Bridge negative force control device and design method

Abstract

The application relates to a bridge negative reaction control device and a design method, and belongs to the technical field of bridge construction, which comprises a distribution beam, the distribution beam is horizontally connected with a beam body penetrating through the bottom surface of a bridge main beam and is movably connected with the beam body, one end of the distribution beam is connected with a bridge pier, the other end of the distribution beam is connected with the bridge pier through a tension structure, the tension structure applies a load to the distribution beam so that the distribution beam applies a downward pre-pressure to the beam body. When the bridge main beam is longitudinally displaced, the distribution beam does not move longitudinally with the beam body, the spatial position of the tension structure is completely fixed, if the tension structure adopts a cable structure, the problem of the fatigue damage of anchoring cables caused by repeated bending and repeated stretching of the cables can be fundamentally avoided, meanwhile, the distribution beam adopts a lever mode to transmit force, the requirement of the load applied to the tension structure is greatly reduced, the distribution beam has the advantages of higher efficiency, the material consumption of the tension structure can be reduced, the maintenance cost is reduced, and the distribution beam is also applicable to the case that the space for arranging the cables is limited.

Description

Technical Field

[0001] This application relates to the field of bridge construction technology, and in particular to a bridge negative reaction force control device and design method. Background Technology

[0002] For long-span bridges, under the influence of dead loads, vehicle loads, train loads, wind loads, temperature loads, and seismic forces, the upward force on the bridge bearings at the piers exceeds the downward force, resulting in negative reaction forces. These negative reaction forces can cause the bearings to detach from the bridge piers, potentially leading to serious consequences such as bridge overturning, major safety accidents, and casualties. Therefore, necessary measures must be taken to control the occurrence of negative reaction forces in bridges.

[0003] In related technologies, there are generally three methods to solve the problem of negative reaction force in bridges: First, install tension-compression bearings between the main beam and the pier to prevent the bearings from coming loose; second, use direct weighting by pouring iron sand concrete at the main beam bearings to increase the self-weight; third, use prestressed cables to install cables between the main beam and the pier to apply prestress to the main beam.

[0004] Tension-compression bearings are a viable option, but the design and construction of large-tonnage tension-compression bearings are complex, and maintenance and replacement are difficult. Direct ballast bearings require a large amount of ferrule concrete, making them less economical. Furthermore, the limitations of the bridge structure make it difficult to support excessive amounts of concrete, requiring careful consideration of the placement of ferrule concrete on the bridge and modifications to the bridge structure. Prestressed cable bearings offer high pressure application efficiency, convenient construction, and good economic benefits, and have been applied to small and medium-span bridges in recent years.

[0005] However, prestressed cable systems also have some drawbacks and application challenges. The main issue is that due to the large longitudinal expansion and contraction displacement at the beam ends of long-span bridges, prestressed cable systems cannot be applied to the longitudinal relative displacement between the main beam and the piers. When large longitudinal relative displacements frequently occur between the main beam and the piers, the anchor points of the cables repeatedly bend, leading to fatigue failure and ultimately cable breakage, affecting bridge traffic safety.

[0006] The relevant patents make some improvements to the prestressed cable design. For example:

[0007] CN113605232B, "A cable counterweight structure and design method," describes setting a pivot at the anchor of the cable to solve the problem of fatigue failure caused by repeated bending of the cable.

[0008] CN116770713A, "An active control device and design method for supporting negative reaction force," describes a device that sets a rotating shaft at one end of a cable and a sliding support at the other end to solve the problem of repeated bending of the cable.

[0009] However, the improvements described in the above patents only apply when there is ample space for cable arrangement and the cables can be very long; they are not suitable for situations where the cables are short. The reasons are as follows:

[0010] Cable length L, bridge expansion / contraction S, cable elastic modulus E, cable rotation angle θ, cable fatigue stress amplitude σ, cable elongation ΔL.

[0011]

[0012] As can be seen from the formula, with E and S remaining constant, when L is large, the fatigue stress amplitude of the cable is small, and when L is small, the stress amplitude of the cable is large. A large fatigue stress amplitude makes the cable more prone to fatigue failure.

[0013] Therefore, there is an urgent need to find effective measures to address the difficulty of prestressed cable systems in adapting to large longitudinal displacements of bridges and to make them widely applicable to various cable arrangement spaces. Summary of the Invention

[0014] This application provides a bridge negative reaction force control device and design method to solve the technical problem in the related art where the cable arrangement space is limited and large longitudinal relative displacement occurs frequently between the main beam and the pier, which leads to repeated bending of the cable and fatigue failure.

