A steel plate composite beam concrete cracking prevention structure in a negative bending moment region

Abstract

The application relates to the field of steel-concrete combined bridge construction, in particular to a steel plate combined beam negative moment area concrete cracking prevention structure, which comprises a mounting plate arranged on a steel plate at the top of a bridge support, anchor seats are arranged on both sides of the mounting plate along the bridge span direction, the anchor seats are arranged on the steel plate at the mid-span positive moment area of the bridge, a height plate is vertically slidably arranged on the mounting plate, a lifting piece for driving the vertical sliding of the height plate is arranged on the mounting plate, a fixing plate and a sliding plate are arranged on the height plate, the sliding plate is horizontally slidably arranged on the height plate, a first cable is arranged between the anchor seat on the side, away from the sliding plate, of the fixing plate and the sliding plate, a second cable is arranged between the anchor seat on the side, away from the fixing plate, of the sliding plate and the fixing plate, and a sliding piece for driving the sliding plate to move away from the fixing plate is arranged on the fixing plate. The application has the effect of improving the bridge construction efficiency.

Description

Technical Field

[0001] This application relates to the field of steel-concrete composite bridge construction, and in particular to a structure for preventing concrete cracking in the negative bending moment zone of a steel plate composite beam. Background Technology

[0002] Steel-concrete composite bridges are widely used worldwide due to their advantages such as large span, light weight, good economy, and convenient construction.

[0003] The negative bending moment zone of a bridge usually refers to the area at and near the support of the beam, the root of the cantilever beam, and the support of the continuous beam. These areas form a negative bending moment due to the tension on the upper part, and the negative bending moment will cause the concrete at the top of the support to crack under tension.

[0004] Currently, the commonly used method to solve the above problems during construction is the counterweight method. Its working principle is to utilize the elastic deformation recovery ability of steel. Before adding the counterweight, the concrete bridge deck in the positive bending moment zone at mid-span is poured first. After it hardens, the counterweight is selected for pre-loading. Then, the concrete bridge deck in the negative bending moment zone is poured. After reaching the design strength, the counterweight is removed. Due to the unloading of the weight in the positive bending moment zone, a reverse positive bending moment is generated near the support, achieving the effect of prestressing.

[0005] However, water tanks are generally used as ballast on construction sites. But using water tanks as ballast involves time-consuming construction processes such as hoisting, filling, and emptying the tanks. In addition, the water in the tanks needs to be transported using specialized equipment, which greatly affects the construction efficiency of the bridge and has its shortcomings. Utility Model Content

[0006] To address the issue of low bridge construction efficiency caused by water tanks acting as ballast, this application provides a structure for preventing concrete cracking in the negative bending moment zone of a steel plate composite beam.

[0007] This application provides a technical solution for preventing concrete cracking in the negative bending moment zone of a steel plate composite beam:

[0008] A concrete crack prevention structure for a steel plate composite beam in the negative bending moment zone includes an installation plate, which is arranged on a steel plate at the top of a bridge bearing. Anchor seats are provided on both sides of the installation plate along the bridge span direction. The anchor seats are installed on the steel plate in the positive bending moment zone at mid-span of the bridge. A height plate is vertically slidably mounted on the installation plate. A lifting component is provided on the installation plate to drive the height plate to slide vertically. A fixed plate and a sliding plate are provided on the height plate. The sliding plate is horizontally slidably mounted on the height plate. A first cable is provided between the anchor seat on the side of the fixed plate facing away from the sliding plate and the sliding plate. A second cable is provided between the anchor seat on the side of the sliding plate facing away from the fixed plate and the fixed plate. A sliding component is provided on the fixed plate to drive the sliding plate away from the fixed plate.

[0009] By adopting the above technical solution, after the steel plates are placed on the bridge, workers fix the mounting plates to the steel plates at the top of the bridge bearings. At the same time, anchors are installed on the steel plates in the positive bending moment zone at the mid-span of the bridge. Then, the distance between the fixed plate and the sliding plate is continuously increased by the sliding component, and the height plate is raised by the lifting component. At this time, the first and second cables will cause the two ends of the steel plates installed on the bridge to bend and deform towards the middle, so that the steel plates have an upward opening arc. Then, the adjacent steel plates are connected and fixed. At this time, a positive bending moment is generated at the bridge bearing location of the steel plates. When concrete is poured on the steel plates, the weight of the concrete will generate a negative bending moment at the bridge bearing location. The positive bending moment generated by the steel plates at the bridge bearing location will offset the negative bending moment brought by the concrete, thereby reducing the possibility of cracking of the concrete at the bridge bearing location. After the concrete solidifies, the mounting plates and their structures are removed, and concrete is poured again to fill and fix the mounting plates and their structures. This helps to improve the construction efficiency of the bridge.

