Reinforced concrete composite bridge based on ECC connection and design and construction method thereof

Abstract

The invention discloses a reinforced concrete composite bridge based on ECC connection and a design and construction method thereof. Aiming at the problems that the traffic interference is large, the cost is high and a hogging moment area at the top of a pier is easy to crack due to the fact that a temporary pier needs to be arranged in the traditional steel-concrete composite bridge construction, an innovative solution is provided: an ECC connecting plate is arranged between bridge deck plate slots of adjacent simply supported composite beams, and continuous force transmission of a bridge deck is realized through steel bar anchoring at two ends; an elastic baffle is additionally arranged at the bottom to isolate deformation constraint; during construction, temporary piers are omitted, the bridge deck slab is poured after the steel beam is directly hoisted, and finally flexible filling of the ECC connecting plate is completed. According to the method, the construction process is remarkably simplified, road-crossing / river-crossing temporary supporting is avoided, meanwhile, crack development is restrained through the strain hardening characteristic of the ECC material, high durability and driving smoothness of the bridge in the whole life cycle are achieved, and the method is suitable for urban and highway bridge construction.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and specifically to a design and construction method of a steel-concrete composite bridge connected by Engineered Cementitious Composites (ECC), which is applicable to the construction of urban and highway bridges. Background Art

[0002] Steel-concrete composite bridges combine the high tensile strength of steel and the compressive performance of concrete, and are widely used in long-span bridge structures. Among them, steel box composite bridges have become the mainstream form due to their clear force transmission path and excellent torsional resistance. When constructing a traditional continuous beam system, temporary piers need to be set near the zero point of the dead load moment, and the steel girders are hoisted in sections and then spliced integrally.

[0003] However, the setting of temporary piers has significant defects: when crossing an existing road, the temporary piers occupy the lane, leading to traffic congestion and safety hazards; when crossing a river, the construction cost of temporary piers in water is high and the safety risk is great. Existing technologies have tried to adopt the scheme of splicing steel girders in the air, but it is difficult to promote due to the difficulty of precision control.

[0004] To solve the above contradictions, it is urgent to develop a new type of deck continuous structure. Conventional concrete deck continuity is prone to cracking in the negative moment area, causing durability problems. Therefore, there is an urgent need for a design and construction method that combines the cancellation of temporary piers and crack control capabilities. Summary of the Invention

[0005] The embodiments of the present application provide a steel-concrete composite bridge connected by ECC and its design and construction method. Starting from the perspective of improving the mechanical properties of the deck continuity at the support, the functions of canceling temporary piers and controlling support cracks can be realized.

[0006] To solve the above technical problems, the technical solution proposed in the present application is:

[0007] The present invention provides a steel-concrete composite bridge connected by ECC, including:

[0008] A capping beam, a bearing, a composite beam, and an ECC connection plate;

[0009] The bearing is arranged on the top of the capping beam;

[0010] The composite beam is a simply supported structure, supported on the bearing, and includes a steel girder and a deck slab. The end of the deck slab is provided with a slot;

[0011] The ECC connection plate is arranged between the slots of the adjacent-span deck slabs;

[0012] Both ends are connected to the deck slab through steel bars, and the length of the steel bar is not less than the sum of its anchorage lengths in the deck slab concrete and the ECC connection plate;

[0013] An elastic isolation board is arranged between the bottom and the bridge deck. The elastic isolation board is bonded to the bridge deck and separated from the ECC connection board.

[0014] Furthermore, it also includes:

[0015] Pile foundation, bearing platform, and bridge pier, where:

[0016] The top of the pile foundation is consolidated with the bottom of the bearing platform;

[0017] The top of the bearing platform is consolidated with the bottom of the bridge pier;

[0018] The top of the bridge pier is consolidated with the bottom of the capping beam.

[0019] Furthermore, two rows of bearings are arranged at each capping beam.

[0020] Furthermore, it also includes:

[0021] Guardrail, which is cast integrally with the bridge deck;

[0022] The elastic isolation board is bonded to the guardrail.

