Bridge splicing seam initial rigidity strengthening device, bridge and construction method

Abstract

The invention belongs to the technical field of bridge widening, and particularly relates to a bridge splicing seam initial rigidity strengthening device, a bridge and a construction method. The initial rigidity strengthening device is arranged at the joint position between a new bridge and an old bridge and comprises a first steel plate and a second steel plate, the first steel plate is arranged on the upper side of a main beam wing plate at the joint position of the new bridge and the old bridge, and the second steel plate is arranged on the lower side of the main beam wing plate at the joint position of the new bridge and the old bridge. The first steel plate and the second steel plate are respectively fastened with the main beam wing plate through anchor bolts, at least one web steel plate is arranged between the first steel plate and the second steel plate, and the web steel plate is vertically arranged between the first steel plate and the second steel plate. The initial rigidity reinforcing device is additionally arranged in the splicing seam, the rigidity between the new main beam and the old main beam is improved, cooperative deformation of the new main beam and the old main beam is guaranteed, the deflection difference of the two sides of the splicing seam is remarkably reduced, then it is guaranteed that joint concrete cannot crack in the forming process, and traffic bridge splicing construction is not interrupted.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge widening, and in particular relates to a device for reinforcing the initial stiffness of a bridge joint, a bridge and a construction method. Background Art

[0002] With the increase in the number of cars in my country, the original road traffic gradually fails to meet the traffic needs. Therefore, in order to fully adapt to the development of our society, a large number of highway bridge reconstruction and expansion projects have been implemented. The ways to widen bridges include: "the upper structure is connected, the lower structure is not connected", "the upper structure is not connected, the lower structure is not connected" and "the upper structure is connected, and the lower structure is also connected". Among them, "the upper structure is connected, the lower structure is not connected" is the most reasonable in terms of structural force and has the widest range of applications. However, during the construction of the upper structure connection, traffic needs to be interrupted to ensure the casting quality of the joints, but interrupting traffic will cause huge economic losses and adverse social impacts.

[0003] The joint forms rigidity through steel bars and concrete, transferring the vehicle load of the old bridge to the new bridge. However, in the process from before the concrete pouring of the joint to the formation of concrete strength, the rigidity of the joint is very small, resulting in a large relative deflection difference on both sides of the joint, causing cracks in the concrete of the joint. At this stage, existing technologies include temporary control measures such as beam shear frames, truss shear frames, and temporary piers. Among them, beam shear frames and truss shear frames have the disadvantages of not obvious rigidity improvement effect, high construction difficulty and high cost; the technical solution of temporary piers is more expensive, and changes the stress characteristics of the original main beam, resulting in more diseases in the later stage of operation. In addition, the existing technical solutions cannot monitor the stress state of the joints, and cannot judge the quality of joint pouring during the construction of the joints without interrupting traffic, which is not conducive to later maintenance. Summary of the invention

[0004] The purpose of the present invention is to provide a device for strengthening the initial stiffness of bridge joints and a method for bridge splicing construction in view of the technical defects in the prior art of low joint stiffness and easy cracking of joint concrete during the forming process due to non-interruption of traffic during the bridge widening construction process.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A device for reinforcing the initial stiffness of a bridge joint, the device being arranged at a joint between a new bridge and an old bridge, the device comprising a first steel plate and a second steel plate, the first steel plate being arranged on the upper side of a main beam wing at the joint between the new bridge and the old bridge, the second steel plate being arranged on the lower side of a main beam wing at the joint between the new bridge and the old bridge, the first steel plate and the second steel plate being fastened to the main beam wing respectively by anchor bolts, at least one web steel plate being arranged between the first steel plate and the second steel plate, the web steel plate being vertically arranged between the first steel plate and the second steel plate, the first end of the web steel plate being connected to a side wall of the main beam wing of the new bridge, and the other end being connected to a side wall of the main beam wing of the old bridge.

[0007] In the technical solution of the present invention, an initial stiffness reinforcement device is added to the joint to improve the stiffness between the new and old main beams, ensure coordinated deformation of the two, significantly reduce the deflection difference on both sides of the joint, and thereby ensure that the joint concrete will not crack during the molding process, thereby achieving uninterrupted traffic bridge splicing construction.

