Design method of temperature deformation regulation system for multi-span continuous bridge

Abstract

The application discloses a design method of a temperature deformation regulation system of a multi-span continuous bridge, and belongs to the technical field of bridge operation and maintenance. The temperature deformation regulation system of the multi-span continuous bridge comprises a main beam, a plurality of piers and longitudinal displacement adjustment components. Each pier is provided with two supports arranged at intervals, and the main beam is arranged on the supports. Each longitudinal displacement adjustment component comprises an upper connecting plate, a lower connecting plate, a force transmission shaft, two guide shaft sleeves, two threaded shaft sleeves and an elastic piece. The top surface of the upper connecting plate is fixed to the bottom surface of the main beam, the bottom surface of the upper connecting plate is provided with two bosses, the bottom surface of the lower connecting plate is fixed to the pier and located between the two supports. The temperature deformation regulation system of the multi-span continuous bridge provided by the application can regulate the temperature deformation of the built and opened bridge through the longitudinal displacement adjustment components, so that the deformation of the beam end expansion device can be adapted, and the structure of the built bridge does not need to be changed.

Description

Technical Field

[0001] This invention belongs to the field of bridge operation and maintenance technology, specifically relating to a temperature deformation control system and design method for multi-span continuous bridges. Background Technology

[0002] Long-span concrete continuous beams possess advantages such as high stiffness, excellent economy, and good durability, and are widely used in railway bridge construction across wide and deep waters and canyons. Long-span continuous beams often employ single fixed piers for continuous restraint. Under temperature changes, the beam ends will experience significant longitudinal expansion and contraction deformation. The design of the track structure at the beam ends needs to fully consider the magnitude and characteristics of this deformation.

[0003] There is an urgent need to upgrade existing long-span bridges, but these bridges often experience significant temperature deformation at the beam ends, which affects the smoothness of the road surface and driving comfort. Therefore, it is necessary to regulate the temperature deformation at the beam ends to accommodate the deformation of the beam-end expansion joints. Currently, there are no relevant engineering practices for temperature deformation control on existing bridges that have already been built and opened to traffic. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a temperature deformation control system and design method for multi-span continuous bridges. The purpose is to: control the temperature deformation of existing bridges that have been built and opened to traffic by setting longitudinal displacement adjustment components, thereby adapting to the deformation of beam end expansion joints, without changing the structure of the existing bridge.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a temperature deformation control system for a multi-span continuous bridge, the multi-span continuous bridge temperature deformation control system comprising a main beam, multiple piers and at least one longitudinal displacement adjustment component;

[0006] Each of the bridge piers has two spaced supports, and the main beam is mounted on multiple of the supports;

[0007] Each of the longitudinal displacement adjustment components includes an upper connecting plate, a lower connecting plate, a force transmission shaft, two guide bushings, two threaded bushings, and an elastic element. The top surface of the upper connecting plate is fixed to the bottom surface of the main beam. The bottom surface of the upper connecting plate has two spaced-apart bosses, which are slidably fitted onto both ends of the force transmission shaft along its axial direction. The bottom surface of the lower connecting plate is fixed to the pier and located between the two supports. The top surface of the lower connecting plate has two spaced-apart stops, and the two ends of the force transmission shaft are respectively inserted into the corresponding stops. The stop block is spaced apart from the corresponding boss to limit the movement of the boss. The two guide bushings, the two threaded bushings, and the elastic element are all located between the two bosses. The elastic element is sleeved on the force transmission shaft and sandwiched between the two threaded bushings. The two threaded bushings are both sleeved on the force transmission shaft. Each guide bushing is slidably sleeved on the corresponding threaded bushing. One end of each guide bushing abuts against the corresponding boss, and the other end of each guide bushing abuts against the elastic element to drive the elastic element to compress.

[0008] Optionally, one end of each guide bushing is provided with an inner flange on its inner peripheral wall. Each inner flange is located between the corresponding boss and the corresponding threaded bushing, and each inner flange is in sliding engagement with the force transmission shaft.

