0# Turnover Bracket for Continuous Rigid Frame Bridge with Large Span, Double-limbed Thin-walled Piers and Its Construction Method

Abstract

The present invention provides a traversable bracket for the 0# block of a large-span double-limb thin-walled pier continuous rigid frame bridge and a construction method. The traversable bracket includes a pre-embedded system, a bearing system and a distribution system; the pre-embedded system includes an embedded component 1 and an embedded component 2, the embedded component 1 includes a first embedded seat and a second embedded seat, and the embedded component 2 includes a third embedded seat and a fourth embedded seat; the bearing system includes mutually connected cross bars and diagonal bars, the cross bars, the diagonal bars, the first embedded seat and the second embedded seat are connected to form a first triangular support structure, and the third embedded seat and the fourth embedded seat are connected through a horizontal support beam and a diagonal brace to form a second triangular support structure; the distribution system includes a transverse distribution beam, a longitudinal distribution beam, a truss and a plurality of sand boxes; the construction method of the bracket is convenient and fast, the various components have good stability, the materials and equipment used can be circulated and recycled after the construction of the 0# block is completed, and it has high application value.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction in construction projects, and in particular to a 0# block rotatable bracket for a long-span double-limb thin-walled pier continuous rigid frame bridge and a construction method thereof. Background Art

[0002] Due to the strong structural integrity of rigid frame bridges and the consolidation of piers and beams, the beams and piers are subjected to forces as a whole. The piers bear not only the vertical pressure caused by the load on the beams, but also the bending moment and horizontal thrust. Under vertical load, the bending moment of the beams of rigid frame bridges is generally smaller than that of continuous beams or simply supported beams of the same span, and they also have excellent seismic performance. Prestressed concrete continuous rigid frame bridges have become one of the main types of long-span bridges in my country and are favored by more and more builders. During the construction of continuous rigid frame bridges, harsh environmental conditions such as rivers and deep valleys may be encountered, making the erection of scaffolding construction more difficult. The use of brackets for 0# block construction has become an important technical means for the cantilever construction of long-span continuous rigid frame bridges. Conventional brackets rely too much on pre-embedded connectors on the piers, and the main components are welded at high altitude, making quality difficult to guarantee and posing a high safety risk. Therefore, it is necessary to invent a 0# block revolving bracket system for long-span double-leg thin-walled pier continuous rigid frame bridges to solve the above problems. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects of the existing technology and provide a 0# block rotatable bracket and construction method for a large-span double-leg thin-walled pier continuous rigid frame bridge, so that the materials and equipment used in the 0# block can be circulated and recycled after the construction of the 0# block is completed, which is economical, safe and has high application value.

[0004] The present invention is achieved in that:

[0005] The present invention provides a 0# block revolvable bracket for a long-span double-limb thin-wall pier continuous rigid frame bridge, comprising a pre-embedded system, a bearing system and a distribution system;

[0006] The embedded system is arranged on the double-limb thin-walled pier, including embedded component 1 and embedded component 2, wherein the embedded component 1 includes a first embedded seat arranged at the upper end of the outer side of the thin-walled pier and a second embedded seat arranged at the lower end of the outer side of the thin-walled pier, and the embedded component 2 includes a third embedded seat arranged at the upper end of the inner side of the thin-walled pier and a fourth embedded seat arranged at the middle part of the inner side of the thin-walled pier;

[0007] The bearing system includes a cross bar and an oblique bar connected to each other, the cross bar is connected to the first embedded seat, the oblique bar is connected to the second embedded seat, the cross bar, the oblique bar, the first embedded seat and the second embedded seat are connected to form a first triangular support structure, the third embedded seat and the fourth embedded seat are connected by a horizontal support beam and an oblique brace to form a second triangular support structure, and the first embedded seat and the third embedded seat are arranged on the same horizontal plane;

[0008] The distribution system includes a transverse distribution beam, a longitudinal distribution beam, a truss and several sand boxes. The sand boxes are fixedly arranged on the first triangular support structure and the second triangular support structure. The sand boxes include an upper support and a lower support. The lower support is filled with sand. A sand unloading hole is opened on the side of the lower support to adjust the height of the sand box. The upper support is embedded in the lower support. The transverse distribution beam and the longitudinal distribution beam are fixed on the sand box, and the truss is arranged on the transverse distribution beam.