[0010] Optionally, the lifting component includes a positioning base plate disposed on the mounting plate, and a vertical hydraulic jack electrically connected to the control system is disposed on the positioning base plate, and the height plate is disposed on the piston rod of the vertical hydraulic jack.

[0011] By adopting the above technical solution, the control system starts the vertical hydraulic jack, the piston rod of the vertical hydraulic jack pushes the height plate to rise, and the rising height plate causes the two ends of the steel plate to bend and deform towards the middle through the first cable and the second cable.

[0012] Optionally, the sliding component includes a transverse hydraulic jack disposed on the fixed plate and electrically connected to the control system, the sliding plate being disposed on the piston rod of the transverse hydraulic jack, and a slide rail with a T-shaped cross-section being disposed on the height plate, the sliding plate being slidably engaged with the slide rail.

[0013] By adopting the above technical solution, the control system starts the transverse hydraulic jack, and the piston rod of the transverse hydraulic jack pushes the sliding plate to slide, thereby increasing the distance between the sliding plate and the fixed plate, and then causing the two ends of the steel plate to bend and deform towards the middle through the first cable and the second cable.

[0014] Optionally, multiple positioning base plates are detachably provided on the mounting plate, and the multiple positioning base plates are evenly arranged along the width direction of the bridge.

[0015] By adopting the above technical solution, the steel plate is subjected to more uniform stress, and the load on a single set of horizontal and vertical hydraulic jacks is reduced.

[0016] Optionally, a first winding wheel is rotatably mounted on the height plate, and a second winding wheel is rotatably mounted on the sliding plate, with the first cable passing over the first winding wheel and the second cable passing over the second winding wheel.

[0017] By adopting the above technical solution, the possibility of wear between the first cable and the height plate, and between the second cable and the height plate, is reduced.

[0018] Optionally, the second cable between the fixed plate and the second winding wheel is arranged horizontally, and the first cable between the sliding plate and the first winding wheel is arranged horizontally.

[0019] By adopting the above technical solution, the first and second cables are subjected to vertical downward force at the height plate, so that the vertical hydraulic jack is subjected to axial load force, which helps to reduce the possibility of damage to the vertical hydraulic jack caused by the inclined load force.

[0020] Optionally, a balance plate is horizontally rotatably mounted on the piston rod of the vertical hydraulic jack, and a balance slide bar with a T-shaped cross-section is provided at the bottom of the height plate. The length direction of the balance slide bar is parallel to the axial direction of the piston rod of the horizontal hydraulic jack, and the balance plate and the balance slide bar are in sliding cooperation.

[0021] By adopting the above technical solution, when the distance between the fixed plate and the sliding plate changes, the force distribution on the height plate will change. The uneven force on the height plate will cause the height plate to slide on the balance plate, thereby achieving automatic balancing and allowing the height plate to reach a state of force balance again.

[0022] Optionally, a stress plate is rotatably mounted on the anchor, the stress plate being used to fix it to a steel plate in the positive bending moment zone at the mid-span of the bridge.

[0023] By adopting the above technical solution, when the distance between the fixed plate and the sliding plate changes, the angle between the first and second cables and the bridge deck will change. During this process, the anchor will rotate around the rotation center on the stress plate, thereby reducing the possibility of the first and second cables bending.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. Workers fix the mounting plate to the steel plate at the top of the bridge bearing. At the same time, the anchor is installed on the steel plate in the positive bending moment zone at the mid-span of the bridge. Then, the distance between the fixed plate and the sliding plate is continuously increased by the sliding component, and the height plate is raised by the lifting component. At this time, the first and second cables will cause the two ends of the steel plate installed on the bridge to bend and deform towards the middle, so that the steel plate has an upward opening arc. Then, the adjacent steel plates are connected and fixed. At this time, a positive bending moment is generated at the bridge bearing of the steel plate. When concrete is poured on the steel plate, the weight of the concrete will generate a negative bending moment at the bridge bearing. The positive bending moment generated by the steel plate at the bridge bearing will offset the negative bending moment brought by the concrete, thereby reducing the possibility of cracking of the concrete at the bridge bearing. After the concrete solidifies, the mounting plate and its structure are removed, and concrete is poured again to fill the position of the fixed mounting plate and its structure. This helps to improve the construction efficiency of the bridge.