[0009] Optionally, each of the stops may be movably fitted with an adjusting bolt, each adjusting bolt being coaxially arranged with the force transmission shaft, and one end of each adjusting bolt abutting against the force transmission shaft.

[0010] Optionally, each of the longitudinal displacement adjustment components further includes two force transmission sleeves, each of the force transmission sleeves being slidably sleeved on the force transmission shaft, the force transmission sleeves being located between the corresponding threaded bushing and the elastic element, and the other end of each of the guide bushings abutting against the corresponding force transmission sleeve.

[0011] Optionally, each of the stops is provided with an adjustment plate on the side facing the boss, and each of the adjustment plates is detachably sleeved on the force transmission shaft.

[0012] Optionally, the elastic element is a plurality of disc springs.

[0013] Secondly, the present invention provides a design method for a temperature deformation control system for a multi-span continuous bridge, the design method being based on a temperature deformation control system for a multi-span continuous bridge according to the first aspect, the design method comprising:

[0014] The temperature deformation adjustment target of the main beam is determined, and the temperature deformation adjustment target includes the corresponding position of the main beam and the temperature deformation range of the main beam;

[0015] Calculate the location of the target temperature deformation zero point of the main beam, and calculate the design displacement and bearing capacity of the longitudinal displacement adjustment component, wherein the design displacement is the gap between the corresponding boss and the stop;

[0016] Based on the design displacement, bearing capacity, and corresponding installation space of the longitudinal displacement adjustment component, the corresponding longitudinal displacement adjustment component is installed on the piers adjacent to the target temperature deformation zero point of the main beam.

[0017] Optionally, the location of the target temperature deformation zero point of the main beam is calculated using the following formula:

[0018] ΔL=α*Δt*L;

[0019] Wherein, △L is the expansion and contraction of the main beam, α is the expansion and contraction coefficient of the main beam, △t is the temperature change, and L is the distance between the position of the target temperature deformation zero point of the main beam and the corresponding position of the main beam.

[0020] Optionally, the load-bearing capacity is calculated in the following manner:

[0021] f0+f1+…+f i +k*x i =f i+1 +k*x i+1 +f i+2 +…+f n +T;

[0022] n is the total number of piers. The longitudinal displacement adjustment component is installed on both the i-th pier and the (i+1)-th pier. The target temperature deformation zero point of the main beam is located between the i-th pier and the (i+1)-th pier. f0, f1, ..., f i ... f n Let be the frictional force between each of the aforementioned supports and the main beam, and the frictional force between each of the aforementioned supports and the main beam is equal; k is the elastic coefficient of the elastic element; T is the bearing capacity of the longitudinal displacement adjustment assembly on the (i+1)th pier; x i Let x be the deformation of the elastic element of the longitudinal displacement adjustment assembly on the i-th pier. i+1 Let be the deformation of the elastic element of the longitudinal displacement adjustment assembly on the (i+1)th pier.

[0023] Optionally, the elastic modulus of the elastic element is 1000-1500 kN / cm.

[0024] In summary, the beneficial effects of the above-described technical solutions conceived by this invention compared with the prior art include:

[0025] In the temperature deformation control system for a multi-span continuous bridge provided in this embodiment of the invention, the longitudinal displacement adjustment component is installed on the corresponding pier. Since the elastic element is sleeved on the force transmission shaft and sandwiched between two threaded bushings, the threaded bushings limit the movement of both ends of the elastic element, while allowing the corresponding guide bushings to compress the elastic element to the left or right. Furthermore, the top surface of the upper connecting plate is fixed to the bottom surface of the main beam, and the bottom surface of the upper connecting plate has two spaced protrusions. These two protrusions are slidably sleeved on both ends of the force transmission shaft along its axial direction. When the pier, corresponding to the main beam, undergoes expansion or contraction deformation, the protrusions move along the force transmission shaft and compress the elastic element through the guide bushings. The restoring force generated by the elastic element then regulates the deformation of the main beam. When the deformation is too large, the boss moves to abut against the stop, achieving a hard limit on the upper connecting plate. Thus, the stop can also play a role in regulating the deformation of the main beam.