[0023] Furthermore, it also includes:

[0024] Asphalt paving, covering the top surfaces of the bridge deck and the ECC connection board.

[0025] Furthermore, the width of the ECC connection board is equal to the inner spacing of the guardrails minus twice the thickness of the elastic isolation board;

[0026] The thickness of the ECC connection board is not greater than 1 / 3 of the standard section thickness of the bridge deck and not less than 10 cm;

[0027] The length of the ECC connection board is not less than 2 m.

[0028] Furthermore, the material of the ECC connection board is engineered cementitious composite material, where the fiber content ≤ 2.0%, the ultimate tensile strain > 3.0%, and the average width of tensile cracks < 100 μm.

[0029] On the other hand, this application also claims to protect a design method for the above steel-concrete composite bridge, including:

[0030] Step 1: Establish a composite beam calculation model in the order of construction stages, where:

[0031] The boundary conditions include:

[0032] The stiffness of the bearings is simulated according to the actual calculated value;

[0033] The full-fixed constraint simulation is adopted between the end nodes of the ECC connection board and the corresponding nodes of the composite beam;

[0034] The intermediate joints of the ECC connecting plate and the corresponding joints of the composite beam are simulated by using only compression elements;

[0035] The vertical compression stiffness of each compression element:

[0036] K1 = K / n, where K is the overall vertical compression stiffness of the elastic baffle and n is the number of compression elements;

[0037] The load conditions include:

[0038] The weights of the steel beam and the bridge deck are borne by the composite beam;

[0039] The weight of the ECC connecting plate is borne by itself;

[0040] The asphalt pavement, guardrails and other loads are borne jointly by the composite beam and the ECC connecting plate;

[0041] Step 2: Run the calculation model and extract the stress and strain of the ECC connecting plate under the standard combination of loads;

[0042] Step 3: Check the ECC connecting plate, which needs to meet:

[0043] Calculated stress value: σ ≤ σ cr , calculated strain value ε ≤ 2.5%

[0044] where σ cr is the test stress value of the ECC material when the first crack appears; ε is the calculated strain value of the ECC connecting plate (7) under the standard combination of loads

[0045] If the check fails, recalculate after increasing the length or thickness of the ECC connecting plate.

[0046] On the other hand, the present application also claims to protect a construction method of the above steel-concrete composite bridge, including:

[0047] Step 1: Weld the steel beam in the factory: Weld the top plate, web plate, web stiffener, bottom plate, and bottom plate stiffener to each other to form a single steel beam;

[0048] Step 2: Pour the lower structure on site: Pour the pile foundation, bearing platform, bridge pier, and capping beam, and install the bearings;

[0049] Step 3: Hoist the steel beam: Transport the steel beam to the site and hoist each piece onto the top of the bearing;

[0050] Step 4: Pour the bridge deck: Use the steel beam as a formwork and pour the bridge deck on site and embed the steel bars;

[0051] Step 5: Install the elastic baffle: After the strength of the bridge deck reaches the standard, pour the guardrail on site, bend and paste the elastic baffle on the bridge deck and the guardrail;

[0052] Step 6: Pour the ECC connecting plate: Pour the ECC connecting plate on site. After the strength reaches the standard, pave the asphalt pavement and ancillary facilities.

[0053] Further, in Step 5, when installing the elastic baffle, it needs to be bent into an L shape. The horizontal section is bonded to the bottom of the bridge deck, and the vertical section is bonded to the side of the guardrail to form a deformation constraint for isolating the ECC connecting plate on three sides.

[0054] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0055] Different from common steel-concrete composite bridges, the structure of the present invention is clear, the force is definite, and the construction is simple. It solves the problem of crack control in the negative moment area at the pier top, realizes the construction of steel-concrete composite bridges without temporary piers, and can be widely applied to the design and construction of urban and highway steel-concrete composite bridges. Description of the Drawings

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0057] Figure 1 It is the overall layout diagram of a steel-concrete composite bridge based on ECC connection.

[0058] Figure 2 It is the partial enlarged view of a steel-concrete composite bridge based on ECC connection.