[0015] In a first aspect, embodiments of this application provide a bridge negative reaction force control device, comprising:

[0016] The distribution beam is horizontally connected to the beam body at the bottom of the main beam of the bridge and is movably connected to the beam body. One end of the distribution beam is connected to the bridge pier.

[0017] A tension structure is provided, wherein the other end of the distribution beam is connected to the pier via the tension structure, and the tension structure applies a load to the distribution beam to cause the distribution beam to apply a downward preload to the beam body.

[0018] In some embodiments, the pier is provided with an abutment, and the end of the distribution beam away from the tension structure is hinged to the abutment.

[0019] In some embodiments, the bridge abutment is provided with a first embedded part, the end of the first embedded part is provided with a lug seat, the end of the distribution beam is provided with a lug plate, and the lug plate is hinged to the lug seat by a first pin.

[0020] In some embodiments, the pier is provided with a column, and the end of the distribution beam away from the tension structure is hinged to the column.

[0021] In some embodiments, the tension structure includes a second embedded part disposed on the pier and a tension member connected to the second embedded part, wherein the tension member is connected to the distribution beam by anchors after being tensioned.

[0022] In some embodiments, the second embedded part is provided with a fixed seat at its end, the tension member is provided with a connecting seat at its end, the connecting seat is connected to the fixed seat through a second pin, and the tension member is a cable or a rod.

[0023] In some embodiments, the distribution beam is connected to the beam body by a sliding support that allows the distribution beam and the beam body to slide relative to each other.

[0024] Secondly, this application provides a design method for a bridge negative reaction force control device, applicable to any of the bridge negative reaction force control devices described above, comprising the following steps:

[0025] Based on the overall bridge structure calculations, determine the negative reaction force generated at the bridge piers and the negative reaction force control safety factor;

[0026] The preload applied by the distribution beam to the beam body is determined based on the negative reaction force and the negative reaction force control safety factor.

[0027] Based on the lever principle, determine the tensile force on the tension member, and then set the design safety factor for the tension member;

[0028] Determine the breaking force of the tension member based on the tensile force and the design safety factor of the tension member;

[0029] Based on the breaking force of the tensile component, consult the relevant design specifications table for the tensile component and select a tensile component with a suitable breaking force.

[0030] Secondly, in some embodiments, the following steps are also included:

[0031] Based on the overall bridge structure calculations, determine the maximum lateral and longitudinal displacements of the bridge. Based on the preload and maximum displacement, consult relevant bearing design standards and specifications to select appropriate sliding bearings.

[0032] Secondly, in some embodiments, the following steps are also included:

[0033] Based on the tensile force on the tension member, and in accordance with the steel structure design code and concrete design code, verify the stress of the second embedded part and the shear force of the pier concrete.

[0034] Calculate the uplift force on the first embedded part based on the preload applied to the beam by the distribution beam and the tensile force on the tension member;

[0035] Based on the uplift force on the first embedded part, the stress of the first embedded part and the shear force of the bridge abutment concrete are verified in accordance with the steel structure design code and the concrete design code.

[0036] According to the steel structure design code, the bending stress and shear stress of the distribution beam are checked.

[0037] The beneficial effects of the technical solution provided in this application include:

[0038] (1) When the main beam of the bridge undergoes longitudinal displacement, since one end of the distribution beam is connected to the pier and the other end is connected to the pier through the tension structure, the distribution beam will not move longitudinally with the beam. The spatial position of the tension structure is completely fixed, and the tension structure does not expand, contract or rotate. If the tension structure adopts a cable structure, the problem of fatigue damage to the anchor cable caused by repeated bending and expansion of the cable can be fundamentally avoided.

[0039] (2) Since the distribution beam is horizontally connected to the beam body at the bottom of the main beam of the bridge and is movably connected to the beam body, the load is applied to the distribution beam by the load-bearing structure so that the distribution beam applies downward preload to the beam body. The distribution beam uses a lever method to transmit force, which greatly reduces the load requirements on the load-bearing structure and has the advantages of higher efficiency. It can reduce the amount of material used in the load-bearing structure and reduce maintenance costs.