[0008] As a preferred solution of the present invention, the first steel plate, the second steel plate and the main beam wing plate on the old bridge side are fastened by first anchor bolts, and the first steel plate, the second steel plate and the main beam wing plate on the new bridge side are fastened and connected by second anchor bolts.

[0009] The length of the web steel plate is matched with the width of the joint seam, and the height of the web steel plate is matched with the height of the joint seam.

[0010] Preferably, the first end of the web plate abuts against the side wall of the wing plate of the main beam of the new bridge, and the other end abuts against the side wall of the wing plate of the main beam of the old bridge. In this way, due to the thickness of the web plate, the contact surface between its end and the side wall of the wing plate of the main beam of the new and old bridges is small, so the flange concrete is prone to local damage.

[0011] In order to improve the above defects, preferably, a stress diffusion steel plate is respectively arranged at the left and right ends of the web steel plate, the surfaces of the stress diffusion steel plates are respectively in contact with the side walls of the main beam wing plates between the splicing seams, and the stress diffusion steel plates are welded to the ends of the web steel plates.

[0012] Preferably, the height of the stress diffusion steel plate is consistent with the height of the web steel plate.

[0013] Preferably, the web steel plate is provided with a plurality of first holes for penetrating the longitudinal steel bars.

[0014] Preferably, the stress diffusion steel plate is provided with a plurality of second holes for penetrating the embedded reinforcement bars.

[0015] Preferably, the upper and lower ends of the web steel plate are respectively welded to the first steel plate and the second steel plate; the upper and lower ends of the stress diffusion steel plate are respectively welded to the first steel plate and the second steel plate.

[0016] As a preferred embodiment of the present invention, the initial stiffness reinforcement device also includes a stiffness reinforcement component, which is respectively arranged on the outer surface of the first steel plate and the outer surface of the second steel plate, and the stiffness reinforcement component includes a stiffness reinforcement steel plate and a connecting piece, and the stiffness reinforcement steel plate is connected to the first steel plate or the second steel plate through the connecting piece.

[0017] As a preferred embodiment of the present invention, the connecting member includes a first angle steel and a second angle steel of the same structure, the first angle steel and the second angle steel are arranged opposite to each other, the gap between the first angle steel and the second angle steel constitutes an inverted T-section slide groove, the longitudinal section of the stiffness-enhanced steel plate is in the shape of the letter "T", and the stiffness-enhanced steel plate can be inserted into the inverted T-section slide groove.

[0018] Specifically, the stiffness-enhanced steel plates include horizontal steel plates and vertical steel plates.

[0019] The optical fiber sensor is adhered to the surface of the first steel plate by strong glue and is used to monitor the stress changes of the steel plate during the construction process.

[0020] A bridge is constructed by widening the bridge using the bridge joint initial stiffness reinforcement device as described above. The initial stiffness reinforcement devices are arranged at intervals along the length direction of the bridge joint.

[0021] In the technical solution of the present invention, the thickness of the first steel plate and the second steel plate of the initial stiffness reinforcement device is preferably 1 cm, and the length is 20 cm added to the width of the joint.

[0022] The thickness of the web steel plate is preferably 1 cm, and the length is the width of the joint, and the width corresponds to the height of the joint. The thickness of the stress diffusion steel plate is preferably 1 cm, and one side length is adapted to the width of the first steel plate, and one side length is adapted to the height of the joint.

[0023] A bridge joint construction method adopts the above-mentioned initial stiffness strengthening device and specifically comprises the following steps:

[0024] Step 1: Calculate the steel plate size of the initial stiffness reinforcement device and the spacing B between adjacent initial stiffness reinforcement devices according to the bridge width data and the on-site survey data;

[0025] Step 2: according to the positions of the embedded reinforcement and the longitudinal reinforcement in the joint of the new and old bridges, the steel plates, the wing plates of the main beams of the new bridge and the wing plates of the main beams of the old bridge are punched accordingly;

[0026] Step 3, complete the installation of the initial stiffness reinforcement device in sequence; perform roughening on the upper and lower contact surfaces of the first steel plate, the second steel plate and the flange, apply anchoring glue, weld the web steel plate and the stress diffusion steel plate to the corresponding positions, construct longitudinal steel bars, anchoring bars and stirrups, and apply steel glue between the stress diffusion steel plate and the side of the flange; install the stress optical fiber sensor, which is bonded to the top of the first steel plate with strong glue and connected to the BOTDA test equipment;

[0027] Step 4: Pour concrete into the joints.