[0059] Figure 3 It is the A-A cross-sectional view of a steel-concrete composite bridge based on ECC connection.

[0060] Figure 4 It is the B-B cross-sectional view of a steel-concrete composite bridge based on ECC connection.

[0061] Figure 5 It is the calculation model diagram of a steel-concrete composite bridge based on ECC connection.

[0062] The reference numerals used in this application are: pile foundation 1, bearing platform 2, bridge pier 3, capping beam 4, bearing 5, composite beam 6, steel beam 61, top plate 611, web 612, web stiffener 613, bottom plate 614, bottom plate stiffener 615, bridge deck 62, ECC connecting plate 7, steel bar 71, elastic baffle 72, fully fixed constraint 701, compression-only unit 702, asphalt pavement 8, guardrail 9. Detailed Embodiments

[0063] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0064] As Figures 1-5 shown, in the embodiment of the present application, a steel-concrete composite bridge based on ECC connection includes:

[0065] a capping beam 4, a bearing 5, a composite beam 6, and an ECC connection plate 7;

[0066] The bearing 5 is arranged on the top of the capping beam 4;

[0067] The composite beam 6 is a simply supported structure and is supported on the bearing 5, and includes a steel beam 61 and a bridge deck 62. A slot is provided at the end of the bridge deck 62;

[0068] The ECC connection plate 7 is arranged between the slots of the adjacent-span bridge decks 62;

[0069] Both ends are connected to the bridge deck 62 through steel bars 71, and the length of the steel bar 71 is not less than the sum of its anchorage lengths in the concrete of the bridge deck 62 and the ECC connection plate 7;

[0070] An elastic barrier 72 is arranged between the bottom and the bridge deck 62. The elastic barrier 72 is bonded to the bridge deck 62 and separated from the ECC connection plate 7.

[0071] In the embodiment of the present application, a steel-concrete composite bridge further includes:

[0072] pile foundations 1, a bearing platform 2, and bridge piers 3, where:

[0073] The top of the pile foundation 1 is rigidly connected to the bottom of the bearing platform 2;

[0074] The top of the bearing platform 2 is rigidly connected to the bottom of the bridge pier 3;

[0075] The top of the bridge pier 3 is rigidly connected to the bottom of the capping beam 4.

[0076] In the embodiment of the present application, for a steel-concrete composite bridge, two rows of bearings 5 are arranged at each capping beam 4.

[0077] In the embodiment of the present application, a steel-concrete composite bridge further includes:

[0078] a guardrail 9, which is cast integrally with the bridge deck 62;

[0079] The elastic baffle 72 is bonded to the guardrail 9.

[0080] In an embodiment of the present application, a steel-concrete composite bridge further includes:

[0081] An asphalt pavement 8 covering the top surfaces of the bridge deck 62 and the ECC connecting plate 7.

[0082] In an embodiment of the present application, for a steel-concrete composite bridge, the width of the ECC connecting plate 7 is equal to the inner spacing of the guardrail 9 minus twice the thickness of the elastic baffle 72;

[0083] The thickness of the ECC connecting plate 7 is not greater than 1 / 3 of the standard section thickness of the bridge deck 62 and not less than 10 cm;

[0084] The length of the ECC connecting plate 7 is not less than 2 m.

[0085] In an embodiment of the present application, for a steel-concrete composite bridge, the material of the ECC connecting plate 7 is engineered cementitious composite material, where the fiber content ≤ 2.0%, the ultimate tensile strain > 3.0%, and the average width of tensile cracks < 100 μm.