[0040] (3) The solution of this application is applicable to situations where the space for cable arrangement is limited. That is, when the tension structure adopts a cable structure, the length of the cable can be adjusted according to the arrangement space. The longitudinal or transverse displacement of the main beam of the bridge will not cause the cable to expand or bend. There is no fatigue problem when using long or short cables. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the structure of an embodiment of this application;

[0043] Figure 2 for Figure 1 Schematic diagram of the cross section at point AA;

[0044] Figure 3 This is a schematic diagram of another embodiment of the present application;

[0045] Figure 4 This is a schematic diagram of the structure of another embodiment of this application.

[0046] The attached diagram lists the components represented by each number as follows:

[0047] 10. Distribution beam; 11. First embedded part; 12. Ear seat; 13. Ear plate; 14. First pin;

[0048] 20. Tension-bearing structure; 21. Second embedded part; 22. Tension member; 23. Anchor; 24. Fixing seat; 25. Connecting seat; 26. Second pin;

[0049] 30. Beam; 40. Pier; 50. Abutment; 60. Sliding bearing; 70. Bridge bearing; 80. Concrete column; 90. Steel column. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] This application provides a bridge negative reaction force control device and design method, which can solve the technical problem in related technologies where the cable arrangement space is limited and large longitudinal relative displacement occurs frequently between the main beam and the pier, resulting in repeated bending of the cables and fatigue failure.

[0052] See Figures 1 to 4 As shown, the first aspect of this application provides a bridge negative reaction force control device, including:

[0053] Distribution beam 10 is horizontally connected to beam 30 at the bottom of the main beam of the bridge and is movably connected to beam 30. One end of distribution beam 10 is connected to pier 40.

[0054] The other end of the distribution beam 10 is connected to the pier 40 through the tension structure 20. The tension structure 20 applies a load to the distribution beam 10 so that the distribution beam 10 applies a downward preload to the beam body 30.

[0055] The distribution beam 10 of the bridge negative reaction force control device in this application embodiment horizontally penetrates the beam body 30 connected to the bottom surface of the main beam of the bridge and is movably connected to the beam body 30. One end of the distribution beam 10 is connected to the pier 40, and the other end of the distribution beam 10 is connected to the pier 40 through the tension structure 20, so that the distribution beam 10 and the beam body 30 can undergo relative displacement to match the lateral and longitudinal displacement of the main beam of the bridge. That is, when the beam body 30 moves laterally or longitudinally with the main beam of the bridge, it will not drive the distribution beam 10 to move. The spatial position of the tension structure 20 is completely fixed, which can avoid fatigue damage to the tension structure 20.

[0056] Specifically, the beam 30 can be a horizontal or longitudinal beam connected to the bottom of the main beam of the bridge. The beam 30 has a pre-drilled installation hole that runs horizontally through it. The distribution beam 10 runs through the beam 30 and slides horizontally connected to it. Rigid members can be fixed on the pier 40 and hinged to one end of the distribution beam 10. The tension structure 20 connected to the other end of the distribution beam 10 can be a cable structure. When the main beam of the bridge moves longitudinally or transversely, the distribution beam 10 can maintain its position, thereby ensuring the cable position is fixed.

[0057] It should be noted that in the diagram, the X direction is the transverse direction of the bridge, and the Y direction is the longitudinal direction of the bridge.

[0058] In addition, the distribution beam 10 uses a lever method to transmit force, which greatly reduces the load requirements on the tension structure 20 and has the advantage of being more efficient. For example, when the tension structure 20 uses a cable structure, if the cable tension is F, under the lever principle, a preload of n*F (n>1) can be generated, which can reduce the amount of cable material used and reduce maintenance costs.

[0059] Since the load requirements on the tension structure 20 are reduced, the solution of this application can be applied to situations where the space for cable arrangement is limited. That is, when the tension structure 20 adopts a cable structure, the length of the cable can be adjusted according to the arrangement space. The longitudinal or lateral displacement of the main beam of the bridge will not cause the cable to expand or bend. There is no fatigue problem when using long or short cables.

[0060] In some alternative embodiments: see Figures 1 to 4 As shown in the figure, this application embodiment provides a bridge negative reaction force control device. The bridge pier 40 of the bridge negative reaction force control device is provided with an abutment 50, and the end of the distribution beam 10 away from the tension structure 20 is hinged to the abutment 50.

[0061] The bridge negative reaction force control device of this application embodiment uses the bridge abutment 50 as the anchoring structure. The bridge abutment 50 at the end of the bridge is an existing large volume concrete. The end of the distribution beam 10 away from the tension structure 20 is hinged to the bridge abutment 50. The weight of the bridge abutment 50 can be used as free counterweight to resist the upward pull force generated at the end of the distribution beam 10, thus avoiding the material waste caused by the use of counterweight concrete in the bridge.

