A slidable support structure and design method thereof

Abstract

The invention discloses a slidable support structure and a design method thereof, wherein the slidable support structure comprises an upper support plate, a lower support plate, a magnetorheological elastic layer, a rubber layer, a sliding friction pair, an electromagnetic mechanism and a baffle plate; an electromagnetic repulsive force is generated by applying a homogeneous magnetic field to the electromagnetic mechanism to partially offset the pressure acting on the sliding friction pair, so that the friction resistance of the deformation of the main beam or the building superstructure in the horizontal direction is reduced and the stress in the horizontal direction is released, and then the application of the homogeneous magnetic field is stopped to avoid unnecessary horizontal sliding of the main beam or the building superstructure; a magnetic field is applied to the magnetorheological elastic layer to increase its compression stiffness, so as to achieve compensation for the vertical differential deformation of the pier or the building foundation; the design method comprises a horizontal deformation control design method and a vertical deformation compensation design method, which provides a basis for the design of the electromagnetic mechanism, the sliding friction pair and the magnetorheological elastic layer.

Description

Technical Field

[0001] The invention relates to the technical field of bridge and building structures, and in particular to a slidable bearing structure and a design method thereof. Background Art

[0002] The purpose of setting expansion joints in bridges is to avoid structural damage caused by longitudinal deformation of the main beam under the effects of material creep and temperature changes. However, expansion joints and their expansion devices have problems such as reduced driving comfort, easy damage and difficult maintenance during use. For long-span bridge structures without expansion joints, how to effectively solve the problem of bridge deformation and displacement coordination has become a factor that determines the success or failure of bridge projects.

[0003] Traditional slidable bearings allow a certain amount of relative slip between the main beam and the pier through a sliding friction pair, thereby releasing the horizontal deformation of the main beam. However, the main beam of a long-span bridge has a large deadweight, which still results in considerable friction resistance on the sliding surface. Secondly, the material of the sliding friction pair will show wear, aging, corrosion, and creep after long-term use, which will increase the friction coefficient of the sliding friction pair. On the other hand, if the friction coefficient of the sliding friction pair is too small, the bridge may easily slip when it is in normal use, such as when it is subjected to smaller external forces such as wind loads and vehicle loads, which will affect the stability of the bridge structure and may even affect driving safety. In the current construction of large-span bridges, there is an urgent need for a simple and feasible method to flexibly adjust the friction resistance of the slidable bearing according to different working conditions.

[0004] Secondly, large bridges across complex terrain are usually equipped with piers of different lengths. Adjacent pier structures will produce different degrees of expansion and contraction deformation under the action of temperature. This differential deformation will affect the linear smoothness of the superstructure and generate additional loads, which is not conducive to the normal use and structural safety of the bridge structure. Traditional methods of compensating for differential deformation of pier structures by adjusting the height of the bearings include using hydraulic jacks or bolts to raise the bearings, replacing pads of different thicknesses, etc. These traditional methods are inefficient, have poor real-time performance, are difficult to implement, and are prone to cause unnecessary damage to the bridge structure during implementation.

[0005] In addition, sliding bearings are beneficial for bridge structures to dissipate seismic energy through sliding friction when encountering earthquakes. However, when encountering strong earthquakes, the energy dissipation function of sliding bearings needs to be further improved, and the sliding amount of sliding bearings may exceed design expectations, resulting in excessive relative displacement between the bridge superstructure and the substructure, affecting the normal use of the bridge after the earthquake.

[0006] Similar problems also exist in building structures with slidable bearings on the foundation. Therefore, it is urgent to develop a new type of slidable bearing structure and design method that can adapt to the longitudinal deformation of the bridge or building superstructure, the longitudinal differential deformation of the pier or building foundation, and improve the seismic resistance of the bridge or building, so as to effectively solve the deformation and displacement coordination problems of large-span bridges or building structures without expansion joints under the action of temperature. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention applies for a slidable bearing structure and a design method thereof, which are suitable for large-span bridges or building bearing structures, and provides a sliding bearing and a design method thereof that can adapt to the deformation of bridges or buildings, which is beneficial to solving the deformation and displacement coordination problems of large-span bridges or buildings when no structural expansion joints are set.

