New and old bridge widening structure for improving shrinkage creep difference influence and construction method

Abstract

The invention relates to a new and old bridge widening structure for improving shrinkage creep difference influence and a construction method. A widening position asphalt concrete pavement layer, a zinc-containing steel plate, a waterproof roll, a profile steel rib plate, a cork block and a longitudinal steel plate are arranged at the widening position of an old bridge box girder and a new bridge box girder; the longitudinal steel plates are arranged at intervals in the longitudinal bridge direction, each longitudinal steel plate is welded to the corresponding load-bearing steel bar in the box girder, grooves are reserved in the two ends of each longitudinal steel plate, and the grooves in the two ends of each longitudinal steel plate are filled with the cork blocks. The zinc-containing steel plates are vertically arranged between every two adjacent longitudinal steel plates, the width-spliced asphalt concrete pavement layer is laid on the tops of the zinc-containing steel plates, kerfs in the longitudinal bridge direction are formed in the left-right middle positions of the surface of the width-spliced asphalt concrete pavement layer, and the kerfs are filled with asphalt horseshoe fat. According to the invention, new and old bridge structures are connected together, and the damage form is always controlled in an asphalt horseshoe fat area, so that the damage of a bridge deck pavement layer is prevented, and the overall stability of the structure is also protected.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and particularly relates to a widened structure for new and old bridges that improves the influence of shrinkage and creep differences and a construction method therefor. Background Art

[0002] With the rapid expansion of traffic flow in China, the load pressure borne by highway bridges has been continuously rising, resulting in the fact that the traffic capacity of existing roads has gradually been unable to match the increasing traffic demand. Compared with new highway projects, the reconstruction and expansion of existing highways show significant advantages in controlling investment costs and shortening the construction period. The reconstruction and expansion of highways will become the main strategy to promote highway widening. On the premise of balancing economy and practicability, by implementing widening and strengthening treatments on existing bridges, not only can the safety and stability of the bridges be ensured, but also the original bridge structure can be efficiently utilized to maximize its economic value.

[0003] Currently, when considering the long-term creep influence of the new bridge during the widening process of new and old bridges, the existing structural forms cannot well connect the new and old bridges and ensure relative displacement, nor do they consider the influence on the structure caused by the longitudinal shrinkage and creep effect of the new bridge. 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 widened structure for new and old bridges and a construction method therefor, which can significantly improve the damage caused by shrinkage and creep differences to the old bridge, and improve the durability, driving comfort and overall stability of the structure.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions: A widened structure for new and old bridges to improve the influence of shrinkage and creep differences, including old bridge box girders and new bridge box girders arranged left and right. At the widened part between the old bridge box girder and the new bridge box girder, there are asphalt concrete paving layers, zinc-containing steel plates, waterproof coiled materials, steel rib plates, soft wood blocks and longitudinal steel plates. The steel rib plates are arranged under the flange plates of the old bridge box girder and press against the flange plates of the old bridge box girder. A number of the longitudinal steel plates are arranged at intervals along the longitudinal direction of the bridge. Each longitudinal steel plate is placed vertically, and both the left and right ends are respectively inserted into the flange plates of the old bridge box girder and the new bridge box girder and welded to the stress-bearing steel bars in the corresponding box girder. Grooves are left at both ends of each longitudinal steel plate, and the soft wood blocks are filled in the grooves at both ends of the longitudinal steel plate. The zinc-containing steel plate is arranged vertically between two adjacent longitudinal steel plates. The front and rear ends of the zinc-containing steel plate are respectively welded to the middle parts of the two longitudinal steel plates. The upper part of the zinc-containing steel plate extends out of the top of the longitudinal steel plate, and the waterproof coiled materials are laid on both the left and right sides of the extended part. The asphalt concrete paving layer at the widened part is laid on the top of the waterproof coiled material and the zinc-containing steel plate. A longitudinal cutting seam is opened at the left and right central positions on the surface of the asphalt concrete paving layer at the widened part. The depth of the cutting seam is half of the laying thickness of the asphalt concrete paving layer at the widened part, and the cutting seam is filled with asphalt mastic. The widths of the longitudinal steel plate, the waterproof coiled material and the asphalt concrete paving layer at the widened part increase in a stepped manner.