[0026] During heating, the longitudinal displacement adjustment components on the main beam expand away from the center of the main beam. This means the main beam moves the upper connecting plate and the boss to the right. As the left boss moves to the right, it compresses the elastic element, which exerts a leftward force on the boss and the upper connecting plate, thus regulating the rightward expansion deformation of the main beam. Conversely, when the temperature rises excessively, the main beam moves the upper connecting plate and the boss to the right until they contact the right-side stop, achieving a hard limit. This also regulates the deformation of the main beam, thus controlling the temperature deformation at the beam ends.

[0027] Similarly, during cooling, the corresponding longitudinal displacement adjustment components on the main beam contract towards the center of the main beam. This means the main beam moves the upper connecting plate and the boss to the left. As the right-side boss moves to the left, it compresses the elastic element. The elastic element exerts a rightward force on the boss and the upper connecting plate, thus regulating the leftward contraction deformation of the main beam. When the cooling is excessive, the main beam moves the upper connecting plate and the boss to the left until they contact the left-side stop, achieving a hard limit. This also regulates the deformation of the main beam, thereby controlling the temperature deformation at the beam ends.

[0028] In other words, the temperature deformation control system for multi-span continuous bridges provided in this embodiment of the invention can control the temperature deformation of existing bridges that have been built and opened to traffic by setting a longitudinal displacement adjustment component, thereby adapting to the deformation of the beam end expansion joint, without changing the structure of the existing bridge. Attached Figure Description

[0029] Figure 1 This is a cross-sectional view of a temperature deformation control system for a multi-span continuous bridge provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the longitudinal displacement adjustment component provided in an embodiment of the present invention;

[0031] Figure 3 This is a longitudinal sectional view of the longitudinal displacement adjustment component provided in an embodiment of the present invention;

[0032] Figure 4 This is a flowchart of a design method for a temperature deformation control system for a multi-span continuous bridge provided in an embodiment of the present invention;

[0033] Figure 5 This is a structural schematic diagram of a railway bridge provided in an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram illustrating the change of the zero deformation point of a bridge under heating conditions, provided in an embodiment of the present invention.

[0035] Figure 7 This is a schematic diagram showing the change of the zero deformation point of a bridge under cooling conditions, as provided in an embodiment of the present invention.

[0036] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically:

[0037] 1. Main beam; 2. Pier; 3. Longitudinal displacement adjustment assembly; 31. Upper connecting plate; 311. Boss; 32. Lower connecting plate; 321. Stop block; 33. Force transmission shaft; 34. Guide bushing; 341. Inner flange; 35. Threaded bushing; 36. Elastic element; 37. Adjusting bolt; 38. Force transmission sleeve; 39. Adjusting plate; 4. Support. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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 invention.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," 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 communication 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 invention according to the specific circumstances.

[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] Example:

[0044] Figure 1 This is a transverse sectional view of a temperature deformation control system for a multi-span continuous bridge provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the temperature deformation control system for a multi-span continuous bridge includes a main beam 1, multiple piers 2, and at least one longitudinal displacement adjustment component 3.

[0045] Each pier 2 has two spaced supports 4, and the main beam 1 is mounted on multiple supports 4.

