New type static load reaction frame for box girder and construction method thereof

Abstract

The application discloses a novel static load counterforce frame for a box girder and a construction method thereof, and belongs to the technical field of bridge static load test devices. The novel static load counterforce frame comprises multiple supporting piers arranged in two rows, a pressure bearing structure arranged above a box girder to be tested, multiple vertical frames and connecting beams arranged in the same direction, a vertical column connected between the end portions of the upper beam and the lower beam, an inner arc surface of the inverted arch beam facing the upper beam, multiple force transmission members arranged vertically and connected between the outer arc surface of the inverted arch beam and the lower beam, two ends of the inverted arch beam being connected to the intersection of the upper beam and the vertical column, and the end portions of the upper beams of the multiple vertical frames and the end portions of the lower beams of the multiple vertical frames being connected with the connecting beams respectively. Multiple jacking members are arranged between each lower beam and the box girder to be tested. A tensioning bar is connected between the connecting beams between the end portions of the upper beams of the multiple vertical frames and the opposite sides of the supporting piers. The application solves the problem of large vertical deformation of the existing counterforce frame for the bridge static load test in the middle span and the side span.

Description

Technical Field

[0001] This invention relates to the field of bridge technology, specifically to a novel static load reaction frame for box girders and its construction method. Background Technology

[0002] Before high-speed railway precast box girders are put into mass production, static load tests must be conducted to determine the overall load-bearing capacity and quality of the precast box girders.

[0003] There are many types of reaction frames used for static load testing of precast box girders in the market, which can be used for static load testing of 24m, 32m and 40m precast box girders. Taking the reaction frame of steel plate girder as an example, the lower beam adopts a steel box girder structure, the middle beam adopts a steel composite structure, the two parts are equipped with force transmission tie rods, and the plate beams are equipped with transverse and horizontal bracing. The stressed plate beams and the middle transverse beams are hinged. Vertical pressure is applied to the reaction frame by loading jacks and acts in the opposite direction on the box girder. The force is then transferred to the box girder by the structural supports, and finally the static load test is completed.

[0004] For example, application number 201710478297 discloses a prestressed steel-concrete composite self-balancing static load test bench for bridge static load testing. Tests showed that during the loading process, the vertical deformation of the reaction frame at the mid-span and side spans was significant.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, a novel static load reaction frame for box girders and its construction method are provided to solve the problem of large vertical deformation in the mid-span and side spans of existing reaction frames used for static load testing of bridges.

[0007] To achieve the above objectives, a novel static load reaction frame for box girders is provided, comprising:

[0008] Multiple supports are arranged in two rows, and the two ends of the box girder to be tested are respectively placed on the opposite sides of the two rows of supports;

[0009] A pressure-bearing structure is installed above the box girder to be tested. The pressure-bearing structure includes multiple vertical frames and connecting beams arranged in the same direction. Each vertical frame includes an upper beam, a lower beam, and an anti-arch beam. A column is connected between the ends of the upper beam and the lower beam. The inner arc surface of the anti-arch beam faces the upper beam. Multiple vertically arranged force transmission components are connected between the outer arc surface of the anti-arch beam and the lower beam. The two ends of the anti-arch beam are respectively connected to the intersection of the upper beam and the column. The connecting beams are respectively connected between the ends of the upper beams of the multiple vertical frames and between the ends of the lower beams of the multiple vertical frames.

[0010] Multiple lifting components are provided, with multiple lifting components placed between each of the lower beams and the box girder to be tested;

[0011] Tie bars are connected between the connecting beams located on the opposite side of the pier and between the ends of the upper beams of the plurality of vertical frames.

[0012] Furthermore, the upper beam is a prestressed beam.

[0013] Furthermore, the lower beam is a box beam.

[0014] Furthermore, the anti-arch beam includes:

[0015] A receiving tube, the receiving tube being arc-shaped, the end of the receiving tube being connected to the confluence;

[0016] Grouting material is injected into the receiving tube to solidify and form a core.

[0017] Furthermore, the receiving tube is fitted with multiple reinforcing sleeves, and the upper end of the force transmission component is supported by the reinforcing sleeves.

[0018] Furthermore, a reinforcing sleeve is fitted at the apex of the receiving tube, and the lower beam is supported by the reinforcing sleeve at the apex of the receiving tube.