[0026] 2. The control system starts the horizontal hydraulic jack. The piston rod of the horizontal hydraulic jack pushes the sliding plate to slide, thereby increasing the distance between the sliding plate and the fixed plate. Then, through the first and second cables, the two ends of the steel plate are bent and deformed towards the middle.

[0027] 3. When the distance between the fixed plate and the sliding plate changes, the force distribution on the height plate will change. The uneven force on the height plate will cause the height plate to slide on the balance plate, thereby achieving automatic balancing and bringing the height plate back to a state of force balance. Attached Figure Description

[0028] Figure 1 This is a structural schematic diagram of an embodiment of this application.

[0029] Figure 2 yes Figure 1 Enlarged view of section A.

[0030] Figure 3 yes Figure 1 Enlarged view of section B.

[0031] Figure 4 This is a structural schematic diagram illustrating the positional relationship between the balance plate, the balance slider, and the height plate in an embodiment of this application.

[0032] Explanation of reference numerals in the attached drawings: 1. Bridge; 2. Steel plate; 3. Mounting plate; 4. Anchor seat; 5. Height plate; 6. Lifting component; 61. Positioning base plate; 62. Vertical hydraulic jack; 7. Fixing plate; 8. Sliding plate; 9. First cable; 10. Second cable; 11. Sliding component; 111. Horizontal hydraulic jack; 112. Slide rail; 12. First winding wheel; 13. Second winding wheel; 14. Balance plate; 15. Balance slide bar; 16. Stress plate; 17. Rubber strip. Detailed Implementation

[0033] The following is in conjunction with the appendix Figures 1-4 This application will be described in further detail.

[0034] This application discloses a structure for preventing concrete cracking in the negative bending moment zone of a steel plate composite beam.

[0035] Reference Figure 1 A concrete crack prevention structure in the negative bending moment zone of a steel plate composite beam includes an installation plate 3, which is bolted to the steel plate 2 at the top of the bridge 1 support by high-strength bolts.

[0036] Reference Figure 1 , Figure 2 and Figure 3 Anchor seats 4 are arranged on both sides of the mounting plate 3 along the span direction of bridge 1. The steel plate 2 between the anchor seats 4 on both sides of the mounting plate 3 is welded from multiple plates. Rubber strips 17 are arranged between two adjacent steel plates 2 along the span direction of bridge 1.

[0037] Reference Figure 1 and Figure 3 An anchor 4 is rotatably connected to a stress plate 16, which is bolted to a steel plate 2 in the mid-span positive bending moment zone of the bridge 1 by high-strength bolts. A height plate 5 is vertically slidably arranged on the mounting plate 3, and a lifting component 6 is arranged on the mounting plate 3 to drive the height plate 5 to slide vertically.

[0038] Reference Figure 2 and Figure 4 The lifting component 6 includes a positioning base plate 61 arranged on the mounting plate 3. Multiple positioning base plates 61 are bolted to the mounting plate 3. The multiple positioning base plates 61 are evenly arranged along the width direction of the bridge 1. A vertical hydraulic jack 62 electrically connected to the control system is bolted to the positioning base plate 61. The height plate 5 is arranged on the piston rod of the vertical hydraulic jack 62.

[0039] Reference Figure 2 and Figure 4A fixed plate 7 and a sliding plate 8 are arranged on the height plate 5. The fixed plate 7 is welded to the height plate 5, and the sliding plate 8 is arranged horizontally on the height plate 5. A first cable 9 is connected between the anchor 4 on the side of the fixed plate 7 facing away from the sliding plate 8 and the sliding plate 8, and a second cable 10 is connected between the anchor 4 on the side of the sliding plate 8 facing away from the fixed plate 7 and the fixed plate 7. Both the first cable 9 and the second cable 10 are high-strength steel cables in the prior art.

[0040] Reference Figure 2 and Figure 4 A first winding wheel 12 is rotatably connected to the height plate 5, and a second winding wheel 13 is rotatably connected to the sliding plate 8. A first cable 9 passes over the first winding wheel 12, and a second cable 10 passes over the second winding wheel 13. The second cable 10 between the fixed plate 7 and the second winding wheel 13 is arranged horizontally, and the first cable 9 between the sliding plate 8 and the first winding wheel 12 is arranged horizontally.