[0086] In an embodiment of the present application, a design method for a steel-concrete composite bridge includes:

[0087] Step 1: Establish a calculation model of the composite beam 6 in the order of construction stages, where:

[0088] The boundary conditions include:

[0089] The stiffness of the support 5 is simulated according to the actual calculated value;

[0090] The full-fixed constraint 701 is used to simulate between the end nodes of the ECC connecting plate 7 and the corresponding nodes of the composite beam 6;

[0091] The only-compression element 702 is used to simulate between the middle nodes of the ECC connecting plate 7 and the corresponding nodes of the composite beam 6;

[0092] The vertical compression stiffness of each compression element 702:

[0093] K1 = K / n, where K is the overall vertical compression stiffness of the elastic baffle 72 and n is the number of compression elements 702;

[0094] The load conditions include:

[0095] The weights of the steel beam 61 and the bridge deck 62 are borne by the composite beam 6;

[0096] The weight of the ECC connecting plate 7 is borne by itself;

[0097] The asphalt pavement 8, the guardrail 9 and other loads are jointly borne by the composite beam 6 and the ECC connecting plate 7;

[0098] Step 2: Run the calculation model to extract the stress and strain of the ECC connection plate 7 under the standard combination of loads;

[0099] Step 3: Check the ECC connection plate 7, which needs to meet the following:

[0100] Calculated stress value: σ ≤ σ cr , and the calculated strain value ε ≤ 2.5%;

[0101] Where σ cr is the test stress value of the ECC material when the first crack appears; ε is the calculated strain value of the ECC connection plate (7) under the standard combination of loads.

[0102] If the check fails, increase the length or thickness of the ECC connection plate 7 and recalculate.

[0103] In the embodiment of the present application, a construction method of a steel-concrete composite bridge includes:

[0104] Step 1: Weld the steel beam 61 in the factory: Weld the top plate 611, web 612, web stiffener 613, bottom plate 614, and bottom plate stiffener 615 to each other to form a single-piece steel beam 61;

[0105] Step 2: Pour the lower structure on-site: Pour the pile foundation 1, bearing platform 2, pier 3, capping beam 4, and install the bearing 5;

[0106] Step 3: Lift the steel beam 61: Transport the steel beam 61 to the site and lift it piece by piece to the top of the bearing 5;

[0107] Step 4: Pour the bridge deck 62: Use the steel beam 61 as a formwork to pour the bridge deck 62 on-site and embed the steel bars 71;

[0108] Step 5: Install the elastic barrier 72: After the strength of the bridge deck 62 reaches the standard, pour the guardrail 9 on-site, bend and paste the elastic barrier 72 on the bridge deck 62 and the guardrail 9;

[0109] Step 6: Pour the ECC connection plate 7: Pour the ECC connection plate 7 on-site, and after the strength reaches the standard, pave the asphalt pavement 8 and ancillary facilities.

[0110] In the embodiment of the present application, in a construction method of a steel-concrete composite bridge, in Step 5, when installing the elastic barrier 72, it needs to be bent into an L shape, the horizontal section is bonded to the bottom of the bridge deck 62, and the vertical section is bonded to the side of the guardrail 9 to form a three-sided deformation constraint for isolating the ECC connection plate 7.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A steel-concrete composite bridge based on ECC connection, characterized in that, include: Cap beam (4), support (5), composite beam (6), ECC connecting plate (7); The support (5) is arranged on the top of the cap beam (4); The composite beam (6) is a simply supported structure, supported on a support (5), and comprises a steel beam (61) and a bridge deck (62), wherein the end of the bridge deck (62) is provided with a slot; The ECC connecting plate (7) is arranged between the slots of adjacent span bridge panels (62); The two ends are connected to the bridge deck (62) by steel bars (71), and the length of the steel bars (71) is not less than the sum of the anchorage lengths thereof in the concrete of the bridge deck (62) and the ECC connecting plate (7); An elastic blocking plate (72) is provided between the bottom and the bridge deck (62); the elastic blocking plate (72) is bonded to the bridge deck (62) and separated from the ECC connecting plate (7).

2. The steel-concrete composite bridge according to claim 1, wherein Also includes: Pile foundation (1), bearing platform (2), bridge pier (3), including: The top of the pile foundation (1) is consolidated with the bottom of the cap (2); The top of the pedestal (2) is consolidated with the bottom of the pier (3); The top of the bridge pier (3) is fixed to the bottom of the cap beam (4).

3. The steel-concrete composite bridge according to claim 1, characterized in that: Two rows of supports (5) are provided at each cap beam (4).

