A bridge deck continuous structure and its design method

Abstract

The present invention proposes a continuous bridge deck structure and a design method thereof, which relates to the field of bridge engineering, including a synthetic rubber plate, the synthetic rubber plate is connected to two adjacent bridge decks, the synthetic rubber plate is composed of a stiffening steel plate and rubber, which are pressed and bonded into one, and the stiffening steel plate is laid flat in the synthetic rubber plate in multiple layers. At the same time, the thickness of the stiffening steel plate required for the synthetic rubber plate is calculated according to the bearing capacity, and the horizontal compression deformation of the synthetic rubber plate is verified according to the thickness of the steel plate and the thickness of the rubber. The synthetic rubber plate of the present invention has a built-in stiffening steel plate, the steel plate can provide the bearing capacity required by the vehicle load, and the rubber can provide the longitudinal deformation of the beam end caused by temperature load, shrinkage creep, etc., which solves the problem of insufficient deformation capacity and easy cracking and damage of the traditional rigid bridge deck continuous structure, and solves the problem of insufficient rigidity of the seamless expansion joint and easy collapse and deformation of the bridge deck. At the same time, the calculation method provided can accurately calculate the stress characteristics of the synthetic rubber plate.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering, and in particular relates to a continuous bridge deck structure and a design method thereof. Technical Background

[0002] The continuous deck structure of a simply supported beam bridge is generally a multi-span bridge, with continuous deck structures between spans. Traditional continuous deck structures generally use reinforced concrete structures, which have insufficient deformation capacity and are difficult to avoid cracking. If the main beam uses a steel plate composite beam, it is more likely to cause the main beam steel to rust after cracking, affecting the durability of the main beam. Therefore, it is urgent to develop a new type of continuous deck structure that has both good deformation capacity to avoid cracking and good support performance to ensure smooth passage of vehicles.

[0003] In recent years, pile-slab road structures have been widely used in Anhui. Pile-slab road structures generally use a span of 6 to 13 meters, and the length of a joint is no more than 100 meters. At the joint end, seamless expansion joints are tried to replace traditional steel joints. Seamless expansion joints are filled with elastomers in the gaps at the ends of beams, and an overlap layer is set above the elastomers. Elastic concrete is laid above the overlap to connect the bridge deck pavement, which can adapt to the deformation caused by thermal expansion and contraction of the bridge structure. During use, it was found that the elastic concrete at the joints is prone to collapse and deformation, which can cause vehicles to jump and affect driving comfort. Therefore, there is an urgent need for a rigid and flexible bridge deck continuous structure to replace the existing seamless expansion joint device, improve the stress state of the bridge deck, and ensure driving safety. Summary of the invention

[0004] In order to solve the above-mentioned problems of bridge deck continuity of simply supported steel plate composite beams, pile-slab roads, and lateral roadbed overlap of pile-slab roads, the present invention provides a bridge deck continuous structure and a design method thereof. A new type of synthetic rubber sheet can provide longitudinal displacement space and meet the requirements of beam end turning angle and upper vehicle load bearing capacity, thereby solving the problems of insufficient deformation capacity of traditional concrete bridge deck continuous structure, easy cracking and damage, insufficient rigidity of flexible seamless expansion joints, and easy collapse and deformation of bridge deck.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] In order to achieve the above object, the present invention provides the following scheme:

[0007] A continuous bridge deck structure includes a synthetic rubber plate, which is connected to two adjacent bridge decks by an upper span. The synthetic rubber plate is composed of a stiffening steel plate and rubber, which are pressed and bonded together and are manufactured in segments with a segment length of 1 to 3 meters. The stiffening steel plates are laid flat in the synthetic rubber plate in multiple layers. The thickness of the synthetic rubber plate is the same as the thickness of the bridge deck pavement on the bridge deck.

[0008] Further technology of the present invention:

[0009] Preferably, the stiffening steel plates in the synthetic rubber plate are staggered and placed in blocks along the longitudinal direction of the bridge, with 5 to 9 vertical layers.