[0006] Preferably, the steel rib plates are fixedly connected to the old bridge box girder by high-strength bolts to strengthen the structural strength of the old bridge.

[0007] Preferably, a group of high-strength bolts are provided on both the front and rear sides of each steel rib plate. Each group of high-strength bolts has 3 to 5 roots and is arranged at intervals left and right to make the force balanced.

[0008] Preferably, the top of the waterproof coiled material is flush with the top of the zinc-containing steel plate, and the bottom of the zinc-containing steel plate is flush with the bottom of the longitudinal steel plate.

[0009] Preferably, an asphalt felt waterproof layer is provided above the waterproof coiled material and the zinc-containing steel plate.

[0010] Preferably, welding plates are provided at both ends of the longitudinal steel plate, and the longitudinal steel plate is welded to the stress-bearing steel bars through the welding plates to increase the welding area.

[0011] A construction method for improving the influence of shrinkage and creep differences in the widening of new and old bridges adopts a widened structure for new and old bridges to improve the influence of shrinkage and creep differences, and the steps are as follows:

[0012] Step 1: Close the adjacent lanes for construction of the old bridge box girder and the new bridge box girder, remove the guardrails of the old bridge box girder, and chisel the concrete paving within the width range of the flange plate of the old bridge box girder to expose the stress-bearing steel bars;

[0013] Step 2: Drill bolt connection holes at the lower part of the flange plate of the old bridge box girder, and install the profiled steel rib plates at the lower part of the old bridge box girder through high-strength bolts;

[0014] Step 3: Chisel out soft wood blocks and longitudinal steel plate installation positions at the corresponding positions of the old bridge box girder and the new bridge box girder, install the longitudinal steel plates, and weld the two ends of the longitudinal steel plates to the corresponding stress-bearing steel bars respectively; Fill soft wood blocks on the front and back sides of the end of the welded longitudinal steel plate;

[0015] Step 4: Install zinc-containing steel plates between adjacent longitudinal steel plates and weld them in place; Fill polyurethane waterproof coiled materials on the left and right of the protruding part of the zinc-containing steel plate, and install an asphalt felt waterproof layer above the zinc-containing steel plate and the polyurethane waterproof coiled materials;

[0016] Step 5: Pour the cast-in-place layer of the old bridge waterproof concrete and the cast-in-place layer of the new bridge waterproof concrete respectively within the full bridge range of the old bridge box girder and the new bridge box girder, and the pouring height is flush with the polyurethane waterproof coiled materials;

[0017] Step 6: Pour the asphalt concrete paving layer at the widened part above the zinc-containing steel plate and the polyurethane waterproof coiled materials, and the asphalt concrete paving layer at the widened part is flush and connected with the asphalt concrete paving layer of the old bridge and the asphalt concrete paving layer of the new bridge;

[0018] Step 7: Cut a longitudinal joint along the longitudinal bridge direction at the center position of the left and right of the asphalt concrete surface layer of the asphalt concrete paving layer at the widened part, and the depth of the joint is half of the thickness of the asphalt concrete paving layer at the widened part; Fill asphalt mastic in the joint;

[0019] Step 8: After the construction is completed, resume traffic;

[0020] Step 9: In the late stage of creep of the new bridge box girder, close the traffic and chisel out the damaged asphalt concrete paving layer above the joint;

[0021] Step 10: Pour concrete into the adjacent zinc-containing steel plates;

[0022] Step 11: Re-lay the asphalt concrete paving layer at the position where it was chiseled out in Step 9, and cut the longitudinal joint and fill asphalt mastic again along the longitudinal bridge direction according to Step 7;

[0023] Step 12: After the construction is completed, resume traffic.