[0062] Specifically, the horizontal beam 30 through which the distribution beam 10 passes is the end crossbeam near the abutment 50. Bridge bearings 70 arranged symmetrically in the transverse direction are installed between the end crossbeam and the pier 40. The bridge bearings 70 can be seismic isolation bearings. A longitudinal through-beam mounting hole is reserved in the middle of the end crossbeam. The distribution beam 10 passes through the mounting hole and is slidably connected to the mounting hole. One end of the distribution beam 10 is hinged to the abutment 50, and the other end of the distribution beam 10 is connected to the pier 40 bearing platform through the tension structure 20.

[0063] When the tension structure 20 applies a downward load to the end of the distribution beam 10, the end of the distribution beam 10 away from the tension structure 20 will generate an upward pull force on the abutment 50. The self-weight of the abutment 50 can resist the upward pull force, so that the weight of the abutment 50 can be used as free counterweight, avoiding the material waste caused by setting up additional concrete counterweight.

[0064] In some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides a bridge negative reaction force control device. The bridge abutment 50 of the bridge negative reaction force control device is provided with a first embedded part 11. The end of the first embedded part 11 is provided with a lug seat 12, and the end of the distribution beam 10 is provided with a lug plate 13. The lug plate 13 is hinged to the lug seat 12 through a first pin 14.

[0065] In this embodiment, a first embedded part 11 is provided on the bridge abutment 50. The first embedded part 11 includes an embedded steel plate and anchor bolts cast in the bridge abutment 50. The ear seat 12 is welded or bolted to the embedded steel plate. The end of the distribution beam 10 is welded with an ear plate 13. The ear plate 13 and the ear seat 12 are hinged by a first pin 14, thereby ensuring stable force transmission and preventing the distribution beam 10 from displacing with the beam body 30 in the transverse or longitudinal direction. At the same time, as the rotation fulcrum of the distribution beam 10, it ensures that the load requirement applied by the tension structure 20 can be reduced through the lever principle.

[0066] In some alternative embodiments: see Figures 1 to 4 As shown in the embodiment of this application, a bridge negative reaction force control device is provided. The bridge pier 40 of the bridge negative reaction force control device is provided with a column, and the end of the distribution beam 10 away from the tension structure 20 is hinged to the column.

[0067] In this embodiment, a column is provided on the pier 40. The end of the distribution beam 10 away from the tension structure 20 is hinged to the column. The column resists the upward pull-out force generated at the end of the distribution beam 10. This embodiment is applicable when the distribution beam 10 is installed far from the abutment 50. By setting a column on the pier 40 to be hinged to the distribution beam 10, the distribution beam 10 is limited. Specifically, the column can be a concrete column 80 cast on the abutment of the pier 40, or a steel column 90 pre-embedded in the abutment. It should be noted that the bridge negative reaction force control device in this embodiment is applicable to both cases with and without abutment 50. This embodiment is an implementation without abutment 50, and the concrete column 80 or steel column 90 can be used instead of abutment 50.

[0068] In some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides a bridge negative reaction force control device. The tension structure 20 of the bridge negative reaction force control device includes a second embedded part 21 set on the pier 40 and a tension member 22 connected to the second embedded part 21. After tensioning, the tension member 22 is connected to the distribution beam 10 through the anchor 23.

[0069] The tension structure 20 in this embodiment includes a second embedded part 21 and a tension member 22. The second embedded part 21 is cast on the pier cap of the bridge pier 40 to ensure force transmission stability. The tension member 22 is fixed or hinged to the second embedded part 21. After tensioning, the tension member 22 is connected to the distribution beam 10 through the anchor 23. The tension member 22 bears the tensile force. The second embedded part 21, the tension member 22, and the anchor 23 work together to ensure that sufficient load can be applied to the distribution beam 10. Specifically, the tension member 22 can be constructed using steel strands, parallel steel wires, steel tie rods, etc.

[0070] In some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides a bridge negative reaction force control device. The second embedded part 21 of the bridge negative reaction force control device is provided with a fixed seat 24 at its end, and the tension member 22 is provided with a connecting seat 25 at its end. The connecting seat 25 is connected to the fixed seat 24 through a second pin 26. The tension member 22 is a cable or a tie rod.