[0010] Preferably, the thickness of the stiffening steel plate in the synthetic rubber plate is determined by the following steps:

[0011] Step 1: Determine the maximum beam end rotation angle θ caused by live loads in adjacent spans max ,θ max Calculated by formula (1);

[0012]

[0013] In formula (1):

[0014] Δ is the maximum allowable deflection of the structure, and the concrete structure is Steel structure L is the calculated span;

[0015] L shot is the smaller span among the adjacent spans;

[0016] Step 2: According to the geometric relationship, determine the moment of inertia I of the synthetic rubber plate per meter along the transverse direction of the bridge. I is calculated by formula (2);

[0017]

[0018] In formula (2):

[0019] h is the vertical thickness of the synthetic rubber sheet per meter;

[0020] Step 3: According to the maximum beam end rotation angle θ max and the moment of inertia I of the synthetic rubber sheet to determine the bending moment M per meter of the synthetic rubber sheet u , M u is calculated by formula (3) and (4), M u It is about the thickness of the stiffening steel plate in the synthetic rubber plate d The calculation formula of

[0021]

[0022]

[0023] A s =t d ×L e (5)

[0024] L e =1000×n(6)

[0025] In formula (3), (4), (5), and (6):

[0026] E c is the converted elastic modulus of the synthetic rubber sheet per meter, and A is the cross-sectional area of ​​the synthetic rubber sheet per meter;

[0027] E s A is the elastic modulus of the stiffening steel plate per meter of synthetic rubber sheet, s L is the cross-sectional area of ​​the stiffening steel plate per meter of synthetic rubber sheet, e is the total length of the stiffening steel plate in the cross section of the synthetic rubber sheet, and n is the number of stiffening steel plate layers in the cross section;

[0028] E r A is the elastic modulus of rubber per meter of synthetic rubber sheet, r is the cross-sectional area of ​​rubber per meter of synthetic rubber sheet;

[0029] L s is the calculated span of the synthetic rubber sheet per meter, and is the distance between the bolts of two adjacent beams;

[0030] Step 4: Based on the assumption of linear strain distribution in the cross section, ignoring the contribution of rubber to the load-bearing capacity and only considering the stiffening steel plate in the synthetic rubber sheet, calculate the bending moment M that can be provided per meter of the synthetic rubber sheet. n , M n is calculated by formula (7), M n It is about the thickness of the stiffening steel plate in the synthetic rubber plate d The calculation formula of

[0031] M n =f sd ×1000×t d ×h1+f sd ×1000×t d ×h2+…f sd ×

[0032] ''''

[0033] 1000×t d ×h i +f sd ×1000×t d ×h1+f sd ×1000×t d ×h2+

[0034] ''

[0035] …f sd ×1000×t d ×h i (6)

[0036] In formula (7):

[0037] f sd is the design value of tensile strength of the stiffening steel plate;

[0038] h i is the distance between the center of the stiffening steel plate and the center of the section;

[0039] f sd ′ is the design value of compressive strength of the stiffening steel plate;

[0040] Step 5: Let M n ≥M u , the thickness of the stiffening steel plate t is calculated d .

[0041] Step 6: According to the vehicle load rear axle weight of 140KN, calculate the thickness of the steel plate t s , t s Calculated by formula (8), take t d and t s The larger value of is taken as the final thickness value t of the stiffening steel plate, and at the same time, the thickness of the steel plate should be greater than 2mm;

[0042]

[0043] In formula (8):

[0044] t r The sum of the thickness of the upper and lower rubber layers of a stiffening steel plate in the synthetic rubber sheet, which can be 10mm or 20mm.

[0045] A e is the area of ​​the pressure-bearing stiffening steel plate;

[0046] σ s The axial tension limit of the stiffening steel plate is taken as 0.65 times the yield strength of the steel.

[0047] Preferably, the longitudinal shear angle tangent of the synthetic rubber sheet is determined by the following steps:

[0048] Step 1: Calculate the vertical compression deformation of the synthetic rubber sheet caused by the vehicle load with a rear axle weight of 140KN m , δ m Calculated by formula (9), in order to limit the vertical compression deformation and not affect the driving comfort performance, δ m ≤1mm;

[0049]

[0050]

[0051] In formula (9) and (10):

[0052] t e It is the sum of the thickness of the vertical rubber layers of the synthetic rubber sheet;

[0053] A c It is the sum of the cross-sectional areas of the stiffening steel plates in the synthetic rubber sheet;

[0054] E e is the compressive elastic modulus of the synthetic rubber sheet;

[0055] E b is the bulk modulus of rubber elastic body;

[0056] G is the shear elastic modulus of the synthetic rubber sheet;