[0008] The first aspect of the present application discloses a slidable support structure, which is arranged between a pier and a main beam or between a building foundation and a building superstructure, and comprises an upper support plate, a lower support plate, a magnetorheological elastic layer, a rubber layer, a sliding friction pair and an electromagnetic mechanism; the upper support plate is fixed below the main beam or the building superstructure, and the lower support plate is fixed above the pier or the building foundation; a receiving platform is provided on the lower support plate, a countersunk hole is opened on the receiving platform, and a receiving cavity is formed between the receiving platform with the countersunk hole and the bottom of the upper support plate, and the magnetorheological elastic layer, the rubber layer and the sliding friction pair are provided in the receiving cavity from bottom to top in sequence. The sliding friction pair is provided with a lining plate, a polytetrafluoroethylene plate and a sliding friction plate in sequence from bottom to top, the sliding friction plate is tightly fitted under the upper support plate, and the bottom surface of the lining plate is fitted with the rubber layer; both ends of the upper support plate are provided with eaves downward, and the eaves are connected to the lower support plate through an electromagnetic mechanism, and the electromagnetic mechanism includes an upper magnetic component and a lower magnetic component, the upper magnetic component is embedded in the eaves, and the lower magnetic component is embedded in the lower support plate on one side of the receiving platform, the upper magnetic component is docked with the lower magnetic component, and is connected to an external controller through a wire.

[0009] Preferably, the magnetorheological elastic layer is made of a composite of a silicone rubber matrix and carbonyl iron particles; a first annular electromagnetic coil is embedded inside the magnetorheological elastic layer and is connected to an external controller via a wire; and the magnetic field generated by the first electromagnetic coil is used to adjust the compression stiffness and damping coefficient of the magnetorheological elastic layer.

[0010] Preferably, the surface of the polytetrafluoroethylene plate is provided with a grease storage groove and filled with graphene grease.

[0011] Preferably, the sliding friction plate is made of a stainless steel plate, the surface of which is mirror-polished and forms a low-friction interface with the polytetrafluoroethylene plate.

[0012] Preferably, the upper magnetic component is a permanent magnet array embedded in the bottom of the upper support plate, and the lower magnetic component is a second electromagnetic coil arranged on the top of the lower support plate; according to the current direction and current intensity of the second electromagnetic coil, a like magnetic field or an opposite magnetic field is generated between the upper magnetic component and the lower magnetic component, thereby generating an electromagnetic repulsion or an electromagnetic attraction between the upper magnetic component and the lower magnetic component.

[0013] Preferably, the lining plate is composed of an upper cylinder and a lower cylinder; the diameter of the lower cylinder is the same as that of the magnetorheological elastic layer and the rubber layer; the diameter of the upper cylinder is larger than the diameter of the lower cylinder and smaller than the diameter of the sliding friction plate; a gap is retained between the upper cylinder and the eaves of the upper support plate in the horizontal direction, and a gap is retained between the upper cylinder and the supporting platform of the lower support plate in the vertical direction.

[0014] Preferably, it also includes a baffle plate, which is made of weather-resistant rubber material and surrounds the electromagnetic mechanism in a ring shape; the top of the baffle plate is connected to the upper support plate, and the bottom is connected to the lower support plate through a slot, and the inside of the baffle plate is filled with inert gas to isolate moisture and corrosive media.

[0015] Preferably, a stress sensor is arranged at the connection between the upper support plate and the main beam or the building superstructure, so as to monitor the horizontal stress of the main beam or the building superstructure in real time; a strain sensor is embedded inside the magnetorheological elastic layer, so as to monitor the compressive deformation of the magnetorheological elastic layer and feed it back to an external controller to adjust the magnetic field strength; a displacement sensor and an acceleration sensor are installed at the pier or the building foundation, so as to monitor the vertical displacement of the pier or the building foundation and the seismic acceleration in real time, respectively.

