Prestress connection integrated double-column pier plastic hinge structure

Abstract

The utility model relates to the technical field of constructional engineering, and discloses a prestress connection integrated double-column pier plastic hinge structure which comprises a cover beam, double-column piers and a bearing platform, the cover beam and the bearing platform are arranged up and down, and the double-column piers are arranged on the two sides of the cover beam and the two sides of the bearing platform; the bent cap, the double-column pier and the bearing platform are connected in series through steel strands, a plastic hinge area is arranged at the position of the double-column pier, and dense stirrups are installed in the plastic hinge area. According to the prestress connection integrated double-column pier plastic hinge structure, the cover beam, the double-column pier and the bearing platform are connected through various measures, the shock resistance among the cover beam, the double-column pier and the bearing platform after assembly is enhanced, and therefore the stability of a follow-up bridge during use is guaranteed, the overall construction speed is increased through the mode, and the construction period is shortened. And the pollution to the surrounding environment is further reduced.

Description

Technical Field

[0001] This utility model relates to the field of building engineering technology, specifically to a prestressed integrated double-column bridge pier plastic hinge structure. Background Technology

[0002] Prefabricated bridges are being widely promoted due to their advantages such as significantly shortening the construction period, saving costs, and improving construction quality. Prefabricated technology is widely used in the superstructure of bridges, but its application in the substructure is concentrated in the construction of some cross-sea bridges, and the construction areas are mainly located in non-seismic or low-intensity areas. In the construction of urban bridges, prefabricated structures are rarely used for the substructure. A hinge is a term in mechanical engineering, which refers to a connection method between components. This connection method can transmit axial force but cannot transmit bending moment. For bridge structures, there is no such ideal hinge. However, under the action of seismic forces, the bottom (top) of the pier may be damaged, resulting in a process of bending stiffness degradation. The mechanical properties exhibited after the stiffness of the pier degrades are similar to those of a "mechanical hinge".

[0003] The actual bending moment that a bridge pier may experience is limited. When the bending moment exceeds a certain value, the bridge pier enters plasticity. Even a small increase in bending moment will bring a large increase in curvature. This nonlinear deformation of the material is usually called yielding. When the stiffness of a bridge pier structure reaches the yield point, the locations where the bending moment cannot be "well" transmitted after failure are called plastic hinges.

[0004] The existing prefabricated double-column piers, cap beams and abutments have poor overall integrity. Under seismic loading, the prestressed connection nodes of the prefabricated double-column piers are prone to brittle failure, which affects the overall stability of the bridge.

[0005] Based on this, it is necessary to propose a prestressed integrated double-column pier plastic hinge structure. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model provides a prestressed integrated double-column pier plastic hinge structure, which has the advantages of improving the integrity between the pier, cap beam and abutment, and enhancing its seismic resistance, thus solving the problems mentioned in the background technology.

[0007] This utility model provides the following technical solution: a prestressed integrated double-column pier plastic hinge structure, including a cap beam, a double-column pier, and a pier cap:

[0008] The cap beam and the pier are arranged vertically, and double-column piers are provided on both sides of the cap beam and the pier.

[0009] The cap beam, double-column piers, and abutment are connected in series by steel strands. A plastic hinge zone is provided at the double-column pier, and dense stirrups are installed inside the plastic hinge zone. Corrugated pipes are pre-embedded at the connection between the cap beam, double-column piers, and abutment. Nuts are threadedly connected to the ends of the double-column piers at the connection between them and the cap beam and abutment. The nuts are limited to the ends of the steel strands. Grooves are provided at both ends of the abutment.

[0010] Preferably, the contact surfaces of the double-column piers with the cap beam and the abutment are coated with epoxy resin.

[0011] Preferably, the cap beam is provided with a grouting port.

[0012] Preferably, the cap beam is constructed of C50 concrete, and the internal longitudinal and web reinforcement bars are HRB400 grade steel bars to match the tension strength of the prestressed steel strands.

[0013] Preferably, the bridge pier is constructed of C40 concrete, and the main internal reinforcement of the bridge pier is HRB400 grade steel bar to match the tension strength of the prestressed steel strand.

[0014] Preferably, the pier is constructed of C30 concrete to match the tension strength of the prestressed steel strands.

[0015] Preferably, the bellows is constructed of metal.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This type of prestressed integrated double-column pier plastic hinge structure strengthens the seismic resistance of the assembled cap beam, double-column pier, and pier cap by using various measures to connect them, thereby ensuring the stability of the bridge during use. Furthermore, this method improves the overall construction speed and further reduces pollution to the surrounding environment. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the device of this utility model;

[0020] Figure 2 This is a schematic diagram showing the pre-embedded location of the corrugated pipe and the wire threading structure of the steel strand in this utility model.

[0021] Figure 3 This is a top view of the corrugated pipe portion of this utility model.

[0022] Figure 4 This utility model Figure 2 Partial structural diagram;

[0023] Figure 5 This is a bottom view of the corrugated pipe portion of this utility model.