[0024] The beneficial effects of the present invention:

[0025] 1) Utilize the welding of the longitudinal steel plates and the stress-bearing steel bars to fix the positions of the old and new bridges, ensure that the structures of the old and new bridges are integrated, and enable the overall joint force of the old and new bridges; At the same time, it is convenient for the installation and alignment of the soft wood blocks. Install soft wood blocks at both ends of the longitudinal steel plates. When the new bridge undergoes longitudinal contraction, the soft wood blocks are used for buffering to reduce the damage to the old bridge caused after the widening of the old and new bridges;

[0026] 2) Vertically insert zinc - containing steel plates between two adjacent longitudinal steel plates to enhance the overall structural strength. Waterproof coiled materials are installed on the left and right sides of the part of the zinc - containing steel plate that extends out of the longitudinal steel plate. Asphalt concrete paving is carried out on it, and then half of the thickness of the asphalt layer is cut from the center position on the left and right of the asphalt layer surface, and asphalt mastic is filled in the cutting seam. When the widened part is affected by the creep of the new bridge, the asphalt mastic can absorb and disperse stress, so that the damage only occurs at the position of the mastic, avoiding the influence of shrinkage creep on the bridge deck pavement layer, and improving the durability, driving comfort and overall stability of the structure;

[0027] 3) The widened structure of the present invention for connecting new and old bridges saves the materials and costs of other anchoring connectors, connects the new and old bridges together, and strengthens the structural strength of the old bridge by steel rib plates at the cantilever section of the old bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of the present invention;

[0029] Figure 2 is a sectional view of the old bridge of the present invention;

[0030] Figure 3 is a top view of the connection position of the new and old bridges in the longitudinal bridge direction;

[0031] In the figure: 1 - Asphalt concrete pavement layer of the old bridge, 2 - Cast - in - place waterproof concrete layer of the old bridge, 3 - Asphalt concrete pavement layer at the widened part, 4 - Asphalt felt waterproof layer, 5 - Asphalt mastic, 6 - Zinc - containing steel plate, 7 - Polyurethane waterproof coiled material, 8 - Asphalt concrete pavement layer of the new bridge, 9 - Cast - in - place waterproof concrete layer of the new bridge, 10 - High - strength bolt, 11 - Steel rib plate, 12 - Stress - bearing steel bar, 13 - Soft wood block, 14 - Longitudinal steel plate, 15 - Old bridge box girder, 16 - New bridge box girder, 17 - Concrete, 18 - Welding plate. DETAILED DESCRIPTION OF THE INVENTION

[0032] 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 accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0033] As Figure 1 shown, a widened structure of new and old bridges for improving the influence of shrinkage creep difference has old bridge box girders 15 and new bridge box girders 16 arranged left and right. The widened structure between the old bridge box girder 15 and the new bridge box girder 16 mainly consists of an asphalt concrete pavement layer 3 at the widened part, a zinc - containing steel plate 6, a waterproof coiled material 7, a steel rib plate 11, a soft wood block 13 and a longitudinal steel plate 14.

[0034] As Figure 2As shown, in order to strengthen the structural strength of the old bridge box girder 15, the steel rib plate 11 is arranged below the flange plate of the old bridge box girder 15 and presses against the flange plate of the old bridge box girder 15, and the steel rib plate 11 is fixedly connected to the old bridge box girder 15 by high-strength bolts 10. In order to make the structure stress balanced and facilitate construction, each steel rib plate 11 is equipped with a group of high-strength bolts 10 on both sides, and each group of high-strength bolts 10 is provided with 3 to 5 bolts, which are arranged at intervals on the left and right.