[0019] Furthermore, a first pair of tie rods are connected between the corresponding reinforcing sleeves on adjacent receiving tubes.

[0020] Furthermore, the lifting component is a jack.

[0021] Furthermore, a second pair of tie rods connects two adjacent upper beams.

[0022] This invention provides a construction method for a novel static load reaction frame for box girders, comprising the following steps:

[0023] Multiple supports are arranged in two rows, such that the distance between the opposite sides of the two rows of supports is adapted to the length of the box girder to be measured.

[0024] The two ends of the box girder to be tested are respectively placed on the opposite sides of the two rows of supports;

[0025] The pressure-bearing structure is hoisted above the box girder to be tested;

[0026] Multiple lifting components are provided between the lower beam of the pressure-bearing structure and the box girder to be tested;

[0027] Install tie rods such that the tie rods are connected between the connecting beams between the opposite side of the pier and the ends of the upper beams of the plurality of vertical frames;

[0028] The lifting components are activated, and multiple lifting components apply vertical pressure to the lower beam to conduct a static load test on the box girder under test.

[0029] The beneficial effects of this invention are that the novel static load reaction frame for box girders utilizes the connection form of vertical frame and anti-arch beam. At the same time, during the loading process, the two ends of the anti-arch beam (the two ends in the arc direction) are subjected to greater force. With the tie rods, the overall structure is stable and has high bearing capacity. During the loading process of the lifting component, the actual deformation in the mid-span and side span is small, which meets the design requirements. Attached Figure Description

[0030] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0031] Figure 1 This is a structural schematic diagram of a novel static load reaction frame for box girders according to an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the end structure of the novel static load reaction frame for box girders according to an embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram comparing the force analysis of the novel static load reaction frame for box girders according to an embodiment of the present invention with that of the existing bridge static load reaction frame. Detailed Implementation

[0034] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] Reference Figures 1 to 3As shown, the present invention provides a novel static load reaction frame for box girders, comprising: multiple supports 1, a pressure-bearing structure 2, multiple lifting components 3, and tie rods 4.

[0037] Specifically, multiple supports 1 are arranged in two rows. The two rows of supports are respectively located below the two adjacent ends to be measured. The two rows of supports have one opposite side and one opposite side. The two ends of the box girder 5 to be measured rest on the opposite sides of the two rows of supports 1. The opposite side of the supports extends to the outside of the box girder to be measured.

[0038] The pressure-bearing structure 2 is positioned above the box girder 5 to be tested. Multiple lifting components are positioned between the box girder to be tested and the pressure-bearing structure.

[0039] Specifically, the pressure-bearing structure 2 includes multiple vertical frames 21 and connecting beams 22. The multiple vertical frames are arranged in the same direction. In this embodiment, there are two vertical frames 2. Each vertical frame has two opposite ends. Connecting beams 22 connect the ends of the two vertical frames respectively.

[0040] The vertical frame 21 includes an upper beam 211, a lower beam 212, and an anti-arch beam 213.

[0041] A column 218 is connected between the ends of the upper beam 211 and the lower beam 212.

[0042] The inverted arch beam is arc-shaped. The inner arc surface of the inverted arch beam 213 faces the upper beam 211. Multiple vertically arranged force transmission components 214 connect the outer arc surface of the inverted arch beam 213 and the lower beam 212. The two ends of the inverted arch beam 213 are respectively connected to the intersection of the upper beam 211 and the column 218.

[0043] In this embodiment, connecting beams 22 are connected between the ends of the upper beams 211 of the plurality of vertical frames 21. In addition, connecting beams 22 are also connected between the ends of the lower beams 212 of the plurality of vertical frames 21.

[0044] Each lifting component 3 is vertically arranged. In this embodiment, the lifting component is a jack. Multiple lifting components 3 are placed between each lower beam 212 and the box girder 5 to be measured. The multiple lifting components are arranged along the length of the lower beam.

[0045] In a preferred embodiment, the lower beam is composed of multiple unit segments spliced ​​together. In this embodiment, the lower beam includes three unit segments. The three unit segments are coaxially arranged and spliced ​​together to form a lower beam that runs the entire length.

[0046] In this embodiment, the lower beam 212 is a box girder, and the upper beam 211 is a prestressed beam. Prestressing tendons are threaded through the upper beam.

