: Driving the guide piles into the soil layer, burying the steel casing, drilling to form holes and hoisting the steel bar cages, and pouring the concrete pile foundations (24).

3. The construction method of precast prestressed concrete hollow slab bridge for rapid construction according to claim 2, characterized in that: Constructing the bottom tie beams (23) and the concrete columns (22) on the top of the concrete pile foundations (24) includes: Chiseling the pile heads at the top of the concrete pile foundations (24), tying steel bars, and erecting formworks to pour the bottom tie beams (23); Hoisting the column steel bar skeletons and then erecting formworks to pour the concrete columns (22).

4. The construction method of precast prestressed concrete hollow slab bridge for rapid construction according to claim 3, characterized in that: Before pouring the concrete of the integral layer (11), constructing the end cross beams (8), including: Tying and welding the end cross beam steel bars, and pouring the end cross beam concrete after erecting the formworks.

5. The precast prestressed concrete hollow slab bridge constructed by the construction method according to claim 1, characterized in that: The precast prestressed concrete hollow slab bridge includes a bridge body (1) and piers (2) below it; The piers (2) include, from bottom to top, two concrete pile foundations (24), bottom tie beams (23) horizontally arranged on the top of the two concrete pile foundations (24), two concrete columns (22), and concrete pier and abutment cap beams (21) horizontally arranged on the top of the two concrete columns (22); The bridge body (1) includes, from bottom to top, precast prestressed concrete hollow slabs (12), an integral layer (11), and a bridge deck pavement layer (10). The precast prestressed concrete hollow slabs (12) are longitudinally laid on the top of the concrete pier and abutment cap beams (21) and are horizontally arranged in parallel at intervals in the cross-bridge direction. The integral layer (11) is constructed on the top of the precast prestressed concrete hollow slabs (12).

6. The precast prestressed concrete hollow slab bridge according to claim 5, characterized in that: A longitudinal wet joint is reserved between adjacent precast prestressed concrete hollow slabs (12) in the transverse direction of the bridge. A steel mesh is arranged on the top of the precast prestressed concrete hollow slabs (12) and in the longitudinal wet joint between the slabs. The integral layer (11) is cast on the top of the precast prestressed hollow slabs (12) and the longitudinal wet joint between the slabs, forming a concrete wet joint (9) between adjacent precast prestressed concrete hollow slabs (12) in the transverse direction of the bridge.

7. The precast prestressed concrete hollow slab bridge according to claim 6, characterized in that: The cross-section of the precast prestressed hollow slab (12) is rectangular, and through holes arranged longitudinally along the bridge are provided inside the slab.

8. The precast prestressed concrete hollow slab bridge according to claim 7, characterized in that: A thin steel pipe (13) is embedded inside the through hole. Studs (14) arranged at intervals with the stirrups inside the slab are provided on the outer side of the thin steel plate of the thin steel pipe (13), and the ends of the thin steel pipe (13) are blocked by steel plates.

9. The precast prestressed concrete hollow slab bridge according to claim 8, characterized in that: Prestressed steel bundles are arranged in the webs of the precast prestressed concrete hollow slabs (12).

10. The precast prestressed concrete hollow slab bridge according to claim 9, characterized in that: End cross beams (8) are provided at the ends of adjacent precast prestressed concrete hollow slabs (12) longitudinally along the bridge and are connected through the concrete wet joint (9).

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