[0016] The second aspect of the present application discloses a slidable bearing structure design method, including a horizontal deformation control design method and a vertical deformation compensation design method; wherein the horizontal deformation control design method includes the following steps:

[0017] S101, determining the range of expected friction resistance: applying a magnetic field of the same polarity between the upper magnetic component and the lower magnetic component to generate an electromagnetic repulsive force, partially offsetting the pressure acting on the sliding friction pair P , which reduces the friction resistance of the main beam along the horizontal deformation. The friction resistance at this time is the expected friction resistance F e , expected friction resistance F e Satisfies the following expression:

[0018]

[0019] in, Pis the pressure acting on the sliding friction pair, m 0 is the initial friction coefficient of the sliding friction pair; α To prevent air loss, the purpose is to avoid the expected friction resistance. F e If the height is too low, the magnetorheological elastic layer and the sliding friction plate may be separated from each other, thereby endangering the structural safety. F d The friction resistance required to prevent the main beam from unnecessary horizontal sliding when sliding is locked;

[0020] S102, determining the value range of the electromagnetic repulsive force: generating the electromagnetic repulsive force by applying a magnetic field of the same polarity between the upper magnetic component and the lower magnetic component F r , satisfying the following expression:

[0021]

[0022] in, m max It is the maximum value of the friction coefficient of the sliding friction pair after material aging;

[0023] S103, determine the value range of the current intensity: determine the current intensity of the second electromagnetic coil through experiments I 2 With magnetic field strength H 2 The functional relationship between H 2 Electromagnetic repulsion F r The functional relationship between I 2 The value range of

[0024] S104. Design of electromagnetic mechanism and sliding friction pair: Based on the initial friction coefficient m 0 and current intensity I 2 The electromagnetic mechanism and the sliding friction pair are designed according to the value range of

[0025] The vertical deformation compensation design method includes the following steps:

[0026] S201. Determine the value range of the compensation displacement: obtain the maximum differential deformation of adjacent piers or building foundations under the action of temperature through numerical simulation calculation, and determine the compensation displacement D The value range of

[0027] S202, determining the change in the compression stiffness of the magnetorheological elastic layer: To achieve displacement compensation, the adjustment target value of the compression stiffness of the magnetorheological elastic layer is K 1 Satisfies the following expression:

[0028]

[0029] in, K 0 is the compression stiffness of the magnetorheological elastic layer under initial conditions, D 0 is the displacement of the magnetorheological elastic layer under initial conditions;

[0030] S203, determine the value range of the current intensity: determine the current intensity of the first electromagnetic coil through experiments I 1 With magnetic field strength H 1 The functional relationship between H 1 The functional relationship between the compressive stiffness of the magnetorheological elastic layer and the magnetorheological elastic layer manufacturing process is determined to determine the current intensity. I 1 The value range of

[0031] S204. Design of magnetorheological elastic layer: according to the current intensity I 1 The design of the magnetorheological elastic layer is carried out based on the value range of and its relationship with the compressive stiffness of the magnetorheological elastic layer.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: in order to solve the deformation and displacement coordination problem of a long-span bridge when a structural expansion joint is not provided, a slidable bearing structure and a design method thereof are disclosed, wherein the slidable bearing structure comprises an upper bearing plate, a lower bearing plate, a magnetorheological elastic layer, a rubber layer, a sliding friction pair, an electromagnetic mechanism and a baffle plate; the slidable bearing structure has three working modes, including a horizontal deformation control mode, a vertical deformation compensation mode and an earthquake emergency mode; the horizontal deformation control mode is to generate an electromagnetic repulsive force by applying a homogeneous magnetic field to the electromagnetic mechanism, partially offsetting the pressure acting on the sliding friction pair, so that the friction resistance of the deformation of the main beam or the building superstructure in the horizontal direction is reduced, and the stress of the main beam or the building superstructure in the horizontal direction is released, and then the application of the homogeneous magnetic field is stopped, so as to form a sliding lock through the existing friction resistance, thereby avoiding unnecessary horizontal sliding of the main beam or the building superstructure; the vertical deformation compensation mode is to apply a magnetic field to the magnetorheological elastic layer to compress it The stiffness is improved, and the compressive deformation of the magnetorheological elastic layer under constant pressure is reduced, which is manifested as the height of the magnetorheological elastic layer rising and causing the upper bearing plate to rise, thereby realizing the compensation of the vertical differential deformation of the pier or the building foundation; the earthquake emergency mode applies a magnetic field to the magnetorheological elastic layer to increase the damping coefficient, reduces the risk of damage to the structure caused by resonance, and applies anisotropic magnetic fields to the electromagnetic mechanism after the earthquake to generate electromagnetic suction, thereby slowly resetting the main beam or the building superstructure to the initial position; the design method includes a horizontal deformation control design method and a vertical deformation compensation design method, which provides a basis for the design of the electromagnetic mechanism, the sliding friction pair and the magnetorheological elastic layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of a slidable support structure of the present invention;