[0028] As a preferred embodiment of the present invention, in step 1, the size of the steel plate is calculated according to the stiffness equivalent formula 1 or 2):

[0029]

[0030] Wherein, in formula 1), I a represents the initial rigid reinforced section moment of inertia;

[0031] W1 represents the thickness of the web steel plate;

[0032] H1 represents the half height of the web steel plate;

[0033] W2 represents the width of the first steel plate;

[0034] H2 represents the thickness of the first steel plate;

[0035]

[0036] The above formula is the initial rigid reinforced section moment of inertia with the rigidity reinforcement component added.

[0037] Among them, W3 represents the width of the horizontal steel plate;

[0038] W4 represents the thickness of the vertical steel plate;

[0039] H3 represents the thickness of the horizontal steel plate;

[0040] H4 represents the height of the vertical steel plate;

[0041] The calculation formula of the section moment of inertia of the joint after concrete forming is 3:

[0042]

[0043] Wherein, B represents the distance between adjacent initial stiffness strengthening devices;

[0044] H represents the thickness of the widened seam;

[0045] The stiffness provided by the cross bridge to the steel bars exists both before and after the concrete is formed, so it is assumed that the stiffness provided by the cross bridge to the steel bars is ignored; according to the target, the initial stiffness provided is greater than the stiffness of the joint section after the bridge is formed. That is, the initial bending section modulus is greater than the joint section modulus after the bridge is formed. That is, formula 4 is satisfied:

[0046] E a I a ≥E b I b 4)

[0047] Among them, E a Indicates the elastic modulus of steel; I a represents the section inertia moment of the initial stiffness enhancement device; E b Represents the elastic modulus of the joint concrete after forming; I b It represents the moment of inertia of the joint section after the joint concrete is formed;

[0048] During the concrete forming process, the elastic modulus will increase from 0 to the elastic modulus after forming. Therefore, the strain of the joint concrete cannot be measured during the pouring and forming process. Therefore, the technical solution of this application adopts the method of measuring the strain of the steel component to replace the concrete stress. The stress limit value during the monitoring process is obtained by finite element calculation.

[0049] The specific calculation method of the stress limit is: establish a solid finite element model of the entire bridge, including an initial stiffness reinforcement device in the modeling process. When the concrete stress reaches cracking, measure the strain at the measuring point of the initial stiffness reinforcement device and use this as the limit for stress monitoring.

[0050] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0051] By designing an initial stiffness reinforcement device, the stiffness between the main beams of the new and old bridges is significantly improved, ensuring their coordinated deformation and significantly reducing the deflection difference on both sides of the joint, thereby ensuring that the joint concrete will not crack during the molding process and achieving uninterrupted traffic bridge splicing construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a cross-sectional view of an initial stiffness enhancing device according to Embodiment 2 of the present invention;

[0053] Figure 2 is a layout diagram of an initial stiffness reinforcement device according to Embodiment 3 of the present invention;

[0054] Figure 3 is a partial schematic diagram of an initial stiffness strengthening device according to Embodiment 2 of the present invention;

[0055] Figure 4is a cross-sectional view of the initial stiffness reinforcement device at the joint of Example 2 of the present invention;

[0056] Figure 5 Schematic diagram of the coordination between the initial stiffness strengthening device and the embedded reinforcement in Example 2 of the present invention;

[0057] Figure 6 is a schematic structural diagram of a stress diffusion steel plate according to Example 2 of the present invention;

[0058] Figure 7 The figure with letter marks corresponding to the calculation of the moment of inertia of the section of the initial stiffness strengthening device of Example 2 of the present invention;

[0059] Figure 8 The figure with letter marks corresponding to the calculation of the moment of inertia of the section of the initial stiffness strengthening device of Example 1 of the present invention;

[0060] Fig. 9 It is a structural schematic diagram of a comparative example of the present invention;

[0061] Fig.10 This is a measured diagram of the deformation difference control effect on both sides of the joint before and after installation of Example 2 of the present invention;

[0062] Icons: 1-wing plate of the main beam of the new bridge; 2-wing plate of the main beam of the old bridge; 3-first steel plate; 4-second steel plate, 5-web steel plate, 6-stress diffusion steel plate, 9-rigidity enhanced steel plate, 10-first angle steel, 11-second angle steel, 12-joint seam, 13-longitudinal steel bar, 14-embedded steel bar, 15-stirrups, 16-BOTDA testing equipment, 17-optical fiber sensor, 18-first anchor bolt, 19-second anchor bolt, 20-I-beam, 21-steel pad, 22-concrete pavement, 23-casing. DETAILED DESCRIPTION

[0063] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0064] The present invention is further described in detail below in conjunction with specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0065] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0066] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0067] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0068] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0069] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threaded connection, abutment, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be a connection between the two elements.

