A construction method for a long-span bridge

Abstract

The invention discloses a construction method for a long-span bridge, and belongs to the technical field of bridge construction. The construction method of the invention includes: S1 foundation pit construction; S2 bridge pier construction: burying the embedded foundation block in the foundation pit, hoisting the base body, the installation platform and the solid pedestal in sequence above the embedded foundation block, and then tying the steel cage above the solid pedestal, enclosing the formwork, pouring concrete, and finally using the climbing formwork method to construct the thin-walled hollow variable diameter section, solid pier top and pier cap of the hollow thin-walled variable diameter pier; S3 prefabricated bridge deck foundation beams in sections; S4 using the cantilever construction method to connect each section of the bridge deck foundation beam into a whole; S5 using the bridge deck foundation beam body as a template, pouring concrete, and completing the bridge construction. The invention can effectively solve the problem that the hollow thin-walled piers are easy to crack during the use of existing long-span bridges, significantly improve the stability and service life of the bridge, and the construction operation is simple and convenient, which is conducive to reducing the construction and later maintenance costs.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, and more specifically, relates to a construction method for a long-span bridge. Background Art

[0002] For some prefabricated beam bridge piers in bridge engineering, when the bridge piers are high and the span is large, most of the lower structures are hollow thin-walled piers. Due to its super strong load-bearing capacity, hollow thin-walled piers have good structural rigidity and strength, light weight, large section modulus and small cross-sectional area, and can save materials and reduce the weight of bridge piers. At the same time, double-walled piers can improve the rigidity of bridge piers, reduce the negative bending moment of the main beam support, and increase the beauty of the bridge. Therefore, hollow thin-walled piers are widely used in high-altitude large-span bridges on railways and highways. In the prior art, there are various construction methods for hollow thin-walled piers, including sliding formwork construction method, climbing formwork construction method, flip formwork construction method, etc.

[0003] When the construction site of the hollow thin-walled pier is located on the water surface or on a geologically complex base surface, the foundation is located on the water surface or in a geologically soft area, especially in large-span bridges, so the hollow thin-walled pier is subjected to a lot of circumferential fluctuations. Not only is the construction process of the hollow thin-walled pier complicated, the construction difficulty is high, and the cost is high. In addition, when the bridge is put into use, the vibration of the large-span bridge deck is mainly concentrated on the upper end of the hollow thin-walled pier, which can easily cause the hollow thin-walled pier to shift in the lateral direction, and then the hollow thin-walled pier will crack, making the later repair and maintenance difficult and the maintenance cost high.

[0004] After searching, the Chinese patent application number is: 201510532564.4, the application date is: August 27, 2015, and the name of the invention is: Hollow thin-walled pier frame cap and bridge. The application includes a hollow thin-walled pier, a cap seat and a plurality of pile foundations. The cap seat includes a plurality of frames that are sequentially surrounded to form a frame. The upper end of each pile foundation is supported on the lower surface of each frame. The pier body of the hollow thin-walled pier is arranged along the upper surface of each frame, and each pile foundation is located directly below the pier body of the hollow thin-walled pier. A bridge is also provided, including the above-mentioned frame cap. In the application, the cap seat of the frame structure is provided to provide the bending strength of the hollow thin-walled pier combination in the vertical direction, so as to facilitate the direct transfer of the bearing capacity of the wall pier to each base. When the structure of the application is difficult to cope with the lateral fluctuation of the wall pier, long-term use will inevitably cause the hollow thin-walled pier to break, which is difficult to repair and costly. Summary of the invention

[0005] 1. Problem to be solved

[0006] In view of the shortcomings of the existing large-span bridges, which are complex and costly to construct, and the hollow thin-walled piers above the solid caps are prone to cracking when put into use after the construction is completed, the present invention provides a large-span bridge construction method. The technical solution of the present invention can effectively eliminate the lateral fluctuation of the hollow thin-walled piers of the large-span bridge, significantly improve the stability of the bridge and extend the service life of the bridge, thereby greatly reducing the maintenance cost and maintenance intensity of the large-span bridge.

[0007] 2. Technical solution

[0008] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] A construction method for a long-span bridge of the present invention comprises the following steps:

[0010] Step 1: Excavation of foundation pit: Based on the geological survey results, the foundation pit is constructed by using cofferdam or deep excavation methods according to the water flow rate, riverbed depth, and hard rock layer depth of the river to be constructed;

[0011] Step 2: Bridge pier construction;

[0012] Step S1, burying the pre-embedded foundation block in the foundation pit; by setting the pre-embedded foundation block, the connection stability between the bridge pier itself and the foundation pit is enhanced, so as to better improve the supporting force of the bridge pier.

[0013] Step S2, hoisting and installing the base body above the embedded base block;

[0014] Step S3, hoisting an installation platform above the base body; by providing the base body and the installation platform, the stress on the pier body can be absorbed and transferred, and the cracking of the thin-walled hollow reducer pier above the solid pier cap can be reduced.

[0015] Step S4, hoist the solid cap above the installation platform, pour concrete, and form a complete roughened surface on the upper surface of the solid cap; the surface of the solid cap is constructed into a roughened surface, which can better connect with the hollow reducer section constructed above it, and the solid cap and the hollow reducer pier become a whole, which enhances the firmness of the connection between the two and is conducive to ensuring the structural strength of the hollow reducer pier.

[0016] Step S5, tying a steel cage above the solid cap, enclosing a formwork above the solid cap, pouring concrete into the space enclosed by the formwork and the solid cap until solidification, and proceeding to the next step; this step improves the structural strength of the solid cap by tying the steel cage and pouring concrete, thereby ensuring the overall strength of the bridge pier.

[0017] Step S6, using a climbing formwork construction method to construct the thin-walled hollow diameter-changing section, the solid pier top and the pier cap of the hollow thin-walled diameter-changing pier from bottom to top;

[0018] Step 3: Prefabricate the bridge deck foundation beam in sections; during prefabrication, stirrups are set on the bridge deck foundation beam, and prestressed steel bar holes are reserved on the bridge deck foundation beam to facilitate the subsequent insertion of prestressed steel bars.