[0046] Figure 2 This is a schematic diagram of the longitudinal displacement adjustment component provided in an embodiment of the present invention. Figure 3 This is a longitudinal sectional view of the longitudinal displacement adjustment component provided in an embodiment of the present invention, combined with... Figure 2 and Figure 3As shown, each longitudinal displacement adjustment component 3 includes an upper connecting plate 31, a lower connecting plate 32, a force transmission shaft 33, two guide bushings 34, two threaded bushings 35, and an elastic element 36. The top surface of the upper connecting plate 31 is fixed to the bottom surface of the main beam 1. The bottom surface of the upper connecting plate 31 has two spaced protrusions 311, which are slidably fitted onto both ends of the force transmission shaft 33 along the axial direction. The bottom surface of the lower connecting plate 32 is fixed to the pier 2 and located between two supports 4. The top surface of the lower connecting plate 32 has two spaced stops 321, and the two ends of the force transmission shaft 33 are respectively inserted into the corresponding stops 321. In section 21, each stop block 321 is spaced apart from the corresponding boss 311 to limit the movement of the boss 311. Two guide bushings 34, two threaded bushings 35, and elastic element 36 are all located between the two bosses 311. The elastic element 36 is sleeved on the force transmission shaft 33 and sandwiched between the two threaded bushings 35. Both threaded bushings 35 are sleeved on the force transmission shaft 33. Each guide bushing 34 is slidably sleeved on the corresponding threaded bushing 35. One end of each guide bushing 34 abuts against the corresponding boss 311, and the other end of each guide bushing 34 abuts against the elastic element 36 to drive the elastic element 36 to compress.

[0047] In the temperature deformation control system for a multi-span continuous bridge provided in this embodiment of the invention, the longitudinal displacement adjustment component 3 is installed on the corresponding pier 2. Since the elastic element 36 is sleeved on the force transmission shaft 33 and sandwiched between two threaded bushings 35, the threaded bushings 35 limit the two ends of the elastic element 36, and at the same time, the corresponding guide bushing 34 can compress the elastic element 36 to the left or right. In addition, the top surface of the upper connecting plate 31 is fixed to the bottom surface of the main beam 1. The bottom surface of the upper connecting plate 31 has two spaced protrusions 311, which are slidably fitted onto both ends of the force transmission shaft 33 along the axial direction. This allows the protrusions 311 to move along the force transmission shaft 33 when the pier 2, corresponding to the main beam, undergoes expansion or contraction deformation. These protrusions then compress the elastic element 36 via the guide sleeve 34, and the restoring force generated by the elastic element 36 regulates the deformation of the main beam. When the deformation is too large, the protrusions 311 displace to abut against the stop block 321, achieving a hard limit on the upper connecting plate 31. Thus, the stop block 321 also regulates the deformation of the main beam.

[0048] During heating, the longitudinal displacement adjustment component 3 on the main beam expands away from the center of the main beam. This means the main beam moves the upper connecting plate 31 and the boss 311 to the right. Simultaneously, the left boss 311's rightward movement compresses the elastic element 36, which exerts a leftward force on the boss 311 and the upper connecting plate 31, thus regulating the rightward expansion deformation of the main beam. Conversely, when the temperature rises excessively, the main beam moves the upper connecting plate 31 and the boss 311 to the right until they contact the right-side stop block 321, achieving a hard limit and similarly regulating the deformation of the main beam.

[0049] Similarly, during cooling, the position of the longitudinal displacement adjustment component 3 on the main beam contracts towards the center of the main beam. That is, the main beam drives the upper connecting plate 31 and the boss 311 to move to the left. As the right boss 311 moves to the left, it squeezes the elastic element 36. The elastic element 36 exerts a rightward force on the boss 311 and the upper connecting plate 31, which plays a role in regulating the leftward contraction deformation of the main beam. When the cooling is too large, the main beam drives the upper connecting plate 31 and the boss 311 to move to the left until they contact the left stop block 321, achieving hard limiting, which can also play a role in regulating the deformation of the main beam.

[0050] In other words, the temperature deformation control system for multi-span continuous bridges provided in this embodiment of the invention can control the temperature deformation of existing bridges that have been built and opened to traffic by setting the longitudinal displacement adjustment component 3, thereby adapting to the deformation of the beam end expansion joint, without changing the structure of the existing bridge.