[0070] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following Figure 1-Figure 9 It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0071] Example 1

[0072] This embodiment provides a device for strengthening the initial stiffness of a bridge joint 12, such as Figure 1-Figure 8 As shown. The initial stiffness strengthening device is set at the joint 12 of the new and old bridges, and is arranged at intervals along the length direction of the bridge joint 12. The old bridge in this embodiment is a cast-in-place single-chamber large box girder with a span of (20+30+20)m. The left side is the main beam wing plate 2 of the old bridge, and the right side is the main beam wing plate 1 of the new bridge. The gap in the middle is the joint 12, the width of the joint 12 is 0.5m, and the thickness of the joint 12 is 20cm. Figure 1 Shown is a schematic diagram of the structure of the initial stiffness reinforcement device at the joint between the new and old bridges;

[0073] The initial stiffness strengthening device includes a first steel plate 3 and a second steel plate 4, wherein the first steel plate 3 is arranged on the upper side of the main beam wing plate at the joint between the new and old bridges, and the second steel plate 4 is arranged on the lower side of the main beam wing plate at the joint between the new and old bridges, and the first steel plate 3 and the second steel plate 4 are respectively fastened to the main beam wing plate by anchor bolts. Specifically, the first steel plate 3, the second steel plate 4 and the main beam wing plate 2 of the old bridge are fastened by first anchor bolts 18, and the first steel plate 3, the second steel plate 4 and the main beam wing plate on the new bridge side are fastened by second anchor bolts 19. Two first anchor bolts 18 and two second anchor bolts 19 are provided.

[0074] As a preferred solution of the present embodiment, at least one web steel plate 5 is arranged between the first steel plate 3 and the second steel plate 4, the web steel plate 5 is vertically arranged between the first steel plate 3 and the second steel plate 4, and the upper and lower ends of the web steel plate 5 are respectively welded to the first steel plate 3 and the second steel plate 4; a stress diffusion steel plate 6 is respectively arranged at the left and right ends of the web steel plate 5, the surfaces of the stress diffusion steel plates 6 are respectively in contact with the side walls of the main beam flanges between the splicing seams 12, and the stress diffusion steel plates 6 are welded to the ends of the web steel plate 5.

[0075] As a preferred solution of this embodiment, a first hole is provided at a corresponding position of the web steel plate 5 according to the number and position of the longitudinal reinforcements 13 in the splicing seam 12. A plurality of second holes for penetrating the reinforcements 14 are provided on the stress diffusion steel plate 6 according to the number and position of the reinforcements 14 in the splicing seam 12.

[0076] More specifically, the upper and lower ends of the web steel plate 5 are respectively welded to the first steel plate 3 and the second steel plate 4 ; the upper and lower ends of the stress diffusion steel plate 6 are respectively welded to the first steel plate 3 and the second steel plate 4 .

[0077] The initial stiffness strengthening device further includes an optical fiber sensor 17, which is disposed on the surface of the first steel plate 3. Specifically, the optical fiber sensor 17 is adhered to the surface of the first steel plate 3 by strong glue, and is used to monitor the stress change of the steel plate during the construction process.

[0078] In this embodiment, the size of the steel plate is calculated according to the stiffness equivalent formula 1: Figure 8 's annotation.

[0079]

[0080] Among them, I a represents the initial rigid reinforced section moment of inertia;

[0081] W1 represents the thickness of the web steel plate; H1 represents the 1 / 2 height of the web steel plate; W2 represents the width of the first steel plate; H2 represents the thickness of the first steel plate.