[0057] t1 is the minimum thickness of a single vertical rubber layer of the synthetic rubber sheet;

[0058] L Z It is the minimum length of each layer of longitudinal steel plate in the synthetic rubber sheet;

[0059] Step 2: Calculate the horizontal deformation ΔL of the beam caused by temperature change. ΔL is calculated by formula (11);

[0060] ΔL=αΔTL(11)

[0061] In formula (11):

[0062] α is the linear expansion coefficient;

[0063] ΔT is the design temperature variation range;

[0064] L is the telescopic beam length;

[0065] Step 3: The tangent value of the longitudinal shear angle of the synthetic rubber sheet should meet the requirements of formula (12);

[0066]

[0067] In formula (12):

[0068] 1.3 is the amplification factor used to consider the influence of other factors besides temperature.

[0069] The invention discloses a continuous bridge deck structure, in which a synthetic rubber plate is anchored to a beam end by means of pre-embedded bolt sleeves and anchor bolts, and has a simple structure and is convenient to install.

[0070] The synthetic rubber plate has built-in stiffening steel plates, which can provide the bearing capacity required for vehicle loads. Through the staggered placement of the stiffening steel plates, the rubber can provide the longitudinal deformation and rotational deformation of the beam ends caused by temperature loads, shrinkage creep, etc., which solves the problem of insufficient deformation capacity of the continuous structure of traditional rigid bridge decks and easy cracking and damage. At the same time, it solves the problem of insufficient stiffness of seamless expansion joints and easy collapse and deformation of the bridge deck.

[0071] The present invention provides a continuous bridge deck structure, which does not require notches to be provided on the main beam bridge deck, and can be installed only within the thickness range of the bridge deck pavement layer. Gaps are left between the transverse and longitudinal stiffening steel plates, and the synthetic rubber sheet can be manufactured along the rubber part segments at the longitudinal gaps, which is convenient for transportation and installation, has the characteristics of light weight and modularization, and is conducive to popularization and application.

[0072] The present invention provides a method for designing a continuous structure of a bridge deck. The thickness of a steel plate required in a synthetic rubber plate is determined according to a specific structural span and a structural form, and the compression deformation of the rubber is verified. The given calculation method can accurately calculate the stress characteristics of the synthetic rubber plate, which is convenient for designers to use and is conducive to promoting the application of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is a schematic diagram of the structure of the present invention;

[0074] Figure 2 It is a schematic diagram of the structure of the synthetic rubber plate in the present invention and a diagram of the calculation of the bearing capacity;

[0075] Figure 3 It is a schematic cross-sectional view of the synthetic rubber sheet in the present invention;

[0076] In the figure: 1. threaded sleeve; 2. synthetic rubber sheet; 3. anchor bolt; 4. stiffening steel plate; 5. rubber; 6. bridge deck; 7. bridge deck pavement. DETAILED DESCRIPTION

[0077] In order to make the technical means, creative features, purpose and efficacy of the present invention easy to understand, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain this description and are not intended to limit the present invention.

[0078] Example: Figure 1-2 The present invention provides a continuous bridge deck structure, including a synthetic rubber plate 2, the synthetic rubber plate 2 is connected to two adjacent bridge decks 6, and a stiffening steel plate 4 is built in the synthetic rubber plate 2. The stiffening steel plates 4 in the synthetic rubber plate 2 are staggered and placed in blocks along the longitudinal direction of the bridge, with 5 to 9 vertical layers.

[0079] In this embodiment, the stiffening steel plates 4 are vertically arranged in 7 layers.

[0080] The synthetic rubber sheet is manufactured in sections, and the section length is 1 to 3 meters.

[0081] The thickness of the synthetic rubber sheet 2 is the same as the thickness of the bridge deck pavement 7 on the bridge deck 6 .

[0082] The bolt sleeve 1 is pre-buried at the top edge of the bridge deck 6, a bolt hole is arranged in the synthetic rubber plate 2, and the synthetic rubber plate 2 and the bridge deck 6 are connected as a whole by the anchor bolts 3 and the threaded sleeve 1.

