A method for installing prefabricated supportless brackets

Abstract

This invention relates to the field of bridge construction technology, and in particular to a method for installing prefabricated pierless supports, comprising the following steps: S1. Calculating the specifications and quantity of each component according to the bridge span and prefabricating them in the factory; S2. Horizontally assembling single-piece supports, erecting the supports, and installing intermediate components to complete the assembly of the prefabricated longitudinal beams; S3. Installing fixing components and main crossbeams at the bridge piers; S4. Hoisting the prefabricated longitudinal beams as a whole; S5. Installing the transverse distribution beam components; S6. Installing the longitudinal distribution beam components. Using the method described in this invention, the connection between the components can be made simpler and more convenient, effectively reducing the assembly difficulty of the prefabricated longitudinal beams and improving the installation accuracy; installing fixing components on the bridge piers eliminates the need for column installation, which helps to shorten the construction period and reduce costs; overall hoisting reduces the time workers spend working at heights, which helps to reduce safety risks, and allows for simultaneous hoisting and assembly of the next prefabricated longitudinal beam, which can significantly shorten the construction period and reduce costs.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a method for installing prefabricated unsupported pier supports. Background Technology

[0002] In the construction of small and medium-sized bridges, the installation of scaffolding plays a crucial controlling role in the construction process. Currently, most bridges use beam-type scaffolding, primarily consisting of Bailey bridges and steel pipe columns. However, the welding of the steel pipe columns still presents a series of problems. For example, the welding workload is large, the weld requirements are high, and it is essentially a high-altitude operation, posing a high safety risk. For soft foundations, foundation treatment is required before welding the steel pipe columns, increasing construction costs and resulting in poor economic efficiency. Furthermore, the different pile lengths and diameters of the steel pipe columns make them difficult to reuse, easily leading to excessive waste of steel.

[0003] The newly developed prefabricated pierless support system can effectively solve the above-mentioned problems. It includes prefabricated longitudinal beams, transverse distribution beam assemblies, and longitudinal distribution beam assemblies. The prefabricated longitudinal beams consist of standard truss sections and adjustable sections at both ends. The standard truss sections can be assembled from units of different specifications, and the length of the adjustable sections can be fine-tuned to achieve length adjustment of the prefabricated longitudinal beams, meeting the construction needs of bridges with different spans. It has great development potential in bridge construction. However, large-scale prefabricated pierless support system products have not yet been developed in China, and there is a lack of a complete set of technical application systems to guide the efficient and precise installation of prefabricated pierless support systems.

[0004] Therefore, it is necessary to propose a prefabricated unsupported pier support installation method to improve the accuracy and efficiency of prefabricated unsupported pier support installation, and shorten the construction period and reduce construction costs under the premise of safe construction, so as to promote the development of prefabricated unsupported pier supports. Summary of the Invention

[0005] The purpose of this invention is to improve the installation accuracy and efficiency of prefabricated unsupported pier supports, shorten the construction period and reduce construction costs, and to provide a method for installing prefabricated unsupported pier supports.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A method for installing a prefabricated unsupported pier support, the prefabricated unsupported pier support comprising prefabricated longitudinal beams, transverse distribution beam assemblies, and longitudinal distribution beam assemblies, wherein the prefabricated longitudinal beams comprise standard truss segments, each standard truss segment comprising at least one detachably connected standard truss segment unit, both ends of each standard truss segment being detachably connected to adjustable sections, the length of each adjustable section being adjustable, each adjustable section comprising a connecting truss and an adjustable support, the adjustable support being telescopically connected to the upper part of the connecting truss, and the adjustable support being connected to the lower part of the connecting truss by a telescopic rod;

[0008] The standard truss segment unit includes standard segment side pieces that are vertically spaced and interconnected. The connecting truss includes connecting segment side pieces that are vertically spaced and interconnected. The connecting segment side pieces, the adjustable support, and the telescopic rod together form an adjustable segment side piece.

[0009] The installation method for the prefabricated unsupported bracket includes the following steps:

[0010] S1. Calculate the specifications and quantity of the standard truss segment units required based on the bridge span, as well as the adjustment length of the adjustable segment;

[0011] The standard section side piece and the connecting section side piece are prefabricated in the factory, wherein the standard section side piece and the connecting section side piece each include an upper chord, a lower chord, and a piece frame assembly;

[0012] S2. Assemble the prefabricated longitudinal beam, including the following steps:

[0013] Arrange the support beams: Place several support beams flat on the assembly site. All the support beams are parallel to each other and spaced apart. Place each component flat on the support beams.