[0082] Example 2

[0083] This embodiment provides an initial stiffness reinforcement device, and its structure is consistent with the initial stiffness reinforcement device in the embodiment, and the only difference is that the initial stiffness reinforcement device in this embodiment further includes a stiffness reinforcement component, and the stiffness reinforcement component is respectively arranged on the outer surface of the first steel plate 3 and the outer surface of the second steel plate 4, and the stiffness reinforcement component includes a stiffness reinforcement steel plate 9 and a connecting member, and the stiffness reinforcement steel plate 9 is connected to the first steel plate 3 or the second steel plate 4 through the connecting member. Specifically, the stiffness reinforcement steel plate 9 is vertically arranged on the first steel plate 3 and the second steel plate 4, and the length direction of the stiffness reinforcement steel plate 9 is consistent with the length direction of the first steel plate 3.

[0084] Further specifically, the connecting member includes a first angle steel 10 and a second angle steel 11, the first angle steel 10 and the second angle steel 11 are arranged relatively to each other, the gap between the first angle steel 10 and the second angle steel 11 constitutes an inverted T-section slide groove, the longitudinal section of the stiffness enhancing steel plate 9 is in the shape of the letter "T", and the stiffness enhancing steel plate 9 can be inserted into the inverted T-section slide groove.

[0085] In this embodiment, the size of each steel plate of the initial stiffness reinforcement device and the spacing B between adjacent initial stiffness reinforcement devices along the length direction of the joint seam 12 are determined according to the following method:

[0086] Specifically, Figure 7 The following is a schematic diagram showing the dimensions of each structure of the initial stiffness reinforcement device:

[0087] Its section moment of inertia I a Determined according to the following formula 1:

[0088]

[0089] W1 represents the thickness of the web steel plate; H1 represents the 1 / 2 height of the web steel plate; W2 represents the width of the first steel plate; H2 represents the thickness of the first steel plate; W3 represents the width of the transverse steel plate; W4 represents the thickness of the vertical steel plate; H3 represents the thickness of the transverse steel plate; H4 represents the height of the vertical steel plate.

[0090] Sectional moment of inertia I of the joint after concrete forming b The calculation formula is as follows:

[0091]

[0092] Wherein, B represents the spacing between adjacent initial stiffness reinforcement devices; H represents the height of the joint 12; the stiffness provided by the cross bridge to the steel bars exists both before and after the concrete is formed, and the stiffness provided by the cross bridge to the steel bars is ignored.

[0093] According to the goal, the stiffness of the initial stiffness reinforcement device provided should be greater than the stiffness of the 12-section joint after the bridge is completed. That is, the initial bending section bending stiffness is greater than the 12-section bending stiffness of the 12-section joint after the bridge is completed:

[0094] E a I a ≥E b I b 3)

[0095] Among them, E a 、E b As known quantities, in order to satisfy equation 3), B and the size of the steel plate can be adjusted by substitution.

[0096] In actual application, in order to take into account the economy, E a I a The value exceeds E b I b 5% or more of the value.

[0097] In this embodiment, the following is calculated by substitution method:

[0098] The first steel plate 3 has a thickness H2 = 1 cm, a width W2 = 12 cm, and a length of 70 cm, which is 20 cm more than the width of the joint 12;

[0099] The parameters of the second steel plate 4 are consistent with those of the first steel plate 3;

[0100] The web steel plate 5 has a thickness W1=1 cm, a width of 20 cm (the value is the thickness of the joint 12), and a length of 49 cm (the value is the joint width minus twice the thickness of the stress diffusion steel plate 6 0.5 cm);

[0101] The stiffness enhancement steel plate 9 is T-shaped and can be divided into a horizontal steel plate and a vertical steel plate, wherein the horizontal steel plate has a thickness of 1 cm, a width of 6 cm, and a length of 70 cm, and the vertical steel plate has a thickness of 2 cm and a width of 23 cm;

[0102] The spacing of the stiffness enhancement devices is 5m. At this time, the bending stiffness of the bridge joint is 115×106N·m 2 The initial stiffness enhancement device can provide a stiffness of 117N·m 2 At this time, the stiffness of the initial stiffness enhancement device is slightly greater than the bending stiffness of the bridge joint. That is, the size setting is basically reasonable and has good economy.