[0041] The workers first placed the steel plate 2 on the top of the bridge 1 support, and then used high-strength bolts to fasten the mounting plate 3 to the steel plate 2 on the top of the bridge 1 support. At the same time, the stress plate 16 was fixed to the steel plate 2 in the positive bending moment zone at the mid-span of the bridge 1 using high-strength bolts. Then, the first cable 9 and the second cable 10 were fixedly connected.

[0042] Reference Figure 2 and Figure 4 A sliding member 11 is arranged on the fixed plate 7 to drive the sliding plate 8 away from the fixed plate 7. The sliding member 11 includes a transverse hydraulic jack 111 that is bolted to the fixed plate 7 and electrically connected to the control system. The sliding plate 8 is bolted to the piston rod of the transverse hydraulic jack 111. A slide rail 112 with a T-shaped cross section is bolted to the height plate 5. The sliding plate 8 and the slide rail 112 are in sliding engagement.

[0043] Reference Figure 2 and Figure 4 A balance plate 14 is horizontally rotatably connected to the piston rod of the vertical hydraulic jack 62. A balance slide bar 15 with a T-shaped cross section is welded to the bottom of the height plate 5. The length direction of the balance slide bar 15 is parallel to the axis of the piston rod of the horizontal hydraulic jack 111. The balance plate 14 and the balance slide bar 15 are in sliding engagement.

[0044] The control system activates the horizontal hydraulic jack 111. The piston rod of the horizontal hydraulic jack 111 pushes the sliding plate 8 to slide, increasing the distance between the sliding plate 8 and the fixed plate 7. At this time, the first cable 9 and the second cable 10 cause the two ends of the steel plate 2 to bend and deform towards the middle.

[0045] Subsequently, the control system activates the vertical hydraulic jack 62. The piston rod of the vertical hydraulic jack 62 pushes the height plate 5 upward. During this process, the force distribution on the height plate 5 will change. Uneven force on the height plate 5 will cause the height plate 5 to slide on the balance plate 14, thereby making the height plate 5 reach the state of force balance again.

[0046] At this time, the two ends of the steel plate 2 are further bent and deformed towards the middle by the first cable 9 and the second cable 10, eventually causing the steel plate 2 to have an upward-opening arc. At this time, a positive bending moment will be generated at the location of the steel plate 2 at the support of the bridge 1. Then, the bent and deformed steel plate 2 is initially fixed to the bridge 1 by bolts. At this time, the positive bending moment generated on the steel plate 2 does not disappear. Subsequently, the gap between two adjacent steel plates 2 is filled by rubber strip 17.

[0047] When concrete is poured onto steel plate 2, the weight of the concrete will generate a negative bending moment at the support of bridge 1. As the concrete gradually solidifies, the workers remove the bolts that fix steel plate 2. At this time, the positive bending moment on steel plate 2 is released. The positive bending moment of steel plate 2 at the support of bridge 1 will offset the negative bending moment brought by the solidifying concrete, thereby reducing the occurrence of cracking of concrete at the support of bridge 1.

[0048] The implementation principle of the concrete crack prevention structure in the negative bending moment zone of a steel plate composite beam according to an embodiment of this application is as follows: the worker first places the steel plate 2 on the top of the bridge 1 support, and then bolts the mounting plate 3 to the steel plate 2 on the top of the bridge 1 support with high-strength bolts. At the same time, the stress plate 16 is fixed to the steel plate 2 in the positive bending moment zone at the mid-span of the bridge 1 with high-strength bolts. Then, the first cable 9 and the second cable 10 are fixedly connected.

[0049] The control system activates the horizontal hydraulic jack 111. The piston rod of the horizontal hydraulic jack 111 pushes the sliding plate 8 to slide, increasing the distance between the sliding plate 8 and the fixed plate 7. At this time, the first cable 9 and the second cable 10 cause the two ends of the steel plate 2 to bend and deform towards the middle.

[0050] Subsequently, the control system activates the vertical hydraulic jack 62. The piston rod of the vertical hydraulic jack 62 pushes the height plate 5 upward. During this process, the force distribution on the height plate 5 will change. Uneven force on the height plate 5 will cause the height plate 5 to slide on the balance plate 14, thereby making the height plate 5 reach the state of force balance again.