[0019] Step 4: construct steel pipe columns fixedly connected to the piers on the top of each pier, hoist the sections of the bridge deck foundation beams prefabricated in step 3 between the piers, use prestressed steel bars to connect the sections of the bridge deck foundation beams into a whole by cantilever construction method, and tighten and fix the sections of the bridge deck foundation beams and the steel pipe columns with inclined cables;

[0020] Step 5: Use the bridge deck foundation beam as a template and pour concrete on the stirrups of the bridge deck foundation beam. After the concrete solidifies to the standard strength, remove the supporting template parts to complete the bridge construction.

[0021] As a further improvement of the present invention, in step S1, in order to ensure the structural strength of the embedded base block, the structure of the embedded base block is designed, and the size of the embedded base block is manufactured strictly according to the design drawings. The embedded base block includes a box cavity and a plug-in board arranged on the box cavity. During construction, the box cavity of the embedded base block is first placed in the foundation pit, and then the horizontal and vertical steel cages are hoisted in the box cavity, and then concrete is poured to improve its structural strength and provide bearing capacity for the components installed above it. When the poured concrete solidifies, the plug-in board is installed on the top of the box cavity, and the plug-in board is used for subsequent connection with the base body.

[0022] As a further improvement of the present invention, in step S2, first, a balanced pile tube and a pre-embedded pile tube are installed on the top of the plug-in board, a locking ring is installed at equal intervals on the side wall of the pre-embedded pile tube, and a locking strip is installed at equal intervals on the locking ring in the circumferential direction. Through the arrangement of the balanced pile tube, the pre-embedded pile tube, the assembly plate and the counterweight body, it is convenient to install the base body as a whole above the pre-embedded base block, thereby forming a reliable and stable connection between the base body and the pre-embedded base block. Then, the assembly plate with the counterweight body installed is hoisted to the top of the balanced pile tube, and the assembly plate is fixed. The counterweight body extends into the balanced pile tube. Through the arrangement of the counterweight body, when the bridge pier is subjected to stress fluctuations, the stress can be effectively converted into the shaking of the counterweight body, thereby avoiding stress concentration in the thin-walled hollow reducer section, improving its structural strength, and reducing cracking. Finally, at least two unit prefabricated panels are installed on the assembly plate, and a buffer sleeve is installed on the board surface of the unit prefabricated panel, which is convenient for subsequent installation with the installation platform above the base body. In addition, it is worth mentioning that the base body in the present invention is not a whole plate structure, but is assembled from multiple sets of unit prefabricated plates. On the basis of ensuring that it has sufficient strength, it can effectively transfer and disperse the lateral fluctuations suffered by the bridge pier.

[0023] As a further improvement of the present invention, in order to realize the counteracting transfer stress effect of the counterweight body, the present invention optimizes the installation method of the counterweight body, specifically: first, the first movable connector and the second movable connector that are hinged to each other are hinged in the middle of the assembly plate, and the first movable connector and the second movable connector are controlled to be perpendicular to the assembly plate. At this time, one end of the connecting rod is then hinged to the second movable connector, and the other end of the connecting rod is installed and connected to the counterweight body.

[0024] In addition, to further ensure that the counterweight body plays a role, the present invention also hinges the first connecting rods at equal intervals in the edge area of ​​the assembly plate, each end of the first connecting rod is hinged to the second connecting rod, and the connecting sleeve is hingedly connected to the end of the second connecting rod. Before installing the connecting rod and the second movable joint, the buffer spring is first installed on the connecting rod, and then the connecting sleeve is slidably installed on the connecting rod, so that the two ends of the buffer spring rest between the bosses of the connecting sleeve and the connecting rod, which can effectively buffer the swing of the counterweight body and achieve the purpose of balancing the force.

[0025] As a further improvement of the present invention, in step S3, when hoisting the installation platform, first hoist the installation platform to the top of the base body, then insert the plug-in rods arranged circumferentially on the edge of the installation platform into the rubber sleeves of the unit prefabricated panels of the base body respectively, and lower the installation platform until the multiple sleeves arranged in the middle of the installation platform are respectively arranged outside the buffer sleeves. By setting the buffer sleeves, it is convenient to buffer and transfer the stress, so as to achieve effective balance when the installation platform is subjected to force. Finally, fill the cavity area below the unit prefabricated panel with concrete to improve the structural strength. When the concrete solidifies, enter step S4;

[0026] More optimally, when implementing step S4 in the present invention, in order to further ensure the connection between the installation platform and the base body and improve the stress buffering effect, buffer rings are first sleeved on the connecting screws around the installation platform, and then the solid base is hoisted above the installation platform, so that multiple reserved longitudinal steel bars arranged in an array in the hoisting groove of the installation platform pass through the reserved strip holes of the solid base; the solid base is lowered so that all the buffer rings on the installation platform are correspondingly inserted into the plug-in holes of the solid base; the solid base is continued to be lowered until the array-arranged interlocking protrusions in the hoisting grooves are inserted into the interlocking grooves in the solid base; finally, slow-setting soil is poured into the reserved strip holes.

[0027] As a further improvement of the present invention, in step S5, first, a pedestal is constructed on the upper surface of the solid cap to prepare for the installation of the formwork, then a steel cage is tied to the reserved longitudinal steel bars, a straight threaded connecting pipe is used to connect the upper end of the reserved longitudinal steel bars with the lower end of the new steel bars, and transverse steel bars are tied to the reserved longitudinal steel bars. The transverse steel bars are distributed at intervals along the length direction of the reserved longitudinal steel bars; before pouring concrete into the space enclosed by the formwork and the solid cap, cement slurry is first poured into the space, and then concrete pouring is started. Each time concrete is poured, a vibrating rod is used to vibrate and compact the concrete to improve the uniformity and quality of pouring.