[0034] Figure 2 A schematic diagram of a liner plate of a slidable support structure according to the present invention;

[0035] Figure 3 A flow chart of a method for designing a slidable support structure according to the present invention;

[0036] Figure numerals: 1-upper support plate, 11-eaves, 2-lower support plate, 21-supporting platform, 3-magnetorheological elastic layer, 4-rubber layer, 5-sliding friction pair, 51-lining plate, 511-upper cylinder, 512-lower cylinder, 52-polytetrafluoroethylene plate, 53-sliding friction plate, 6-electromagnetic mechanism, 61-upper magnetic component, 62-lower magnetic component, 7-enclosing plate. DETAILED DESCRIPTION

[0037] The following is a more detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and the accompanying drawings so that a person skilled in the art can implement the embodiments after reading the description. 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.

[0038] The first aspect of the present application discloses Figure 1-2 A slidable bearing structure is shown, which is arranged between a pier and a main beam of a bridge or between a building foundation and a building superstructure, and comprises an upper bearing plate 1, a lower bearing plate 2, a magnetorheological elastic layer 3, a rubber layer 4, a sliding friction pair 5 and an electromagnetic mechanism 6; the upper bearing plate 1 is fixed below the main beam or the building superstructure, and the lower bearing plate 2 is fixed above the pier or the building foundation; a receiving platform 21 is provided on the lower bearing plate 2, and a countersunk hole (not shown in the figure) is opened on the receiving platform 21, and a receiving cavity (not shown in the figure) is formed between the receiving platform 21 with the countersunk hole and the bottom of the upper bearing plate 1, and the magnetorheological elastic layer 3, the rubber layer 4 and the sliding friction pair 5 are arranged in sequence from bottom to top in the receiving cavity, and the sliding friction pair 5 is provided in the lower bearing plate 2. The friction pair 5 is provided with a lining plate 51, a polytetrafluoroethylene plate 52 and a sliding friction plate 53 in sequence from bottom to top, the sliding friction plate 53 is tightly fitted under the upper support plate 1, and the bottom surface of the lining plate 51 is fitted with the rubber layer 4; the two ends of the upper support plate 1 are provided with eaves 11 downwardly, and the eaves 11 are connected to the lower support plate 2 through an electromagnetic mechanism 6, and the electromagnetic mechanism 6 includes an upper magnetic component 61 and a lower magnetic component 62, the upper magnetic component 61 is embedded in the eaves 11, and the lower magnetic component 62 is embedded in the lower support plate 2 located on one side of the receiving platform 21, the upper magnetic component 61 is connected to the lower magnetic component 62, and is connected to an external controller through a wire.

[0039] In a specific implementation, the magnetorheological elastic layer 3 is made of a composite of a silicone rubber matrix and carbonyl iron particles; a first annular electromagnetic coil is embedded inside the magnetorheological elastic layer 3 and is connected to an external controller through a wire; the magnetic field generated by the first electromagnetic coil is used to adjust the compression stiffness and damping coefficient of the magnetorheological elastic layer 3.

[0040] In a specific implementation, a grease storage groove is provided on the surface of the polytetrafluoroethylene plate 52 and is filled with graphene grease.

[0041] In a specific implementation, the sliding friction plate 53 is made of a stainless steel plate, the surface of which is mirror-polished and forms a low-friction interface with the polytetrafluoroethylene plate 52 .

[0042] In a specific implementation, the upper magnetic component 61 is a permanent magnet array embedded in the bottom of the upper support plate 1, and the lower magnetic component 62 is a second electromagnetic coil arranged on the top of the lower support plate 2; according to the current direction and current intensity of the second electromagnetic coil, a like magnetic field or an opposite magnetic field is generated between the upper magnetic component 61 and the lower magnetic component 62, thereby generating an electromagnetic repulsion or an electromagnetic attraction between the upper magnetic component and the lower magnetic component.