[0014] Install the adjustable support: connect the adjustable support to the upper chord of the connecting section side plate, adjust the extension length of the adjustable support and fix it in place;

[0015] Install the telescopic rod: First, connect one end of the telescopic rod to one of the adjustable support and the connecting section side piece, adjust the angle and length of the telescopic rod, and then connect the other end of the telescopic rod to the other of the adjustable support and the connecting section side piece to form the adjustable section side piece;

[0016] Assemble a single-piece bracket: Connect and fix all the standard section side pieces and the adjustable section side pieces at both ends to form a single-piece bracket;

[0017] Install the intermediate component: Align the two single-piece brackets upright and leave an installation gap in the middle, and install the intermediate component between the two single-piece brackets;

[0018] The intermediate component includes a cross brace, tie rods, and a cross brace. The cross brace is perpendicular to the single-piece support. The four corners of the cross brace are fixed to the upper chord and lower chord of two adjacent single-piece supports. The tie rods intersect in pairs to form an X shape. The tie rods are fixed between the upper chord and the lower chord of two adjacent single-piece supports. The cross brace is parallel to the cross brace. The cross brace is fixed between the upper chord and the lower chord of adjacent single-piece supports.

[0019] S3. Install the fasteners and main crossbeam, including the following steps:

[0020] Install the fastener: The fastener is installed below the top of the bridge pier column, and the fastener hugs the bridge pier column;

[0021] Erecting the main crossbeam: The main crossbeam is erected on the adjacent fixing member in the transverse direction of the bridge, and the main crossbeam is fixedly connected to the fixing member;

[0022] Steps S2 and S3 can be interchanged;

[0023] S4. Hoisting the prefabricated longitudinal beam: hoist the prefabricated longitudinal beam as a whole, and place the adjustable support on the main crossbeams at both ends of the bridge span;

[0024] The number of prefabricated longitudinal beams in the same bridge span is at least two, and the prefabricated longitudinal beams are arranged below the bridge web or below the webs.

[0025] S5. Install the transverse distribution beam assembly: The transverse distribution beam assembly is located above the prefabricated longitudinal beam. The transverse distribution beam assembly includes at least two transverse distribution beams, with adjacent transverse distribution beams spaced apart. All transverse distribution beams are arranged transversely along the prefabricated longitudinal beam.

[0026] S6. Install the longitudinal distribution beam assembly: The longitudinal distribution beam assembly is located above the transverse distribution beam assembly. The longitudinal distribution beam assembly includes at least two longitudinal distribution beams, which are spaced apart from each other. All the longitudinal distribution beams are arranged transversely along the transverse distribution beams.

[0027] The prefabricated unsupported pier bracket installation method of the present invention uses a horizontal assembly method to assemble the single bracket pieces, and then aligns and installs the intermediate components on the upright single bracket pieces. This makes the connection between the components simpler and more convenient, effectively reducing the assembly difficulty of the prefabricated longitudinal beam and improving the installation accuracy. Installing the fixing components on the bridge pier and erecting the main crossbeam eliminates the need for column installation, which helps to shorten the construction period and reduce costs. The assembled prefabricated longitudinal beam is hoisted to the bridge span as a whole, reducing the time workers spend working at height, which helps to reduce safety risks. Furthermore, it allows for simultaneous hoisting and assembly of the next prefabricated longitudinal beam, which can significantly shorten the construction period and reduce costs.

[0028] This invention proposes a complete set of installation steps for prefabricated unsupported pier supports, which effectively solves the problems of high cost, low efficiency, poor accuracy and high risk in the previous installation of prefabricated unsupported pier supports, and is conducive to the promotion and application of prefabricated unsupported pier supports.

[0029] As a preferred method of the present invention, in step S2, a hand chain hoist is used to adjust the angle of the telescopic rod. The hand chain hoist is low in cost and simple to operate, and can quickly adjust the angle of the telescopic rod.

[0030] As a preferred method of the present invention, in step S2, the adjacent standard segment side pieces and the standard segment side pieces and the adjustable segment side pieces are all connected by a suspended splicing method, which can reduce the resistance encountered when moving the standard segment side pieces or the adjustable segment side pieces, reduce the difficulty of connection, and improve the efficiency and accuracy of connection.