4. The steel-concrete composite bridge according to claim 1, characterized in that, Also includes: The guardrail (9) is cast integrally with the bridge deck (62); The elastic blocking plate (72) is bonded to the guardrail (9).

5. The steel-concrete composite bridge according to claim 1, wherein, Also includes: Asphalt pavement (8) covers the bridge deck (62) and the top surface of the ECC connecting plate (7).

6. The steel-concrete composite bridge according to claim 1, characterized in that: The width of the ECC connecting plate (7) is equal to the inner spacing of the guardrail (9) minus twice the thickness of the elastic barrier plate (72); The thickness of the ECC connecting plate (7) is not greater than 1 / 3 of the thickness of the standard section of the bridge deck (62) and is not less than 10 cm; The length of the ECC connecting plate (7) is not less than 2m.

7. The steel-concrete composite bridge according to claim 1, characterized in that: The material of the ECC connecting plate (7) is an engineering cement-based composite material, wherein the fiber content is ≤2.0%, the ultimate tensile strain is >3.0%, and the average width of the tensile crack is <100 μm.

8. A design method for the steel-concrete composite bridge according to any one of claims 1-7, characterized in that, include: Step 1: Establish the calculation model of the composite beam (6) according to the construction stage sequence, where: Boundary conditions include: The stiffness of the support (5) is simulated according to the actual calculated value; The end nodes of the ECC connecting plate (7) and the corresponding nodes of the composite beam (6) are simulated using full fixed constraints (701); The compression-only element (702) is used to simulate the connection between the middle node of the ECC connecting plate (7) and the corresponding node of the composite beam (6); The vertical compression stiffness of each compression unit (702): K1=K / n, where K is the overall vertical compression stiffness of the elastic barrier plate (72), and n is the number of compression units (702); Loading conditions include: The weight of the steel beam (61) and the bridge deck (62) is borne by the composite beam (6); The weight of the ECC connecting plate (7) is borne by itself; Asphalt pavement (8), guardrail (9) and other loads are jointly borne by composite beam (6) and ECC connecting plate (7); Step 2: Run the calculation model to extract the stress and strain of the ECC connecting plate (7) under the standard combination of loads; Step 3: Check the ECC connecting plate (7), and it is required to meet: Calculated stress value: σ ≤ σ cr , calculated strain value ε ≤ 2.5% Among which, σ cr is the test stress value of the ECC material when the first crack appears; ε is the calculated strain value of the ECC connecting plate (7) under the standard combination of loads. If the check fails, recalculate after increasing the length or thickness of the ECC connecting plate (7).

9. The construction method of the steel-concrete composite bridge according to any one of claims 1-7, characterized in that, Including: Step 1: Weld the steel beam (61) in the factory: Weld the top plate (611), web (612), web stiffener (613), bottom plate (614), and bottom plate stiffener (615) to each other to form a single-piece steel beam (61); Step 2: Pour the lower structure on-site: Pour the pile foundation (1), bearing platform (2), bridge pier (3), and capping beam (4), and install the bearing (5); Step 3: Lift the steel beam (61): Transport the steel beam (61) to the site and lift it piece by piece to the top of the bearing (5); Step 4: Pour the bridge deck (62): Use the steel beam (61) as a formwork to pour the bridge deck (62) on-site and embed the steel bars (71); Step 5: Install the elastic barrier plate (72): After the strength of the bridge deck (62) reaches the standard, pour the guardrail (9) on-site, bend and paste the elastic barrier plate (72) on the bridge deck (62) and the guardrail (9); Step 6: Pour the ECC connecting plate (7): Pour the ECC connecting plate (7) on-site, and after the strength reaches the standard, pave the asphalt pavement (8) and ancillary facilities.

10. The construction method according to claim 9, wherein: In step 5, when installing the elastic barrier plate (72), it needs to be bent into an L shape, the horizontal section is bonded to the bottom of the bridge deck (62), and the vertical section is bonded to the side of the guardrail (9) to form a three-sided deformation constraint for isolating the ECC connecting plate (7).

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