[0035] like Figure 3 As shown, in order to make the new and old bridge structures connected as one and bear stress together, a number of longitudinal steel plates 14 are arranged between the old bridge box girder 15 and the new bridge box girder 16 along the longitudinal direction of the bridge. Each longitudinal steel plate 14 is placed vertically and its left and right ends are respectively inserted into the flange plates of the old bridge box girder 15 and the new bridge box girder 16 and welded to the stress-bearing steel bars 12 in the corresponding box girder. Welding plates 18 are provided at both ends of the longitudinal steel plate 14, and the longitudinal steel plate 14 is welded to the stress-bearing steel bars 12 through the welding plates 18 to increase the welding area. Grooves are left at both ends of each longitudinal steel plate 14, and cork blocks 13 are filled in the grooves at both ends of the longitudinal steel plate 14. When the new bridge shrinks longitudinally, the cork blocks 13 provide buffering to reduce the damage to the old bridge caused by the widening of the new and old bridges.

[0036] A zinc-containing steel plate 6 is vertically arranged between two adjacent longitudinal steel plates 14, and the front and rear ends of the zinc-containing steel plate 6 are respectively welded to the middle of the two longitudinal steel plates 14, and the bottom of the zinc-containing steel plate 6 is flush with the bottom of the longitudinal steel plate 14. The upper part of the zinc-containing steel plate 6 extends out of the top of the longitudinal steel plate 14. Waterproofing coiled materials 7 are laid on the left and right sides of the extended part of the zinc-containing steel plate 6, and the top of the waterproofing coiled materials 7 is flush with the top of the zinc-containing steel plate 6, and an asphalt felt waterproofing layer 4 is arranged above the waterproofing coiled materials 7 and the zinc-containing steel plate 6.

[0037] The asphalt concrete pavement layer 3 at the widening part is laid on the top of the waterproof coiled material 7 and the zinc-containing steel plate 6. A slit is opened along the longitudinal direction of the bridge at the center of the surface of the asphalt concrete pavement layer 3 at the widening part. The depth of the slit is half of the laying thickness of the asphalt concrete pavement layer 3 at the widening part. The slit is filled with asphalt horseshoe grease 5. When the widening part is affected by the creep of the new bridge, the asphalt horseshoe grease 5 can absorb and disperse the stress, so that the damage only occurs at the position of the asphalt horseshoe grease 5, avoiding the bridge deck pavement layer from being affected by the shrinkage creep. At the same time, the width of the longitudinal steel plate 14, the width of the waterproof coiled material 7, and the width of the asphalt concrete pavement layer 3 at the widening part are increased in a step-by-step manner, which is convenient for construction.

[0038] A construction method for improving the influence of shrinkage creep difference when widening a new bridge and an old bridge is provided, and a new bridge widening structure for improving the influence of shrinkage creep difference is adopted, and the steps are as follows:

[0039] Step 1: Close the adjacent lanes for the construction of the old bridge box girder 15 and the new bridge box girder 16. Remove the guardrail of the old bridge box girder 15, and chisel the concrete pavement within the width range of the flange plate of the old bridge box girder 15 to expose the stress-bearing steel bars 12;

[0040] Step 2: Drill bolt connection holes at the lower part of the flange plate of the old bridge box girder 15, and install the profiled steel rib plate 11 at the lower part of the old bridge box girder 15 through high-strength bolts 10;

[0041] Step 3: Chisel out the installation positions of the soft wood blocks 13 and the longitudinal steel plates 14 at the corresponding positions of the old bridge box girder 15 and the new bridge box girder 16. Install the longitudinal steel plates 14 and weld the two ends of the longitudinal steel plates 14 to the corresponding stress-bearing steel bars 12 respectively; Fill the soft wood blocks 13 at the front and back sides of the end of the welded longitudinal steel plate 14;

[0042] Step 4: Install and weld the zinc-containing steel plates 6 between the adjacent longitudinal steel plates 14; Fill the polyurethane waterproof coiled materials 7 on the left and right of the protruding part of the zinc-containing steel plates 6, and install the asphalt felt waterproof layer 4 above the zinc-containing steel plates 6 and the polyurethane waterproof coiled materials 7;