[0051] For example, there are two force transmission shafts 33 and four bosses 311 and stops 321, that is, one force transmission shaft 33 corresponds to two bosses 311 and two stops 321, thereby achieving reliable support for the upper connecting plate 31.

[0052] See also Figure 3 Each guide bushing 34 has an inner flange 341 on its inner peripheral wall at one end. Each inner flange 341 is located between the corresponding boss 311 and the corresponding threaded bushing 35, and each inner flange 341 is in sliding fit with the force transmission shaft 33. The inner flange 341 provides support and guidance for one end of the guide bushing 34.

[0053] In this embodiment, each stop block 321 is movably fitted with an adjusting bolt 37, each adjusting bolt 37 is coaxially arranged with the force transmission shaft 33, and one end of each adjusting bolt 37 abuts against the force transmission shaft 33.

[0054] In the above embodiment, the adjusting bolt 37 can push the force transmission shaft 33, causing the force transmission shaft 33 to move along its axial direction until the distance between the boss 311 and the corresponding stop 321 is equal (that is, the gap between the corresponding boss 311 and the stop 321 is equal), thereby ensuring that the two bosses 311 are symmetrically arranged relative to the two stops 321 during the installation of the longitudinal displacement adjustment component 3, thereby achieving equal control of expansion and contraction.

[0055] Similarly, each stop 321 is provided with an adjustment plate 39 on the side facing the boss 311. Each adjustment plate 39 is detachably sleeved on the force transmission shaft 33. Thus, by inserting the adjustment plate 39, the gap between the corresponding boss 311 and the stop 321 can be made equal, making the operation simpler.

[0056] In addition, each longitudinal displacement adjustment component 3 also includes two force transmission sleeves 38, each force transmission sleeve 38 being slidably sleeved on the force transmission shaft 33. The force transmission sleeve 38 is located between the corresponding threaded bushing 35 and the elastic element 36, and the other end of each guide bushing 34 abuts against the corresponding force transmission sleeve 38.

[0057] In the above embodiment, the force transmission sleeve 38 plays the role of transmitting force to the guide sleeve 34, which can increase the contact area between the guide sleeve 34 and the elastic element 36, making the elastic force of the guide sleeve 34 on the elastic element 36 more uniform.

[0058] For example, the elastic element 36 can be multiple disc springs. Disc springs have a reliable structure, a high elastic modulus, and a better effect on controlling the temperature deformation of the bridge.

[0059] Figure 4 This is a flowchart illustrating a design method for a temperature deformation control system for a multi-span continuous bridge, as provided in an embodiment of the present invention. Figure 4 As shown, this design method is based on the aforementioned temperature deformation control system for multi-span continuous bridges. The design method includes:

[0060] S1. Determine the temperature deformation adjustment target of the main beam 1. The temperature deformation adjustment target includes the corresponding position of the main beam 1 and the temperature deformation range of the main beam 1.

[0061] S2. Calculate the location of the target temperature deformation zero point of the main beam 1, and calculate the design displacement and bearing capacity of the longitudinal displacement adjustment component 3.

[0062] The design displacement is the gap between the corresponding boss 311 and the stop 321.

[0063] S3. Based on the design displacement, bearing capacity and corresponding installation space of the longitudinal displacement adjustment component 3, corresponding longitudinal displacement adjustment components 3 are installed on the piers 2 adjacent to the target temperature deformation zero point of the main beam 1.

[0064] The design method of the temperature deformation control system for a multi-span continuous bridge provided in this embodiment of the invention can not only control the temperature deformation of the completed and opened bridge by setting the longitudinal displacement adjustment component 3, but also set two adjacent longitudinal displacement adjustment components 3 to adjust the temperature deformation of the bridge, that is, adjust the position of the zero point of temperature deformation of the main beam 1, thereby meeting the requirements of the temperature deformation adjustment target of the main beam 1.