[0031] As a preferred method of the present invention, the standard section side plates are connected to each other and the adjustable section side plates by means of female and male head butt joints, which can increase the tightness of the connection, facilitate the transmission and distribution of force, and improve the structural strength of the connection point.

[0032] As a preferred method of the present invention, after the female head and the male head are connected, they are fixed by a pin, which can ensure the strength of the connection point and is easy to operate.

[0033] As a preferred method of the present invention, in step S2, the single-piece support is erected using a crane and supported by a figure-eight brace.

[0034] As a preferred method of the present invention, in step S2, when installing the intermediate component, the cross brace is installed first, then the tie rod is installed, and finally the cross brace is installed. The cross brace has high rigidity and can constrain the distance between two adjacent single-piece supports, thus preventing deformation of the tie rod and the cross brace due to changes in the distance.

[0035] As a preferred method of the present invention, the cross brace is installed in the order of first the two ends and then the middle. Starting from the two ends, the single bracket has a large deformation range, which facilitates the alignment of bolt holes, significantly reduces the installation difficulty, and improves the installation efficiency.

[0036] As a preferred method of the present invention, the fixing member is a steel clamp, and a rubber partition is pasted on the inner side of the fixing member. The rubber partition can increase the friction between the steel clamp and the bridge pier, reduce the displacement of the steel clamp, and ensure the accurate position of the upper unsupported pier support.

[0037] As a preferred method of the present invention, in step S4, the prefabricated longitudinal beam is hoisted by a dual-machine lifting method, and the position is adjusted by tying traction ropes to both sides of the adjustable section. Dual-machine lifting can better ensure the stability of the prefabricated longitudinal beam during hoisting. Tying traction ropes to both sides of the adjustable section facilitates control of the installation position of the prefabricated longitudinal beam and helps to improve installation accuracy.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] 1. The prefabricated unsupported pier bracket installation method of the present invention uses a horizontal assembly method to assemble single bracket pieces, and then aligns the single bracket pieces vertically and installs intermediate components. This makes the connection between components simpler and more convenient, effectively reducing the assembly difficulty of prefabricated longitudinal beams and improving installation accuracy. Fixing components are installed on bridge piers and main crossbeams are erected, eliminating the need for column installation, which helps to shorten the construction period and reduce costs. The assembled prefabricated longitudinal beams are hoisted to the bridge span as a whole, reducing the time workers spend working at heights, which helps to reduce safety risks. Furthermore, hoisting and assembly of the next prefabricated longitudinal beam can be carried out simultaneously, which can significantly shorten the construction period and reduce costs.

[0040] 2. The prefabricated unsupported pier support installation method of the present invention effectively solves the problems of high cost, low efficiency, poor accuracy and high risk of previous prefabricated unsupported pier support installations, and is conducive to the promotion and application of prefabricated unsupported pier supports. Attached image description:

[0041] Figure 1 This is a schematic diagram (front view) of the prefabricated unsupported support structure described in this invention.

[0042] Figure 2 for Figure 1 Side view.

[0043] Figure 3 This is a schematic diagram (front view) of the prefabricated longitudinal beam structure described in this invention.

[0044] Figure 4 for Figure 3 Side view.

[0045] Figure 5 This is a schematic diagram of the standard segment side plate structure described in this invention.

[0046] Figure 6 This is a schematic diagram of the adjustable side plate structure described in this invention.

[0047] Figure 7 This is a schematic diagram of the adjustable support structure described in this invention.

[0048] Figure 8 This is a top view of the standard truss segment unit described in this invention.

[0049] Figure 9 This is a top view of the adjustable section described in this invention.

[0050] Figure 10 This is a schematic diagram of the overall hoisting of the prefabricated longitudinal beam described in this invention.

