Resilient function assembled bridge based on hierarchical damping mechanism and design method

Abstract

The present application relates to the technical field of bridge engineering, in particular to a recoverable function fabricated bridge based on hierarchical damping mechanism and a design method, ordinary piers and self-resetting rocking piers are alternately arranged along the longitudinal direction of the bridge, pier bearings are arranged between the ordinary piers, self-resetting rocking piers and the main girder, damping tenon assemblies are arranged between the ordinary piers and the main girder, and regulating assemblies are arranged between the self-resetting rocking piers and the main girder; the regulating assembly allows the main girder and the self-resetting rocking pier to have horizontal displacement within a range, wherein the range is the maximum horizontal displacement allowed by the regulating assembly. The present application combines the damping tenon assembly with the self-resetting rocking pier, and uses the regulating assembly to control the timing of the two to participate in damping and energy dissipation, thereby solving the problem that the traditional damping structure mainly relies on single component function and cannot automatically switch the control strategy according to the magnitude of the earthquake.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge engineering, in particular to a recoverable function fabricated bridge based on a hierarchical damping mechanism and a design method. BACKGROUND

[0002] Compared with the traditional construction method of site pouring, the fabricated bridge has the advantages of short construction period, high engineering efficiency and more accurate quality control, and has broad application prospects. However, under the action of earthquakes, the connection parts between the piers and the foundation of the fabricated bridge often become the weak links of the structure. In strong earthquakes, the damage of these parts may lead to the overall destruction of the bridge, thereby affecting the traffic safety and the service life of the bridge. In order to cope with the challenges brought by earthquakes, seismic design has become an important part of bridge design. Traditional seismic design methods include additional damping dowels and the use of self-centering rocking piers. These methods have achieved certain results in reducing the impact of earthquakes on bridges, but there are also some obvious shortcomings.

[0003] As a common damping device, the damping dowel can absorb the energy generated by earthquakes through plastic hysteresis deformation process, thereby reducing the vibration of the bridge and reducing the structural damage. However, one of the main shortcomings of the damping dowel is that it cannot automatically reset. Under the action of strong earthquakes, the damping dowel will yield and deform, although it effectively absorbs the energy of the earthquake, but after yielding, it needs manual intervention to restore to its original position. This not only increases the maintenance cost and workload in the later stage, but also may cause the loss of bridge function for a certain period of time after the earthquake. In addition, the damping dowel may not be able to fully absorb the energy when facing extremely strong earthquakes, resulting in a large vibration of the bridge, thereby affecting its overall seismic effect.

[0004] The self-centering rocking pier is a design that consumes seismic energy through the rocking of the pier during an earthquake, has a self-centering function, and can automatically restore to the original position after the earthquake, avoiding the problem of frequent manual repair. However, when used alone, the self-centering rocking pier also has some defects. The self-centering rocking pier consumes the energy of seismic waves through rocking, but frequent rocking may cause cumulative damage to the connection parts between the pier and the foundation, especially under the action of multiple earthquakes, the damage to these connection parts may gradually increase, affecting the long-term stability and safety of the bridge.

[0005] In summary, there is an urgent need for a recoverable function fabricated bridge based on a hierarchical damping mechanism and a design method to solve the shortcomings of using a single damping device in bridge seismic resistance in the prior art. SUMMARY

[0006] The purpose of this invention is to provide a recoverable prefabricated bridge based on a graded damping mechanism, aiming to address the shortcomings of traditional single damping devices in bridge seismic resistance. The specific technical solution is as follows:

[0007] A recoverable prefabricated bridge based on a graded vibration reduction mechanism is provided, in which ordinary piers and self-resetting swaying piers are alternately arranged along the longitudinal direction of the bridge. Pier supports are provided between the ordinary piers and the main beams, vibration reduction fasteners are provided between the ordinary piers and the main beams, and adjustment components are provided between the self-resetting swaying piers and the main beams.

[0008] The control component allows for movement between the main beam and the self-resetting swaying pier. Horizontal displacement occurs within the interval;

[0009] Under the action of a small earthquake At this time, the control component does not produce a limiting effect, the self-resetting swaying pier does not sway, and the shock-absorbing latch component undergoes elastic deformation.

