CN115726285A - Method for simply erecting multi-connected multi-span steel truss bridge in sequence - Google Patents

Abstract

A multi-connection and multi-span steel truss girder bridge construction method first continuous and then simply supported, comprising the following steps: ① prefabricating steel truss girder units in a factory; ② erecting multiple Set up temporary assembly brackets; ③The crawler crane station is located on the existing trestle, assemble the steel truss beams at the initial section on the assembly brackets and temporary piers, and complete the assembly of the first span steel truss girders; ④Use the bridge deck crane to install within the hoisting range Steel truss members complete the installation of the joint steel truss girder; ⑤The bridge deck crane moves forward to the adjacent steel truss girder, and continues to install the joint steel truss girder to the adjacent pier to complete the whole collapse installation; use the semi-automatic cutting machine Cut the combined rods at the junction of the joints, grind and paint, and complete the conversion of the stress system of the installation of two adjacent steel truss beams from continuous to simply supported; ⑥Repeat steps The method of doing is to complete the construction of the remaining joint steel beams. The invention has a short construction period, saves labor and material costs, and is safe and efficient.

Description

A construction method of continuous multi-span steel truss girder bridge

technical field

The invention relates to the technical field of highway bridge construction, in particular to a multi-connection and multi-span steel truss girder bridge erection method which is continuous first and then simply supported.

Background technique

With the rapid development of urban construction in my country and the increasing maturity and development of steel structure bridge fatigue, welding, vibration, and bridge upper and lower structure design, manufacturing, and construction technologies, steel structure bridges have been widely used in railways, highways, and public rail dual-purpose bridges. The field of long-span bridges such as pedestrian bridges and pedestrian bridges is a structure type that the country is vigorously promoting at present.

Traditional steel truss girders are mostly erected by means of large-scale floating crane hoisting, cantilever installation and jacking construction. Floating crane hoisting is mostly suitable for deep water and areas where large equipment can enter and exit; cantilever assembly is mostly suitable for multi-span continuous standard section steel truss beams; jacking construction is mostly suitable for straight line standard section steel truss beams. For simply supported steel truss girders, the traditional method usually adopts methods such as erecting double-sided trestle bridges and installing cross-pier gantry cranes or using large-scale floating cranes for overall hoisting. The above-mentioned methods require large material investment and long construction periods, and are not suitable for areas where large equipment cannot enter such as shallow water areas. The traditional cantilever assembly erection method is more suitable for single-joint multi-span continuous steel truss girders, but for multi-joint construction, the initial section of each joint can only be erected by the bracket method, which increases the construction period and material costs. Continuous operation cannot be formed, and the overall construction efficiency is low.

Therefore, it is necessary to provide a steel truss girder bridge that is first continuous and then simply supported to solve the above problems.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for constructing a multi-connected steel truss girder bridge that is continuous first and then simply supported, with a short construction period, saving labor and material costs, and being safe and efficient.

In order to solve the above problems, the technical solution of the present invention is: a multi-connection multi-span steel truss girder bridge is first continuous and then simply supported, erecting N-connection steel truss girders, where N is an integer greater than or equal to 2, and each connection of steel truss The beam has several piers, characterized in that the method comprises the steps of:

① Steel truss units are prefabricated in the factory, including the combined members at the junction of joints and joints, and then transported to the site for easy installation;

②Multiple sets of temporary assembly supports shall be erected between the first pier and the second pier of the first joint erection section, and a set of temporary support pier shall be erected at the mid-span position between every two adjacent pier after the second pier;

③The crawler crane station is located on the existing trestle bridge, assemble the steel truss girder of the initial section on the assembly bracket and temporary pier, complete the assembly of the steel truss girder of the first span, and assemble two bridge deck cranes on the steel truss girder of the first span machine;

④ Use the bridge deck crane to install the steel truss members within the lifting range, and complete the installation of the joint steel truss girders by cantilever assembly, including the installation of the combined members at the junction of the joints and the joints. The steel truss girders are placed on temporary supports On the seat, and the preset height of the pad;

⑤ The bridge deck crane moves forward to the adjacent steel truss girder, and continues to install the steel truss girder to the adjacent pier to complete the whole collapse installation; use a semi-automatic cutting machine to cut the combined rods at the junction of the joint and the joint, grind, Coating, to complete the conversion of the load-bearing system from continuous to simply supported in the installation of two adjacent steel truss girders;

⑥Repeat the fourth to fifth steps, and complete the construction of the remaining joint steel beams according to the method of doing two joints.

Preferably, the composite rod at the junction of the joint and the joint is made of the upper chord and the lower chord on both sides of the expansion joint to form a composite rod respectively.

Preferably, the assembled support in the initial section is a single row of pipe piles, and there are 3 to 4 sets of assembled supports between the two piers in the initial section, and the stress points of each set are at the node of the lower chord.

Preferably, the preset height of the steel truss pad is 200-500mm.