[0103] To further verify the implementation effect of the initial stiffness reinforcement device of the present invention, before pouring the joint concrete, two 55t vehicles were driven side by side across the bridge in the state where the joint stiffness reinforcement device was installed and the state where the joint stiffness reinforcement device was not installed. The relative deflection difference on both sides of the joint is as follows: Fig.10 As shown. Without the initial stiffness strengthening device of the present invention, the maximum deflection difference on both sides of the widening joint of the bridge of the present application is 1.14mm; with the initial stiffness strengthening device of the present invention, the maximum deflection difference on both sides of the widening joint of the bridge of the present application is 0.25mm, and the relative deflection difference is reduced by 78.1%. The above measured data can show that the initial stiffness strengthening device of the present invention can effectively improve the initial stiffness of the joint and ensure the molding quality of the joint concrete.

[0104] Example 3

[0105] This embodiment provides a bridge joint 12 construction method, comprising the following steps:

[0106] Step 1: Calculate the steel plate size of the initial stiffness reinforcement device and the spacing B between adjacent initial stiffness reinforcement devices according to the bridge width data and the on-site survey data;

[0107] Step 2: According to the positions of the embedded reinforcement 14 and the longitudinal reinforcement 13 in the joint 12 of the new and old bridges, the steel plate, the flange of the new bridge and the flange of the old bridge are punched accordingly;

[0108] Specifically, according to the calculation method in Example 2, the first steel plate 3, the second steel plate 4, the web steel plate 5, and the stress diffusion steel plate 6 are prefabricated, wherein the longitudinal steel bars 13 include 10, the spacing between the longitudinal steel bars 13 is 10 cm, the thickness of the protective layer is 4 cm, and the diameter of the longitudinal steel bars 13 is d16. Then, according to the position of the longitudinal steel bars 13 in the design drawing, holes are opened at the corresponding positions of the web steel plate 5, and the diameter of the holes is 20 mm. The web steel plate 5 includes two rows of holes, the first row includes five holes, and the second row includes five holes.

[0109] The diameter of the embedded steel bar 14 is d12, and a hole is opened on the stress diffusion steel plate 6 according to the position of the embedded steel bar 14 in the design drawing. In addition, the first angle steel 10 and the second angle steel 11 should be welded to the corresponding positions of the first steel plate 3 and the first steel plate 3 in the factory.

[0110] Step 3, complete the installation of the initial stiffness strengthening device in sequence;

[0111] Specifically, holes are drilled at the corresponding positions of the bridge flanges of the new and old bridges, and the position of the steel bars in the bridge is first detected by a steel bar detector to prevent structural damage caused by drilling. When the installation position coincides with the position of the steel bars, the installation position can be appropriately offset. The upper and lower contact surfaces of the first steel plate 3, the second steel plate 4 and the flange are roughened and coated with rebar glue. Then the first steel plate 3 and the second steel plate 4 are installed and tightly connected by the first anchor bolt 18 and the second anchor bolt 19.

[0112] Weld the web steel plate 5 and the stress diffusion steel plate 6 to the corresponding positions. Construct the longitudinal steel bars 13, the embedded bars 14 and the stirrups 15. Apply steel glue between the stress diffusion steel plate 6 and the side of the flange, and weld the stress diffusion steel plate 6 to the corresponding hole position to ensure that the hole position can be used for the embedded bars 14, and then carry out the construction of the embedded bars 14. The construction of the embedded bars 14 should meet the requirements of the "Technical Specifications for Highway Bridge Reinforcement Construction". The embedded bars 14 include two weldings. First, the upper and lower L-shaped steel bars are welded into a U shape, and then the left and right embedded bars 14 are welded to form a whole. Pass the longitudinal steel bars 13 through the holes of the web steel plate 5, and construct the stirrups 15 according to the drawings.

[0113] Finally, the rigidity-enhanced steel plate 9 is installed, and the rigidity-enhanced steel plate 9 is installed on the first steel plate 3 and the second steel plate 4 through the inverted T-shaped cross-section slide of the connector. The stress optical fiber sensor 17 is further installed. The stress optical fiber sensor 17 should be installed on the top of the first steel plate 3 by means of strong adhesive bonding. The stress optical fiber sensor 17 is installed on the first steel plate 3 at the mid-span position and connected to the BOTDA test equipment 16.

[0114] According to the spacing in Example 2, the installation spacing of the initial stiffness reinforcement device is 5m, and starting from the mid-span position, an initial stiffness reinforcement device is installed every 5m.

[0115] Taking one bridge head as the benchmark, the installation positions are: 5m, 10m, 15m, 25m, 30m, 35m, 40m, 45m, 55m, 60m and 65m, a total of 11.