[0009] Furthermore, the first embedded seat and the second embedded seat are both composed of welded facade steel plates and shear grooves, a U-shaped steel bar is welded on one side of the facade steel plate, the U-shaped steel bar is connected and fixed to the main reinforcement of the thin-walled pier, and a hinge seat is embedded on the other side of the facade steel plate.

[0010] Furthermore, a pin hole is provided on the hinge seat, and a pin is passed through the pin hole to fixedly connect the first embedded seat and the cross bar, and the second embedded seat and the oblique bar.

[0011] Furthermore, the third embedded seat and the horizontal support beam are welded and fixed, the fourth embedded seat and the diagonal brace are welded and fixed, and the horizontal support beam and the diagonal brace are welded and fixed.

[0012] Furthermore, the first embedded seat and the third embedded seat are pressed against the pier wall by the fine-rolled threaded steel bars. The first embedded seat and the third embedded seat are connected by the fine-rolled threaded steel bars, and the fine-rolled threaded steel bars transversely penetrate the concrete structure of the thin-walled pier.

[0013] Furthermore, the lower support is provided with slide rails at positions on both sides of the sand unloading hole, and a clamping plate is slidably installed on the slide rails to open or block the sand unloading hole, and lifting hooks are also provided on both sides of the sand box.

[0014] Furthermore, both the transverse distribution beam and the longitudinal distribution beam adopt double-piece I45a, connected by a stiffener in the middle, and the truss is set to match the longitudinal linear characteristics of the 0# block to adapt to the changes in the bottom mold linear shape.

[0015] The present invention also provides a construction method of the above-mentioned turnover bracket, comprising the following steps:

[0016] Step S1: Process components according to the drawings and transport them to the construction site for inspection and acceptance of each component;

[0017] Step S2: when constructing a double-limb thin-wall pier, pouring the embedded component 1, the embedded component 2 and the prestressed duct into the pier column concrete according to the designed position;

[0018] Step S3: Connect the horizontal bar, the diagonal bar and the hinge seat on the ground. After the concrete strength of the pier column reaches the requirement, insert the hinge seat into the embedded component 1 or embedded component 2. Weld the horizontal support beam and the diagonal brace to the ground and then hoist them to the designed position. Weld the third embedded seat to the horizontal support beam as a whole, and weld the fourth embedded seat to the diagonal brace as a whole. Insert the fine-rolled threaded steel bar into the first embedded seat, the hinge seat, the prestressed channel and the third embedded seat in sequence. Tighten the nuts at both ends and press them against each other with a jack so that the two components are synergistically stressed.

[0019] Step S4: Load the sand into the sand box, pre-press it according to the designed height, and fix it on the crossbar after pre-pressing.

[0020] Step S5: Complete the installation of the longitudinal distribution beam, the transverse distribution beam and the truss;

[0021] Step S6: Install the bottom formwork required for pouring on the transverse distribution beams and trusses, and perform pre-pressing;

[0022] Step S7: After the pre-pressing is qualified, the side formwork, inner formwork, end formwork, etc. are installed to complete the installation of steel bars and prestressing;

[0023] Step S8, pouring 0# block concrete, and after the concrete reaches the requirements and the prestressing is completed, the formwork, transverse distribution beam, truss, longitudinal distribution beam, triangular bracket and hinge seat are removed in sequence. The removed parts are used for other double-leg thin-walled pier 0# blocks or the next project.

[0024] Furthermore, the sand box is back-pressured by a jack, and the back-pressure load is not less than 80t.

