Left and right part separation type existing bridge widening structure and construction method thereof

Abstract

The invention relates to a left-right separated existing bridge widening structure and a construction method thereof. A UHPC cast-in-place belt and two pieces of combined book end profile steel are arranged at the widening position between a left bridge flange plate and a right bridge flange plate. The two pieces of combined book end profile steel are installed at the ends of the left side bridge flange plate and the right side bridge flange plate correspondingly and symmetrically connected in a back-to-back mode. The UHPC cast-in-place belt is poured at the width splicing position and filled between the two pieces of combined book end profile steel, the whole UHPC cast-in-place belt is in a T shape, and the two ends of the UHPC cast-in-place belt are connected with the left side concrete leveling layer and the right side concrete leveling layer respectively. The corresponding combined book end section steel is arranged below the bridge flange plates on the left side and the right side to conduct transverse stiffening framework connection, the overall bending and shearing resistance rigidity of the widened structure is enhanced, and the UHPC integrally in a T shape is poured between the two corresponding combined book end section steel to enhance the overall strength.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and particularly relates to a widening structure for a separated left and right span existing bridge and a construction method thereof. Background Art

[0002] With the rapid expansion of the traffic flow borne by highway bridges, the traffic capacity of existing roads has gradually become unable to match the increasing traffic demand. The reconstruction and expansion of existing highways show significant advantages in controlling investment costs and shortening the construction period, and highway reconstruction and expansion will become the main strategy to promote highway widening. By implementing widening and strengthening treatments on existing bridges, not only can the safety and stability of the bridges be ensured, but the original bridge structure can also be efficiently utilized to maximize its economic value.

[0003] Currently, for the structural form of widening a separated left and right span existing bridge, the existing left and right span bridges cannot be well connected, and longitudinal cracks on the existing left and right span bridge decks and damage to the paving layer are reduced. Summary of the Invention

[0004] Aiming at the defects existing in the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a widening structure for a separated left and right span existing bridge and a construction method thereof, which can ensure the perfect connection of the existing left and right span bridges and avoid longitudinal cracks on the existing left and right span bridge decks and damage to the paving layer.

[0005] To solve the above technical problem, the present invention adopts the following technical solution: A widening structure for a separated left and right span existing bridge includes a left bridge flange plate and a right bridge flange plate. At the widening part between the left bridge flange plate and the right bridge flange plate, there are arranged a UHPC cast-in-place belt and two combined book clip steel profiles. The two combined book clip steel profiles are respectively installed at the ends of the left bridge flange plate and the right bridge flange plate and are symmetrically connected back to back; the combined book clip steel profile includes an upper steel plate, vertical high-strength bolts, and a lower steel profile. The upper steel plate is a U-shaped clamping plate formed by bending a steel plate to match the contour of the beam flange plate end. The lower steel profile is installed at the bottom of the upper steel plate. A plurality of vertical high-strength bolts penetrate through the upper steel plate and the lower steel profile to fixedly install them on the corresponding beam flange plate; the UHPC cast-in-place belt is poured at the widening part and filled between the two combined book clip steel profiles, and the whole is in a "T" shape. The two ends of the UHPC cast-in-place belt are respectively connected to the left concrete leveling layer and the right concrete leveling layer.

[0006] Preferably, the upper steel plate includes an upper horizontal section, a middle vertical section, and a lower inclination. The two upper steel plates are connected by transverse high-strength bolts passing through the middle vertical section. The ends of the two lower steel profiles are welded together, and weld stiffeners are additionally provided at the welding position to improve the connection strength.

[0007] Preferably, vertical stiffeners are provided inside the upper steel plate, and top weld stiffeners are provided at the tops of the vertical stiffeners to ensure the stability of the downward inclination of the upper steel plate and prevent deformation.

[0008] Preferably, a set of vertical high-strength bolts is provided on each of the front and rear sides of each combined book clip section steel. Each set of vertical high-strength bolts includes 4 to 8 bolts, which are evenly spaced left and right to ensure balanced stress.

[0009] Preferably, the upper steel plate is fixedly connected to the beam flange plate through T-shaped anti-disengagement stud bolts welded at the top, and the T-shaped anti-disengagement stud bolts are cast into the UHPC cast-in-place belt.

[0010] Preferably, the T-shaped anti-disengagement stud bolts are arranged between adjacent vertical high-strength bolts.

[0011] Preferably, there are two upper and lower transverse high-strength bolts, and they are through high-strength bolts.