[0116] Step 4, pouring concrete for the joint 12. Pour self-leveling small stone anti-disturbance concrete. The poured concrete has the characteristics of anti-disturbance, micro-expansion, and self-leveling. The concrete can be purchased as commercial concrete.

[0117] After the concrete strength is formed, the rigid reinforcement steel plate is removed and the degree reinforcement steel plate connecting steel plate is cut. The remaining components will be retained in the joint 12 as a permanent structure.

[0118] During the concrete forming process, the elastic modulus will increase from 0 to the elastic modulus after forming. Therefore, the strain of the joint concrete cannot be measured during the pouring and forming process. Therefore, the present invention adopts the method of measuring the strain of the steel component to replace the concrete stress. The stress limit value during the monitoring process is obtained by finite element calculation.

[0119] The specific calculation method is to establish a solid finite element model, and the modeling process includes a stiffness enhancement device. When the concrete stress reaches cracking, the strain at the measuring point of the steel component is measured and used as the limit value for stress monitoring.

[0120] After simulation calculation, when the strain of the first steel plate 3 exceeds 120 microstrain, the joint 12 has the risk of cracking. The maximum strain during the construction process measured by the BOTDA test device 16 is 50 microstrain. The test results show that the initial stiffness enhancement device proposed in the present invention effectively improves the stiffness of the joint and has excellent effect.

[0121] Through the calculation formula of the stiffness equivalent principle proposed in this application, the selection of steel plate size can be more reasonably obtained, which is convenient for improving economic efficiency. In the technical solution of this application, the stiffness enhanced steel plate is a detachable structure and can be reused, thereby improving economic efficiency. The forming quality of the joint is guaranteed by strain monitoring.

[0122] Comparative Example 1

[0123] This comparative example is a 30m+30m cast-in-place box girder. Fig. 9 As shown, this comparative example uses a temporary steel beam to improve the joint stiffness, which specifically includes an I-beam 20, a steel pad 21, a concrete pavement 22, and a casing 23. Since there are supports between the steel beam and the upper and lower flanges, and there is no vertical steel plate to make the upper and lower steel beams a whole, the stiffness improvement effect is limited.

[0124] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for strengthening the initial stiffness of a bridge joint, characterized in that: The initial stiffness reinforcement device is arranged at the joint position between the new bridge and the old bridge, and comprises a first steel plate (3) and a second steel plate (4). The first steel plate (3) is arranged on the upper side of the main beam wing plate at the joint between the new bridge and the old bridge, and the second steel plate (4) is arranged on the lower side of the main beam wing plate at the joint between the new bridge and the old bridge. The first steel plate (3) and the second steel plate (4) are respectively fastened to the main beam wing plate by anchor bolts. At least one web steel plate (5) is arranged between the first steel plate (3) and the second steel plate (4). The web steel plate (5) is vertically arranged between the first steel plate (3) and the second steel plate (4). The first end of the web steel plate (5) is connected to the side wall of the main beam wing plate (1) of the new bridge, and the other end is connected to the side wall of the main beam wing plate (2) of the old bridge.

2. The device for strengthening the initial stiffness of bridge joints according to claim 1, characterized in that: The first steel plate (3), the second steel plate (4) and the main beam wing plate (2) of the old bridge are fastened and connected via first anchor bolts (18), and the first steel plate (3), the second steel plate (4) and the main beam wing plate (1) of the new bridge are fastened and connected via second anchor bolts (19).

3. The device for strengthening the initial stiffness of bridge joints according to claim 1, characterized in that: A stress diffusion steel plate (6) is provided at the left and right ends of the web steel plate (5), respectively. The surfaces of the stress diffusion steel plates (6) are in contact with the side walls of the main beam wing plates between the joint seams (12), respectively. The stress diffusion steel plates (6) are welded to the ends of the web steel plate (5), and the height of the stress diffusion steel plates (6) is consistent with the height of the web steel plate (5).

4. The device for strengthening the initial stiffness of bridge joints according to claim 1, characterized in that: The web steel plate (5) is provided with a plurality of first holes for penetrating the longitudinal steel bars (13); the stress diffusion steel plate (6) is provided with a plurality of second holes for penetrating the embedded steel bars (14); the upper and lower ends of the web steel plate (5) are respectively welded to the first steel plate (3) and the second steel plate (4); the upper and lower ends of the stress diffusion steel plate (6) are respectively welded to the first steel plate (3) and the second steel plate (4).