[0047] After the pressure-bearing structure is installed on the box girder to be tested, the tie rod 4 is tied between the connecting beam 22 between the opposite side of the pier 1 and the end of the upper beam 211 of the multiple vertical frames 21.

[0048] In a preferred embodiment, the anti-arch beam 213 includes: a receiving pipe and grouting material. The receiving pipe and the upper beam are steel pipes. The grouting material is concrete slurry.

[0049] Specifically, the receiving tube is arc-shaped. The ends of the receiving tube are connected at the junction. Grout is poured into the receiving tube to solidify and form the tube core.

[0050] In this embodiment, the receiving tube is fitted with multiple reinforcing sleeves 215. These reinforcing sleeves are spaced apart along the length of the receiving tube. Specifically, each receiving tube is fitted with at least three reinforcing sleeves. The upper end of the force transmission member 214 is supported by the reinforcing sleeves 215.

[0051] A reinforcing sleeve 215 is fitted at the apex of the receiving tube. The lower beam 212 is supported by the reinforcing sleeve 215 at the apex of the receiving tube.

[0052] A first pair of tie rods 216 connects the corresponding reinforcing sleeves 215 on adjacent receiving tubes. A second pair of tie rods 217 connects the two adjacent upper beams 211.

[0053] This invention provides a construction method for a novel static load reaction frame for box girders, comprising the following steps:

[0054] S1: Arrange multiple supports 1 in two rows, so that the distance between the opposite sides of the two rows of supports 1 is adapted to the length of the box girder 5 to be measured.

[0055] S2: Place the two ends of the box girder 5 to be tested on opposite sides of the two rows of supports 1 respectively.

[0056] S3: Hoist the pressure-bearing structure 2 above the box girder 5 to be tested.

[0057] S4: Multiple lifting components 3 are provided between the lower beam 212 of the pressure-bearing structure 2 and the box beam 5 to be tested.

[0058] S5: Install tie rods 4 such that the tie rods 4 are connected to the connecting beams 22 between the opposite side of the support 1 and the ends of the upper beams 211 of the multiple vertical frames 21.

[0059] S6: Activate the lifting component 3. Multiple lifting components 3 apply vertical pressure to the lower beam 212 to conduct a static load test on the box girder 5 to be tested.

[0060] The box girder of this invention is assembled using a novel static load reaction frame bearing structure and then hoisted to the top of the box girder to be tested using a beam lifting machine. It is then fixed to the box girder by supports and tie rods. During the static load test, a lifting component (i.e., a jack) applies a vertical force, which is transmitted through the bearing structure to the supports at the bottom of the box girder and acts on it, simulating the load-bearing capacity of the box girder under load. The deformation of the box girder is observed using monitoring equipment.

[0061] The novel static load reaction frame for box girders of this invention can be matched and assembled according to different models of precast box girders. The novel static load reaction frame for box girders of this invention is connected by components such as a lower beam and an anti-arch beam. Most connections are made with bolts, facilitating overall assembly and disassembly. The connecting bolts are large hexagonal high-strength bolts with a diameter of 25cm, and the connection points are padded with 5cm thick steel plates. The anti-arch beam's disassembly and assembly points use a reinforcing sleeve connection to the force transmission components, strengthening the rigidity of the connection. The two ends of the anti-arch beam are connected by prestressed beams to enhance its rigidity and reduce deformation; the lower beam and the anti-arch beam are connected by vertical force transmission components. The two vertical frames are fixedly connected by connecting beams, a first pair of tie rods, and a second pair of tie rods to prevent lateral overturning during loading. The tie rods are made of steel strands.

[0062] In this invention, by investigating the structural characteristics and usage of existing static load reaction frames, a static load reaction frame structure with simple structure, low steel consumption, high load-bearing capacity, and small deformation is optimized and designed, thereby providing a new type of static load reaction frame for box girders.

[0063] The novel static load reaction frame for box girders of the present invention adopts a structural form in which an anti-arch beam is set in the vertical frame, combined with other supporting components to improve the overall load-bearing capacity.