[0083] A bridge deck continuous structure design method is provided, wherein the design method is to calculate the thickness of the stiffening steel plate required for the synthetic rubber plate according to the bearing capacity, and to verify the horizontal compression deformation of the synthetic rubber plate according to the thickness of the steel plate and the thickness of the rubber. According to the bridge deck continuous structure design method of the present invention, a continuous example of a two-span 40m simply supported steel plate composite beam bridge deck is designed, including the following steps:

[0084] Step 1: Determine the maximum beam end rotation angle θ caused by live loads in adjacent spans max ,

[0085] Step 2: Based on the geometric relationship, determine the moment of inertia I of the synthetic rubber sheet per meter, bridge deck pavement h = 100 mm,

[0086] Step 3: The longitudinal length of the synthetic rubber sheet is 400mm, the bolt spacing is 300mm, L s =300, assuming that the vertical number of stiffening steel plates is 7, and the number of stiffening steel plates in the cross section is 4. Figure 3 , L e =1000×4=4000mm, A s =t d ×L e =4000t d ; E s =2.06×10 5 MPa; E r =1000MPa; A=1000×100=1×10 5 mm 2 ;

[0087]

[0088]

[0089] Step 4: Based on the assumption of linear strain distribution in the cross section, ignoring the contribution of rubber to the load-bearing capacity and only considering the stiffening steel plate in the synthetic rubber sheet, calculate the bending moment M that can be provided per meter of the synthetic rubber sheet. n ,like Figure 2As shown, h1 = 60mm; h2 = 75mm; h3 = 90mm; h1′ = 30mm; h2′ = 15mm; the reinforcing steel plate is made of Q235 steel, f sd =f sd ′=215MPa

[0090] M n =215×1000×t d ×60+215×1000×t d ×75+215×1000

[0091] ×t d ×90-215×1000×t d ×30-215×1000×t d

[0092] ×15=3.87×10 7 t d N.mm

[0093] Step 5: Let M n ≥M u , the thickness of the stiffening steel plate t is calculated d ≥0.3mm;

[0094] Step 6: According to the vehicle load rear axle weight of 140KN, calculate the thickness of the steel plate t s , A e =1000×110=1.1×10 4 mm 2 , σ s =0.65×235=152.75MPa, Therefore, the thickness of the steel plate can be taken as t = 2 mm;

[0095] Step 7: Calculate the compressive elastic modulus E of the synthetic rubber sheet e , shear modulus of synthetic rubber sheet G = 1.0MPa, bulk modulus of rubber elastic body E b =2000MPa, the sum of the thickness of the vertical rubber layer of the synthetic rubber sheet t e =100-2×7=86mm, the minimum thickness of the vertical rubber layer of the synthetic rubber sheet is t1=10mm, and the minimum length of each longitudinal steel plate in the synthetic rubber sheet is L Z =235mm, the sum of the cross-sectional areas of the stiffening steel plates in the synthetic rubber sheet A c =2×1000×235=470000mm 2 ;

[0096]

[0097] Calculate the vertical compression deformation δ of the synthetic rubber sheet caused by the vehicle load with a rear axle weight of 140KN m , Meet the requirements.

[0098] Step 8: Calculate the horizontal deformation ΔL of the beam body caused by temperature change. The design temperature change range is: -10℃-45℃; linear expansion coefficient α=0.000012; ΔL=αΔTL=0.000012×(45-(-10))×40000=26.4mm;

[0099] Step 9: Cutting angle tangent of synthetic rubber sheet, Meet the requirements.