[0025] The present invention has the following beneficial effects:

[0026] 1. The materials and equipment used in the bracket are all dismantled and can be recycled after the 0# block construction is completed. It has the characteristics of easy dismantling, economical and safe, and pollution-free, and has high application value;

[0027] 2. The first and second triangular support structures are installed on both sides of the thin-walled pier, which provide stable support and can transfer the upper load to the pier column. The first and second triangular support structures are connected to form a force-bearing whole, which can effectively reduce the unbalanced bending moment of the pier body.

[0028] 3. The bracket connects the 0# block template through the sand box, transverse distribution beam, longitudinal distribution beam and truss. The truss has the function of adjusting the linear shape of the 0# block bottom plate and can well adapt to the changes in the linear shape of the bottom mold. The sand box is also equipped with a sand discharge hole to adjust the elevation;

[0029] 4. In the construction method of the present invention, the connection and installation of the embedded system and the bearing system are completed first, and the coordinated force of the double-limb thin-walled pier is completed. Then, the distribution system is set on the constructed first triangular support structure and the second triangular support structure. In conjunction with the longitudinal linear characteristics of the 0# block, the installation and coordination design of each component in the overall construction process is reasonable, and the disassembly of each component is also convenient. After completing the construction of the 0# block, the installed components can be quickly removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 This is the longitudinal section layout drawing of the 0# turnaround bracket;

[0032] Figure 2 This is the layout of the brackets between the pier columns of the double-limbed thin-walled pier;

[0033] Figure 3 It is a structural diagram of embedded component one;

[0034] Figure 4 This is a structural diagram of the embedded component 2;

[0035] Figure 5 It is the layout diagram of the sand box;

[0036] Figure 6 It is the layout diagram of longitudinal and transverse distribution beams.

[0037] In the figure: 1-embedded system; 2-bearing system; 3-distribution system; 4-first embedded seat; 5-second embedded seat; 6-hinge seat; 7-fine-rolled threaded steel bar; 8-truss; 9-third embedded seat; 10-fourth embedded seat; 15-sand box; 16-transverse distribution beam; 17-longitudinal distribution beam; 18-vertical steel plate; 19-shear groove; 20-U-shaped steel bar; 21-pin shaft hole; 23-horizontal support beam; 24-diagonal brace; 25-upper support; 26-lower support; 28-sand unloading hole; 29-clamping plate; 30-lifting hook; 31-stiffening plate. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] See also Figure 1 An embodiment of the present invention provides a 0# block rotatable bracket for a long-span double-limb thin-walled pier continuous rigid frame bridge, including a pre-embedded system 1, a bearing system 2 and a distribution system 3.

[0040] See also Figure 2 、 3 4. The embedded system 1 is provided on the double-limb thin-walled pier and includes an embedded component 1 and an embedded component 2. The embedded component 1 includes a first embedded seat 4 provided at the upper end of the outer side of the thin-walled pier and a second embedded seat 5 provided at the lower end of the outer side of the thin-walled pier. The first embedded seat 4 and the second embedded seat 5 are embedded before the concrete of the double-limb thin-walled pier is poured. The first embedded seat 4 and the second embedded seat 5 are pressed tightly against the pier wall by a pair of finely rolled threaded steel bars 7 that pass through the concrete structure of the thin-walled pier transversely.

[0041] The bearing system 2 includes interconnected cross bars and diagonal bars, both of which are made of section steel. The cross bars are connected to the first embedded seat 4, and the diagonal bars are connected to the second embedded seat 5. The cross bars, diagonal bars, the first embedded seat 4 and the second embedded seat 5 are connected to form a first triangular support structure.