[0051] The markings in the diagram are: 1-Prefabricated longitudinal beam, 2-Standard truss segment, 3-Standard truss segment unit, 4-Adjustable segment, 5-Connecting truss, 6-Adjustable support, 7-Telescopic rod, 8-Standard segment side piece, 9-Connecting segment side piece, 11-Upper chord, 12-Lower chord, 13-Frame assembly, 14-Diagonal brace, 21-Female end, 22-Male end, 23-Round hole, 24-Pin hole, 31-Horizontal brace, 32-Tie rod, 33-Horizontal bracing, 40-Bridge pier, 41-Transverse distribution beam, 42-Longitudinal distribution beam, 43-Fixed component, 44-Main crossbeam, 45-Truck crane. Detailed Implementation

[0052] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0053] Example 1

[0054] like Figure 1-9 As shown, a prefabricated unsupported support frame includes a prefabricated longitudinal beam 1, a transverse distribution beam assembly, and a longitudinal distribution beam assembly. The prefabricated longitudinal beam 1 includes a standard truss segment 2, and the standard truss segment 2 includes at least one detachably connected standard truss segment unit 3. Adjustable segments 4 are detachably connected to both ends of the standard truss segment 2. The length of the adjustable segment 4 can be adjusted. The adjustable segment 4 includes a connecting truss 5 and an adjustable support 6. The adjustable support 6 is telescopically connected to the upper part of the connecting truss 5, and a telescopic rod 7 is connected to the lower part of the connecting truss 5. The standard truss segment unit 3 includes vertically spaced and interconnected standard segment side pieces 8. The connecting truss 5 includes vertically spaced and interconnected connecting segment side pieces 9. The connecting segment side pieces 9 and the adjustable support 6 together form the adjustable segment side pieces.

[0055] In this embodiment, the total length of the prefabricated unsupported pier support is 25 meters, including two 4.5-meter-long adjustable sections 4, one 7-meter-long standard truss section unit 3, and one 9-meter-long standard truss section unit 3. Each standard truss section unit 3 includes two vertically spaced standard section side pieces 8, with adjacent side pieces detachably connected. Each standard section side piece 8 includes an upper chord 11, a lower chord 12, and a frame assembly 13. The frame assembly 13 includes vertical web members and diagonal web members. The frame assembly 13 is used to connect the upper chord 11 and the lower chord 12 and maintain the structural stability of the standard section side piece 8. See Figure 5 .

[0056] Furthermore, the adjustable section 4 includes a connecting truss 5 and an adjustable support 6. Each connecting truss 5 includes two vertically spaced connecting section side plates 9. The connecting section side plates 9 also include an upper chord 11, a lower chord 12, and a plate frame assembly 13. At least two circular holes 23 can be opened on the upper chord 11 at one end of the connecting section side plate 9, and multiple circular holes 23 can be correspondingly opened on the adjustable support 6. By aligning and fixing the different circular holes 23 on the adjustable support 6 with the circular holes 23 on the connecting section side plate 9, the length of the adjustable section 4 can be adjusted. A telescopic rod 7 is connected to the end of the adjustable support 6 away from the connecting section side plate 9. The other end of the telescopic rod 7 is connected to the end of the lower chord 12 of the connecting section side plate 9. The length of the telescopic rod 7 is adjustable to accommodate the telescopic connection between the adjustable support 6 and the connecting section side plate 9. A diagonal rod 14 is also provided on the side of the connecting section side plate 9 near the adjustable support 6. The diagonal rod 14 connects the upper chord 11 and the lower chord 12 to enhance the structural strength of the adjustable section 4.

[0057] A method for installing a prefabricated, unsupported bracket includes the following steps:

[0058] S1. Based on the bridge span, calculate the specifications and quantity of the required standard truss segment unit 3, as well as the adjustment length of the adjustable segment 4, and prefabricate the standard segment side piece 8 and the connecting segment side piece 9 in the factory.

[0059] S2. Assemble the prefabricated longitudinal beam 1, including the following steps:

[0060] Arrange the support beams: Place several support beams flat on the assembly site, with all support beams parallel to each other and spaced apart. Place each component flat on the support beams.

[0061] Four to five I-beams with equal cross-sections can be used as support beams to ensure that the cross-sections are oriented in the same direction. They should be placed flat at certain intervals on the assembly site. A total station can be used to determine the elevation of the support beams to ensure that they are basically on the same horizontal plane. Steel stakes can also be used to limit the position of each support beam around its perimeter.

[0062] Install the adjustable support 6: Connect the adjustable support 6 to the upper chord 11 of the connecting section side plate 9, adjust the extension length of the adjustable support 6 and fix it.

