Construction method of steel-concrete composite beam with coordinated load-bearing with bridge erection machine

Abstract

The present invention discloses a construction method of a steel-concrete composite beam that is subjected to force in coordination with a bridge erection machine, including: ① prefabricating steel beam segments, constructing the lower structure of the bridge; ② installing a bridge erection machine with a telescopic diagonal brace on the top at the position of the first hole bridge pier; ③ connecting the steel beam segments of the first hole with the diagonal brace, adjusting them to the design elevation and connecting them longitudinally; ④ installing the bridge deck and pouring wet joints; ⑤ removing the bridge erection machine; ⑥ constructing the second hole steel beam, and connecting it with the first hole steel beam as a whole, completing the "simply supported to continuous" conversion; ⑦ installing the bridge deck and pouring the mid-span wet joint and the pier top bottom plate; ⑧ releasing the connection between the diagonal brace and the second hole steel beam, installing the bridge deck in the negative bending moment area of ​​the pier top and pouring the wet joint in the negative bending moment area of ​​the pier top; ⑨ repeating steps 6 to 8 to complete the construction of the remaining bridge holes of the whole bridge. The present invention has the advantages of both traditional steel-concrete composite beams with and without brackets, and the equipment used is simple and highly operable, and can give full play to the combined force performance of the steel-concrete composite beams in the bridge completion stage.

Description

Technical Field

[0001] The invention relates to the technical field of steel-concrete composite beam construction, in particular to a steel-concrete composite beam construction method that is coordinated with a bridge erection machine to bear force. Background Art

[0002] Steel-concrete composite beams can make full use of the characteristics of concrete under compression and steel under tension. Under the condition of satisfying the structural stress, the steel consumption can be reduced and the structural rigidity can be increased. The structure is light and highly assembled, making it a highly competitive bridge solution for crossing roads and areas with sensitive construction periods. Based on the structural characteristics of steel-concrete composite beams, the stress state after the bridge is completed is closely related to the construction method and construction process. For example: 1) Through the construction with support method, the weight of the steel beam and concrete is borne by the support during the construction stage, and all loads are borne by the composite structure during the bridge completion stage. The steel beam and concrete are highly integrated, the steel consumption is low, and the bridge erection method is more flexible, but the construction of the support is time-consuming and labor-intensive, and the cost is high; 2) Through the construction without support method, the steel beam bears its own weight and the weight of the concrete bridge deck during the construction stage, and the composite structure only bears live loads and secondary loads during the bridge completion stage. The steel beam and concrete are relatively low in integration, the steel consumption of the steel beam is large, and the erection of the steel beam is greatly affected by the site environment under the bridge. It can be seen that both of the above schemes have defects, and the construction process of steel-concrete composite beams can be further optimized. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a steel-concrete composite beam construction method which is efficient, convenient, has a high steel utilization rate, and has no restrictions on the site under the bridge and is coordinated with the bridge erection machine to bear the force. Specifically, the following technical solutions can be adopted:

[0004] The method for constructing a steel-concrete composite beam that is subjected to force in coordination with a bridge erecting machine of the present invention comprises the following steps:

[0005] In the first step, the steel beam segments are prefabricated in the factory according to the design requirements, and the bridge substructure is constructed at the same time;

[0006] The second step is to install a bridge erection machine at the position of the first hole bridge pier and adjust the bridge erection machine to the designed elevation. The bridge erection machine includes several sets of telescopic diagonal braces located at the top;

[0007] The third step is to use a crane to hoist the steel beam segment of the first hole to the top of the bridge erection machine, connect the steel beam segment with the diagonal brace, then adjust the length of the diagonal brace to make the steel beam segment reach the designed elevation, and connect the steel beam segment longitudinally into a whole;

[0008] Step 4: Install the precast concrete bridge deck on the first hole steel beam obtained in step 3, and pour the wet joint concrete of the bridge deck;

[0009] Step 5: After the wet joint concrete of the bridge deck reaches the design strength, release the connection between the diagonal brace and the first hole steel beam, and dismantle the bridge erection machine;

[0010] Step 6: Install the bridge erection machine at the position of the second hole bridge pier, construct the second hole steel beam according to the method described in step 3, and connect it with the first hole steel beam as a whole, completing the working condition conversion of the second hole steel beam from "simply supported to continuous";

[0011] Step 7: Install the precast concrete bridge deck in the middle span of the second span steel beam, and pour the wet joint concrete of the bridge deck in the middle span and the concrete of the pier top and bottom slab;

[0012] Step 8: After the wet joint concrete of the bridge deck in the mid-span area reaches the design strength, release the connection between the diagonal brace and the second-hole steel beam, then install the precast concrete bridge deck in the negative bending moment area of ​​the pier top, and pour the wet joint concrete of the bridge deck in the negative bending moment area of ​​the pier top;

[0013] Step 9. Repeat steps 6 to 8 to complete the construction of the remaining bridge openings of the entire bridge.

[0014] Preferably, the bridge-building machine is a downward-type bridge-building machine.