[0042] Specifically, the first embedded seat 4 and the second embedded seat 5 are both composed of a vertical steel plate 18 and a shear groove 19 welded together. A U-shaped steel bar is welded on one side of the vertical steel plate 18. The U-shaped steel bar 20 is connected and fixed to the main reinforcement of the thin-walled pier through the fine-rolled threaded steel bar 7. A hinge seat 6 is embedded on the other side of the vertical steel plate 18. The hinge seat 6 is welded by several steel plates and is provided with a pin hole 21. A pin is passed through the pin hole 21 to fix the first embedded seat 4 and the cross bar, the second embedded seat 5 and the diagonal bar. Each force transmission connection node is connected by a pin, which effectively transfers the upper load to the pier column. When the bracket is constructed and installed, the cross bar and the diagonal bar are assembled on the ground. The first embedded seat 4 and the second embedded seat 5 are distributed and the hinge seat 6 is hoisted to the predetermined position after assembly. During the installation process, the entry depths of the cross bar, the diagonal bar and the hinge seat 6 are ensured to be basically consistent, which facilitates the accurate installation of the cross bar, the diagonal bar, the first embedded seat 4 and the second embedded seat 5.

[0043] The second embedded component includes a third embedded seat 9 provided at the upper end of the inner side of the thin-walled pier and a fourth embedded seat 10 provided in the middle part of the inner side of the thin-walled pier. The third embedded seat 9 and the fourth embedded seat 10 are embedded during the pier column reinforcement binding process. The third embedded seat 9 is welded and fixed to the horizontal support beam 23, the fourth embedded seat 10 is welded and fixed to the diagonal brace 24, the horizontal support beam 23 is welded and fixed to the diagonal brace 24, and the third embedded seat 9 and the fourth embedded seat 10 are connected by the horizontal support beam 23 and the diagonal brace 24 to form a second triangular support structure.

[0044] The first embedded seat 4 and the third embedded seat 9 are arranged on the same horizontal plane and are connected by the finely rolled threaded steel bar 7 that runs horizontally through the concrete structure of the thin-walled pier, so that the first triangular support structure and the second triangular support structure are connected to form a force-bearing whole to coordinate the force, which can effectively reduce the unbalanced bending moment of the pier body. The finely rolled threaded steel bar 7 runs horizontally through the concrete structure of the thin-walled pier to form a prestressed channel, which facilitates the installation of the embedded component 1 and the embedded component 2;

[0045] See also Figure 1 The distribution system 3 includes a transverse distribution beam 16, a longitudinal distribution beam 17, a truss 8 and several sand boxes 15, see Figure 5 , (a) is a side view of the sand box 15, and (b) is a main view of the sand box 15. A card slot is provided at the bottom of the sand box 15, which can be firmly installed on the first triangular support structure and the second triangular support structure. The sand box 15 includes an upper support 25 and a lower support 26. The upper support 25 is embedded in the lower support 26, and the lower support 26 is filled with sand. A sand unloading hole 28 is opened on the side of the lower support 26, and slide rails are provided on both sides of the lower support 26 corresponding to the sand unloading hole 28. A card plate 29 is slidably installed on the slide rail to open or block the sand unloading hole 28 for adjusting the elevation. The sand box 15 is also provided with lifting hooks on both sides to facilitate the lifting of the sand box 15. The maximum adjustable height of the sand box 15 can reach 10 cm.

[0046] The transverse distribution beam 16 and the longitudinal distribution beam 17 are arranged on the top of the upper support 25. For details, see Figure 1 、 Figure 6 The longitudinal distribution beam 17 and the transverse distribution beam 16 both adopt a double-piece I45a structure, connected by a stiffener 31 in the middle. The transverse distribution beam 16 is fixed on the sand box 15 on both sides of the double-limb thin-walled pier, and the longitudinal distribution beam 17 is fixed on the sand box 15 between the double-limb thin-walled piers; the truss 8 is a double-piece 18-section steel, welded in the factory, and matched according to the longitudinal linear characteristics of the 0# block to adapt to the changes in the bottom mold linear shape.