[0063] like Figure 6-7 As shown, in this embodiment, two circular holes 23 with a diameter of D1 are opened at the end of the upper chord 11 at one end of the connecting section side plate 9, and the center distance between the holes is L. On the adjustable support 6, five circular holes 23 with a diameter of D1 are correspondingly provided at the connection with the connecting section side plate 9, and the center distance between the holes is also L. Among them, D1 is preferably 51mm and L is preferably 100mm. When it is necessary to configure an adjustable section 4 with a length of 4.5 meters, two circular holes 23 on the adjustable support 6 that are close to the connecting section side plate 9 are selected and aligned with the two circular holes 23 on the connecting section side plate 9. The circular holes 23 are connected with a pin and fixed with a pin.

[0064] To install the telescopic rod: First, connect one end of the telescopic rod to one of the adjustable support or the connecting side plate, and adjust the angle and length of the telescopic rod. Then, connect the other end of the telescopic rod to the other of the adjustable support or the connecting side plate to form the adjustable side plate.

[0065] Assemble the single-piece bracket: Connect and fix all standard section side pieces 8 and the adjustable section side pieces at both ends to form a single-piece bracket.

[0066] Install the intermediate component: Align the two single-piece brackets upright and leave an installation gap of about 1.8 meters in the middle, and install the intermediate component between the two single-piece brackets.

[0067] The intermediate components include a cross brace 31, tie rods 32, and a cross brace 33. In this embodiment, the cross brace 31 is welded from a round tube and channel steel, resulting in high overall rigidity. The four corners of the cross brace 31 are connected to the upper chord 11 and lower chord 12 of two adjacent single-piece supports, respectively. The tie rods 32 are welded from a round tube and a connector, and can be arranged in pairs to form an X-shape, connecting to the upper chord 11 of two adjacent single-piece supports, or to the lower chord 12 of two adjacent single-piece supports. The cross brace 33 is made of channel steel and can be spaced apart on the upper chord 11 or lower chord 12 of two adjacent single-piece supports. The cross brace 33 is perpendicular to the single-piece support and parallel to the cross brace 31. Figure 8-9 .

[0068] After all intermediate components are installed, the assembly of the prefabricated longitudinal beam 1 is complete.

[0069] S3. Install the fastener 43 and the main crossbeam 44, including the following steps:

[0070] Installation fastener 43: Fastener 43 is installed below the top of bridge pier 40, and fastener 43 hugs bridge pier 40.

[0071] Erecting the main crossbeam 44: The main crossbeam 44 is erected on the adjacent fixing member 43 in the transverse direction of the bridge, and the main crossbeam 44 is fixedly connected to the fixing member 43.

[0072] Those skilled in the art will understand that the fastener 43 is a structure fixed to the bridge pier 40 and supporting the prefabricated longitudinal beam 1. Preferably, the fastener 43 can be a steel clamp, which typically includes two clamping plates. Each clamping plate includes an arc segment and a parallel segment. The arc segment is used to enclose the bridge pier 40. The parallel segments of the two clamping plates are aligned with each other and are equipped with connectors. The connectors can ensure that the steel clamp tightly hugs the bridge pier 40. By hugging the bridge pier 40, the fastener 43 can transfer its own weight and the weight of the superstructure to the bridge pier 40, eliminating the need to install steel pipe columns to support the prefabricated longitudinal beam 1.

[0073] A 2-3mm rubber layer can be pasted on the inside of the steel clamp. The rubber layer can protect the concrete from being scratched by the steel clamp and also increase the friction between the steel clamp and the bridge pier 40, so that the steel clamp can be better fixed to the bridge pier 40.

[0074] Furthermore, when installing steel clamps, the upper and lower edge positions of the steel clamps can be initially marked on the bridge pier column 40. Then, the steel clamps are installed at the marked positions. During the installation process, a total station is used to repeatedly check the elevation and axis position of the steel clamps to achieve high-precision installation of the steel clamps.

[0075] The main crossbeam 44 can be made of I-beams. The main crossbeam 44 is erected on the parallel section of the adjacent steel clamps and is fixedly connected to the steel clamps. The main crossbeam 44 is provided on both the left and right sides of each bridge pier 40. The prefabricated longitudinal beam 1 can be installed on the two main crossbeams 44 on the left and right sides of the same bridge span.

[0076] Since S2 and S3 are carried out in different locations, the assembly of the prefabricated longitudinal beam 1 and the installation of the fasteners 43 and the main crossbeam 44 can be interchanged or carried out simultaneously to shorten the construction period.

[0077] S4. Hoisting and installing prefabricated longitudinal beam 1: hoist the prefabricated longitudinal beam 1 as a whole, and place the adjustable support 6 on the main crossbeams 44 at both ends of the bridge span. The number of prefabricated longitudinal beams 1 in the same bridge span shall be at least two. The prefabricated longitudinal beam 1 shall be arranged below the bridge web or below the web.