[0064] See Figure 3 As shown, existing bridge static load reaction frames use a positive arch frame form, with the entire structure under tension. In contrast, the novel static load reaction frame for box girders of this invention uses a reverse arch beam form, with the structure under compression. Existing bridge static load reaction frames, when under tension, use steel strands, resulting in significant longitudinal deformation of the positive arch frame. Furthermore, with longer vertical connecting members of the same size, the stiffness is lower, leading to greater deformation under compression and failing to meet design requirements. In contrast, the reverse arch beam of the novel static load reaction frame for box girders of this invention is under compression. The two ends of the reverse arch beam are connected by an upper beam, resulting in relatively smaller vertical deformation of the lower beam. The shorter force transmission members also contribute to relatively greater stiffness and smaller deformation, allowing for a reduction in the amount of steel used in the vertical members. Moreover, the reverse arch beam uses a steel-concrete composite structure, combining the compressive strength of concrete to further reduce deformation.

[0065] The novel static load reaction frame for box girders of this invention utilizes the connection between the vertical frame and the anti-arch beam. At the same time, during the loading process, the two ends of the anti-arch beam (the two ends in the arc direction) are subjected to greater forces. With the tie rods, the overall structure is stable and has high bearing capacity. During the loading process of the lifting component, the actual deformation of the mid-span and side spans is small, which meets the design requirements.

[0066] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A novel static load reaction frame for box girders, characterized in that, include: Multiple supports are arranged in two rows, and the two ends of the box girder to be tested are respectively placed on the opposite sides of the two rows of supports; A pressure-bearing structure is installed above the box girder to be tested. The pressure-bearing structure includes multiple vertical frames and connecting beams arranged in the same direction. Each vertical frame includes an upper beam, a lower beam, and an anti-arch beam. A column is connected between the ends of the upper beam and the lower beam. The inner arc surface of the anti-arch beam faces the upper beam. Multiple vertically arranged force transmission components are connected between the outer arc surface of the anti-arch beam and the lower beam. The two ends of the anti-arch beam are respectively connected to the intersection of the upper beam and the column. The connecting beams are respectively connected between the ends of the upper beams of the multiple vertical frames and between the ends of the lower beams of the multiple vertical frames. Multiple lifting components are provided, with multiple lifting components placed between each of the lower beams and the box girder to be tested; Tie bars are connected between the connecting beams located on the opposite side of the pier and between the ends of the upper beams of the plurality of vertical frames.

2. The novel static load reaction frame for box girders according to claim 1, characterized in that, The upper beam is a prestressed beam.

3. The novel static load reaction frame for box girders according to claim 1, characterized in that, The lower beam is a box girder.

4. The novel static load reaction frame for box girders according to claim 1, characterized in that, The anti-arch beam includes: A receiving tube, the receiving tube being arc-shaped, the end of the receiving tube being connected to the confluence; Grouting material is injected into the receiving tube to solidify and form a core.

5. The novel static load reaction frame for box girders according to claim 4, characterized in that, The receiving tube is fitted with multiple reinforcing sleeves, and the upper end of the force transmission component is supported by the reinforcing sleeves.

6. The novel static load reaction frame for box girders according to claim 5, characterized in that, A reinforcing sleeve is fitted at the apex of the accommodating tube, and the lower beam is supported by the reinforcing sleeve at the apex of the accommodating tube.

7. The novel static load reaction frame for box girders according to claim 5, characterized in that, A first pair of tie rods connects the corresponding reinforcing sleeves on adjacent receiving tubes.

8. The novel static load reaction frame for box girders according to claim 1, characterized in that, The lifting component is a jack.

9. The novel static load reaction frame for box girders according to claim 1, characterized in that, A second pair of tie rods connects the two adjacent upper beams.

10. A construction method for a novel static load reaction frame for box girders as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Multiple supports are arranged in two rows, such that the distance between the opposite sides of the two rows of supports is adapted to the length of the box girder to be measured. The two ends of the box girder to be tested are respectively placed on the opposite sides of the two rows of supports; The pressure-bearing structure is hoisted above the box girder to be tested; Multiple lifting components are provided between the lower beam of the pressure-bearing structure and the box girder to be tested; Install tie rods such that the tie rods are connected between the connecting beams between the opposite side of the pier and the ends of the upper beams of the plurality of vertical frames; The lifting components are activated, and multiple lifting components apply vertical pressure to the lower beam to conduct a static load test on the box girder under test.

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