[0043] In a specific implementation, the lining plate 51 is composed of an upper cylinder 511 and a lower cylinder 512; the diameter of the lower cylinder 512 is the same as that of the magnetorheological elastic layer 3 and the rubber layer 4; the diameter of the upper cylinder 511 is larger than the diameter of the lower cylinder 512, and smaller than the diameter of the sliding friction plate 53; a gap is retained between the upper cylinder 511 and the eaves 11 of the upper support plate 1 in the horizontal direction, and a gap is retained between the upper cylinder 511 and the receiving platform 21 of the lower support plate 2 in the vertical direction.

[0044] In a specific implementation, it also includes a baffle plate 7, which is made of weather-resistant rubber material and surrounds the electromagnetic mechanism 6 in a ring shape; the top of the baffle plate 7 is connected to the upper support plate 1, and the bottom is connected to the lower support plate 2 through a slot, and the inside of the baffle plate 7 is filled with inert gas to isolate moisture and corrosive media.

[0045] In a specific implementation, a stress sensor is arranged at the connection between the upper support plate 1 and the main beam or the building superstructure, so as to monitor the horizontal stress of the main beam or the building superstructure in real time; a strain sensor is embedded inside the magnetorheological elastic layer 3, so as to monitor the compression deformation of the magnetorheological elastic layer 3 and feed it back to an external controller to adjust the magnetic field strength; a displacement sensor and an acceleration sensor are installed at the pier or the building foundation, so as to monitor the vertical displacement of the pier or the building foundation and the seismic acceleration in real time, respectively.

[0046] In a specific implementation, the slidable support structure has three working modes, including a horizontal deformation control mode, a vertical deformation compensation mode and an earthquake emergency mode; the horizontal deformation control mode is for the horizontal deformation of the main beam or the building superstructure. When the monitored horizontal stress of the main beam or the building superstructure reaches a threshold, an electromagnetic repulsive force is generated by applying a homogeneous magnetic field between the upper magnetic component 61 and the lower magnetic component 62 to partially offset the pressure acting on the sliding friction pair 5, so that the friction resistance of the deformation of the main beam or the building superstructure in the horizontal direction is reduced. Subsequently, after confirming that the stress in the horizontal direction of the main beam or the building superstructure is released according to the measured horizontal stress of the main beam or the building superstructure, the homogeneous magnetic field between the upper magnetic component 61 and the lower magnetic component 62 is stopped, so as to form a sliding lock through the existing friction resistance, thereby avoiding unnecessary horizontal sliding of the main beam or the building superstructure;

[0047] The vertical deformation compensation mode is aimed at the vertical differential deformation of the piers or building foundations. When the differential deformation of adjacent piers or building foundations obtained by monitoring reaches a threshold value, a magnetic field is applied to the magnetorheological elastic layer 3 to increase its compression stiffness. At this time, the compression deformation of the magnetorheological elastic layer 3 under constant pressure is reduced, which is manifested as the height of the magnetorheological elastic layer 3 being raised and causing the upper support plate 1 to be raised, thereby achieving compensation for the vertical differential deformation of the piers or building foundations; at this time, the height increase of the magnetorheological elastic layer 3 is the compensation displacement;

[0048] The earthquake emergency mode includes an emergency stage and a safety reset stage. When the monitored seismic acceleration reaches a threshold value, the emergency stage is entered, and the magnetic field between the upper magnetic component 61 and the lower magnetic component 62 is stopped, and the sliding friction of the sliding friction pair 5 is used to dissipate the seismic energy. At the same time, a magnetic field is applied to the magnetorheological elastic layer 3 to increase the damping coefficient and reduce the risk of damage to the structure caused by resonance. When the seismic acceleration obtained through monitoring confirms that the earthquake is over, the safety reset stage is entered, and an opposite magnetic field is applied between the upper magnetic component 61 and the lower magnetic component 62 to generate electromagnetic attraction, so as to slowly reset the main beam or the building superstructure to its initial position.