[0071] The second embedded part 21 in this embodiment includes an embedded steel plate and anchor bolts cast in the pier cap of the bridge pier 40. The fixing seat 24 is welded to the embedded steel plate in the pier cap. The connecting seat 25 is anchored to the end of the tension member 22, so that the connecting seat 25 can be hinged to the fixing seat 24 through the second pin 26. The tension member 22 is fixed to the distribution beam 10 by the anchor 23. The distribution beam 10 is provided with a through hole for the tension member 22 to pass through. The tension member 22 can be a cable or a tie rod, both of which can meet the force requirements. The anchor 23 can be an anchor head, so that the tension member 22 can be tensioned and fixed to the distribution beam 10.

[0072] In some alternative embodiments: see Figures 1 to 4 As shown, this application embodiment provides a bridge negative reaction force control device, wherein the distribution beam 10 of the bridge negative reaction force control device is connected to the beam 30 by a sliding support 60 that allows the distribution beam 10 and the beam 30 to slide relative to each other.

[0073] In this embodiment of the application, a sliding support 60 is installed between the distribution beam 10 and the beam body 30. The sliding support 60 connects the distribution beam 10 and the beam body 30 and can transmit preload. Specifically, the sliding support 60 includes an upper part bolted to the distribution beam 10 and a lower part bolted to the beam body 30. The upper and lower parts of the sliding support 60 can slide and rotate relative to each other to match the transverse and longitudinal displacements of the beam body 30, thus effectively applicable to situations where the main beam of the bridge undergoes transverse and longitudinal displacements. For example, the sliding support 60 can be a spherical steel support, a rubber sliding plate support, etc.

[0074] See Figures 1 to 4 As shown, a second aspect of this application provides a design method for a bridge negative reaction force control device, applicable to the bridge negative reaction force control device of any of the above embodiments. It includes the following steps:

[0075] S1. Based on the overall bridge structure calculation, determine the negative reaction force and the negative reaction force control safety factor generated at 40 piers;

[0076] S2. Based on the negative reaction force and the negative reaction force control safety factor, determine the preload applied by the distribution beam 10 to the beam 30;

[0077] S3. Based on the lever principle, determine the tension force on the tension member 22, and then set the design safety factor of the tension member 22;

[0078] S4. Determine the breaking force of the tension member 22 based on the tensile force on the tension member 22 and the design safety factor of the tension member 22;

[0079] S5. Based on the breaking force of the tension member 22, consult the relevant design specifications table of the tension member 22 and select the tension member 22 with a suitable breaking force.

[0080] In step S2 of this embodiment, the preload applied by the distribution beam 10 to the beam 30 is T2, where T2 = K1 * T1, K1 is the negative reaction force control safety factor (K1 > 1), and T1 is the negative reaction force generated at the pier 40. In step S3, the tension force on the tension member 22 is S. According to the lever principle, S * L1 = T2 * L2, where L1 is the distance from the hinge point at the end of the distribution beam 10 to the connection point between the distribution beam 10 and the tension structure 20, T2 is the preload applied by the distribution beam 10 to the beam 30, and L2 is the distance from the point of application of the preload to the hinge point at the end of the distribution beam 10.

[0081] In step S4, the breaking force of the tension member 22 is D, where D = S * K2, and S is the tensile force on the tension member 22, and K2 is the design safety factor of the tension member 22 (K2 > 3). The tension member 22 can be a cable or a tie rod. By consulting the relevant design specification tables of parallel steel wires, steel strands, and prestressed tie rods, the cable specification that is closest to and greater than the breaking force D can be found, and the cable of this specification can be used as the anchor cable. The tie rod can also be selected in the same way.

[0082] It should be noted that the negative reaction force control safety factor K1 and the design safety factor K2 of the tension member 22 can both be determined by the designer based on experience.

[0083] In some alternative embodiments: see Figures 1 to 4 As shown in the figure, this application provides a design method for a bridge negative reaction force control device, which further includes the following steps:

[0084] Based on the overall bridge structure calculation, the maximum lateral and longitudinal displacements of the bridge are determined. Based on the preload and maximum displacement, relevant bearing design standards and specifications are consulted to select a suitable sliding bearing 60 to ensure that the sliding bearing 60 can meet the preload and displacement requirements.

[0085] In some alternative embodiments: see Figures 1 to 4 As shown in the figure, this application provides a design method for a bridge negative reaction force control device, which further includes the following steps:

[0086] Based on the tensile force on the tension member 22, and in accordance with the steel structure design code and concrete design code, the stress of the second embedded member 21 and the shear force of the concrete of the pier 40 are verified.