5. The device for reinforcing the initial stiffness of a bridge joint according to any one of claims 1 to 4, characterized in that: The initial stiffness reinforcement device further comprises a stiffness reinforcement component, wherein the stiffness reinforcement component is respectively arranged on the outer surface of the first steel plate (3) and the outer surface of the second steel plate (4), and the stiffness reinforcement component comprises a stiffness reinforcement steel plate (9) and a connecting piece, wherein the stiffness reinforcement steel plate (9) is connected to the first steel plate (3) or the second steel plate (4) via the connecting piece.

6. The device for reinforcing the initial stiffness of bridge joints according to claim 5, characterized in that: The connecting member comprises a first angle steel (10) and a second angle steel (11), wherein the first angle steel (10) and the second angle steel (11) are arranged opposite to each other, and a gap between the first angle steel (10) and the second angle steel (11) forms an inverted "T"-shaped cross-section slide groove, and the longitudinal section of the stiffness-enhancing steel plate (9) is "T"-shaped, and the stiffness-enhancing steel plate (9) can be inserted into the inverted "T"-shaped cross-section slide groove.

7. A bridge, characterized in that: The bridge widening construction is carried out using the initial stiffness reinforcement device for bridge joints as described in any one of claims 1 to 6, wherein the initial stiffness reinforcement device is arranged at intervals along the length direction of the bridge joints.

8. A bridge joint construction method, characterized in that: The initial stiffness strengthening device according to any one of claims 1 to 6 comprises the following steps: Step 1: Calculate the steel plate size of the initial stiffness reinforcement device and the spacing B between adjacent initial stiffness reinforcement devices according to the bridge width data and the on-site survey data; Step 2, according to the positions of the embedded reinforcement (14) and the longitudinal reinforcement (13) in the joint (12) between the new and old bridges, the steel plate, the wing plate of the main beam of the new bridge (1) and the wing plate of the main beam of the old bridge (2) are punched accordingly; Step 3, complete the installation of the initial stiffness reinforcement device in sequence; the first steel plate (3), the second steel plate (4) and the upper and lower contact surfaces of the flange are roughened, and the anchoring glue is applied, the web steel plate (5) and the stress diffusion steel plate (6) are welded to the corresponding positions, the longitudinal steel bars (13), anchoring bars (14) and stirrups (15) are constructed, and the steel glue is applied between the stress diffusion steel plate (6) and the side of the flange; Installing a stress optical fiber sensor (17), wherein the stress optical fiber sensor (17) is bonded to the top of the first steel plate (3) using a strong adhesive and connected to a BOTDA testing device (16); Step 4: pouring concrete into the joint (12).

9. The bridge joint construction method according to claim 8, characterized in that: In step 1, the steel plate size of the initial stiffness reinforcement device is determined as follows: Step 11: Sectional moment of inertia I of the initial stiffness reinforcement device a Calculate according to formula 1): In formula 1), W1 represents the thickness of the web steel plate; H1 represents the half height of the web steel plate; W2 represents the width of the first steel plate; H2 represents the thickness of the first steel plate; Step 12: Sectional moment of inertia I of the joint after concrete forming b Calculate according to formula 2): In formula 2), B represents the distance between adjacent initial stiffness reinforcement devices; H represents the height of the joint (12); The stiffness provided by the cross bridge to the steel bar exists both before and after the concrete is formed, so the stiffness provided by the cross bridge to the steel bar is ignored; Step 13, according to the initial stiffness reinforcement device, the stiffness is greater than the section stiffness requirement of the joint (12) after the bridge is formed, that is, the initial bending section modulus is greater than the section modulus of the joint (12) after the bridge is formed: E a I a ≥E b I b 3) Among them, E a represents the initial bending section modulus of the initial stiffness reinforcement device; E b represents the section modulus of the concrete in the joint (12); E a 、E b As known quantities, adjust B and the size of the steel plate by substitution to satisfy equation 3).

10. The bridge joint construction method according to claim 8, characterized in that: After the concrete strength is formed, the rigidity reinforcing steel plate (9) is removed and the connecting parts are cut, and the remaining components are retained in the joint (12) as a permanent structure.

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