[0078] Prefabricated longitudinal beams 1 are preferably installed below the webs on both sides of the bridge. If the bridge is wide, prefabricated longitudinal beams 1 can also be installed below the webs. For a bridge with a width of 11 meters, three prefabricated longitudinal beams 1 are usually installed.

[0079] S5. Install the transverse distribution beam assembly: The transverse distribution beam assembly is located above the prefabricated longitudinal beam 1. The transverse distribution beam assembly includes at least two transverse distribution beams 41, with adjacent transverse distribution beams 41 spaced apart. All transverse distribution beams 41 are arranged transversely along the prefabricated longitudinal beam 1.

[0080] S6. Install the longitudinal distribution beam assembly: The longitudinal distribution beam assembly is located above the transverse distribution beam assembly. The longitudinal distribution beam assembly includes at least two longitudinal distribution beams 42, with adjacent longitudinal distribution beams 42 spaced apart. All longitudinal distribution beams 42 are arranged transversely along the transverse distribution beam 41.

[0081] In this embodiment, the transverse distribution beam 41 can be made of steel profiles and have rows of bolt holes on the lower flange. It is installed at different intervals in the solid section, transition section and general section of the cast-in-place box girder. The longitudinal distribution beam 42 can be made of 10cm×10cm square timber and arranged according to the weight of the bridge segment.

[0082] It should be noted here that: the transverse direction of the prefabricated longitudinal beam 1 is the cross-sectional direction of the prefabricated longitudinal beam 1; the transverse direction of the transverse distribution beam 41 is the cross-sectional direction of the transverse distribution beam 41.

[0083] A transverse distribution beam assembly is installed above the prefabricated longitudinal beam 1, and a longitudinal distribution beam assembly is installed on the transverse distribution beam assembly. The longitudinal distribution beam assembly is used to support the casting template, so that the overall structure of the prefabricated pierless support is clearly stressed and the structural safety control is simpler.

[0084] Example 2

[0085] In this embodiment, the scheme is similar to that of embodiment 1, except that in S2, a hand chain hoist is used to adjust the angle of the telescopic rod 7. Specifically, one end of the telescopic rod 7 is first hinged to the adjustable support 6, the hand chain hoist is fixed to the upper chord 11 of the connecting section side plate 9, the hand chain hoist hooks the free end of the telescopic rod 7, the hand chain hoist is started to drive the telescopic rod 7 to rotate, and the length of the telescopic rod 7 is adjusted. The other end of the telescopic rod 7 is then fixed to the connecting section side plate 9.

[0086] Similarly, one end of the telescopic rod 7 can be hinged to the side plate 9 of the connecting section first. After adjusting the angle and length of the telescopic rod 7, the other end of the telescopic rod 7 can be fixed to the adjustable support 6.

[0087] Example 3

[0088] In this embodiment, the scheme is similar to that of Embodiment 2, except that in S2, the single brackets are connected by a suspended splicing method. For example, the adjustable side piece is the first horizontal splicing segment. The four corners of the 7-meter standard side piece 8 can be tied diagonally with steel wire ropes, and then the crane is used to lift it up and bring it close to the adjustable side piece. The operator guides the connection and fixes it.

[0089] Furthermore, to ensure the connection strength between the two side plates, a female head 21 and a male head 22 can be respectively provided on the upper chord 11 or lower chord 12 of the two mating side plates. The female head 21 is a concave structure, and the male head 22 is a convex structure. The male head 22 can be inserted into the female head 21 and fixed, which can improve the tightness of the connection between the side plates. The upper chord 11 and lower chord 12 on the same side of the side plate can be staggered to form female heads 21 and male heads 22. The staggered arrangement is conducive to the uniform distribution of stress and improves the strength of the connection.

[0090] Furthermore, pin holes 24 can be opened on the sides of the female head 21 and the male head 22. After the female head 21 is inserted into the male head 22, the pin is inserted into the pin hole 24 to fix the male and female heads. The pin can be fixed with a pin. Before the docking begins, the impurities in the pin hole 24 of the female head 21 and the male head 22 can be cleaned and an appropriate amount of grease can be applied to reduce the resistance when the pin is installed.

