A connection structure between a hingeless steel truss arch and an arch seat and a construction method thereof

Abstract

The present invention discloses a connection structure of a hingeless steel truss arch and an arch seat and a construction method thereof. The structure comprises a pressure plate, the pressure plate is connected to the surface of the arch seat through a skeleton embedded in the arch seat, the skeleton is connected to the arch seat through a skeleton connection system, the top surface of the pressure plate is connected to the end surface of the arch foot chord, and the top surface of the pressure plate is provided with a protective structure around the arch foot chord. The use of this structure can effectively reduce the dead weight of the chord, save costs, and facilitate flipping, adjustment and positioning, which is convenient for construction and hoisting. In addition, the pressure plate and the arch foot chord have high processing accuracy, and the arch foot chord is installed and positioned by connecting the pressure plate and the skeleton, which is convenient to install and has high positioning accuracy, can effectively improve the installation quality, and does not require additional brackets during installation, which is conducive to reducing construction costs and shortening construction periods. By arranging a protective structure on the pressure plate, it is conducive to improving the connection stability of the pressure plate and the arch foot chord, and ensuring the force performance of the arch foot.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, and in particular to a connection structure of a hingeless steel truss arch and an arch seat and a construction method thereof. Background Art

[0002] The connection structure between the steel truss arch and the arch seat is the transitional junction between the concrete arch seat and the steel arch ring. It is the key part for the accurate positioning of the arch foot, the smooth installation of the segments, and the final closure of the arch ring. Its positioning accuracy needs to reach the millimeter level, which is very demanding.

[0003] In the prior art, there are two main types of connections between steel truss arches and arch seats: hinged connection and plug-in connection. The hinged connection is to set a hinge at the arch foot to release the bending moment of the arch foot and reduce the additional internal force caused by the displacement of the arch seat, temperature change, etc. This structure is suitable for hinged arches, such as the New River Valley Bridge in the United States (main span 518m). The arch ring structure of this bridge is a two-hinged arch, and the upper and lower chords of the arch ribs are hinged to the support at the arch seat position. Although the hinged connection can reduce the force on the arch foot of the arch ring, the stiffness of the arch ring becomes smaller, which is not suitable for railway bridges with high stiffness requirements, and there is also the problem of difficulty in later maintenance. The inserted connection is that a part of the arch foot chord of the arch ring is inserted into the arch seat and pre-buried, so that the arch ring and the arch seat become an integral whole. This structure is mainly suitable for hingeless arches, such as the Linzhixian Najie River Bridge (main span 352m). The arch foot and arch seat of this bridge are completely fixed, and the arch ribs (upper and lower chords) of the steel arch bridge extend into the concrete arch seat and a connection reinforcement structure is set. The arch ring with this structure has greater rigidity, but the arch foot chord lacks a positioning reference in the arch seat, so the positioning accuracy is poor and installation and positioning are difficult. At the same time, the arch foot chord needs to be inserted into the arch seat to a certain depth (generally greater than or equal to 2 times the smaller of the chord length or width) to meet the force requirements, resulting in an increase in the actual length of the arch foot chord, heavier weight, more difficult flipping and adjustment, increased steel usage, and poor economy. At present, in order to accurately position, the bracket method is generally used for construction, which will increase construction costs. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the arch foot connection structure of the hingeless arch in the prior art, such as inconvenient positioning, inconvenient construction, poor economy, and the need for additional brackets, and to provide a connection structure of a hingeless steel truss arch and an arch seat and a construction method thereof.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A connection structure between a hingeless steel truss arch and an arch seat, comprising a pressure plate, wherein the pressure plate is connected to the surface of the arch seat via a skeleton pre-buried in the arch seat, the skeleton is connected to the arch seat via a skeleton connection system, the top surface of the pressure plate is connected to the end surface of an arch foot chord, and a protective structure is provided around the top surface of the pressure plate along the arch foot chord.