[0047] The present invention also provides a construction method for the above-mentioned large-span double-limb thin-walled pier continuous rigid frame bridge 0# block revolving bracket, comprising the following steps:

[0048] S1. Process components in the factory according to the drawings and deliver them to the construction site for inspection and acceptance of the quantity, size and welding quality of each component;

[0049] S2. When constructing a double-limb thin-wall pier, pour the embedded component 1, embedded component 2 and prestressed duct into the pier column concrete according to the designed position;

[0050] S3. Connect the horizontal bar, diagonal bar and hinge seat 6 on the ground. After the concrete strength of the pier column reaches the requirement, insert the hinge seat 6 into the embedded component 1 or embedded component 2. Weld the horizontal support beam 23 and the diagonal brace 24 on the ground and then hoist them to the designed position. Weld the third embedded seat 9 to the horizontal support beam 23 as a whole, and the fourth embedded seat 10 to the diagonal brace 24 as a whole. Insert the fine-rolled threaded steel bar 7 into the first embedded seat, hinge seat 6, prestressed channel and third embedded seat in sequence. Tighten the nuts at both ends and press them together with the jack so that the two components are stressed in coordination.

[0051] S4. The sand should be dried before being loaded into the sand box 15, and preset according to the designed height. After the pre-compression is completed, it should be fixed on the crossbar;

[0052] S5, complete the installation of the longitudinal distribution beam 17, the transverse distribution beam 16 and the truss 8;

[0053] S6. Install the bottom formwork required for pouring on the transverse distribution beam 16 and the truss 8 and perform pre-pressing;

[0054] S7. After the preloading is qualified, install the side formwork, inner formwork, end formwork, etc., and complete the installation of steel bars and prestressing;

[0055] S8. Pour 0# block concrete. After the concrete reaches the requirements and prestressing is completed, remove the formwork in sequence, including the transverse distribution beam 16, truss 8, longitudinal distribution beam 17, triangular bracket and hinge seat 6. The removed parts will be used for other double-leg thin-walled pier 0# blocks or the next project.

[0056] During the installation and construction process, the sand box 15 is back-pressed by the jack, and the back-pressure load is not less than 80t. The steel structure welding welds adopt a combination of butt welds and fillet welds, and the weld grade is not less than Level 2. The steel structure is made of Q345 material, and the steel plate is made of Q235 material. In this construction method, the various components of the turnover bracket are first pre-assembled according to the design drawings, which is convenient to call and improves the installation efficiency. The connection and installation of the embedded system 1 and the bearing system 2 complete the coordinated force of the double-limb thin-walled pier, and then the distribution system 3 is set on the constructed first triangular support structure and the second triangular support structure. In conjunction with the longitudinal linear characteristics of the 0# block, the installation and coordination design of each component during the overall construction process is reasonable, and the disassembly of each component is also convenient. The installed components can be quickly removed after the construction of the 0# block is completed.