[0091] Example 4

[0092] In this embodiment, the scheme is similar to that of embodiment 3, except that in S2, a crane is used to erect the single-piece bracket and a figure-eight brace is used for fixation. Two lifting points can be selected on the left and right sides of the upper chord 11 of the single-piece bracket. After the lifting points are tied with steel wire ropes, the crane is used to lift the single-piece bracket upright. The upright single-piece bracket is placed on the pad beam and supported by a figure-eight brace. The figure-eight brace consists of a group of three steel pipes, which are respectively set on both sides of the single-piece bracket to fix and support it. The above operation is repeated to erect and fix another single-piece bracket.

[0093] Example 5

[0094] In this embodiment, the scheme is similar to that of embodiment 4, except that in S2, when installing the intermediate components, the cross brace 31 is installed first, then the tie rod 32 is installed, and finally the cross brace 33 is installed. The cross brace 31 has high rigidity and can constrain the two single-piece supports, avoiding damage to the tie rod 32 and the cross brace 33 caused by changes in the spacing between the single-piece supports.

[0095] Furthermore, when installing the cross brace 31, it should be installed in the order of first the two ends and then the middle. A crane can be used to hoist the cross brace 31 to the vicinity of the preset position. Then, the workers can use an electric wrench to align and fix the cross brace 31 with the preset bolt holes on the single bracket to complete the installation of the cross brace 31. The tie rod 32 and the cross brace 33 are relatively light and can be manually moved to the preset position and fixed.

[0096] Example 6

[0097] like Figure 10 As shown, in this embodiment, the scheme is similar to that of embodiment 5, except that in S4, the prefabricated longitudinal beam 1 is hoisted by a dual-machine lifting method. First, a tower crane or a truck crane 45 is selected according to the lifting weight of the prefabricated longitudinal beam 1, and the position of the lifting point is determined by stress analysis. The lifting point is tied with steel wire rope, and the prefabricated longitudinal beam 1 is hoisted by two truck cranes 45 to the main crossbeam 44 of the bridge span. During the hoisting process, the horizontal angle of the steel wire rope should be controlled between 30° and 60°.

[0098] Furthermore, in order to ensure the accurate positioning of the prefabricated longitudinal beam 1, traction ropes can be tied to both sides of the adjustable section 4 at the end, and the position can be adjusted by pulling left and right with the traction ropes. At the same time, the swing amplitude of the prefabricated longitudinal beam 1 should be avoided. Finally, a total station can be used to check the axis deviation and elevation.

[0099] 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 within the protection scope of the present invention.