[0049] The second aspect of the present application discloses Figure 3 A design method for a slidable bearing structure is shown, comprising a horizontal deformation control design method and a vertical deformation compensation design method; wherein the horizontal deformation control design method comprises the following steps:

[0050] S101, determine the range of expected friction resistance: by applying a magnetic field of the same polarity between the upper magnetic component 61 and the lower magnetic component 62 to generate an electromagnetic repulsive force, partially offsetting the pressure acting on the sliding friction pair 5 P , which reduces the friction resistance of the main beam or building superstructure in the horizontal direction. The friction resistance at this time is the expected friction resistance. F e , expected friction resistance F e Satisfies the following expression:

[0051] (1)

[0052] in, P is the pressure acting on the sliding friction pair, m 0 is the initial friction coefficient of the sliding friction pair; α To prevent air loss, the purpose is to avoid the expected friction resistance. F eIf the height is too low, the magnetorheological elastic layer and the sliding friction plate may be separated from each other, thereby endangering the structural safety. F d The friction resistance required to prevent unnecessary horizontal sliding of the main beam or building superstructure when sliding is locked;

[0053] In a specific implementation, the pressure of the bridge or building superstructure acting on the sliding friction pair 5 P 3400kN, the friction resistance required to prevent unnecessary horizontal sliding of the main beam or building superstructure when sliding is locked F d is 150kN, then the initial friction coefficient of the sliding friction pair is m 0 According to formula (1), the calculation is as follows:

[0054] (2)

[0055] That is, the initial friction coefficient between the polytetrafluoroethylene plate 52 and the sliding friction plate 53 is required to be m 0 Not less than 0.044; in specific implementation, the initial friction coefficient is required m 0 is 0.05;

[0056] In the specific implementation, the anti-emptying safety factor α Take it as 0.2, the expected friction resistance F e According to formula (1), the calculation is as follows:

[0057] (3)

[0058] Expected friction resistance F e The value range is from 34kN to 170kN;

[0059] S102, determining the value range of the electromagnetic repulsive force: generating the electromagnetic repulsive force by applying a magnetic field of the same polarity between the upper magnetic component 61 and the lower magnetic component 62 F r , satisfying the following expression:

[0060] (4)

[0061] in, m max It is the maximum value of the friction coefficient of the sliding friction pair after material aging;

[0062] In the specific implementation, in order to ensure a certain design margin, the maximum friction coefficient of the sliding friction pair after material aging is m max Take it as 0.2, the expected friction resistance F e Take it as 34kN, the electromagnetic repulsion F r According to formula (4), the calculation is as follows:

[0063] (5)

[0064] That is, it is required to apply a magnetic field of the same polarity between the upper magnetic component 61 and the lower magnetic component 62 to generate an electromagnetic repulsive force. F r At least 646 kN;

[0065] S103, determine the value range of the current intensity: determine the current intensity of the second electromagnetic coil through experiments I 2 With magnetic field strength H 2 The functional relationship between H 2 Electromagnetic repulsion F r The functional relationship between I 2 The value range of

[0066] S104. Design of electromagnetic mechanism and sliding friction pair: Based on the initial friction coefficient m 0 and current intensity I 2 The electromagnetic mechanism 6 and the sliding friction pair 5 are designed according to the value range of

[0067] The vertical deformation compensation design method includes the following steps:

[0068] S201. Determine the value range of the compensation displacement: obtain the maximum differential deformation of adjacent piers or building foundations under the action of temperature through numerical simulation calculation, and determine the compensation displacement D The value range of

[0069] S202, determining the change in the compression stiffness of the magnetorheological elastic layer: To achieve displacement compensation, the adjustment target value of the compression stiffness of the magnetorheological elastic layer is K 1 Satisfies the following expression:

[0070] (6)

[0071] in, K 0 is the compression stiffness of the magnetorheological elastic layer under initial conditions,D 0 is the displacement of the magnetorheological elastic layer under initial conditions;

[0072] In a specific implementation, the compression stiffness of the magnetorheological elastic layer under the initial condition is K 0 is 500 kN / mm, and the displacement of the magnetorheological elastic layer under the initial condition is D 0 6.8mm, compensation displacement D is 4 mm, then the target value for adjusting the compression stiffness of the magnetorheological elastic layer is K 1 According to formula (6), the calculation is as follows:

[0073] (7)

[0074] That is, the target value for adjusting the compression stiffness of the magnetorheological elastic layer is K 1 1214.3 kN / mm;

[0075] S203, determine the value range of the current intensity: determine the current intensity of the first electromagnetic coil through experiments I 1 With magnetic field strength H 1 The functional relationship between H 1 The functional relationship between the compressive stiffness of the magnetorheological elastic layer and the magnetorheological elastic layer manufacturing process is determined to determine the current intensity. I 1 The value range of

[0076] S204. Design of magnetorheological elastic layer: according to the current intensity I 1 The design of the magnetorheological elastic layer is carried out based on the value range of and its relationship with the compressive stiffness of the magnetorheological elastic layer.