[0057] In summary, the bracket used in the present invention can be dismantled and recycled after the construction of the 0# block is completed, and the materials and equipment used can be recycled after the construction of the 0# block is completed. It has the characteristics of easy dismantling, economical and safe, and pollution-free, and has high application value.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. The construction method of the 0# block revolving bracket of the long-span double-limb thin-walled pier continuous rigid frame bridge is characterized by: The 0# block recyclable bracket includes a pre-embedded system, a bearing system and a distribution system; The embedded system is arranged on the double-limb thin-walled pier, including embedded component 1 and embedded component 2, wherein the embedded component 1 includes a first embedded seat arranged at the upper end of the outer side of the thin-walled pier and a second embedded seat arranged at the lower end of the outer side of the thin-walled pier, and the embedded component 2 includes a third embedded seat arranged at the upper end of the inner side of the thin-walled pier and a fourth embedded seat arranged at the middle part of the inner side of the thin-walled pier; The bearing system includes a cross bar and an oblique bar connected to each other, the cross bar is connected to the first embedded seat, the oblique bar is connected to the second embedded seat, the cross bar, the oblique bar, the first embedded seat and the second embedded seat are connected to form a first triangular support structure, the third embedded seat and the fourth embedded seat are connected by a horizontal support beam and an oblique brace to form a second triangular support structure, and the first embedded seat and the third embedded seat are arranged on the same horizontal plane; The distribution system includes a transverse distribution beam, a longitudinal distribution beam, a truss and a plurality of sand boxes. The sand boxes are fixedly arranged on the first triangular support structure and the second triangular support structure. The sand boxes include an upper support and a lower support. The lower support is filled with sand. A sand unloading hole is opened on the side of the lower support to adjust the height of the sand box. The upper support is embedded in the lower support. The transverse distribution beam and the longitudinal distribution beam are fixed on the sand box. The truss is arranged on the transverse distribution beam. The lower support is provided with slide rails at both sides of the sand unloading hole, and a card is slidably installed on the slide rails to open or block the sand unloading hole. There are also lifting hooks on both sides of the sand box. The first embedded seat and the second embedded seat are both welded by a facade steel plate and a shear groove, a U-shaped steel bar is welded on one side of the facade steel plate, the U-shaped steel bar is connected and fixed to the main reinforcement of the thin-walled pier, and a hinge seat is embedded on the other side of the facade steel plate; The hinge seat is provided with a pin hole, through which a pin is passed to fixedly connect the first embedded seat and the cross bar, and the second embedded seat and the oblique bar; The third embedded seat is welded and fixed to the horizontal support beam, the fourth embedded seat is welded and fixed to the diagonal brace, and the horizontal support beam is welded and fixed to the diagonal brace; The first embedded seat and the third embedded seat are pressed against the pier wall by the precision-rolled threaded steel bars, and the first embedded seat and the third embedded seat are connected by the precision-rolled threaded steel bars; The construction method of the 0# block revolvable bracket of the large-span double-limb thin-walled pier continuous rigid frame bridge comprises the following steps: Step S1: Process components according to the drawings and transport them to the construction site for inspection and acceptance of each component; Step S2: when constructing a double-limb thin-wall pier, pouring the embedded component 1, the embedded component 2 and the prestressed duct into the pier column concrete according to the designed position; Step S3: Connect the horizontal bar, the diagonal bar and the hinge seat on the ground. After the concrete strength of the pier column reaches the requirement, insert the hinge seat into the embedded component 1 or embedded component 2. Weld the horizontal support beam and the diagonal brace to the ground and then hoist them to the designed position. Weld the third embedded seat to the horizontal support beam as a whole, and weld the fourth embedded seat to the diagonal brace as a whole. Insert the fine-rolled threaded steel bar into the first embedded seat, the hinge seat, the prestressed channel and the third embedded seat in sequence. Tighten the nuts at both ends and press them against each other with a jack so that the two components are synergistically stressed. Step S4: sand is loaded into the sand box, which is preset according to the designed height. After pre-pressing, it is clamped on the crossbar and fixed. The sand box is back-pressed by a jack, and the back-pressure load is not less than 80t; Step S5: Complete the installation of the longitudinal distribution beam, the transverse distribution beam and the truss; Step S6: Install the bottom formwork required for pouring on the transverse distribution beams and trusses, and perform pre-pressing; Step S7: After the pre-stressing is qualified, the side formwork, inner formwork, and end formwork are installed to complete the installation of steel bars and prestressing; Step S8, pouring 0# block concrete, and after the concrete reaches the requirements and the prestressing is completed, the formwork, transverse distribution beam, truss, longitudinal distribution beam, triangular bracket and hinge seat are removed in sequence. The removed parts are used for other double-leg thin-walled pier 0# blocks or the next project.

2. The construction method of the 0# block revolvable bracket of the long-span double-limb thin-walled pier continuous rigid frame bridge according to claim 1 is characterized by: Both the transverse distribution beam and the longitudinal distribution beam adopt double-piece I45a, connected by stiffeners in the middle. The trusses are set to match the longitudinal linear characteristics of the 0# block to adapt to the changes in the bottom formwork linear shape.

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