[0051] At this time, the two ends of the steel plate 2 are further bent and deformed towards the middle by the first cable 9 and the second cable 10, eventually causing the steel plate 2 to have an upward-opening arc. At this time, a positive bending moment will be generated at the location of the steel plate 2 at the support of the bridge 1. Then, the bent and deformed steel plate 2 is initially fixed to the bridge 1 by bolts. At this time, the positive bending moment generated on the steel plate 2 does not disappear. Subsequently, the gap between two adjacent steel plates 2 is filled by rubber strip 17.

[0052] When concrete is poured onto steel plate 2, the weight of the concrete will generate a negative bending moment at the support of bridge 1. As the concrete gradually solidifies, the workers remove the bolts that fix steel plate 2. At this time, the positive bending moment on steel plate 2 is released. The positive bending moment of steel plate 2 at the support of bridge 1 will offset the negative bending moment brought by the solidifying concrete, thereby reducing the occurrence of cracking of concrete at the support of bridge 1.

[0053] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A structure for preventing concrete cracking in the negative bending moment zone of a steel plate composite beam, characterized in that: The system includes an installation plate (3) which is placed on a steel plate (2) at the top of the bridge (1) support. Anchor seats (4) are provided on both sides of the installation plate (3) along the span direction of the bridge (1). The anchor seats (4) are installed on the steel plate (2) at the mid-span positive bending moment region of the bridge (1). A height plate (5) is vertically slidably mounted on the installation plate (3). A lifting component (6) is provided on the installation plate (3) to drive the height plate (5) to slide vertically. A fixing plate (6) is provided on the height plate (5). 7) and sliding plate (8), the sliding plate (8) is horizontally slidably disposed on the height plate (5), the anchor (4) on the side of the fixed plate (7) facing away from the sliding plate (8) is provided with a first cable (9) and the sliding plate (8), the anchor (4) on the side of the sliding plate (8) facing away from the fixed plate (7) is provided with a second cable (10) and the fixed plate (7) is provided with a sliding component (11) on the fixed plate (7) to drive the sliding plate (8) away from the fixed plate (7).

2. The concrete cracking prevention structure in the negative bending moment zone of a steel plate composite beam according to claim 1, characterized in that: The lifting component (6) includes a positioning base plate (61) disposed on the mounting plate (3), and a vertical hydraulic jack (62) electrically connected to the control system is disposed on the positioning base plate (61). The height plate (5) is disposed on the piston rod of the vertical hydraulic jack (62).

3. The concrete cracking prevention structure in the negative bending moment zone of a steel plate composite beam according to claim 2, characterized in that: The sliding component (11) includes a transverse hydraulic jack (111) disposed on the fixed plate (7) and electrically connected to the control system. The sliding plate (8) is disposed on the piston rod of the transverse hydraulic jack (111). The height plate (5) is provided with a slide rail (112) with a T-shaped cross section. The sliding plate (8) and the slide rail (112) are slidably engaged.

4. The concrete cracking prevention structure in the negative bending moment zone of a steel plate composite beam according to claim 3, characterized in that: Multiple positioning base plates (61) are detachably provided on the mounting plate (3), and the multiple positioning base plates (61) are evenly arranged along the width direction of the bridge (1).

5. The concrete cracking prevention structure in the negative bending moment zone of a steel plate composite beam according to claim 3, characterized in that: The height plate (5) is rotatably provided with a first winding wheel (12), and the sliding plate (8) is rotatably provided with a second winding wheel (13). The first cable (9) passes around the first winding wheel (12), and the second cable (10) passes around the second winding wheel (13).

6. The concrete cracking prevention structure in the negative bending moment zone of a steel plate composite beam according to claim 5, characterized in that: The second cable (10) between the fixed plate (7) and the second winding wheel (13) is arranged horizontally, and the first cable (9) between the sliding plate (8) and the first winding wheel (12) is arranged horizontally.

7. The concrete cracking prevention structure in the negative bending moment zone of a steel plate composite beam according to claim 6, characterized in that: A balance plate (14) is horizontally rotatably mounted on the piston rod of the vertical hydraulic jack (62). A balance slide bar (15) with a T-shaped cross-section is mounted on the bottom of the height plate (5). The length direction of the balance slide bar (15) is parallel to the axis of the piston rod of the horizontal hydraulic jack (111). The balance plate (14) and the balance slide bar (15) are in sliding cooperation.

8. The concrete cracking prevention structure in the negative bending moment zone of a steel plate composite beam according to claim 1, characterized in that: A stress plate (16) is rotatably mounted on the anchor (4), and the stress plate (16) is used to fix the steel plate (2) in the positive bending moment zone at the mid-span of the bridge (1).

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