Claims

1. A method for installing a prefabricated, unsupported bracket, characterized in that, The prefabricated unsupported support includes a prefabricated longitudinal beam (1), a transverse distribution beam assembly and a longitudinal distribution beam assembly. The prefabricated longitudinal beam (1) includes a standard truss section (2). The standard truss section (2) includes at least one detachably connected standard truss section unit (3). The two ends of the standard truss section (2) are detachably connected to adjustable sections (4). The length of the adjustable section (4) is adjustable. The adjustable section (4) includes a connecting truss (5) and an adjustable support (6). The adjustable support (6) is telescopically connected to the upper part of the connecting truss (5). The adjustable support (6) is connected to the lower part of the connecting truss (5) by a telescopic rod (7). The standard truss segment unit (3) includes standard segment side pieces (8) that are vertically spaced and interconnected. The connecting truss (5) includes connecting segment side pieces (9) that are vertically spaced and interconnected. The connecting segment side pieces (9), the adjustable support (6), and the telescopic rod (7) together form an adjustable segment side piece. The installation method for the prefabricated unsupported bracket includes the following steps: S1. Calculate the specifications and quantity of the standard truss segment unit (3) required based on the bridge span, as well as the adjustment length of the adjustable segment (4); The standard section side piece (8) and the connecting section side piece (9) are prefabricated in the factory. Each of the standard section side piece (8) and the connecting section side piece (9) includes an upper chord (11), a lower chord (12), and a piece frame assembly (13). S2. Assemble the prefabricated longitudinal beam, including the following steps: Arrange the support beams: Place several support beams flat on the assembly site. All the support beams are parallel to each other and spaced apart. Place each component flat on the support beams. Install the adjustable support (6): Connect the adjustable support (6) to the upper chord (11) of the connecting section side plate (9), adjust the extension length of the adjustable support (6) and fix it; Install the telescopic rod (7): First, connect one end of the telescopic rod (7) to one of the adjustable support (6) and the connecting section side piece (9), adjust the angle and length of the telescopic rod (7), and then connect the other end of the telescopic rod (7) to the other of the adjustable support (6) and the connecting section side piece (9) to form the adjustable section side piece; Assemble a single-piece bracket: Connect and fix all the standard section side pieces (8) and the adjustable section side pieces at both ends to form a single-piece bracket; Install the intermediate component: Align the two single-piece brackets upright and leave an installation gap in the middle, and install the intermediate component between the two single-piece brackets; The intermediate component includes a cross brace (31), a tie rod (32), and a cross brace (33). The cross brace (31) is perpendicular to the single-piece bracket. The four corners of the cross brace (31) are fixed to the upper chord (11) and lower chord (12) of two adjacent single-piece brackets. The tie rods (32) intersect each other in an X-shape. The tie rods (32) are fixed between the upper chord (11) and the lower chord (12) of two adjacent single-piece brackets. The cross brace (33) is parallel to the cross brace (31). The cross brace (33) is fixed between the upper chord (11) and the lower chord (12) of adjacent single-piece brackets. S3. Install the fasteners (43) and the main crossbeam (44), including the following steps: Install the fastener (43): The fastener (43) is installed below the top of the bridge pier (40), and the fastener (43) hugs the bridge pier (40); Erecting the main crossbeam (44): The main crossbeam (44) is erected on the adjacent fixing member (43) in the transverse direction of the bridge, and the main crossbeam (44) is fixedly connected to the fixing member (43); Steps S2 and S3 can be interchanged; S4. Hoisting the prefabricated longitudinal beam (1): hoist the prefabricated longitudinal beam (1) as a whole, and place the adjustable support (6) on the main crossbeam (44) at both ends of the bridge span; The number of prefabricated longitudinal beams (1) in the same bridge span is at least two, and the prefabricated longitudinal beams (1) are arranged below the bridge web or below the webs. S5. Install the transverse distribution beam assembly: The transverse distribution beam assembly is located above the prefabricated longitudinal beam (1). The transverse distribution beam assembly includes at least two transverse distribution beams (41). Adjacent transverse distribution beams (41) are spaced apart. All transverse distribution beams (41) are arranged transversely along the prefabricated longitudinal beam (1). S6. Install the longitudinal distribution beam assembly: The longitudinal distribution beam assembly is located above the transverse distribution beam assembly. The longitudinal distribution beam assembly includes at least two longitudinal distribution beams (42), adjacent longitudinal distribution beams (42) are spaced apart, and all longitudinal distribution beams (42) are arranged transversely along the transverse distribution beam (41).

2. The method for installing a prefabricated supportless bracket according to claim 1, characterized in that, In step S2, a hand chain hoist is used to adjust the angle of the telescopic rod (7).

3. The method for installing a prefabricated supportless bracket according to claim 1, characterized in that, In S2, the adjacent standard section side pieces (8) and the standard section side pieces (8) and the adjustable section side pieces are connected by a suspended splicing method.

4. The method for installing a prefabricated supportless bracket according to claim 3, characterized in that, The standard section side pieces (8) are connected to each other and the adjustable section side pieces are connected by mating the male head (21) and the female head (22).

5. The method for installing a prefabricated supportless bracket according to claim 4, characterized in that, After the female head (21) and the male head (22) are connected, they are fixed with a pin.

6. The method for installing a prefabricated supportless bracket according to claim 1, characterized in that, In step S2, the single-piece support is erected using a crane and supported by a figure-eight brace.

7. The method for installing a prefabricated supportless bracket according to claim 1, characterized in that, In S2, when installing the intermediate component, the cross brace (31) is installed first, then the tie rod (32) is installed, and finally the cross brace (33) is installed.

8. The method for installing a prefabricated supportless bracket according to claim 7, characterized in that, The cross bracing (31) is installed in the order of first the two ends, then the middle.

9. The method for installing a prefabricated supportless bracket according to claim 1, characterized in that, The fastener (43) is a steel clamp, and a rubber diaphragm is pasted on the inner side of the fastener (43).

10. A method for installing a prefabricated supportless bracket according to any one of claims 1-9, characterized in that, In S4, the prefabricated longitudinal beam (1) is hoisted by a dual-machine lifting method, and its position is adjusted by tying it to both sides of the adjustable section (4) with traction ropes.

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