[0007] The hingeless steel truss arch and arch seat connection structure described in the present invention is adopted, the pressure plate is connected to the surface of the arch seat, the pressure plate is connected to the frame, the frame is positioned by the frame connection system, the frame connection system is composed of steel components, and the positioning is completed after being directly installed in the arch seat. The installation is simple, the positioning is accurate, and the accuracy can reach the millimeter level, thereby improving the installation accuracy of the frame and the arch foot chord and the arch seat. The arch foot chord is connected to the top surface of the pressure plate, that is, the arch foot chord does not need to extend into the arch seat, so the dead weight of the chord can be effectively reduced, the amount of steel used can be reduced, and the cost can be saved. It is convenient to flip and adjust the positioning during installation, which is convenient for construction and hoisting. In addition, the pressure plate, arch foot chord, frame and frame The frame connection system is all prefabricated parts with high processing accuracy. The pressure plate and the arch foot chord can be pre-connected in the factory to further improve the positioning accuracy. The arch foot chord is installed and positioned by connecting the pressure plate with the frame. It is easy to install and has high positioning accuracy. It can effectively improve the installation quality. Compared with the installation in the concrete arch seat, no additional bracket is required during installation, which is beneficial to reducing construction costs and shortening the construction period. By arranging a protective structure on the pressure plate, the shape and size of the protective structure are adapted to the shape and size of the arch foot chord, and the depth of the protective structure is determined according to design requirements, which is beneficial to improving the connection stability of the pressure plate and the arch foot chord and ensuring the force-bearing performance of the arch foot.

[0008] Preferably, the frame is connected to the pressure plate via a plurality of bolts, and the ends of all the bolts located on one side of the pressure plate form the enclosure structure.

[0009] By forming the enclosure structure together with the ends of all the bolts used for connection, the bolts can play the dual role of anchoring and positioning the arch ring chord, and at the same time, can effectively reduce the size of the pressure plate, thereby helping to reduce the size of the arch seat, reduce the amount of work, and save costs.

[0010] Further preferably, all of the end caps are evenly distributed along the circumference of the enclosure structure.

[0011] Further preferably, the end head comprises a top plate and three side plates, the nut of the bolt abuts against the top surface of the top plate, the bottom of the inner wall of the arch foot chord is provided with stiffening ribs and a cross partition, and the position of the top plate is adapted to the position of the cross partition.

[0012] A box chamber with an opening is formed by the top plate and the three side plates, and the opening faces the inner side of the enclosure structure. The bottom surface of the side plate is arranged on the pressure plate, and the top surface of the side plate is connected to the top plate. The nut of the bolt abuts against the top surface of the top plate. Double nuts are used for anchoring to enhance the stability of the connection. At the same time, the top of the bolt is exposed to facilitate anchoring and corrosion protection by maintenance personnel, and maintenance is convenient. The position of the top plate is adapted to the position of the diaphragm to prevent stress concentration on the arch foot chord.

[0013] Further preferably, the skeleton comprises an upper steel frame and a lower steel frame, the upper steel frame and the lower steel frame are connected by a connecting piece 1, and an end 2 of the bolt located in the arch seat is anchored to the lower steel frame.

[0014] That is, the connection between the frame and the pressure plate is anchored on the lower steel frame, the bolts pass through the lower steel frame, the upper steel frame, the pressure plate and the top plate, and nuts are also provided on the top surface of the upper steel frame to further maintain the force stability and positioning accuracy of the frame.

[0015] Further preferably, the upper steel frame and the lower steel frame each include two hollow steel plates, and the two steel plates are connected by a stiffening plate.

[0016] With the above arrangement, the hollow part of the frame is used to pass steel bars, so as to enhance the stability of the connection between the frame and the arch seat. The arch seat is reinforced according to the structure, and the frame and the structural steel bars are welded and connected firmly.

[0017] Further preferably, the bolt is a prestressed bolt, the bolt is tensioned by a post-tensioning method, and the anchoring depth of the bolt extending into the arch seat is greater than or equal to 25d, where d is the bolt diameter.

[0018] By adopting the above-mentioned setting mode, according to the full pressure design of the pressure plate, the prestressed bolts are used to overcome the axial force and bending moment of the arch ring, and the friction surface under the pressure plate is used to overcome the shear force of the arch ring. The design is simple and the force is clear.