[0028] As a further improvement of the present invention, in step S6, the thin-walled hollow reducer is constructed in layers, and the construction method of the first layer of the hollow reducer is as follows: first, the inner and outer operating platforms of the scaffolding are set up on the solid foundation, and then the inner formwork is installed on the outer side of the inner scaffolding, and the outer formwork is installed on the inner side of the outer scaffolding. The inner and outer formworks constitute a tubular cavity, and concrete is poured into the tubular cavities of the inner and outer formworks, and the mold is turned over after the concrete solidifies; then the next layer of the hollow reducer is further constructed according to the above method until all layers of the hollow reducer are constructed. In the present invention, the casting of the hollow reducer is constructed in layers, which reduces the construction difficulty on the one hand, and facilitates the improvement of the casting quality on the other hand, so that not only the strength of the hollow reducer after casting is guaranteed, but also the molding quality is better and the appearance is more beautiful.

[0029] As a further improvement of the present invention, in step S6, the construction method of the solid pier top and pier cap is: use the scaffolding of the central inner formwork of the thin-walled hollow reducer section as support, install the bottom formwork and chamfer formwork of the solid section of the pier bottom, tie the steel bars, install the pier body formwork and pier cap formwork, pour slow-setting soil, and wait for the concrete to solidify to complete the construction of the membrane hollow pier.

[0030] Compared with the prior art, the construction method of a long-span bridge of the present invention can effectively solve the problem of cracking of piers during the use of traditional long-span bridges through the design of the base body and the installation platform, which is conducive to further improving the structural strength and stability of the pier body;

[0031] At the same time, the assembled base body, installation platform and solid cap are hoisted on site, and then the above structures are installed and fixed, and concrete is poured; subsequently, the thin-walled hollow variable diameter section, solid pier top and pier cap of the hollow thin-walled variable diameter pier are poured by the climbing formwork construction method; then the bridge deck foundation beam is prefabricated in sections, and the hoisting and cantilever construction methods are used to complete the connection between the bridge deck foundation beam and the bridge pier, which is simple and convenient to construct;

[0032] In addition, the present invention significantly improves the structural strength and stability of the pier body by optimizing the connection method between the embedded base block and the base, the base and the installation platform, and the installation platform and the solid abutment, and can better support the bridge body. The structure has high strength and good stability. Especially when the pier is subjected to lateral fluctuations or the bridge is subjected to load impact, the lateral fluctuations and impact force of the bridge body can be effectively transferred, dispersed and eliminated, avoiding damage to the bridge structure caused by stress concentration, and greatly reducing the occurrence of cracking in the thin-walled hollow variable diameter section of the pier. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the main structure of the thin-walled variable-diameter high bridge pier structure in the present invention;

[0034] Figure 2 It is a schematic diagram of the main structure of the thin-walled variable-diameter high bridge pier structure after the base body, the installation platform, the solid cap and the embedded base block are installed in the present invention;

[0035] Figure 3 It is a schematic diagram of the three-dimensional structure after the base body, the installation platform, the solid cap and the embedded base block in the thin-wall variable diameter high bridge pier structure of the present invention are installed;

[0036] Figure 4 for Figure 3 Schematic diagram of the structure from another perspective;

[0037] Figure 5 It is a schematic diagram of the three-dimensional structure after the base body, the installation platform and the embedded base block are installed in the thin-walled variable diameter high bridge pier structure of the present invention;

[0038] Figure 6 It is a schematic diagram of the three-dimensional structure of the thin-wall variable-diameter high bridge pier structure after the base body and the installation platform are installed in the present invention;

[0039] Figure 7 for Figure 6 The schematic diagram of the three-dimensional structure after the balance foundation pile cylinder is removed;

[0040] Figure 8 It is a schematic diagram of the three-dimensional structure of the base body in the present invention;

[0041] Fig. 9 It is a schematic diagram of the three-dimensional structure after the base body and the counterweight body 130 are installed in the present invention;

[0042] Fig.10 This is a schematic diagram of the main structure after the installation platform and the unit prefabricated panels are installed in the present invention;

[0043] Fig.11 It is a schematic diagram of the three-dimensional structure after the installation platform and the unit prefabricated panels in the present invention are installed;

[0044] Fig.12 It is a schematic diagram of the three-dimensional structure of the solid cap in the present invention;

[0045] Fig.13 for Fig.12 Schematic diagram of the structure from another perspective.

[0046] In the figure:

[0047] 100, base body; 110, unit prefabricated plate; 111, notch; 120, balance pile cylinder; 130, counterweight body; 140, embedded pile cylinder; 141, locking ring; 142, locking strip; 150, assembly plate; 151, connecting pile; 152, first movable joint; 153, second movable joint; 154, first connecting rod; 155, second connecting rod; 156, connecting sleeve; 157, buffer spring; 160, rubber sleeve;

[0048] 200, installation platform; 210, sleeve; 220, plug-in rod; 230, connecting screw rod; 231, screw nut; 232, buffer ring; 240, welt; 250, lifting groove; 251, fitting protrusion; 260, reserved longitudinal reinforcement;

[0049] 300, buffer sleeve;

[0050] 400, solid cap; 410, plug-in hole; 420, fitting groove; 430, reserved strip hole; 440, thin-walled hollow reducer; 450, solid pier top; 460, pier cap;

[0051] 500, embedded base block; 510, box cavity; 520, plug-in pile; 530, plug-in board. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention.

[0053] It should be noted that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0054] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0055] The construction method of the present invention will be described in detail below with reference to the accompanying drawings.