[0065] In this embodiment, the location of the target temperature deformation zero point of the main beam is calculated using the following formula:

[0066] ΔL=α*Δt*L; (1)

[0067] Where △L is the expansion and contraction of the main beam, α is the expansion and contraction coefficient of the main beam, △t is the temperature change, and L is the distance between the position of the target temperature deformation zero point of the main beam and the corresponding position of the main beam.

[0068] In addition, the load-bearing capacity is calculated in the following way:

[0069] f0 + f1 + ... + f i +k*x i = f i+1 +k*x i+1 + f i+2 +…+ f n +T; (2)

[0070] n is the total number of piers. Longitudinal displacement adjustment components are installed on both the i-th and (i+1)-th piers. The target temperature deformation zero point of the main beam is located between the i-th and (i+1)-th piers. f0, f1, ..., f i ... f n Let be the frictional force between each support and the main beam, and assume that the frictional force between each support and the main beam is equal; k is the elastic coefficient of the elastic element; T is the bearing capacity of the longitudinal displacement adjustment component on the (i+1)th pier; x i Let x be the deformation of the elastic element of the longitudinal displacement adjustment component on the i-th pier. i+1 Let be the deformation of the elastic element of the longitudinal displacement adjustment component on the (i+1)th pier.

[0071] It is easy to understand that the above formula (2) is based on the fact that the forces acting on the main beam on both sides of the main beam reach equilibrium at the position of the target temperature deformation zero point of the main beam.

[0072] For example, the elastic modulus of the elastic element is 1000-1500 kN / cm.

[0073] The above design method will be described below with reference to specific embodiments:

[0074] like Figure 5 A railway bridge has 9 spans. The main girder is a prestressed concrete box girder, and the piers are solid concrete piers. The spans of the multi-span continuous beams are: l1, l9 = 48m, l2-l8 = 80m. Both ends of the continuous beams are connected to standard span 32m concrete simply supported beams.

[0075] Step 1: In order to improve the safety and efficiency of railway operation and eliminate the track defects caused by excessive temperature deformation at the beam end of the curved section, the temperature deformation adjustment target of the main beam is: the temperature deformation on the right side of the simply supported beam next to the main beam at pier No. 9 should not exceed 30mm.

[0076] Step 2: The temperature variation range at the bridge site is ±15℃ (i.e., the temperature variation Δt is ±15℃), and the expansion coefficient α of the main beam is 0.00001. The temperature span is calculated according to formula (1), yielding ΔL = (30) / (0.00001 / ×15) = 200m, and L2 = ΔL - l0 = 200 - 32 = 168m. That is, the target temperature deformation zero point is located at the exact midpoint between piers ⑥ and ⑦.

[0077] Step 3: According to the principle of deformation coordination, the bridge span between piers ⑥ and ⑦ is l7 = 80m. When the temperature change range is ±15℃, based on formula (1), the length change of the main beam between piers ⑥ and ⑦ is ±12mm. In order to ensure that the zero point of temperature deformation is located at the mid-span under the ±15℃ condition (the distance between the two piers and the target zero point of temperature deformation corresponds to the ±12mm change of the length of the main beam between piers ⑥ and ⑦), the design displacement e of the corresponding longitudinal displacement adjustment component is 6mm (since the target zero point of temperature deformation is located in the middle of the two piers, the gap between the corresponding boss and the stop is 6mm).

[0078] Taking into account the stiffness of piers ⑥ and ⑦, the design displacement k of the longitudinal displacement adjustment component is 1200kN / cm. The most unfavorable working condition is when the temperature rise and fall of the bridge is at its maximum. According to formula (2), f0+f1+f2+f3+f4+f5+f6+k*x6=f7+k*x7+T+f8+f9;

[0079] Among them, f0, f1, f2, f3, f4, f5, f6, f7, f8, and f9 are all equal. Calculated using formula (1), the deformations x6 and x7 of the main beams at piers ⑥ and ⑦ are both 6mm. The friction between each support and the main beam is 0.03. The designed vertical bearing capacity of each support is 35000kN. When the actual vertical bearing capacity of each support is calculated as 0.8 times the vertical bearing capacity, and one pier corresponds to two supports, then T = 4f i =4*2*0.03*0.8*35000=6720kN, and the corresponding load-bearing capacity is taken as 7000kN.