[0012] A construction method for widening a separated left and right lanes existing bridge uses the separated left and right lanes existing bridge widening structure as described above. The steps are as follows:

[0013] Step 1: Close the adjacent lanes of the left and right old bridges under construction, remove the guardrails, and chisel the original concrete paving layer on the corresponding sides of the old bridges to expose the tops of the bridge flange plates on both sides.

[0014] Step 2: Drill through holes for the vertical high-strength bolts on the left and right bridge flange plates, and also drill corresponding through holes for the vertical high-strength bolts on the combined book clip section steel.

[0015] Step 3: Install the combined book clip section steel, align the holes of the combined book clip section steel with the holes of the corresponding side bridge flange plate, and connect and fix them through vertical high-strength bolts. The book clip section steels on both sides are connected through transverse high-strength bolts, and finally install the bottom weld stiffeners.

[0016] Step 4: Pour UHPC between the left and right concrete leveling layers. The UHPC can flow into a T shape between the two combined book clip section steels, and level the surface of the UHPC to form a UHPC cast-in-place belt. The two ends of the UHPC cast-in-place belt are respectively connected and flush with the left and right concrete leveling layers.

[0017] Step 5: Pour concrete above the UHPC cast-in-place belt and level it to form the asphalt concrete surface layer at the widened part. The asphalt concrete surface layer at the widened part is connected to the asphalt concrete surface layers of the left and right old bridges.

[0018] Step 6: After the concrete solidifies, the construction is completed and the traffic is restored.

[0019] Preferably, in step three, after the combined book clip steel is installed, T-shaped anti-disengagement studs are welded to the top of the upper steel plate, and the T-shaped anti-disengagement studs are poured into the UHPC cast-in-place belt in step four to enhance the connection strength.

[0020] Preferably, in step two, the through holes drilled in the left bridge flange and the right bridge flange are staggered from the positions of the transverse prestressed steel bars of the beam flange.

[0021] Beneficial effects of the present invention:

[0022] 1) By arranging corresponding combined book clip steels under the bridge flanges on both the left and right sides to connect the transverse stiffening skeletons, the overall flexural and shear stiffness of the widened structure is enhanced, and a UHPC in an overall "T" shape is poured between the corresponding two combined book clip steels to enhance the overall strength;

[0023] 2) The two sides of the bridge are connected by the combined book clip steels to form a common stress-bearing whole at the cantilever ends of the adjacent wing flanges of the left and right existing bridges, which can effectively provide the overall stiffness of the widened bridge structure, avoid longitudinal cracks in the existing bridge deck and damage to the paving layer, have a good widening effect, and improve the durability and driving comfort of the structure;

[0024] 3) By pouring UHPC above the bridge flange, compared with ordinary concrete, the bearing capacity and durability of the structure are enhanced, and its toughness is improved, making it not easy to crack when subjected to impact or stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a structural schematic diagram of the invention;

[0026] Figure 2 is a structural schematic diagram of the combined book clip steel;

[0027] In the figure: 1-left old bridge asphalt concrete surface layer, 2-left concrete leveling layer, 3-widened asphalt concrete surface layer, 4-T-shaped anti-disengagement stud, 5-UHPC cast-in-place belt, 6-right concrete leveling layer, 7-right old bridge asphalt concrete surface layer, 8-left bridge flange, 9-combined book clip steel, 901-upper steel plate, 902-high-strength bolt, 903-lower steel section, 904-top weld stiffener, 905-bottom connection stiffener, 906-transverse high-strength bolt, 10-right bridge flange. DETAILED DESCRIPTION OF THE INVENTION

[0028] In order to better understand the improvements made by the present invention compared with the prior art, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0029] AsFigure 1 As shown in the figure, a widening structure for an existing separated left and right lane bridge mainly consists of a left bridge flange plate 8 and a right bridge flange plate 10. At the widening section between the left bridge flange plate 8 and the right bridge flange plate 10, a UHPC cast-in-place belt 5 and two combined book clip steel shapes 9 are provided. The two combined book clip steel shapes 9 are respectively installed at the ends of the left bridge flange plate 8 and the right bridge flange plate 10 and are symmetrically connected back to back.

[0030] The combined book clip steel shape 9 mainly consists of an upper steel plate 901, vertical high-strength bolts 902, and a lower steel shape 903. The lower steel shape 903 is installed at the bottom of the upper steel plate 901. The upper steel plate 901 is a U-shaped clamping plate formed by bending a steel plate to match the contour of the beam flange plate end. The U-shaped clamping plate consists of an upper horizontal section, a middle vertical section, and a lower inclination. To ensure the lower inclination of the upper steel plate 901 and avoid deformation, vertical stiffeners are provided inside the upper steel plate 901, and a top weld stiffener 904 is provided at the top of the vertical stiffeners.