[0056] Example 1

[0057] like Figure 1-13 As shown, a construction method of a long-span bridge in this embodiment includes the following steps:

[0058] Step 1: Based on the geological survey results, the foundation pit is constructed by using cofferdams or deep excavation methods according to the water flow rate, riverbed depth, and hard rock layer depth of the river to be constructed;

[0059] Step 2: Bridge pier construction;

[0060] Step S1, burying the pre-embedded base block 500 in the foundation pit;

[0061] Step S2: Use a hoisting device to hoist and install the base body 100 above the embedded base block 500;

[0062] Step S3, hoisting the installation platform 200 above the base body 100;

[0063] Step S4, hoisting the solid cap 400 above the installation platform 200, pouring concrete, and forming a complete roughened surface on the upper surface of the solid cap 400;

[0064] Step S5, tying a steel cage above the solid cap 400, and enclosing a template above the solid cap 400, pouring concrete into the space enclosed by the template and the solid cap 400 until solidification, and then proceeding to the next step;

[0065] Step S6, using a climbing formwork construction method, respectively constructing the thin-walled hollow diameter-reducing section 440, the solid pier top 450 and the pier cap 460 of the hollow thin-walled diameter-reducing pier from bottom to top;

[0066] Step 3: prefabricate the bridge deck foundation beam in sections; during prefabrication, stirrups are provided on the bridge deck foundation beam, and prestressed steel bar holes are reserved on the bridge deck foundation beam;

[0067] Step 4: construct steel pipe columns fixedly connected to the piers on the top of each pier, hoist each section of the bridge deck foundation beam between the piers, connect each section of the bridge deck foundation beam into one by using prestressed steel bars using a traditional cantilever construction method, and tighten and fix each section of the bridge deck foundation beam to the steel pipe columns with inclined cables;

[0068] Step 5: Use the bridge deck foundation beam as a template and pour concrete on the stirrups of the bridge deck foundation beam. After the concrete solidifies to the standard strength, remove the cable-stayed cables and steel pipe columns from the middle to both ends of the bridge to complete the bridge construction.

[0069] In this embodiment, by optimizing the design of the construction method of the pier, providing a new type of thin-walled variable diameter high pier structure and optimizing its construction method, the pier structure after construction is compared with the existing piers. On the basis of improving the support stability of the entire hollow thin-walled pier, more importantly, the pier of the present invention has a certain ability to resist lateral fluctuations. Since the locations where the existing large-span bridge piers are set are relatively complex, such as on the water surface and in soft land, they are easily subjected to various fluctuations during use. During actual construction, the pier of the present invention increases the stability of the entire thin-walled variable diameter pier by extending the base body 100 under the foundation, and an installation platform 200 is set above the base body 100, a gap is reserved between the installation platform 200 and the base body 100, and a buffer sleeve 300 is set in the movable gap, so that the solid pedestal 400, the thin-walled hollow variable diameter section 440, the solid solid pier top 450 and the pier cap 460 above the installation platform 200 can be in a swinging state under the circumferential stress, thereby avoiding the problem of fracture caused by stress concentration. The bridge constructed by using the thin-walled variable diameter pier of the present invention has good overall structural rigidity and strength, high stability, and can effectively cope with various circumferential fluctuations, which is beneficial to eliminating the lateral fluctuations of the hollow thin-walled piers of the long-span bridge, significantly improving the stability of the bridge, and extending the service life of the bridge, thereby greatly reducing the maintenance cost and maintenance intensity of the long-span bridge.

[0070] Example 2

[0071] The main operation of the construction method of a large-span bridge of this embodiment is basically the same as that of Embodiment 1, and the main difference is that in step S1, the box cavity 510 of the embedded base block 500 is first placed in the foundation pit, and then the horizontal and vertical steel cages are hoisted in the box cavity 510, and then concrete is poured until the concrete solidifies; finally, the plug-in plate 530 is installed on the top of the box cavity 510.

[0072] It should be noted that if Figure 1-5As shown, the embedded base block 500 described in this embodiment is processed as a whole into a rectangular box-shaped structure, which is buried in the foundation pit as a whole, and forms a reliable connection with the foundation pit to provide support for the components installed above it. In addition, in the actual construction process, the prepared embedded base block 500 can be transported to the vicinity of the foundation pit in advance for hoisting and burying. The structural shape of the embedded base block 500 can also be designed as a cylindrical, quadrilateral, polygonal and other structures, which is mainly designed according to the specific conditions of the foundation pit, and the size of the embedded base block 500 is determined according to the actual design drawings, which is not specifically limited in the present invention. In this embodiment, for the convenience of description, it is designed as a rectangular box-shaped structure.

[0073] Specifically, the box cavity 510 is a rectangular box with a certain height, and a horizontal and vertical steel cage is arranged inside. By pouring concrete in the box cavity 510 with the horizontal and vertical steel cage hoisted, the overall structural stability of the embedded base block 500 can be effectively improved, thereby further improving the foundation stability of the entire hollow thin-walled pier. The plug-in board 530 is integrally covered above the box cavity 510, and a plug-in pile 520 is fixedly installed above the box cavity 510. A plug-in hole for the plug-in pile 520 to be inserted is processed at the position corresponding to the plug-in pile 520 on the plug-in board 530, and the plug-in pile 520 is matched with the plug-in hole to complete the installation of the plug-in board 530 and the box cavity 510.

[0074] As a further optimization of this embodiment, a plurality of plug piles 520 are provided, all of which are equidistantly distributed along the circumferential edge of the box cavity 510, and the plug piles 520 are arranged perpendicular to the box cavity 510 and the plug board 530, so as to facilitate the firm connection between the box cavity 510 and the plug board 530. At the same time, the length of the plug pile 520 is greater than the height of the plug board 530, and the top of the plug pile 520 can extend out of the surface of the plug board 530 after installation, and the contact area between the embedded base block 500 and the concrete can be increased during the subsequent pouring of concrete, and the connection is firm, so as to facilitate the stable installation of the embedded base block 500 in the foundation pit, thereby further improving the structural strength of the overall pier foundation.

[0075] In step S2, first, the balancing pile tube 120 and the embedded pile tube 140 are installed on the top of the plug-in board 530, the locking rings 141 are installed at equal intervals on the side walls of the embedded pile tube 140, and the locking strips 142 are installed at equal intervals in the circumferential direction on the locking rings 141; then, the assembly plate 150 installed with the counterweight body 130 is hoisted to the top of the balancing pile tube 120, and the assembly plate 150 is fixed, and the counterweight body 130 extends into the balancing pile tube 120; finally, at least two unit prefabricated panels 110 are installed on the assembly plate 150, and the buffer sleeve 300 is installed on the upper surface of the unit prefabricated panel 110.