[0080] Step 4: Based on the on-site measurement data, there is a large planar space between the two supports, which meets the conditions for installing the longitudinal displacement adjustment component. The height from the top of the pier to the bottom of the beam is 60cm, and the installation height of the longitudinal displacement adjustment component is 60±3cm. The longitudinal displacement adjustment component is installed based on the design displacement and the load displacement.

[0081] The following, in conjunction with the attached diagram, details the displacement of the zero-point of temperature deformation of the aforementioned bridge under temperature rise and fall conditions, as follows:

[0082] Figure 6 This is a schematic diagram illustrating the change of the zero deformation point of a bridge under heating conditions, as provided in an embodiment of the present invention. Figure 6 As shown, the deformation under the heating condition is divided into two stages: First stage: When the temperature rises by 3℃, the zero point of deformation moves from the mid-span of the entire span to pier #7, and the elastic displacement of pier #7 is 6mm (calculated by formula (1)), forming a fixed limit. Second stage: When the temperature continues to rise to 15℃, the zero point of deformation shifts from pier #7 towards the mid-span of piers #6 and #7.

[0083] Figure 7 This is a schematic diagram illustrating the change of the zero deformation point of a bridge under cooling conditions, as provided in an embodiment of the present invention. Figure 7 As shown, in the first stage, when the temperature drops by 3℃, the zero point of deformation moves from the mid-span of the entire span to pier #7, and the elastic displacement of pier #7 is 6mm, forming a fixed limit; in the second stage, when the temperature continues to drop to 15℃, the zero point of deformation shifts from pier #7 towards the mid-span of piers #6 and #7.

[0084] In other words, this design method can not only regulate the temperature deformation of existing bridges by setting longitudinal displacement adjustment components, but also adjust the temperature deformation of the bridge by setting two adjacent longitudinal displacement adjustment components in coordination, that is, adjust the position of the zero point of temperature deformation of the main beam, thereby meeting the requirements of the temperature deformation adjustment target of the main beam.

[0085] Those skilled in the art will readily understand that the above description is merely 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 within the scope of protection of the present invention.