[0019] Preferably, mortar is filled between the arch seat and the pressure plate, and a steel mesh is provided under the mortar.

[0020] With the above arrangement, the steel mesh is connected to the structural steel bars in the arch seat so as to disperse the huge concentrated force of the bridge transmitted from the pressure plate to the arch seat and improve the bearing capacity of the arch seat.

[0021] Preferably, the skeleton connection system includes pillars, connecting parts 2 and embedded parts.

[0022] The pillars, the second connector and the embedded parts serve as the skeleton connection system, the embedded parts are embedded for positioning, the second connector and the pillars are connected to the embedded parts at one end and connected to the skeleton at the other end to form the skeleton connection system, which itself has the function of a positioning reference, and the positioning accuracy problem of the arch foot chord is solved from the beginning of the structural design, which can significantly improve the positioning accuracy of the arch foot, and the skeleton can well realize the positioning transition from the arch seat in the concrete part to the arch foot chord in the steel part through the pillars, the second connector and the embedded parts, thereby effectively ensuring accurate positioning.

[0023] A construction method for a connection structure of a hingeless steel truss arch and an arch seat, applied to any of the above-mentioned connection structures of a hingeless steel truss arch and an arch seat, comprises the following steps:

[0024] a. After the concrete of the arch seat is poured to the predetermined position, the skeleton connection system is installed, and the skeleton connection system includes pillars, connecting parts 2 and embedded parts;

[0025] b. Weld the frame to the frame connection system, then pass the bolts through the corresponding mounting holes 1 on the frame, and anchor the ends 2 of each bolt;

[0026] c. Continue pouring to complete the arch seat construction;

[0027] d. Install the connected pressure plate and arch foot chord rod on the arch seat as a whole, and after the pressure plate is fine-tuned into place, fill mortar between the pressure plate and the arch seat;

[0028] e. Apply prestress to the bolts and tighten the nuts to complete the connection between the hingeless steel truss arch and the arch seat.

[0029] The construction method of the connection structure of a hingeless steel truss arch and an arch seat described in the present invention can improve the positioning accuracy of the connection between the arch foot of the steel truss arch and the arch seat. There is no need to set up a bracket, the structure has a light weight, and the arch foot chord can be connected to the arch seat by hoisting construction, which reduces the difficulty of positioning. The on-site installation steps are few, the construction operation is simple, and the economy is good. It is beneficial to improve the construction efficiency and construction quality, and provides a guarantee for the smooth installation of subsequent segments and the final closure of the arch ring.

[0030] Preferably, the step of connecting the pressure plate and the arch foot chord includes: welding the arch foot chord to the pressure plate, opening two mounting holes for connecting the bolts around the arch foot chord, installing side plates and top plates around each of the two mounting holes, and opening corresponding mounting holes three on the top plate to form a protective structure.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] 1. By adopting the connection structure of a hingeless steel truss arch and an arch seat described in the present invention, the arch foot chord does not need to extend into the arch seat, which can effectively reduce the deadweight of the chord, reduce the amount of steel used, and thus save costs. It is convenient to flip and adjust the positioning during installation, which is convenient for construction and hoisting. In addition, the pressure plate and the arch foot chord have high processing accuracy and can be pre-connected in the factory to further improve the positioning accuracy. The arch foot chord is installed and positioned by connecting the pressure plate with the skeleton, which is convenient to install and has high positioning accuracy, can effectively improve the installation quality, and does not require additional brackets during installation, which is beneficial to reducing construction costs and shortening construction periods. By arranging a protective structure on the pressure plate, it is beneficial to improve the connection stability of the pressure plate and the arch foot chord, and ensure the force-bearing performance of the arch foot.

[0033] 2. The construction method of the connection structure of a hingeless steel truss arch and an arch seat described in the present invention can improve the positioning accuracy of the connection between the arch foot of the steel truss arch and the arch seat. There is no need to set up a bracket, the structure has a light weight, and the arch foot chord can be connected to the arch seat by hoisting construction, which reduces the difficulty of positioning. The on-site installation steps are few, the construction operation is simple, and the economy is good, which is conducive to improving the construction efficiency and construction quality, and provides a guarantee for the smooth installation of subsequent segments and the final closure of the arch ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of a connection structure between a hingeless steel truss arch and an arch seat according to the present invention;

[0035] Figure 2 It is a structural schematic diagram of the upper steel frame in Example 1;

[0036] Figure 3 for Figure 1 AA cross-sectional view in.