[0024] Figure 6 This is a schematic diagram showing the detailed arrangement of the reinforced stirrups in the plastic hinge zone of this utility model;

[0025] Figure 7 This is a schematic diagram of the prestress applied to the four sets of steel strands of this utility model.

[0026] The attached diagram lists the components represented by each number as follows:

[0027] 1. Cap beam; 2. Double-column pier; 3. Abutment; 4. Steel strand; 5. Plastic hinge zone; 6. Nut; 7. Corrugated pipe; 8. Reinforced stirrups; 9. Groove. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 A prestressed integrated double-column pier plastic hinge structure, comprising a cap beam 1, a double-column pier 2, and a pier cap 3, characterized in that:

[0030] The cap beam 1 and the pier cap 3 are arranged vertically, and double-column piers 2 are provided on both sides of the cap beam 1 and the pier cap 3.

[0031] The cap beam 1, double-column pier 2 and pier cap 3 are connected in series by steel strands 4. A plastic hinge zone 5 is provided at the double-column pier 2. The plastic hinge zone 5 is equipped with reinforced stirrups 8. Corrugated pipes 7 are embedded at the connection between the cap beam 1, double-column pier 2 and pier cap 3. Nuts 6 are threaded at the connection between the two ends of the double-column pier 2 and the cap beam 1 and pier cap 3. Nuts 6 are limited to the ends of the steel strands 4. Grooves 9 are provided at both ends of the pier cap 3. Epoxy resin is applied to the contact surfaces of the double-column pier 2 and the cap beam 1 and pier cap 3. Grouting ports are provided on the cap beam 1.

[0032] Further steps include the following construction steps:

[0033] Step 1: Before prefabricating the double-column pier 2, the length of the plastic hinge of the double-column pier 2 needs to be calculated. Based on the calculated length of the plastic hinge zone 5, the stirrups 8 in this zone are densified. The calculated length of the plastic hinge is 0.0375m ≤ L. p ≤0.1875m, here we take 0.04m as the plastic hinge zone 5, and adjust the spacing of the dense stirrups 8 in the plastic hinge zone 4 from 120mm to 80mm;

[0034] Step 2: When prefabricating the components, the corrugated pipe 7 needs to be pre-embedded in the cap beam 1, double column pier 2, and abutment 3. Then, the steel strand 4 is threaded through it. During the concrete pouring process, the steel strand 4 should be pulled out periodically to prevent the corrugated pipe 7 from leaking grout and fixing the steel strand 4 in the reserved channel, which would affect the tensioning of the steel strand 4 later. After the concrete is poured, the steel strand 4 is fixed in the reserved channel with nuts 6. At the same time, a layer of epoxy resin with a thickness of 1-3mm is applied to the contact surface between the cap beam and the pier, and between the pier and the abutment.

[0035] Step 3: After the prestressed steel strand 4 is installed, it needs to be tensioned. Tensioning is done by tensioning one end, and the prestressed steel strand 4 is controlled by two indicators: the elongation and the tension force. The elongation is measured with a millimeter ruler, and the tension force is measured with a vibration pickup. By measuring the first-order vibration angular frequency ω when tensioning the prestressed steel strand 4, the prestress that should be applied to the four steel strands 4 can be calculated.

[0036] Step 4: After the prestressing tensioning is completed, cement mortar is injected into the prestressing ducts to achieve anti-corrosion treatment of the prestressing tendons. To ensure that the grouting is fully compacted, a 4 cm deep groove 9 is reserved at the position of the double column pier 2 corresponding to the abutment 3. The grout is injected from the grouting port of the cap beam 1. When the joint is fully filled, it overflows from the top of the groove 9. At this time, it is sealed in time. The grouting is completed when grout flows out from all sides.

[0037] As a preferred technical solution of this utility model, the cap beam 1 is constructed of C50 concrete, and the internal longitudinal bars and web bars of the cap beam 1 are HRB400 grade steel bars to match the tension strength of the prestressed steel strands 4.

[0038] As a preferred technical solution of this utility model, the bridge pier 2 is constructed of C40 concrete, and the main reinforcement inside the bridge pier 2 is HRB400 grade steel bar with a cross-sectional dimension of 375mm×375mm square and a height of 1.7m, in order to match the tension strength of the prestressed steel strand 4.

[0039] As a preferred technical solution of this utility model, the foundation 3 is made of C30 concrete to match the tension strength of the prestressed steel strand 4, and the size is 3537mm×900mm×700mm; the prestressed tendons are 4 bundles of 3×9.5 steel strand 4, the corrugated pipe (7) is made of metal parts, and the diameter of the corrugated pipe 7 is 40mm.

[0040] Furthermore, the precast double-column pier with prestressed connection consists of four parts: cap beam 1, double-column pier 2, pier cap 3, and prestressed steel strand 4. The prestressed steel strand 4 passes through the reserved duct at the center of the cross-section of double-column pier 2 and the cap beam 1 and pier cap 3 corresponding to the center of the cross-section of double-column pier 2, thereby connecting the precast components of the above three parts in series. However, the concrete at the connection nodes of cap beam 1 and double-column pier 2, and double-column pier 1 and pier cap 3 after series connection is prone to compression and breakage. Therefore, it is necessary to calculate the location of the plastic hinge of the double-column pier and densify the reinforcement in the plastic hinge zone.