[0031] When installing the combined book clip steel shape 9, several vertical high-strength bolts 902 penetrate the upper steel plate 901 and the lower steel shape 903 to fix it on the corresponding beam flange plate. To ensure balanced force, 4 to 8 vertical high-strength bolts 902 are evenly spaced left and right in each group. At the same time, to strengthen the connection between the upper steel plate 901 and the beam flange plate, the upper steel plate 901 is fixedly strengthened with the beam flange plate through T-shaped anti-disengagement studs 4 welded at the top. The T-shaped anti-disengagement studs 4 are arranged between adjacent vertical high-strength bolts 902. The two corresponding combined book clip steel shapes 9 installed with the beam flange plate are connected by horizontal high-strength bolts 906 passing through the middle vertical sections of the two upper steel plates 901. There are two upper and lower horizontal high-strength bolts 906, both of which are through high-strength bolts. And they are welded and connected at the end positions of the two lower steel shapes 903, and a weld stiffener 905 is added at the welding position to strengthen the connection between the two combined book clip steel shapes 9.

[0032] The UHPC cast-in-place belt 5 is poured at the widening section and filled to the middle of the two combined book clip steel shapes 9, showing a "T" shape as a whole. The two ends of the UHPC cast-in-place belt 5 are respectively connected to the left concrete leveling layer 2 and the right concrete leveling layer 6, and the T-shaped anti-disengagement studs 4 are poured into the UHPC cast-in-place belt 5.

[0033] A construction method for widening an existing separated left and right lane bridge, using the widening structure for an existing separated left and right lane bridge, the steps are as follows:

[0034] Step 1: Close the adjacent lanes of the left and right old bridges under construction, remove the guardrails, and chisel the original concrete paving layer on the corresponding side of the old bridge to expose the top of the bridge flange plates on both sides of the old bridge.

[0035] Step 2: Drill through-holes for the vertical high-strength bolts 902 on the left bridge flange 8 and the right bridge flange 10, and also drill corresponding through-holes for the vertical high-strength bolts 902 on the combined book clip section steel 9. The through-holes drilled on the left bridge flange 8 and the right bridge flange 10 are staggered from the positions of the transverse prestressed steel bars of the beam flange.

[0036] Step 3: Install the combined book clip section steel 9, align the holes of the combined book clip section steel 9 with the hole positions of the corresponding side bridge flange, and connect and fix them with vertical high-strength bolts 902. The book clip section steels 9 on both sides are connected by transverse high-strength bolts 906, and finally install the bottom weld stiffeners 905. After the combined book clip section steel 9 is installed, weld the T-shaped anti-disengagement studs 4 on the top of the upper steel plate 901.

[0037] Step 4: Pour UHPC between the left concrete leveling layer 2 and the right concrete leveling layer 6. The UHPC can flow into a T-shape between the two combined book clip section steels 9, and level the surface of the UHPC to form the UHPC cast-in-place belt 5. At the same time, pour the T-shaped anti-disengagement studs 4 into the UHPC cast-in-place belt 5. Both ends of the UHPC cast-in-place belt 5 are connected to and flush with the left concrete leveling layer 2 and the right concrete leveling layer 6 respectively.

[0038] Step 5: Pour concrete above the UHPC cast-in-place belt 5 and level it to form the asphalt concrete surface layer 3 at the widened part. The asphalt concrete surface layer 3 at the widened part is connected to the left old bridge asphalt concrete surface layer 1 and the right old bridge asphalt concrete surface layer 7.

[0039] Step 6: After the concrete solidifies, the construction is completed and the traffic is restored.

[0040] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A left-right separated existing bridge widening structure, comprising a left bridge flange plate (8) and a right bridge flange plate (10), characterized in that: A UHPC cast-in-place strip (5) and two combined book-clamp steel sections (9) are provided at the widened portion between the left bridge flange plate (8) and the right bridge flange plate (10). The two combined book-clamp steel sections (9) are respectively installed at the ends of the left bridge flange plate (8) and the right bridge flange plate (10) and are symmetrically connected in a back-to-back manner. The combined book-clamp steel section (9) comprises an upper steel plate (901), vertical high-strength bolts (902) and a lower steel section (903). The upper steel plate (901) is made of a bent steel plate. A U-shaped clamping plate with a matching profile at the end of the beam flange plate, a lower steel section (903) is installed at the bottom of the upper steel plate (901), and a plurality of vertical high-strength bolts (902) penetrate the upper steel plate (901) and the lower steel section (903) to fix it on the corresponding beam flange plate; the UHPC cast-in-place strip (5) is cast at the widened part and filled between the two combined book clamp steel sections (9), and the whole is in a "T" shape, and the two ends of the UHPC cast-in-place strip (5) are respectively connected to the left concrete leveling layer (2) and the right concrete leveling layer (6).