Preferably, the lateral distance of the temporary pier between two adjacent piers is the center distance between the upstream and downstream main chords, and the temporary pier is composed of 8 steel pipes and connecting systems, the steel pipes and connecting systems The selection needs to be obtained through calculation.

Preferably, the bridge deck crane is a single-arm full-slewing rotary crane with a maximum lifting capacity of 50 tons at a height of 28m and a rotation angle of 360°.

The beneficial effects of the present invention are: the present invention is suitable for construction in various external environments such as deep water and shallow water, can solve the problem that the traditional cantilever assembly cross-connection construction cannot form continuous operations, and reduces the need for erecting the initial section assembly brackets of each connection, large-scale mechanical equipment, etc. With the input of materials, only a set of temporary piers needs to be built, which shortens the construction period, saves costs, greatly improves the construction speed, and has good safety and reliability.

Description of drawings

Fig. 1 is the schematic diagram of construction structure of step 3;

Fig. 2 is the schematic diagram of construction structure of step 4;

Fig. 3 is the schematic diagram of construction structure of step 5;

Fig. 4 is the enlarged schematic view of A in Fig. 2;

Fig. 5 is the enlarged schematic diagram of B in Fig. 3;

Fig. 6 is a schematic diagram of the lifting curve of the bridge deck crane of the present invention;

In the figure: 1-deck crane; 2-steel truss girder; 21-the first upper chord; 22-the last lower chord; 23-the first lower chord; 24-the last lower chord; 25- Upper chord composite member; 26-lower chord composite member; 3-assembled bracket; 4-temporary support pier; 5-bridge pier; 51-first bridge pier; 52-second bridge pier; four piers;

Detailed ways

The construction method of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific examples, but the present invention is not limited to the following examples.

As shown in Figure 1-6, a steel truss girder bridge is first continuous and then simply supported. N steel truss girders are erected, N is an integer greater than or equal to 2, and each steel truss girder has several piers. In this embodiment, take N as 2 as an example for illustration, each link is a multi-span continuous steel truss girder, including several piers, and each span includes 7 internode steel truss girders. The present invention comprises the following steps:

① Steel truss girder unit 2 is prefabricated in the factory, including the composite members 25 and 26 at the junction of joints and joints, and then transported to a location convenient for installation on site;

In this embodiment, the combined rod 25 at the junction of the joints is composed of upper chords 21 and 22 on both sides of the expansion joint, and the combined rod 26 at the junction of the joints is composed of upper chords 21 and 22 on both sides of the expansion joint. The lower chords 23 and 24 are composed, and the solid-web steel plates of the combined rods 25 and 26 are all cut and blanked, assembled and welded in the factory once, and the effective combined length between the upper chords 21 and 22 and the lower chords 23 and 24 is based The size of the expansion joint is obtained, and the size of the parts is guaranteed by CNC flame cutting machine, plasma cutting machine and machining, and the inner side adopts a circular arc transition to eliminate stress concentration.

② Multiple sets of temporary assembly supports 3 are erected between the first pier 51 and the second pier 52 of the first bridge pier section, and a set of temporary assembly brackets 3 are erected at the mid-span position between every two adjacent pier 5 behind the second pier 51. buttress 4;

In this embodiment, the assembled support 3 in the initial section is a single row of pipe piles, and there are 3 to 4 groups of assembled supports 3 between the two piers 51 and 52 in the initial section, and the stress point of each group is at the node of the lower chord.

In this embodiment, the lateral distance of the temporary support pier 4 between the two adjacent bridge piers is the center distance between the upstream and downstream main chords, and the temporary support pier 4 is composed of 8 steel pipes and a connecting system, The selection of steel pipe and connecting system shall be obtained through calculation.

③The crawler crane station is located on the existing trestle, assemble the steel truss girder 2 of the initial section on the assembly bracket 3 and the temporary pier 4, complete the assembly of the steel truss girder 2 of the first span, and assemble the two steel truss girders on the first span Bridge Deck Crane 1;

In this embodiment, the specific steps for assembling the steel truss girder 2 at the initial section between the first pier 51 and the second pier 52 are: lower chord → lower railway deck system → web bar → upper chord → upper road deck system

④Use the bridge deck crane 1 to install the steel truss girder 2 members within the lifting range, and complete the installation of the joint steel truss girder 2 through cantilever assembly, including the installation of the combined members 25 and 26 at the junction of the joint and the joint, and the steel truss girder The beams are all placed on temporary supports, and the pads are placed at a preset height;

In this embodiment, before lifting, check in advance whether the gravity of the bar is within the rated lifting force of the corresponding lifting distance of the bridge deck crane 1, and then lift without accident after the trial lifting; The specific steps of inter-steel truss girder 2 are: lower chord → web → upper chord → lower railway deck system → upper road deck system

In this embodiment, the preset height of the steel truss girder 2 is 200-500 mm, and the preset height should meet the working requirements of the semi-automatic cutting machine.