Claims

1. A design method for a temperature deformation control system for a multi-span continuous bridge, characterized in that, The design method is based on a temperature deformation control system for a multi-span continuous bridge, which includes a main beam (1), multiple piers (2) and at least one longitudinal displacement adjustment component (3). Each of the piers (2) has two spaced supports (4), and the main beam (1) is mounted on multiple supports (4); Each of the longitudinal displacement adjustment components (3) includes an upper connecting plate (31), a lower connecting plate (32), a force transmission shaft (33), two guide bushings (34), two threaded bushings (35), and an elastic element (36). The top surface of the upper connecting plate (31) is fixed to the bottom surface of the main beam (1). The bottom surface of the upper connecting plate (31) has two spaced bosses (311). The two bosses (311) are slidably fitted onto both ends of the force transmission shaft (33) along the axial direction. The bottom surface of the lower connecting plate (32) is fixed to the pier (2) and located between the two supports (4). The top surface of the lower connecting plate (32) has two spaced stops (321). The two ends of the force transmission shaft (33) are respectively inserted into the corresponding stops (321). Each of the aforementioned stops (321) is spaced apart from the corresponding boss (311) to limit the movement of the boss (311). The two guide bushings (34), the two threaded bushings (35), and the elastic element (36) are all located between the two bosses (311). The elastic element (36) is sleeved on the force transmission shaft (33) and sandwiched between the two threaded bushings (35). The two threaded bushings (35) are both sleeved on the force transmission shaft (33). Each of the aforementioned guide bushings (34) is slidably sleeved on the corresponding threaded bushing (35). One end of each of the aforementioned guide bushings (34) abuts against the corresponding boss (311), and the other end of each of the aforementioned guide bushings (34) abuts against the elastic element (36) to drive the elastic element (36) to compress. The design method includes: Determine the temperature deformation adjustment target of the main beam (1), the temperature deformation adjustment target includes the corresponding position of the main beam (1) and the temperature deformation range of the main beam (1); Calculate the position of the target temperature deformation zero point of the main beam (1), and calculate the design displacement and bearing capacity of the longitudinal displacement adjustment component (3), wherein the design displacement is the gap between the corresponding boss (311) and stop (321); Based on the design displacement, bearing capacity and corresponding installation space of the longitudinal displacement adjustment component (3), the corresponding longitudinal displacement adjustment component (3) is installed on the pier (2) adjacent to the target temperature deformation zero point of the main beam (1). The location of the target temperature deformation zero point of the main beam (1) is calculated using the following formula: Wherein, △L is the expansion and contraction of the main beam (1), α is the expansion and contraction coefficient of the main beam (1), △t is the temperature change, and L is the distance between the position of the target temperature deformation zero point of the main beam (1) and the corresponding position of the main beam (1). The load-bearing capacity is calculated using the following method: f0+ f1+…+f i +k*x i = f i+1 +k*x i+1 + f i+2 +…+ f n +T; n is the total number of the bridge piers (2). The longitudinal displacement adjustment component (3) is installed on both the i-th bridge pier (2) and the (i+1)-th bridge pier (2). The target temperature deformation zero point of the main beam (1) is located between the i-th bridge pier (2) and the (i+1)-th bridge pier (2). f0, f1, ..., f i ... f n The frictional force between each of the supports (4) and the main beam (1) is equal, k is the elastic coefficient of the elastic element (36), T is the bearing capacity of the longitudinal displacement adjustment component (3) on the (i+1)th pier (2), and x is the frictional force between each of the supports (4) and the main beam (1). i Let x be the deformation of the elastic element (36) of the longitudinal displacement adjustment component (3) on the i-th pier (2). i+1 The deformation of the elastic element (36) of the longitudinal displacement adjustment component (3) on the (i+1)th pier (2) is given.

2. The design method of a temperature deformation control system for a multi-span continuous bridge according to claim 1, characterized in that, Each of the guide bushings (34) has an inner flange (341) on one end of its inner peripheral wall. Each inner flange (341) is located between the corresponding boss (311) and the corresponding threaded bushing (35), and each inner flange (341) is in sliding fit with the force transmission shaft (33).

3. The design method of a temperature deformation control system for a multi-span continuous bridge according to claim 1, characterized in that, Each of the stops (321) is movably fitted with an adjusting bolt (37), each adjusting bolt (37) is coaxially arranged with the force transmission shaft (33), and one end of each adjusting bolt (37) abuts against the force transmission shaft (33).

4. The design method of a temperature deformation control system for a multi-span continuous bridge according to claim 1, characterized in that, Each of the longitudinal displacement adjustment components (3) further includes two force transmission sleeves (38), each of the force transmission sleeves (38) being slidably sleeved on the force transmission shaft (33), the force transmission sleeves (38) being located between the corresponding threaded bushing (35) and the elastic element (36), and the other end of each of the guide bushings (34) abutting against the corresponding force transmission sleeve (38).

5. The design method of a temperature deformation control system for a multi-span continuous bridge according to any one of claims 1-4, characterized in that, Each of the stops (321) is provided with an adjustment plate (39) on the side facing the boss (311), and each of the adjustment plates (39) is detachably sleeved on the force transmission shaft (33).

6. The design method of a temperature deformation control system for a multi-span continuous bridge according to any one of claims 1-4, characterized in that, The elastic element (36) is a plurality of disc springs.

7. The design method of a temperature deformation control system for a multi-span continuous bridge according to claim 1, characterized in that, The elastic modulus of the elastic element (36) is 1000-1500 kN / cm.

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