[0077] It can be seen that the slidable support structure has three working modes, including horizontal deformation control mode, vertical deformation compensation mode and earthquake emergency mode; the horizontal deformation control mode is to generate electromagnetic repulsion by applying a homogeneous magnetic field to the electromagnetic mechanism, partially offsetting the pressure acting on the sliding friction pair, so that the friction resistance of the deformation of the main beam or the building superstructure in the horizontal direction is reduced, and the stress of the main beam or the building superstructure in the horizontal direction is released, and then stop applying the homogeneous magnetic field, so as to form a sliding lock through the existing friction resistance, avoiding unnecessary horizontal sliding of the main beam or the building superstructure; the vertical deformation compensation mode is to apply a magnetic field to the magnetorheological elastic layer to make it The compression stiffness is increased, and the compression deformation of the magnetorheological elastic layer under constant pressure is reduced, which is manifested as the height of the magnetorheological elastic layer rising and causing the upper bearing plate to rise, thereby realizing the compensation of the vertical differential deformation of the pier or building foundation; the earthquake emergency mode applies a magnetic field to the magnetorheological elastic layer to increase the damping coefficient, reduce the risk of damage to the structure caused by resonance, and after the earthquake, apply an anisotropic magnetic field to the electromagnetic mechanism and generate electromagnetic suction, thereby slowly resetting the main beam or building superstructure to the initial position; the design method includes a horizontal deformation control design method and a vertical deformation compensation design method, which provides a basis for the design of the electromagnetic mechanism, the sliding friction pair and the magnetorheological elastic layer.

[0078] The above are one or more embodiments of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A slidable support structure, provided between a pier column and a main beam or between a building foundation and a building superstructure, characterized in that: It includes an upper support plate, a lower support plate, a magnetorheological elastic layer, a rubber layer, a sliding friction pair, an electromagnetic mechanism and a baffle plate; the upper support plate is fixed below the main beam or the upper structure of the building, and the lower support plate is fixed above the pier or the foundation of the building; a receiving platform is provided on the lower support plate, a countersunk hole is opened on the receiving platform, and a receiving cavity is formed between the receiving platform with the countersunk hole and the bottom of the upper support plate, and the magnetorheological elastic layer, the rubber layer and the sliding friction pair are arranged in sequence from bottom to top in the receiving cavity, and the sliding friction pair is provided with a lining plate, a polymer layer and a rubber layer from bottom to top in sequence. A tetrafluoroethylene plate and a sliding friction plate, wherein the sliding friction plate is tightly attached to the lower side of the upper support plate, and the bottom surface of the lining plate is attached to the rubber layer; both ends of the upper support plate are downwardly provided with eaves, and the eaves are connected to the lower support plate through an electromagnetic mechanism, and the electromagnetic mechanism includes an upper magnetic component and a lower magnetic component, the upper magnetic component is embedded in the eaves, and the lower magnetic component is embedded in the lower support plate on one side of the receiving platform, and the upper magnetic component is connected to the lower magnetic component and connected to an external controller through a wire; The magnetorheological elastic layer is made of a composite of a silicone rubber matrix and carbonyl iron particles; a first annular electromagnetic coil is embedded inside the magnetorheological elastic layer and connected to an external controller through a wire; the magnetic field generated by the first electromagnetic coil is used to adjust the compression stiffness and damping coefficient of the magnetorheological elastic layer; The sliding friction plate is made of a stainless steel plate, the surface of which is mirror-polished and forms a low-friction interface with the polytetrafluoroethylene plate; the surface of the polytetrafluoroethylene plate is provided with a grease storage groove and filled with graphene grease; The upper magnetic component is a permanent magnet array embedded in the bottom of the upper support plate, and the lower magnetic component is a second electromagnetic coil arranged on the top of the lower support plate; according to the current direction and current intensity of the second electromagnetic coil, a homogeneous magnetic field or an opposite magnetic field is generated between the upper magnetic component and the lower magnetic component, thereby generating an electromagnetic repulsion or an electromagnetic attraction between the upper magnetic component and the lower magnetic component; The lining plate is composed of an upper cylinder and a lower cylinder; the diameter of the lower cylinder is the same as that of the magnetorheological elastic layer and the rubber layer; the diameter of the upper cylinder is larger than that of the lower cylinder and smaller than that of the sliding friction plate; a gap is reserved between the upper cylinder and the eaves of the upper support plate in the horizontal direction, and a gap is reserved between the upper cylinder and the receiving platform of the lower support plate in the vertical direction; The baffle plate is made of weather-resistant rubber material and surrounds the electromagnetic mechanism in a ring shape; the top of the baffle plate is connected to the upper support plate, and the bottom is connected to the lower support plate through a slot, and the interior of the baffle plate is filled with inert gas to isolate moisture and corrosive media.