[0037] Markings in the figure: 1-pressure plate, 2-arch seat, 3-arch foot chord, 31-cross partition, 4-bolt, 41-end one, 51-upper steel frame, 52-lower steel frame, 53-connector one, 6-mortar, 7-steel mesh, 81-pillar, 82-connector two, 83-embedded parts, 91-stiffening plate. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with test examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0039] Example 1

[0040] The connection structure of a hingeless steel truss arch and an arch seat described in the present invention comprises a pressure plate 1, wherein the pressure plate 1 is connected to the surface of the arch seat 2 via a skeleton pre-buried in the arch seat 2, and the skeleton is connected to the arch seat 2 via a skeleton connection system, and the top surface of the pressure plate 1 is connected to the end surface of the arch foot chord 3, and a protective structure is provided around the top surface of the pressure plate 1 along the arch foot chord 3.

[0041] Specifically, as in this embodiment, see Figure 1-3 As shown, the skeleton is embedded in the arch seat 2, and the skeleton connection system includes a support 81, a second connector 82 and an embedded part 83, which itself has the function of a positioning reference. The positioning accuracy problem of the arch foot chord 3 is solved from the beginning of the structural design, and the positioning accuracy of the arch foot can be significantly improved, so that the skeleton can well realize the positioning transition function from the concrete part of the arch seat 2 to the steel part of the arch foot chord 3, and effectively ensure accurate positioning. The skeleton includes an upper steel frame 51 and a lower steel frame 52, and the upper steel frame 51 and the lower steel frame 52 each include two hollow rectangular steel plates, and the two steel plates are connected by a stiffening plate 91, and the stiffening plates 91 are evenly distributed along the four sides. The hollow part of the skeleton is used to penetrate steel bars to facilitate strengthening the stability of the connection between the skeleton and the arch seat 2. The arch seat 2 is reinforced according to the structure, and the skeleton is welded to the structural steel bars. A mounting hole 1 is opened on the steel plate, and each mounting hole 1 is provided with a stiffening plate 91 on both sides. Figure 2 As shown, the structure of the lower steel frame 52 is consistent with that of the upper steel frame 51. The upper steel frame 51 and the lower steel frame 52 are connected by a connecting piece 53, and the connecting piece 53 is connected to each corner, and each corner is provided with two connecting pieces 53.

[0042] The frame is connected to the pressure plate 1 by a plurality of bolts 4. The second end of the bolt 4 located in the arch seat 2 is anchored on the lower steel frame 52. The top surface of the upper steel frame 51 is also provided with nuts to further maintain the force stability and positioning accuracy of the frame. The end 41 of the bolt 4 located on one side of the pressure plate 1 forms the enclosure structure. Figure 3As shown, the cross section of the arch foot chord 3 is rectangular, the pressure plate 1 is also rectangular, the four outer corners of the pressure plate 1 are chamfered, and all the end heads 41 are arranged along the outer wall of the arch foot chord 3. The end heads 41 of all the bolts 4 used for connection together form the enclosure structure, the end heads 41 include a steel top plate and three steel side plates, the nuts of the bolts 4 abut against the top surface of the top plate, the bottom of the inner wall of the arch foot chord 3 is provided with stiffening ribs and diaphragms 31, the stiffening ribs are used to disperse the huge concentrated pressure of the arch ring, the position of the top plate is flush with the position of the diaphragm 31, so as to prevent the stress concentration of the arch foot chord 3. A box chamber with an opening is formed by the top plate and the three side plates, and the opening faces the inner side of the enclosure structure. The bottom surface of the side plate is welded to the pressure plate 1, and the top surface of the side plate is welded to the top plate. The top plate is provided with two mounting holes for the bolt 4 to pass through. The nut of the bolt 4 abuts against the top surface of the top plate. For example, a double nut is used for anchoring to enhance the stability of the connection. At the same time, the top of the bolt 4 is exposed to facilitate anchoring and anti-corrosion by maintenance personnel, and maintenance is convenient. That is, the lower end of the bolt 4 connecting the skeleton with the pressure plate 1 is anchored on the lower steel frame 52, and the bolt 4 passes through the lower steel frame 52, the upper steel frame 51, the pressure plate 1 and the top plate in sequence. The upper end of the bolt 4 is anchored on the top plate. The bolt 4 can play a dual role of anchoring and positioning the arch ring chord. At the same time, it can also effectively reduce the size of the pressure plate 1, thereby helping to reduce the size of the arch seat 2, reduce the amount of work, and save costs.