[0087] The upward pull-out force on the first embedded part 11 is calculated based on the preload applied by the distribution beam 10 to the beam body 30 and the tension force on the tension member 22.

[0088] Based on the uplift force on the first embedded part 11, the stress of the first embedded part 11 and the shear force of the concrete of the bridge abutment 50 are verified in accordance with the steel structure design code and the concrete design code.

[0089] According to the steel structure design code, the bending stress and shear stress of the distribution beam 10 are checked.

[0090] In this embodiment, the upward pull-out force on the first embedded part 11 is F, where F = T2 - S, and T2 is the preload applied by the distribution beam 10 to the beam 30, and S is the tension force on the tension member 22.

[0091] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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 communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0092] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0093] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A design method for a bridge negative reaction force control device, characterized in that, The device includes: Distribution beam (10), the distribution beam (10) horizontally passes through the beam body (30) connected to the bottom surface of the main beam of the bridge and is movably connected to the beam body (30), one end of the distribution beam (10) is connected to the pier (40); A tension structure (20) is provided, wherein the other end of the distribution beam (10) is connected to the pier (40) via the tension structure (20), and the tension structure (20) applies a load to the distribution beam (10) so that the distribution beam (10) applies a downward preload to the beam body (30); A bridge abutment (50) is provided on the pier (40), and the end of the distribution beam (10) away from the tension structure (20) is hinged to the bridge abutment (50); The tension structure (20) includes a second embedded part (21) set on the pier (40) and a tension member (22) connected to the second embedded part (21). After tensioning, the tension member (22) is connected to the distribution beam (10) through an anchor (23). A sliding support (60) is provided between the distribution beam (10) and the beam body (30) to allow the distribution beam (10) and the beam body (30) to slide relative to each other. The methods include: Based on the overall calculation of the bridge structure, the negative reaction force generated at pier (40) and the negative reaction force control safety factor are determined; Based on the negative reaction force and the negative reaction force control safety factor, determine the preload applied by the distribution beam (10) to the beam body (30); Using the distribution beam (10) as the force lever, and based on the lever principle, determine the tension force on the tension member (22), and then set the design safety factor of the tension member (22); The breaking force of the tension member (22) is determined based on the tensile force on the tension member (22) and the design safety factor of the tension member (22); Based on the breaking force of the tensile member (22), consult the relevant design specifications table of the tensile member (22) and select the tensile member (22) with a suitable breaking force.

2. The design method of the bridge negative reaction force control device as described in claim 1, characterized in that: The bridge abutment (50) is provided with a first embedded part (11), the end of the first embedded part (11) is provided with a lug seat (12), the end of the distribution beam (10) is provided with a lug plate (13), and the lug plate (13) is hinged to the lug seat (12) through a first pin (14).

3. The design method of the bridge negative reaction force control device as described in claim 1, characterized in that: A column is provided on the pier (40), and the end of the distribution beam (10) away from the tension structure (20) is hinged to the column.

4. The design method of the bridge negative reaction force control device as described in claim 1, characterized in that: The second embedded part (21) is provided with a fixed seat (24) at its end, and the tension member (22) is provided with a connecting seat (25) at its end. The connecting seat (25) is connected to the fixed seat (24) through a second pin (26). The tension member (22) is a cable or a rod.

5. The design method of the bridge negative reaction force control device as described in claim 1, characterized in that, It also includes the following steps: Based on the overall calculation of the bridge structure, determine the maximum lateral and longitudinal displacements of the bridge. Based on the preload and the maximum displacement, consult the relevant bearing design standards and specifications, and select the appropriate sliding bearing (60).

6. The design method of the bridge negative reaction force control device as described in claim 2, characterized in that, It also includes the following steps: Based on the tensile force on the tension member (22), the stress of the second embedded member (21) and the shear force of the concrete of the pier (40) are verified in accordance with the steel structure design code and the concrete design code. The uplift force on the first embedded part (11) is calculated based on the preload applied by the distribution beam (10) to the beam body (30) and the tension force on the tension member (22); Based on the uplift force on the first embedded part (11), the stress of the first embedded part (11) and the shear force of the concrete of the bridge abutment (50) are verified in accordance with the steel structure design code and the concrete design code. According to the steel structure design code, the bending stress and shear stress of the distribution beam (10) are verified.

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