[0043] Step 5: Pour the old bridge waterproof concrete cast-in-place layer 2 and the new bridge waterproof concrete cast-in-place layer 9 respectively within the full bridge range of the old bridge box girder 15 and the new bridge box girder 16, and the pouring height is flush with the polyurethane waterproof coiled materials 7;

[0044] Step 6: Pour the widened asphalt concrete pavement layer 3 above the zinc-containing steel plates 6 and the polyurethane waterproof coiled materials 7, and the widened asphalt concrete pavement layer 3 is flush and connected with the old bridge asphalt concrete pavement layer 1 and the new bridge asphalt concrete pavement layer 8;

[0045] Step 7: Cut a longitudinal joint along the longitudinal bridge direction at the left-right center position of the asphalt concrete surface layer of the widened asphalt concrete pavement layer 3, and the depth of the joint is half of the thickness of the widened asphalt concrete pavement layer 3; Fill the joint with asphalt mastic 5;

[0046] Step 8: After the construction is completed, resume the traffic;

[0047] Step 9: During the late creep stage of the new bridge box girder 16, close the traffic and chisel the damaged asphalt concrete pavement layer 3 above the joint;

[0048] Step 10: Pour the concrete 17 into the adjacent zinc-containing steel plates 6;

[0049] Step 11: Re-lay the asphalt concrete pavement layer 3 at the position where it was chiseled in Step 9, and cut the longitudinal joint and fill the asphalt mastic 5 again along the longitudinal bridge direction according to Step 7;

[0050] Step 12: After the construction is completed, resume the traffic.

[0051] The above are only the preferred specific embodiments 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, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A new and old bridge widening structure for improving the influence of shrinkage creep difference, comprising an old bridge box girder (15) and a new bridge box girder (16) arranged on the left and right, characterized in that: An asphalt concrete pavement layer (3), a zinc-containing steel plate (6), a waterproofing membrane (7), a steel rib plate (11), a cork block (13) and a longitudinal steel plate (14) are arranged at the widening part of the old bridge box girder (15) and the new bridge box girder (16). The steel rib plate (11) is arranged below the flange plate of the old bridge box girder (15) and presses against the flange plate of the old bridge box girder (15); a plurality of longitudinal steel plates (14) are arranged at intervals along the longitudinal direction of the bridge, each longitudinal steel plate (14) is placed vertically and its left and right ends are respectively inserted into the flange plates of the old bridge box girder (15) and the new bridge box girder (16) and welded to the stress-bearing steel bars (12) in the corresponding box girder; grooves are left at both ends of each longitudinal steel plate (14), and the cork blocks (13) are filled in the grooves at both ends of the longitudinal steel plate (14); the zinc-containing The steel plate (6) is vertically arranged between two adjacent longitudinal steel plates (14), the front and rear ends of the zinc-containing steel plate (6) are respectively welded to the middle of the two longitudinal steel plates (14), the upper part of the zinc-containing steel plate (6) extends out of the top of the longitudinal steel plate (14), and the waterproof membrane (7) is laid on the left and right sides of the extended part, the asphalt concrete pavement layer (3) at the widening part is laid on the top of the waterproof membrane (7) and the zinc-containing steel plate (6), and a slit along the longitudinal bridge direction is opened at the left and right center positions of the surface of the asphalt concrete pavement layer (3) at the widening part, the depth of the slit is half of the laying thickness of the asphalt concrete pavement layer (3) at the widening part, and the slit is filled with asphalt horseshoe grease (5), and the width of the longitudinal steel plate (14), the width of the waterproof membrane (7), and the width of the asphalt concrete pavement layer (3) at the widening part are increased in a step-by-step manner.

2. The new and old bridge widening structure for improving the shrinkage creep difference effect according to claim 1 is characterized by: The steel rib plate (11) is fixedly connected to the old bridge box girder (15) via high-strength bolts (10).