[0041] The moment-rotation angle of a hinge consists of two parts: one is influenced by the bending moment inside the member, and the other is influenced by the bending moment at the member's ends. Therefore, when defining the moment-rotation angle of a plastic hinge, the distribution law of the bending moment inside the member needs to be defined first. The hinge ends can be defined as follows: first, assume the initial stiffness acting on the member, and then simulate the bending moment within the element to obtain the following calculation:

[0042] (1) A simply supported beam with the same magnitude and opposite direction of bending moments at both ends

[0043]

[0044] The moment-displacement relationship of a two-dimensional beam element is as follows: V in the formula a M a Represent Figure 1 Shear force and bending moment on the left side of the beam element, V b M b Represent Figure 1The shear force and bending moment on the right side of the beam element. E represents the modulus of elasticity, I represents the moment of inertia of the section, EI represents the bending stiffness of the beam in mechanics of materials, L represents the length of the beam, and θ represents the rotation angle.

[0045] (2) The deformation shape of the beam member when there is a bending moment at only one end (M0=0)

[0046]

[0047] Based on the above situation, v a =v b =0, θ a =θ b Therefore, the formula in equation (1) can be simplified to the following formula: Further derivation yields: The initial flexibility and initial stiffness of the beam element are given by the following formula: When the two ends of the member are subjected to bending moments of the same magnitude but opposite directions, θ is calculated. a =θ b M a =M b Therefore there is

[0048] (3) Deformation shape of beam member when the magnitude and sign of the bending moments at both ends are the same (M) b =M a )

[0049]

[0050]

[0051] Based on the above situation, v a =v b =0, M b =0, so the moment-displacement relationship of the beam can be expressed as follows: When a bending moment acts on one side of a beam member, the initial flexibility and initial stiffness of the beam element under bending moment are given by the following formula: The formula can be derived from the formulas of the first two: in:

[0052] (4) According to case (b) in (3), we have v a =v b =0, M b =-M a Therefore, the moment-displacement relationship of a beam can be expressed by the following formula: The member is subjected to bending moments of the same magnitude and direction at both ends. The initial flexibility and initial stiffness of the beam member are obtained as follows: The following formula can be derived from the two formulas above: When calculating the bending moment-curvature of internal hinges in beam-column members, it is necessary to first define the stress state of the hinge, and then calculate the flexibility and stiffness matrices of the structure. It is worth noting that plastic hinges generally appear at the ends of beams and columns, so the Gauss-Legendre integration method is typically used for numerical integration. Finally, the formula for calculating the plastic hinge region is:

[0053] Where: L p : Length of plastic hinge (m); h: Distance from the bottom of the pier to the point where the inertial force of the superstructure acts (m); D: Diameter of the cross section (m).

[0054] In the description of this utility model, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "other end", "upper", "side", "top", "inner", "front", "center", "both ends", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0055] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0056] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A prestressed integrated double-column pier plastic hinge structure, comprising a cap beam (1), a double-column pier (2), and a pier cap (3), characterized in that: The cap beam (1) and the pier (3) are arranged vertically, and double-column piers (2) are provided on both sides of the cap beam (1) and the pier (3); The cap beam (1), double-column pier (2) and abutment (3) are connected in series by steel strands (4). A plastic hinge zone (5) is provided at the double-column pier (2). The plastic hinge zone (5) is equipped with reinforced stirrups (8). Corrugated pipes (7) are pre-embedded at the connection between the cap beam (1), double-column pier (2) and abutment (3). Nuts (6) are threaded at the connection between the two ends of the double-column pier (2) and the cap beam (1) and abutment (3). The nuts (6) are limited to the ends of the steel strands (4). Grooves (9) are provided at both ends of the abutment (3).

2. The prestressed integrated double-column pier plastic hinge structure according to claim 1, characterized in that: The contact surfaces of the double-column pier (2) with the cap beam (1) and the abutment (3) are coated with epoxy resin.

3. The prestressed integrated double-column pier plastic hinge structure according to claim 1, characterized in that: A grouting port is provided on the cap beam (1).

4. The prestressed integrated double-column pier plastic hinge structure according to claim 1, characterized in that: The cap beam (1) is constructed of C50 concrete, and the internal longitudinal and web reinforcement of the cap beam (1) are HRB400 grade steel bars to match the tension strength of the prestressed steel strands (4).

5. The prestressed integrated double-column pier plastic hinge structure according to claim 1, characterized in that: The pier (2) is constructed of C40 concrete, and the main reinforcement inside the pier (2) is HRB400 grade steel bar to match the tension strength of the prestressed steel strand (4).

6. The prestressed integrated double-column pier plastic hinge structure according to claim 1, characterized in that: The foundation (3) is constructed of C30 concrete to match the tension strength of the prestressed steel strands (4).

7. The prestressed integrated double-column pier plastic hinge structure according to claim 1, characterized in that: The bellows (7) is constructed of metal.

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