[0076] Specifically, Figure 1-13As shown, in this embodiment, the base body 100 is processed as a whole into a rectangular structure. It is the same as the embedded base block 500. Its structure and size can be determined according to actual conditions. In this embodiment, it is specifically described as a rectangular structure. The base body 100 described in this embodiment is not a structure of an integral plate, but is assembled by at least two unit prefabricated plates 110. The number of unit prefabricated plates 110 is also selected according to actual conditions. The present invention does not impose specific restrictions on the number and size of the unit prefabricated plates. It only needs to be able to support the upper structure. The number design can meet the convenience of construction. In this embodiment, four unit prefabricated plates 110 are specifically assembled. The unit prefabricated plates 110 are pre-produced and transported to the installation foundation pit position. After the foundation pit construction is completed, the foundation pit is compacted, and the pre-embedded foundation pile barrel 140 extends into the foundation pit. The counterweight body 130 set in the balance foundation pile barrel 120 realizes the reliable combination of the entire base body 100 and the foundation pit.

[0077] The balanced pile barrel 120 is installed in the middle position of the whole formed by splicing multiple unit prefabricated panels 110, that is, the center of the bottom of the base body 100. A counterweight body 130 is provided in the middle of the balanced pile barrel 120. The counterweight body 130 is movably connected to the unit prefabricated panels 110. Through the setting of the counterweight body 130, when the pier structure inevitably suffers from external lateral fluctuations, the stress on the pier can be transferred, dispersed and reduced by means of the shaking of the counterweight body 130 in the balanced pile barrel 120, thereby further avoiding the cracking of the thin-walled hollow reducer.

[0078] The number of the embedded foundation pile barrels 140 is the same as the number of unit prefabricated panels 110, and they are vertically arranged with the balanced foundation pile barrels 120, parallel to each other, and multiple embedded foundation pile barrels 140 are distributed in a circumferential direction around the balanced foundation pile barrels 120. The symmetrical structure is conducive to ensuring that the base body 100 is evenly stressed when supporting the upper installation components, thereby further improving the installation stability of the entire pier. At the same time, multiple locking rings 141 are sleeved on the length direction of the side wall of the embedded foundation pile barrel 140, and each locking ring 141 is also provided with locking strips 142 at intervals in the circumferential direction. By optimizing the specific structure of the embedded foundation pile barrel 140, the combined area of ​​the base body 100 and the foundation pit is further increased, and when pouring concrete in the pit, the stability of the entire base body 100 can be effectively improved.

[0079] As a further optimization of this embodiment, Figure 6-7 and Fig.11As shown, in order to realize reliable connection between the four groups of unit prefabricated panels 110, a notch 111 is processed at the corner position on one side plate of the unit prefabricated panel 110. The notch 111 is processed into an arc shape, and its diameter matches the balance foundation pile barrel 120, and is slightly larger than the balance foundation pile barrel 120, so as to facilitate the installation and fixing of the balance foundation pile barrel 120 after being engaged. After the four groups of unit prefabricated panels 110 are spliced ​​together, a circular groove is formed around the four notches 111. An assembly plate 150 is installed in the circular groove, and the balance foundation pile barrel 120 is engaged in the circular groove formed around the notch 111, and is fixedly connected to the assembly plate 150 in the groove. In addition, a connecting pile 151 is provided on the side where the assembly plate 150 and the unit prefabricated plate 110 are in contact. The connecting pile 151 is perpendicular to the assembly plate 150 and the unit prefabricated plate 110 and is arranged through the unit prefabricated plate 110. In this way, the assembly plate 150 can be connected to the four groups of unit prefabricated plates 110 through the connecting pile 151. Through the above structural connection, the stability of the connection between the entire base body 100 and the foundation pit can be further improved. At the same time, the four groups of unit prefabricated plates 110 also rely on the setting of the assembly plate 150 to achieve assembly connection. More optimally, the connecting pile 151 described in this embodiment passes through the unit prefabricated plate 110 and extends outward for a certain length, and is inserted into the buffer sleeve 300 fixedly installed on the unit prefabricated plate 110. The installation platform 200 is installed above the buffer sleeve 300. When lateral fluctuations occur, the lateral fluctuations generated on the installation platform 200 enable the buffer sleeve 300 to effectively absorb the lateral impact force generated by the fluctuations, thereby achieving effective balance when the installation platform 200 is subjected to force.

[0080] It is worth noting that the installation method of the counterweight body 130 is as follows: first, the first movable joint 152 and the second movable joint 153, which are hinged to each other, are hinged in the middle of the assembly plate 150, and the first movable joint 152 and the second movable joint 153 are controlled to be perpendicular to the assembly plate 150; then, one end of the connecting rod is hinged on the second movable joint 153, and the other end of the connecting rod is connected to the counterweight body 130. By installing the first movable joint 152, the second movable joint 153 and the connecting rod, the counterweight body 130 can be installed in a multi-directional movable manner on the lower plate surface of the assembly plate 150. When an earthquake occurs, the counterweight body 130 is in a swinging state. Under the connection of the first movable joint 152 and the second movable joint 153, the counterweight body 130 swings to achieve the effect of balancing the swinging force.

[0081] More optimally, in order to further improve the stability of the swing of the counterweight 130, the first connecting rods 154 are hinged at equal intervals in the edge area of ​​the assembly plate 150, and the ends of each first connecting rod 154 are hinged to the second connecting rod 155, and the connecting sleeve 156 is hinged at the end of the second connecting rod 155. Before installing the connecting rod and the second movable joint 153, the buffer spring 157 is first sleeved on the connecting rod, and then the connecting sleeve 156 is slidably installed on the connecting rod, so that the two ends of the buffer spring 157 are against the connecting sleeve 156 and the boss of the connecting rod. Through the arrangement of the first connecting rod 154, the second connecting rod 155, the connecting sleeve 156 and the buffer spring 157, the buffering effect of the swing of the counterweight 130 is effectively achieved, so that the swing amplitude of the counterweight 130 is not too large, especially when an earthquake occurs or the bridge pier is strongly impacted by water flow, the lateral swing of the counterweight 130 can be effectively weakened to achieve the effect of balancing force, thereby better dispersing the system stress impact and ensuring the stability of the bridge pier structure.