2. According to claim 1, a left-right separated existing bridge widening structure is characterized by: The upper steel plate (901) comprises an upper horizontal section, a middle vertical section and a lower inclination. The two upper steel plates (901) are connected by transverse high-strength bolts (906) passing through the middle vertical section. The two lower steel sections (903) are welded together at the end positions and weld stiffening ribs (905) are added at the welding positions.

3. According to claim 2, the left and right separated existing bridge widening structure is characterized by: The upper steel plate (901) is provided with vertical reinforcing ribs, and the top of the vertical reinforcing ribs is provided with top weld stiffening ribs (904).

4. According to claim 1, the left and right separated existing bridge widening structure is characterized by: A group of vertical high-strength bolts (902) are respectively arranged on the front and rear sides of each of the combined book clip steel sections (9), and each group of vertical high-strength bolts (902) includes 4 to 8 bolts, which are evenly spaced from left to right.

5. According to claim 4, the left and right separated existing bridge widening structure is characterized by: The upper steel plate (901) is fixedly connected to the beam flange plate via a T-shaped anti-detachment bolt (4) welded on the top, and the T-shaped anti-detachment bolt (4) is cast into the UHPC cast-in-place belt (5).

6. The left-right separated existing bridge widening structure according to claim 5 is characterized by: The T-shaped anti-dropping bolt (4) is arranged between adjacent vertical high-strength bolts (902).

7. The left-right separated existing bridge widening structure according to claim 2 is characterized by: The transverse high-strength bolts (906) are provided with two upper and lower ones, and are through-penetrating high-strength bolts.

8. A construction method for widening an existing bridge with left and right separated sections, characterized in that: The left and right separated existing bridge widening structure according to any one of claims 1 to 7 is adopted, and the steps are as follows: Step 1: Close the adjacent lanes of the left and right old bridges for construction, remove the guardrails, and chisel open the original concrete pavement on the corresponding side of the old bridges to expose the tops of the bridge flange plates of the old bridges on both sides; Step 2: Drilling holes for vertical high-strength bolts (902) on the left bridge flange plate (8) and the right bridge flange plate (10), and drilling corresponding holes for vertical high-strength bolts (902) on the combined book clip steel (9); Step 3: Install the combined book clip steel (9), align the combined book clip steel (9) with the hole position of the corresponding side bridge flange plate, and connect and fix them through vertical high-strength bolts (902), connect the book clip steels (9) on both sides through transverse high-strength bolts (906), and finally install the bottom weld stiffening rib (905); Step 4: pouring UHPC between the left concrete leveling layer (2) and the right concrete leveling layer (6), the UHPC can flow into the space between the two combined book clip steels (9) in a T shape, smoothing the surface of the UHPC to form a UHPC cast-in-place belt (5), the two ends of the UHPC cast-in-place belt (5) are respectively connected to the left concrete leveling layer (2) and the right concrete leveling layer (6) and are flush; Step 5: pour concrete on the UHPC cast-in-place strip (5) and smooth it to form the asphalt concrete surface layer (3) at the widening part, and the asphalt concrete surface layer (3) at the widening part is connected to the asphalt concrete surface layer (1) of the old bridge on the left and the asphalt concrete surface layer (7) of the old bridge on the right; Step 6: After the concrete solidifies, the construction is completed and traffic is resumed.

9. The method for widening an existing left-right separated bridge according to claim 8, characterized in that: In step three, after the combined book clip steel (9) is installed, a T-shaped anti-dropping bolt (4) is welded on the top of the upper steel plate (901), and the T-shaped anti-dropping bolt (4) is cast into the UHPC cast-in-place belt (5) in step four.

10. The method for widening an existing left-right separated bridge according to claim 8, characterized in that: In step 2, the through holes drilled on the left bridge flange plate (8) and the right bridge flange plate (10) are staggered with the positions of the transverse prestressed steel bars of the beam flange plates.

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