2. A slidable support structure according to claim 1, characterized in that: A stress sensor is provided at the connection between the upper support plate and the main beam or the building superstructure, for real-time monitoring of the horizontal stress of the main beam or the building superstructure; a strain sensor is embedded inside the magnetorheological elastic layer, for monitoring the compression deformation of the magnetorheological elastic layer and feeding back to an external controller to adjust the magnetic field strength; Displacement sensors and acceleration sensors are installed at the piers or building foundations to monitor the vertical displacement of the piers or building foundations and the seismic acceleration in real time, respectively.

3. A method for designing a slidable support structure, characterized in that: A slidable support structure for use in any one of claims 1 to 2, comprising a horizontal deformation control design method and a vertical deformation compensation design method; wherein the horizontal deformation control design method comprises the following steps: S101, determining the range of expected friction resistance: applying a magnetic field of the same polarity between the upper magnetic component and the lower magnetic component to generate an electromagnetic repulsive force, partially offsetting the pressure acting on the sliding friction pair P , which reduces the friction resistance of the main beam or building superstructure in the horizontal direction. The friction resistance at this time is the expected friction resistance. F e , expected friction resistance F e Satisfies the following expression: in, P is the pressure acting on the sliding friction pair, μ 0 is the initial friction coefficient of the sliding friction pair; α To prevent air loss, the purpose is to avoid the expected friction resistance. F e If the height is too low, the magnetorheological elastic layer and the sliding friction plate may be separated from each other, thereby endangering the structural safety. F d The friction resistance required to prevent unnecessary horizontal sliding of the main beam or building superstructure when sliding is locked; S102, determining the value range of the electromagnetic repulsive force: generating the electromagnetic repulsive force by applying a magnetic field of the same polarity between the upper magnetic component and the lower magnetic component F r , satisfying the following expression: in, μ max It is the maximum value of the friction coefficient of the sliding friction pair after material aging; S103, determine the value range of the current intensity: determine the current intensity of the second electromagnetic coil through experiments I 2 With magnetic field strength H 2 The functional relationship between H 2 Electromagnetic repulsion F r The functional relationship between I 2 The value range of S104. Design of electromagnetic mechanism and sliding friction pair: Based on the initial friction coefficient μ 0 and current intensity I 2 The electromagnetic mechanism and the sliding friction pair are designed according to the value range of The vertical deformation compensation design method includes the following steps: S201. Determine the value range of the compensation displacement: obtain the maximum differential deformation of adjacent piers or building foundations under the action of temperature through numerical simulation calculation, and determine the compensation displacement D The value range of S202, determining the change in the compression stiffness of the magnetorheological elastic layer: To achieve displacement compensation, the adjustment target value of the compression stiffness of the magnetorheological elastic layer is K 1 Satisfies the following expression: in, K 0 is the compression stiffness of the magnetorheological elastic layer under initial conditions, D 0 is the displacement of the magnetorheological elastic layer under initial conditions; S203, determine the value range of the current intensity: determine the current intensity of the first electromagnetic coil through experiments I 1 With magnetic field strength H 1 The functional relationship between H 1 The functional relationship between the compressive stiffness of the magnetorheological elastic layer and the magnetorheological elastic layer manufacturing process is determined to determine the current intensity. I 1 The value range of S204. Design of magnetorheological elastic layer: according to the current intensity I 1 The design of the magnetorheological elastic layer is carried out based on the value range of and its relationship with the compressive stiffness of the magnetorheological elastic layer.

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