[0100] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A continuous bridge deck structure, characterized in that: The synthetic rubber plate (2) comprises a synthetic rubber plate (2) which is connected to two adjacent bridge decks (6) by an upper span. The synthetic rubber plate (2) is composed of a stiffening steel plate (4) and rubber (5) which are pressed and bonded into one piece and are manufactured in sections. The section length is 1 to 3 meters. The stiffening steel plate (4) is laid flat in the synthetic rubber plate (2) in multiple layers. The thickness of the synthetic rubber plate (2) is the same as the thickness of the bridge deck pavement (7) on the bridge deck (6). The thickness of the stiffening steel plate (4) in the synthetic rubber plate (2) is determined by the following steps: Step 1: Determine the maximum beam end rotation angle θ caused by live loads in adjacent spans max ,θ max Calculated by formula (1); In formula (1): Δ is the maximum allowable deflection of the structure, and the concrete structure is Steel structure L is the calculated span; L shot is the smaller span among the adjacent spans; Step 2: According to the geometric relationship, determine the moment of inertia I of the synthetic rubber plate per meter along the transverse direction of the bridge. I is calculated by formula (2); In formula (2): h is the vertical thickness of the synthetic rubber sheet per meter; Step 3: According to the maximum beam end rotation angle θ max and the moment of inertia I of the synthetic rubber sheet to determine the bending moment M per meter of the synthetic rubber sheet u , M u is calculated by formula (3) and (4), M u It is about the thickness of the stiffening steel plate in the synthetic rubber plate d The calculation formula of A s =t d ×L e (5) L e =1000×n (6) In formula (3), (4), (5), and (6): E c is the converted elastic modulus of the synthetic rubber sheet per meter, and A is the cross-sectional area of ​​the synthetic rubber sheet per meter; E s A is the elastic modulus of the stiffening steel plate per meter of synthetic rubber sheet, s L is the cross-sectional area of ​​the stiffening steel plate per meter of synthetic rubber sheet, e is the total length of the stiffening steel plate in the cross section of the synthetic rubber sheet, and n is the number of stiffening steel plate layers in the cross section; E r A is the elastic modulus of rubber per meter of synthetic rubber sheet, r is the cross-sectional area of ​​rubber per meter of synthetic rubber sheet; L s is the calculated span of the synthetic rubber sheet per meter, and is the distance between the bolts of two adjacent beams; Step 4: Based on the assumption of linear strain distribution in the cross section, ignoring the contribution of rubber to the load-bearing capacity and only considering the stiffening steel plate in the synthetic rubber sheet, calculate the bending moment M that can be provided per meter of the synthetic rubber sheet. n , M n is calculated by formula (7), M n It is about the thickness of the stiffening steel plate in the synthetic rubber plate d The calculation formula of M n =f sd ×1000×t d ×h1+f sd ×1000×t d ×h2+…f sd ×1000×t d ×h i -f sd ′×1000×t d ×h1′-f sd ′×1000×t d ×h2′-…f sd ′×1000×t d ×h i ′ (6) In formula (7): f sd is the design value of tensile strength of the stiffening steel plate; f sd ′ is the design value of compressive strength of the stiffening steel plate; Step 5: Let M n ≥M u , the thickness of the stiffening steel plate t is calculated d ; Step 6: According to the vehicle load rear axle weight of 140KN, calculate the thickness of the steel plate t s , t s Calculated by formula (8), take t d and t s The larger value of is taken as the final thickness value t of the stiffening steel plate, and at the same time, the thickness of the steel plate should be greater than 2mm; In formula (8): t r The sum of the thickness of the upper and lower rubber layers of a stiffening steel plate in the synthetic rubber sheet, which can be 10mm or 20mm. A e is the area of ​​the pressure-bearing stiffening steel plate; σ s The axial tensile force limit of the stiffening steel plate is 0.65 times the yield strength of the steel; The longitudinal shear angle tangent value of the synthetic rubber sheet (2) is determined by the following steps: Step 1: Calculate the vertical compression deformation of the synthetic rubber sheet caused by the vehicle load with a rear axle weight of 140KN m , δ m Calculated by formula (9), in order to limit the vertical compression deformation and not affect the driving comfort performance, δ m ≤1mm; In formula (9) and (10): t e It is the sum of the thickness of the vertical rubber layers of the synthetic rubber sheet; A c It is the sum of the cross-sectional areas of the stiffening steel plates in the synthetic rubber sheet; E e is the compressive elastic modulus of the synthetic rubber sheet; E b is the bulk modulus of rubber elastic body; G is the shear elastic modulus of the synthetic rubber sheet; t1 is the minimum thickness of a single vertical rubber layer of the synthetic rubber sheet; L Z It is the minimum length of each layer of longitudinal steel plate in the synthetic rubber sheet; Step 2: Calculate the horizontal deformation ΔL of the beam caused by temperature change. ΔL is calculated by formula (11); ΔL=αΔTL (11) In formula (11): α is the linear expansion coefficient; ΔT is the design temperature variation range; L is the telescopic beam length; Step 3: The tangent value of the longitudinal shear angle of the synthetic rubber sheet should meet the requirements of formula (12); In formula (12): 1.3 is the amplification factor used to consider the influence of other factors besides temperature.

2. A continuous bridge deck structure according to claim 1, characterized in that: The reinforcing steel plates (4) in the synthetic rubber plate (2) are staggered and placed in blocks along the longitudinal direction of the bridge, with 5 to 9 layers in the vertical direction.

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