[0043] The bolt 4 is a prestressed bolt, and the anchoring depth of the bolt 4 inserted into the arch seat 2 is greater than or equal to 25d, where d is the diameter of the bolt 4. Mortar 6 is filled between the arch seat 2 and the pressure plate 1 to fill the gap between the pressure plate 1 and the arch seat 2. Several layers of steel mesh 7 are provided under the mortar 6, and the steel mesh 7 is connected to the structural steel bars in the arch seat 2 to disperse the huge concentrated force of the bridge transmitted to the arch seat 2 by the pressure plate 1, which is beneficial to improving the bearing capacity of the arch seat 2. The pressure plate 1 is designed to be fully compressed, and the prestressed bolts are used to overcome the axial force and bending moment of the arch ring. The friction surface below the pressure plate 1 is used to overcome the shear force of the arch ring. The design is simple and the force is clear.

[0044] The construction method using the connection structure described in this embodiment includes the following steps:

[0045] a. After the concrete of the arch seat 2 is poured to the predetermined position, a skeleton connection system is installed, wherein the skeleton connection system comprises a support 81, a second connection piece 82 and an embedded piece 83;

[0046] b. Weld the frame to the frame connection system, then pass the bolts 4 through the corresponding mounting holes 1 on the frame, and anchor the ends 2 of each bolt 4;

[0047] c. Continue pouring to complete the construction of the arch seat 2;

[0048] d. Install the connected pressure plate 1 and the arch foot chord 3 as a whole on the arch seat 2. After the pressure plate 1 is fine-tuned into place, fill the space between the pressure plate 1 and the arch seat 2 with mortar 6;

[0049] e. Apply prestress to the bolts 4 and tighten the nuts to complete the connection between the hingeless steel truss arch and the arch seat.

[0050] The arch seat 2 is poured with concrete in layers. After pouring to the position where the embedded part 83 is to be installed, the embedded part 83 is installed and poured to fix it. Then, the support 81 and the second connector 82 are installed on the embedded part 83 to complete the preliminary positioning of the skeleton connection system.

[0051] The frame formed by assembling the prefabricated upper steel frame 51 and lower steel frame 52 is welded and connected to the frame connection system, and then all the bolts 4 are coated with butter and wrapped with high-strength glass cloth, and then passed through the corresponding mounting hole 1 on the frame, and the end 2 of each bolt 4 is anchored, and the steel mesh 7 is laid on the frame. Other existing measures can also be used on the surface of the bolts 4 to form a gap between them and the arch seat concrete, so as to tension the prestress. Then continue to cast the remaining parts to complete the construction of the arch seat 2.

[0052] The pressure plate 1, the arch foot chord 3, the frame and the frame connection system are all prefabricated parts with high processing accuracy. The pressure plate 1 and the arch foot chord 3 can be welded and connected in the factory, which greatly reduces the workload of on-site processing and is conducive to shortening the construction period. After the pressure plate 1 and the arch foot chord 3 are connected, a number of mounting holes 2 are opened around the arch foot chord 3, side plates and top plates are installed around each mounting hole 2, and mounting holes 3 are correspondingly opened on the top plate to form the enclosure structure. At the construction site, the pressure plate 1 and the arch foot chord 3 that have been connected as one are hoisted on the arch seat 2, and the bolts 4 are respectively passed through the mounting holes 2 and 3, and then the arch foot chord 3 is accurately positioned and measured, and the pressure plate 1 is fine-tuned according to the measurement results. After the fine-tuning is in place, the gap between the pressure plate 1 and the arch seat 2 is filled with the mortar 6.