[0015] Preferably, a lug plate for connecting the diagonal brace is provided at the bottom of the steel beam segment, and the lug plate and the top of the diagonal brace are connected by a pin shaft, which simplifies the construction.

[0016] Preferably, the diagonal braces are all formed by sleeve-connecting an outer tube and an inner rod, and the tops of the diagonal braces of the same group are connected together, and the bottoms are dispersedly arranged on the top of the bridge erection machine, which not only makes it convenient to adjust the length of the diagonal braces, but also improves the load-bearing capacity of the grouped diagonal braces.

[0017] Preferably, the steel beam segments are connected by bolting or welding.

[0018] Preferably, the span of the steel beam formed by the steel beam segments is 50-120m per hole.

[0019] The steel-concrete composite beam construction method provided by the present invention, which is coordinated with the bridge-erecting machine to bear force, is efficient, environmentally friendly, and convenient to construct. By arranging multiple groups of diagonal braces for connecting steel beam segments on the top of the bridge-erecting machine, the steel beam and the bridge-erecting machine form a truss structure. The steel beam serves as the upper chord of the truss structure, and the bridge-erecting machine serves as the lower chord of the truss structure. The two are coordinated to bear force and jointly bear the weight of the concrete bridge deck during the construction process. Since the above-mentioned truss structure has a large rigidity, the deformation amplitude generated during the installation of the bridge deck can be greatly reduced, the combination efficiency of the composite beam can be significantly improved, the steel consumption can be reduced, and it has extremely high economy.

[0020] Compared with the existing construction method, the advantages of the present invention are specifically embodied in:

[0021] 1) The present invention changes the construction method of traditional steel-concrete composite beams, and the combination efficiency of the obtained steel-concrete composite beams is close to 1, which greatly reduces the amount of steel and the project cost;

[0022] 2) The steel beam segments of the present invention are prefabricated in the factory and assembled on site, which can not only ensure the quality of the steel beam, but also reduce the weight of the hoisting, and are convenient for transportation and have strong applicability;

[0023] 3) The use of the present invention to erect steel-concrete composite beams has little impact on traffic under the bridge;

[0024] 4) In the process of erecting the steel-concrete composite beam, the present invention can freely adjust the main beam line shape, and well control the stress of the steel beam and concrete, and the bridge deck line shape;

[0025] 5) The bridge erecting machine used as the lower chord in the present invention has a large cross-sectional rigidity, which can effectively reduce the deformation of the main beam during the construction process and significantly improve the bonding efficiency of the steel-concrete composite beam;

[0026] 6) The bridge erecting machine used in the present invention can form a truss structure with steel beams to bear the load together, and its deadweight is reduced by about 25% compared with the traditional bridge erecting machine.

[0027] In summary, the present invention combines the advantages of traditional scaffolding construction and scaffolding-free construction of steel-concrete composite beams. The equipment used is simple and highly operable. It can give full play to the combined stress performance of steel-concrete composite beams in the bridge completion stage and is extremely competitive in the construction of bridges across intersections and in areas with sensitive construction periods. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1-9 It is a construction step diagram of the present invention.

[0029] Fig.10 yes Figure 3 AA section view in.

[0030] Fig.11 yes Fig.10 Schematic diagram of the structure of the prefabricated steel beam segment. DETAILED DESCRIPTION

[0031] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific construction process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0032] The steel-concrete composite beam construction method that cooperates with the bridge-building machine to bear force described in the present invention is suitable for steel beams with a span of 50-120m per hole. The steel beam segments are supported by a bridge-building machine with diagonal braces arranged on the top, thereby effectively reducing the deformation of the steel beam during the construction process, improving material utilization, and achieving efficient, convenient, and green construction.

[0033] like Figure 1-11 As shown, the specific construction steps of the present invention are as follows:

[0034] The first step is to construct the bridge substructure according to the design requirements, and prefabricate the steel beam segment 1 in the factory; in order to facilitate lifting and installation, two pairs of temporary hanging pieces 12 are welded on the flange 11 of the steel beam segment 1, and two pairs of ear plates 14 are welded on the bottom plate 13 (see Fig.11 ).

[0035] The second step is to install the bridge erection machine 2 at the position of the first hole pier and adjust the bridge erection machine 2 to the designed elevation. The bridge erection machine 2 includes several groups of telescopic diagonal braces 3 located at the top. The above-mentioned bridge erection machine 2 adopts a downward bridge erection machine; the diagonal braces 3 are all formed by the sleeve connection of an outer tube and an inner rod, which can be flexibly extended and locked when they reach a suitable length. The tops of the diagonal braces 3 in the same group are connected together through a mounting plate, and the bottoms are dispersedly arranged on the top of the bridge erection machine 2; the top of the above-mentioned mounting plate is welded with an ear seat to facilitate the connection with the ear plate 14 at the bottom of the steel beam segment 1. The size, load-bearing capacity and installation position of the diagonal braces 3 are determined according to the steel beam design plan.