[0082] Furthermore, Fig. 9 As shown, the first connecting rod 154 is installed at the edge of the assembly plate 150, and its angle after installation forms a certain angle with the assembly plate 150. The first connecting rod 154 is not arranged perpendicular to the assembly plate 150, but slightly leans toward the connecting rod. The second connecting rod 155 is arranged perpendicular to the connecting rod, and is installed with the connecting rod through the connecting sleeve 156. By controlling the tilting setting of the first connecting rod 154, in actual use, when the bridge pier is subjected to lateral impact, when the stress is transmitted to the installation platform 200 and absorbed by the buffer sleeve 300, it is transmitted to the assembly plate 150 through the unit prefabricated plate 110, which not only helps to transfer and disperse the stress, but also facilitates to stabilize the lateral swing amplitude of the counterweight body 130.

[0083] The pier structure of the present invention, when the pier is in use, the lateral force applied to the pier acts on the entire base body 100, and the lateral force generated by the balancing pile cylinder 120 can be further balanced through the swing of the counterweight body 130, and the force is released from the balancing pile cylinder 120 through the counterweight body 130, thereby making the base body 100 more stable. The installation platform 200 is arranged on the base body 100, which can further improve the bonding strength between the entire hollow thin-walled pier and the foundation pit, and avoid the cracking problem of the hollow thin-walled pier.

[0084] Example 3

[0085] The construction method of a large-span bridge of this embodiment has the same main operations as those of Embodiment 2, with the main difference being that in step S3, when hoisting the installation platform 200, the installation platform 200 is first hoisted to the top of the base body 100, and then the plug-in rods 220 circumferentially spaced on the edges of the installation platform 200 are respectively inserted into the rubber sleeves 160 of the unit prefabricated panels 110 of the base body 100, and the installation platform 200 is lowered until the multiple sleeves 210 provided in the middle of the installation platform 200 are respectively sleeved on the outside of the buffer sleeves 300, and finally, concrete is filled in the cavity area below the unit prefabricated panels 110 until the concrete solidifies and then the step S4 operation is performed.

[0086] In this embodiment, since the base body 100 is formed by splicing four unit prefabricated panels 110, a buffer sleeve 300 is provided at the position corresponding to the connection pile 151 on each unit prefabricated panel 110, and the buffer sleeve 300 is sleeved on the surface of the connection pile 151, and the number of the buffer sleeves 300 is the same as the number of the unit prefabricated panels 110. Accordingly, in this embodiment, the sleeve 210 of the mounting platform 200 is arranged at the position corresponding to the buffer sleeve 300, and the sleeve 210 matches the buffer sleeve 300, so that the sleeve 210 is sleeved outside the buffer sleeve 300, thereby realizing a further anti-vibration connection between the mounting platform 200 and the unit prefabricated panel 110, so as to achieve the purpose of absorbing the lateral force of the mounting platform 200.

[0087] More optimized, such as Figure 5 and Figure 6 As shown, a plurality of spaced plug-in rods 220 are vertically installed around one side of the installation platform 200 along the vertical direction. The plug-in rods 220 are inserted into the rubber sleeve 160 and penetrate the unit prefabricated plate 110. In addition to completing the connection with the base body 100 through the buffer sleeve 300 and the sleeve 210, the installation platform 200 is also connected to the rubber sleeve 160 through the plug-in rods 220 arranged around, which effectively ensures the stability of the installation of the installation platform 200 and has excellent stress absorption capacity. Therefore, when the installation platform 200 is subjected to lateral impact force, it can rely on the joint buffering effect of the rubber sleeve 160 and the buffer sleeve 300 to effectively resist higher levels of lateral impact force and the impact of lateral crosswind.

[0088] In step S4, firstly, the buffer ring 232 is sleeved on the connecting screw rod 230 around the installation platform 200, and then the solid base 400 is hoisted above the installation platform 200, so that the multiple reserved longitudinal steel bars 260 arranged in an array in the hoisting groove 250 of the installation platform 200 pass through the reserved strip holes 430 of the solid base 400; the solid base 400 is lowered, so that all the buffer rings 232 on the installation platform 200 are correspondingly inserted into the plug-in holes 410 of the solid base 400; the solid base 400 is continued to be lowered until the array-arranged interlocking protrusions 251 in the hoisting groove 250 are inserted into the interlocking grooves 420 in the solid base 400; finally, slow-setting soil is poured into the reserved strip holes 430.

[0089] Specifically, the installation platform 200 described in this embodiment is processed as a rectangular structure as a whole. Like the base body 100, its specific structural shape and size are designed according to actual conditions. The installation platform 200 is provided with fillets 240 on all sides. The fillets 240 enclose a groove-shaped structure. The connecting screws 230 are evenly spaced and fixed on the fillets 240 along the vertical direction. The solid pedestal 400 is processed with a plug hole 410 for the connecting screw 230 to pass through. The diameter of the plug hole 410 matches the outer diameter of the buffer ring 232. The connecting screw 230 is inserted into the buffer ring 232. In the present invention, the buffer ring 232 is used to connect with the plug hole 410 of the solid pedestal 400. When the entire pier is in use, the impact force on the installation platform 200 is absorbed laterally by the buffer ring 232 and the rubber sleeve 160, thereby avoiding the cracking problem of the thin-walled pier.

[0090] More optimally, a screw nut 231 is further provided at the end of the connecting screw rod 230, and a gasket is provided at one end of the screw nut 231. One end of the buffer ring 232 abuts against the gasket and can be used to lock the buffer ring 232. During installation, the screw nut 231 can be screwed to make the buffer ring 232 be located at a suitable height on the connecting screw rod 230. When the hoisting equipment hoists the prefabricated solid pedestal 400 to a position above the installation platform 200 with the plate surface horizontal, the connecting screw rod 230 is inserted into the plug hole 410, and as the solid pedestal 400 descends, the buffer ring 232 can be reliably inserted into the plug hole 410, and then the buffer ring 232 can be effectively filled between the solid pedestal 400 and the installation platform 200, so that the lateral force generated by the solid pedestal 400 can be absorbed, thereby improving the structural strength of the entire hollow thin-walled pier. As a further improvement of this embodiment, Fig.12 and 13As shown, in order to further ensure the reliable combination of the solid base 400 and the installation platform 200 and improve the accuracy and convenience of the combination of the lifting equipment and the installation platform 200, a lifting groove 250 is processed on the upper plate surface of the installation platform 200, and a plurality of engaging protrusions 251 are arranged in an array in the lifting groove 250. On the lower plate surface of the solid base 400, a plurality of engaging grooves 420 matching the engaging protrusions 251 are arranged in a corresponding array, and the engaging grooves 420 cooperate with the engaging protrusions 251.