[0053] Then prestress is applied to all the bolts 4. The applied pretension is generally not greater than 30% of the ultimate tension. After the pretension construction is completed, the double nuts are tightened and anti-corrosion coating is applied to complete the connection between the hingeless steel truss arch and the arch seat.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A connection structure between a hingeless steel truss arch and an arch seat, characterized in that: The invention comprises a pressure-bearing plate (1), wherein the pressure-bearing plate (1) is connected to the surface of the arch seat (2) via a frame pre-buried in the arch seat (2), the frame is connected to the arch seat (2) via a frame connection system, the top surface of the pressure-bearing plate (1) is connected to the end surface of the arch foot chord (3), the top surface of the pressure-bearing plate (1) is provided with a protective structure around the arch foot chord (3), the frame connection system is located in the arch seat (2), the frame is connected to the pressure-bearing plate (1) via a plurality of bolts (4), all the bolts (4) are located at an end head (41) on one side of the pressure-bearing plate (1) to form the protective structure, the end head (41) comprises a top plate and three side plates, the bottom surface of the side plate is arranged on the pressure-bearing plate (1), the side plate The top surface of the top plate is connected to the top plate, the nut of the bolt (4) abuts against the top surface of the top plate, the bottom of the inner wall of the arch foot chord (3) is provided with a stiffening rib and a diaphragm (31), the position of the top plate is adapted to the position of the diaphragm (31), the skeleton comprises an upper steel frame (51) and a lower steel frame (52), the upper steel frame (51) and the lower steel frame (52) are connected by a connecting piece 1 (53), the end 2 of the bolt (4) located in the arch seat (2) is anchored on the lower steel frame (52), the skeleton connection system comprises a pillar (81), a connecting piece 2 (82) and an embedded part (83), the connecting piece 2 (82) and the pillar (81) are both connected to the embedded part (83) at one end and connected to the skeleton at the other end.

2. The connection structure according to claim 1, characterized in that: The upper steel frame (51) and the lower steel frame (52) each comprise two hollow steel plates, and the two steel plates are connected via a stiffening plate (91).

3. The connection structure according to claim 1, characterized in that: The bolt (4) is a prestressed bolt, and the anchoring depth of the bolt (4) inserted into the arch seat (2) is greater than or equal to 25d, where d is the diameter of the bolt (4).

4. The connection structure according to any one of claims 1 to 3, characterized in that: Mortar (6) is filled between the arch seat (2) and the pressure plate (1), and a steel mesh (7) is provided under the mortar (6).

5. A construction method for a connection structure between a hingeless steel truss arch and an arch seat, characterized in that: A connection structure between a hingeless steel truss arch and an arch seat as described in any one of claims 1 to 4 comprises the following steps: a. After the concrete of the arch seat (2) is poured to a predetermined position, a skeleton connection system is installed, wherein the skeleton connection system comprises a support (81), a second connection piece (82) and an embedded piece (83); b. Welding the frame to the frame connection system, then passing the bolts (4) through the corresponding mounting holes 1 on the frame, and anchoring the ends 2 of each of the bolts (4); c. Continue pouring to complete the construction of the arch seat (2); d. Install the connected pressure plate (1) and the arch foot chord (3) on the arch seat (2) as a whole, and after the pressure plate (1) is fine-tuned into place, fill the space between the pressure plate (1) and the arch seat (2) with mortar (6); e. Apply prestress to the bolts (4) and tighten the nuts to complete the connection between the hingeless steel truss arch and the arch seat.

6. The construction method according to claim 5, characterized in that: The step of connecting the pressure plate (1) and the arch foot chord (3) comprises: welding the arch foot chord (3) on the pressure plate (1), opening two mounting holes for connecting the bolts (4) around the arch foot chord (3), installing side plates and top plates around each of the two mounting holes, and opening three mounting holes on the top plate to form a protective structure.

Images