[0036] The third step is to use a crane to hoist the steel beam segment 1 of the first hole to the top of the bridge erection machine 2, and connect the steel beam segment 1 and the diagonal brace 3 together through a pin (see Figure 1 , Fig.10 ), then adjust the length of the diagonal brace 3 to make the steel beam segment 1 reach the designed elevation, and connect the steel beam segment 1 longitudinally into a whole by bolt connection or welding (see Figure 2 ), and obtain the first hole steel beam.

[0037] At this time, the first hole steel beam and the bridge erection machine 2 form a truss structure, the steel beam serves as the upper chord of the truss structure, and the bridge erection machine 2 serves as the lower chord of the truss structure. The two work together to bear the weight of the concrete bridge deck 4 during the construction process.

[0038] Step 4: Install the precast concrete bridge deck 4 on the first hole steel beam and pour the bridge deck wet joint concrete (see Figure 3 );

[0039] Step 5: After the wet joint concrete of the bridge deck reaches the design strength, the connection between the diagonal brace 3 and the first hole steel beam is released, and the bridge erection machine 2 is dismantled;

[0040] Step 6: Install the bridge erecting machine 2 at the second hole bridge pier position (see Figure 4 ), construct the second hole steel beam according to the method in step 3, and connect it with the first hole steel beam as a whole, completing the working condition conversion of the second hole steel beam from "simply supported to continuous" (see Figure 5 , Figure 6 );

[0041] Step 7: Install the precast concrete bridge deck 4 in the middle span of the second steel beam, and pour the wet joint concrete of the bridge deck in the middle span and the concrete of the pier top and bottom plate 5 (see Figure 7 );

[0042] Step 8: After the wet joint concrete of the bridge deck in the mid-span area reaches the design strength, the connection between the diagonal brace 3 and the second hole steel beam is released, and then the precast concrete bridge deck 6 in the negative bending moment area of ​​the pier top is installed, and the wet joint concrete of the bridge deck in the negative bending moment area of ​​the pier top is poured;

[0043] Step 9. Repeat steps 6 to 8 to complete the construction of the remaining bridge openings of the entire bridge.

[0044] Taking a steel-concrete composite continuous beam with a span of 100m and a bridge width of 16.06m as an example, the steel consumption of the present invention is 350kg / ㎡, which is about 10% lower than that of the traditional scaffolding-free construction method; the combination efficiency of the steel-concrete composite beam is 100%, which is 100% higher than that of the traditional scaffolding-free construction method.

[0045] It should be noted that, in the description of the present invention, terms indicating orientation or positional relationships, such as "front", "rear", "left", "right", "vertical", "horizontal", "inside", "outside", etc., are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

Claims

1. A method for constructing a steel-concrete composite beam that is coordinated with a bridge erection machine, characterized in that: The steps include: In the first step, the steel beam segments are prefabricated in the factory according to the design requirements, and the bridge substructure is constructed at the same time; The second step is to install a bridge erection machine at the position of the first hole bridge pier and adjust the bridge erection machine to the designed elevation. The bridge erection machine includes several sets of telescopic diagonal braces located at the top; The third step is to use a crane to hoist the steel beam segment of the first hole to the top of the bridge erection machine, connect the steel beam segment with the diagonal brace, then adjust the length of the diagonal brace to make the steel beam segment reach the designed elevation, and connect the steel beam segment longitudinally into a whole; Step 4: Install the precast concrete bridge deck on the first hole steel beam obtained in step 3, and pour the wet joint concrete of the bridge deck; Step 5: After the wet joint concrete of the bridge deck reaches the design strength, release the connection between the diagonal brace and the first hole steel beam, and dismantle the bridge erection machine; Step 6: Install the bridge erection machine at the position of the second hole bridge pier, construct the second hole steel beam according to the method described in step 3, and connect it with the first hole steel beam as a whole, completing the working condition conversion of the second hole steel beam from "simply supported to continuous"; Step 7: Install the precast concrete bridge deck in the middle span of the second span steel beam, and pour the wet joint concrete of the bridge deck in the middle span and the concrete of the pier top and bottom slab; Step 8: After the wet joint concrete of the bridge deck in the mid-span area reaches the design strength, release the connection between the diagonal brace and the second-hole steel beam, then install the precast concrete bridge deck in the negative bending moment area of ​​the pier top, and pour the wet joint concrete of the bridge deck in the negative bending moment area of ​​the pier top; Step 9, repeat steps 6 to 8 to complete the construction of the remaining bridge openings of the entire bridge; The bridge erecting machine is a down-type bridge erecting machine; The bottom of the steel beam segment is provided with an ear plate for connecting the diagonal brace, and the ear plate and the top of the diagonal brace are connected by a pin shaft; The diagonal bracing rods are all formed by sleeve-connecting an outer tube and an inner rod, and the tops of the diagonal bracing rods in the same group are connected together, and the bottoms are dispersedly arranged on the top of the bridge erecting machine.

2. The method for constructing a steel-concrete composite beam in coordination with a bridge erecting machine according to claim 1, characterized in that: The steel beam segments are connected by bolting or welding.

3. The method for constructing a steel-concrete composite beam in coordination with a bridge erecting machine according to claim 1, characterized in that: The span of the steel beam formed by the steel beam segments is 50-120m per hole.

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