[0091] During hoisting, the hoisting equipment is a synchronous hoisting equipment arranged on both sides of the base surface. The synchronous hoisting equipment makes the solid base 400 appear horizontal and vertically descend, and forms a plug-in fit with the connecting screw 230, so that the buffer ring 232 can be effectively filled between the solid base 400 and the installation platform 200; in addition, the connecting screw 230 and the insert 240 form a rotational fit. After the solid base 400 and the installation platform 200 are reliably combined, the connecting screw 230 is manually screwed into the reserved threaded hole on the insert 240, and the buffer ring 232 can also be reliably introduced into the plug-in hole 410. This structure can effectively reduce the difficulty of hoisting the solid base 400 with the hoisting equipment, and effectively reduce the construction difficulty.

[0092] More optimally, in order to further reduce the construction difficulty in this embodiment, reserved longitudinal steel bars 260 are arranged in an array in the hoisting groove 250, and reserved strip holes 430 are arranged on the solid cap 400. The reserved strip holes 430 are arranged in multiple groups at equal intervals along the width direction of the solid cap 400 for the reserved longitudinal steel bars 260 to pass through. The upper plate surface of the solid cap 400 is a roughened surface, which is convenient for the construction of the hollow reducer 440. In this embodiment, when constructing the solid cap 400, for the convenience of construction, it is also necessary to tie steel bars between the solid cap 400 and the hollow reducer 440, and then perform secondary pouring. It should be noted that the upper plate surface of the solid cap 400 is processed into a roughened surface, and the existing roughened surface operation is extremely inconvenient. In this regard, the present invention provides a reserved strip hole 430 on the solid cap 400, so that the cap 400 can be prefabricated with a roughened surface in advance through a mold during prefabrication, which can significantly reduce the construction difficulty. In addition, when the solid cap 400 of the present invention is installed, the solid cap 400 can be hoisted to the installation platform 200 by a hoisting device, so that the reserved longitudinal steel bar 260 passes through the reserved strip hole 430, and the reserved longitudinal steel bar 260 protrudes from the upper position of the solid cap 400, and the reserved strip hole 430 is filled with concrete to form a complete whole of the solid cap 400, and then further construction is carried out on the solid cap 400, which can significantly reduce the actual construction intensity.

[0093] Example 4

[0094] The construction method of a large-span bridge of this embodiment is basically the same as that of Embodiment 3, and the main difference is that in step S5, a pedestal is first constructed around the upper plate surface of the solid cap 400, with a height of 5 cm and a width of 10 cm, in preparation for the installation of the template, and then a steel cage is tied on the reserved longitudinal steel bar 260, and a torque wrench is used to connect the upper end of the reserved longitudinal steel bar 260 with the lower end of the new steel bar through a straight threaded connecting pipe, and transverse steel bars are tied on the reserved longitudinal steel bar 260, and the transverse steel bars are distributed at intervals along the length direction of the reserved longitudinal steel bar 260. Before pouring concrete into the space surrounded by the template and the solid cap 400, cement slurry is first poured into the box cavity formed by the template and the solid cap 400 by a pump truck, and then concrete is poured into the box cavity formed by the template and the solid cap 400 in batches, and each time the concrete is poured, a vibrating rod is used for vibration and compaction.

[0095] Example 5

[0096] The construction method of a large-span bridge of the present embodiment has the same main operation as that of embodiment 3, and the main difference is that in step S6, thin-walled hollow reducer sections 440 are constructed in layers, and the construction method of the first layer of hollow reducer sections 440 is as follows: first, an inner and outer operating platform of a scaffold is set up on the solid base 400, and then an inner formwork is installed on the outer side of the inner scaffold, and an outer formwork is installed on the inner side of the outer scaffold, the inner and outer formworks constitute a tubular cavity, concrete is poured into the tubular cavities of the inner and outer formworks, and the mold is turned over after the concrete solidifies; then, the next layer of hollow reducer sections 440 is further constructed according to the above method until all layers of hollow reducer sections 440 are constructed.

[0097] In step S6, the construction method of the solid pier top 450 and the pier cap 460 is: use the scaffolding of the central inner formwork of the thin-walled hollow reducer section 440 as support, install the bottom formwork and chamfer formwork of the solid section of the pier bottom, tie the steel bars, install the pier body formwork and the pier cap formwork, pour the slow-setting soil, and wait for the concrete to solidify. The construction of the membrane hollow pier can be completed, and then the construction of the bridge body is carried out until the construction of the entire bridge is completed.