3. The new and old bridge widening structure for improving the shrinkage creep difference effect according to claim 2 is characterized by: Each of the steel ribs (11) is provided with a group of high-strength bolts (10) on both the front and rear sides. Each group of high-strength bolts (10) is provided with 3 to 5 bolts, which are arranged at intervals on the left and right sides.

4. The new and old bridge widening structure for improving the shrinkage creep difference effect according to claim 1 is characterized in that: The top of the waterproof coiled material (7) is flush with the top of the zinc-containing steel plate (6), and the bottom of the zinc-containing steel plate (6) is flush with the bottom of the longitudinal steel plate (14).

5. The new and old bridge widening structure for improving the shrinkage creep difference effect according to claim 2 is characterized in that: An asphalt felt waterproof layer (4) is provided above the waterproof coiled material (7) and the zinc-containing steel plate (6).

6. The new and old bridge widening structure for improving the shrinkage creep difference effect according to claim 1 is characterized by: Welding plates (18) are provided at both ends of the longitudinal steel plate (14), and the longitudinal steel plate (14) is welded to the stressed steel bars (12) via the welding plates (18) to increase the welding area.

7. A construction method for improving the influence of shrinkage creep difference between new and old bridges, characterized in that: The new and old bridge widening structure for improving the shrinkage and creep difference effect according to any one of claims 1 to 6 is adopted, and the steps are as follows: Step 1: close the adjacent lanes for construction of the old bridge box girder (15) and the new bridge box girder (16), remove the guardrail of the old bridge box girder (15), and chisel away the concrete pavement within the width of the flange plate of the old bridge box girder (15) to expose the stress-bearing steel bars (12); Step 2: Drill bolt connection holes at the lower part of the flange plate of the old bridge box girder (15), and install the steel rib plate (11) at the lower part of the old bridge box girder (15) by high-strength bolts (10); Step 3: chiseling out cork blocks (13) and installation positions of the longitudinal steel plates (14) at corresponding positions of the old bridge box beam (15) and the new bridge box beam (16), installing the longitudinal steel plates (14) and welding the two ends of the longitudinal steel plates (14) to the corresponding stress-bearing steel bars (12) respectively; filling the front and rear sides of the welded ends of the longitudinal steel plates (14) with cork blocks (13); Step 4: Install the zinc-containing steel plate (6) between adjacent longitudinal steel plates (14) and fix them by welding; fill the left and right sides of the extended part of the zinc-containing steel plate (6) with a polyurethane waterproofing membrane (7), and install an asphalt felt waterproofing layer (4) above the zinc-containing steel plate (6) and the polyurethane waterproofing membrane (7); Step 5: pouring the old bridge waterproof concrete cast-in-place layer (2) and the new bridge waterproof concrete cast-in-place layer (9) respectively within the entire bridge range of the old bridge box girder (15) and the new bridge box girder (16), and the pouring height is flush with the polyurethane waterproof membrane (7); Step 6: pouring the asphalt concrete pavement layer (3) at the widening part on the zinc-containing steel plate (6) and the polyurethane waterproof membrane (7), and the asphalt concrete pavement layer (3) at the widening part is flush with the asphalt concrete pavement layer (1) of the old bridge and the asphalt concrete pavement layer (8) of the new bridge; Step 7: cutting a slit in the longitudinal direction of the asphalt concrete surface layer of the asphalt concrete pavement layer (3) at the widening position, the depth of the slit being half the thickness of the asphalt concrete pavement layer (3) at the widening position; filling the slit with asphalt horseshoe grease (5); Step 8: Construction completed, traffic restored; Step 9: At the late stage of creep of the new bridge box girder (16), close the traffic and chisel out the damaged asphalt concrete pavement layer (3) above the cut; Step 10: pouring concrete (17) in the adjacent zinc-containing steel plates (6); Step 11: re-paving the asphalt concrete pavement layer (3) at the position removed in step 9, and cutting the seam along the longitudinal direction of the bridge again and filling it with asphalt horseshoe grease (5) according to step 7; Step 12: Construction completed and traffic restored.

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