⑤ The bridge deck crane 1 moves forward to the adjacent steel truss girder, and continues to install the steel truss girder 2 to the adjacent pier 54 to complete the whole collapse installation; use a semi-automatic cutting machine to cut the combined rods at the junction of the steel truss 25, 26, grinding and painting, complete the conversion of the force system from continuous to simple support in the installation of adjacent two steel truss girders;

In this embodiment, the track of the semi-automatic cutting machine can be adsorbed on the steel truss beam 2, and the combined rods 25 and 26 can be cut and separated as a whole along the cutting line when the temperature is low and relatively stable, and the cutting parts can be cut according to the requirements of the original design documents. Grinding, painting and anti-corrosion treatment.

⑥Repeat steps 4 to 5, and follow the method of two joints, that is, first process the upper chords 21 and 22 and the lower chords 23 and 24 on both sides of the expansion joints of the remaining joints into combined rods 25 in the factory , 26, according to the method of cantilever assembly to complete the erection of the adjacent joint first span, then cut the combined rods 25, 26 to complete the transition from continuous to simply supported force system, and finally lower the steel truss girder 2 as a whole to the design elevation by jack , adjust the vertical and horizontal plane positions, install permanent supports, and complete the installation of the remaining steel truss beams.

The bridge deck crane 1 described in the above steps is a single-arm full-slewing rotary crane, as shown in Figure 6, with a maximum lifting capacity of 50 tons at a height of 28 m and a rotation angle of 360°.

Compared with the prior art, the erection method of the steel truss girder in the present invention is continuous first and then simply supported, which eliminates the problem that the steel truss girder 2 cantilever erection can not continue to work, and a large number of assembled supports 3 need to be erected, and only one set of Temporary piers greatly reduce the investment in auxiliary materials and mechanical equipment, save costs and improve construction efficiency.

The present invention has been exemplarily described above in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above-mentioned manner, as long as various improvements of the method concept and technical solutions of the present invention are adopted, or directly applied to other methods without improvement. Occasions, all within the protection scope of the present invention.

Claims (6)

1. A method for erecting a multi-connected multi-span steel truss girder bridge by simply supporting the bridge after continuous is provided, N is an integer which is more than or equal to 2, each steel truss girder is provided with a plurality of piers, and the method is characterized by comprising the following steps:

(1) prefabricating a steel truss girder unit in a factory, wherein the steel truss girder unit comprises a combined rod piece at a connection and connection junction, and then transporting the combined rod piece to a position convenient for field installation;

(2) a plurality of groups of temporary splicing supports are erected between a first pier and a second pier of the first frame connection frame section, and a group of temporary buttresses are erected at the midspan position between every two adjacent piers behind the second pier;

(3) the crawler crane station is positioned on the existing trestle, the initial section steel truss girder is assembled on the assembling support and the temporary buttress to complete the assembling of the first span steel truss girder, and two bridge deck cranes are assembled on the first span steel truss girder;

(4) installing steel truss girder rods in a hoisting range by using a bridge deck crane, and completing the installation of the steel truss girders in a cantilever assembly mode, wherein the installation of the combined rods at the junction of a girder and a girder is included, the steel truss girders are all placed on temporary supports, and the preset height of a shoveling pad is realized;

(5) the bridge deck crane moves forward to the adjacent steel truss girder, and the steel truss girder is continuously installed to the adjacent bridge pier to complete the whole-collapse installation; cutting the combined rod piece at the junction of the two steel trusses by using a semi-automatic cutting machine, polishing and coating to complete the conversion of a continuous stress system to a simply supported stress system in the installation of the two adjacent steel trusses;

(6) and repeating the fourth step to the fifth step, and completing construction of the rest connected steel beams according to the two-connection manufacturing method.

2. The method for erecting a multi-connected multi-span steel truss girder bridge according to claim 1, wherein the method comprises the following steps: the combined member at the junction of the link and the link is made of an upper chord and a lower chord at two sides of the expansion joint respectively.

3. The method for erecting a multi-connected multi-span steel truss girder bridge according to claim 1, wherein the method comprises the following steps: the initial section assembly support is a single-row tubular pile, 3-4 groups of the initial section assembly supports are arranged between two piers, and each group of stress points are located at the nodes of the lower chord members.

4. The method for erecting a multi-connected multi-span steel truss girder bridge according to claim 1, wherein the method comprises the following steps: the preset height of the steel truss girder shoveling mat is 200-500 mm.

5. The method for erecting a multi-connected multi-span steel truss girder bridge according to claim 1, wherein the method comprises the following steps: the transverse distance of the temporary buttress between two adjacent piers is the central distance between the upstream main truss chord member and the downstream main truss chord member, the temporary buttress is composed of 8 steel pipes and a connection system, and the selection of the steel pipes and the connection system needs to be obtained through calculation.

6. The method for erecting a multi-connected multi-span steel truss girder bridge according to claim 1, wherein the method comprises the following steps: the bridge deck crane is a single-boom full-rotation type rotary crane, the maximum lifting capacity at 28m is 50 tons, and the rotation angle is 360 degrees.

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