[0098] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A construction method for a long-span bridge, characterized in that: The steps include: Step 1: Based on the geological survey results, the foundation pit is constructed by using cofferdams or deep excavation methods according to the water flow rate, riverbed depth, and hard rock layer depth of the river to be constructed; Step 2: Bridge pier construction; S1, burying the pre-buried foundation block (500) in the foundation pit; First, the box cavity (510) of the embedded foundation block (500) is placed in the foundation pit, and then the horizontal and vertical steel cages are hoisted in the box cavity (510), and then concrete is poured until the concrete solidifies; finally, the plug-in board (530) is installed on the top of the box cavity (510); S2, hoisting the base body (100) above the embedded base block (500); First, a balancing pile cylinder (120) and a pre-buried pile cylinder (140) are installed on the top of the plug-in board (530), locking rings (141) are installed at equal intervals on the side wall of the pre-buried pile cylinder (140), and locking strips (142) are installed on the locking rings (141) at equal intervals in the circumferential direction; then, an assembly plate (150) installed with a counterweight (130) is hoisted to the top of the balancing pile cylinder (120), and the assembly plate (150) is fixed, and the counterweight (130) extends into the balancing pile cylinder (120); finally, at least two unit prefabricated panels (110) are installed on the assembly plate (150), and a buffer sleeve (300) is installed on the upper surface of the unit prefabricated panel (110); The method for installing the counterweight body (130) is as follows: first, a first movable joint (152) and a second movable joint (153) that are hinged to each other are hinged at the middle of the assembly plate (150), and the first movable joint (152) and the second movable joint (153) are controlled to be perpendicular to the assembly plate (150); then, one end of a connecting rod is hinged to the second movable joint (153), and the other end of the connecting rod is installed and connected to the counterweight body (130); First connecting rods (154) are hinged at equal intervals on the edge area of ​​the assembly plate (150), and the end of each first connecting rod (154) is hinged to the second connecting rod (155), and the end of the second connecting rod (155) is hinged to the connecting sleeve (156). Before installing the connecting rod and the second movable joint (153), the buffer spring (157) is first sleeved on the connecting rod, and then the connecting sleeve (156) is slidably installed on the connecting rod, so that the two ends of the buffer spring (157) are abutted between the connecting sleeve (156) and the boss of the connecting rod; S3, hoisting the installation platform (200) above the base body (100); S4, hoisting the solid cap (400) above the installation platform (200), pouring concrete, and forming a complete roughened surface on the upper surface of the solid cap (400); S5, tying a steel cage above the solid cap (400), and enclosing a formwork above the solid cap (400), pouring concrete into the space enclosed by the formwork and the solid cap (400) until it solidifies, and proceeding to the next step; S6. Using a climbing formwork construction method, construct the thin-walled hollow reducer section (440), the solid pier top (450) and the pier cap (460) of the hollow thin-wall reducer pier from bottom to top; Step 3: prefabricate the bridge deck foundation beam in sections; during prefabrication, stirrups are provided on the bridge deck foundation beam, and prestressed steel bar holes are reserved on the bridge deck foundation beam; Step 4: construct steel pipe columns fixedly connected to the piers on the top of each pier, hoist the sections of the bridge deck foundation beams prefabricated in step 3 between the piers, use prestressed steel bars to connect the sections of the bridge deck foundation beams into a whole by cantilever construction method, and tighten and fix the sections of the bridge deck foundation beams and the steel pipe columns with inclined cables; Step 5: Use the bridge deck foundation beam as a template and pour concrete on the stirrups of the bridge deck foundation beam. After the concrete solidifies to the standard strength, remove the cable-stayed cables and steel pipe columns from the middle to both ends of the bridge to complete the bridge construction.

2. The method for constructing a long-span bridge according to claim 1, characterized in that: In step S3, when hoisting the installation platform (200), the installation platform (200) is first hoisted to the top of the base body (100), and then the plug-in rods (220) circumferentially arranged on the edge of the installation platform (200) are respectively inserted into the rubber sleeves (160) of the unit prefabricated panels (110) of the base body (100), and the installation platform (200) is lowered until the plurality of sleeves (210) arranged in the middle of the installation platform (200) are respectively sleeved on the outside of the buffer sleeves (300), and finally concrete is filled into the cavity area below the unit prefabricated panels (110) until the concrete solidifies, and then the operation proceeds to step S4.

3. The construction method of a long-span bridge according to claim 1, characterized in that: In step S4, buffer rings (232) are first sleeved on the connecting screw rods (230) around the installation platform (200), and then the solid cap (400) is hoisted above the installation platform (200) so that the plurality of reserved longitudinal steel bars (260) arranged in an array in the hoisting groove (250) of the installation platform (200) pass through the reserved strip holes (430) of the solid cap (400); the solid cap (400) is lowered so that all the buffer rings (232) on the installation platform (200) are correspondingly inserted into the plug holes (410) of the solid cap (400); the solid cap (400) is continuously lowered until the array-arranged engaging protrusions (251) in the hoisting groove (250) are inserted into the engaging grooves (420) in the solid cap (400); and finally, slow-setting soil is poured into the reserved strip holes (430).

4. The method for constructing a long-span bridge according to claim 3, characterized in that: In step S5, a pedestal is first constructed around the upper plate surface of the solid cap (400) to prepare for the installation of the formwork, and then a steel cage is tied to the reserved longitudinal steel bars (260). The upper end of the reserved longitudinal steel bars (260) and the lower end of the new steel bars are connected using a straight threaded connecting pipe, and transverse steel bars are tied to the reserved longitudinal steel bars (260). The transverse steel bars are distributed at intervals along the length direction of the reserved longitudinal steel bars (260). Before pouring concrete into the space enclosed by the formwork and the solid cap (400), cement slurry is first poured into the space, and then concrete is poured. Each time the concrete is poured, a vibrating rod is used for vibration and compaction.

5. The method for constructing a long-span bridge according to claim 1, characterized in that: In step S6, the thin-walled hollow reducer (440) is constructed in layers. The construction method of the first layer of the hollow reducer (440) is as follows: first, an inner and outer operating platform of a scaffold is set up on the solid foundation (400), and then an inner formwork is installed on the outer side of the inner scaffold, and an outer formwork is installed on the inner side of the outer scaffold. The inner and outer formworks form a tubular cavity. Concrete is poured into the tubular cavities of the inner and outer formworks, and the mold is turned over after the concrete solidifies; then, the next layer of the hollow reducer (440) is further constructed according to the above method until all layers of the hollow reducer (440) are constructed.

6. The method for constructing a long-span bridge according to claim 1, characterized in that: In step S6, the construction method of the solid pier top (450) and the pier cap (460) is as follows: using the scaffolding of the central inner formwork of the thin-walled hollow reducer section (440) as support, installing the bottom formwork and chamfer formwork of the solid section of the pier top, tying steel bars, installing the pier body formwork and the pier cap formwork, pouring slow-setting soil, and waiting for the concrete to solidify, the construction of the membrane hollow pier is completed.

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