[0010] Under moderate earthquake action At this time, the control component does not produce a limiting effect, the self-resetting swaying pier still does not sway, and the shock-absorbing fastener component further undergoes plastic deformation to dissipate energy.

[0011] Under the action of a major earthquake At this time, the control component produces a limiting effect, and the self-resetting swaying pier swings to dissipate energy.

[0012] in, To control the maximum allowable horizontal displacement of the component, This refers to the horizontal displacement that occurs between the main beam and the self-resetting swaying pier under minor earthquake conditions. This refers to the horizontal displacement that occurs between the main girder and the self-resetting swaying pier under moderate earthquake conditions. This refers to the horizontal displacement that occurs between the main beam and the self-resetting swaying pier under the action of a major earthquake.

[0013] Preferably, the control component includes a limiting top plate and a base assembly. The limiting top plate is fixedly disposed on the bottom surface of the main beam and has a movable cavity thereon. The base assembly is fixedly disposed on the upper end surface of the self-resetting swaying pier and its upper end extends into the movable cavity.

[0014] The upper end of the base assembly is centrally located within the movable cavity, and the maximum horizontal distance from the upper end of the base assembly to the inner wall of the movable cavity is [missing information]. .

[0015] Preferably, the base assembly comprises a base plate, a rod body and a limiting block, the base plate is arranged on the upper end surface of the self-resetting rocking pier, one end of the rod body is arranged on the base plate, the other end of the rod body is provided with the limiting block, the limiting block is arranged in the movable cavity, and the maximum horizontal distance of the limiting block to the inner wall of the movable cavity is .

[0016] Preferably, the movable cavity and the limiting block are one of a cylindrical structure and a spherical structure.

[0017] Preferably, under the action of small earthquakes, the horizontal displacement of the damping dowel assembly satisfies: ;

[0018] Under the action of medium earthquakes, the horizontal displacement of the damping dowel assembly satisfies: ;

[0019] Under the action of large earthquakes, the horizontal displacement of the damping dowel assembly satisfies: ;

[0020] wherein, is the initial horizontal gap of the damping dowel assembly, is the horizontal yield displacement of the damping dowel assembly, is the horizontal ultimate displacement of the damping dowel assembly, is an adjustment coefficient.

[0021] Preferably, under the action of small earthquakes, the horizontal force borne by the damping dowel assembly is less than the elastic limit bearing capacity thereof;

[0022] Under the action of medium earthquakes, the horizontal force borne by the damping dowel assembly is greater than or equal to the elastic limit bearing capacity thereof and less than or equal to the horizontal yield force corresponding to the horizontal ultimate displacement thereof; times the horizontal ultimate displacement thereof.

[0023] Under the action of large earthquakes, the horizontal force borne by the damping dowel assembly is less than or equal to the horizontal yield force corresponding to the horizontal ultimate displacement thereof.

[0024] Preferably, the adjustment coefficient .

[0025] Preferably, the control assembly needs to satisfy that it does not yield under the action of small earthquakes, medium earthquakes and large earthquakes.

[0026] The application also provides a design method of the recoverable functional assembled bridge based on the hierarchical damping mechanism, comprising:

[0027] S1, a bridge dynamic analysis model is established, and the initial stiffness of the damping dowel assembly is set , initial horizontal gap , post-yield stiffness , horizontal yield displacement , and horizontal ultimate displacement , while setting the stiffness of the control assembly and the maximum horizontal displacement allowed by the control assembly , wherein the stiffness satisfies that the control assembly does not yield under the action of small earthquakes, medium earthquakes and large earthquakes;

[0028] S2, load the small earthquake working condition excitation to the bridge dynamic analysis model, first calculate the horizontal displacement between the main beam and the self-centering rocking pier at this time , if , increase , and recalculate , if , calculate the maximum horizontal displacement of the damping dowel assembly at this time , if , increase , and recalculate , if , go to the next step;

[0029] S3, load the medium earthquake working condition excitation to the bridge dynamic analysis model, first calculate the horizontal displacement between the main beam and the self-centering rocking pier at this time , if , increase , and recalculate , if , calculate the maximum horizontal displacement of the damping dowel assembly at this time , if , decrease , and return to step S2, if , increase value, and recalculate , if , go to the next step, is an adjustment coefficient;

[0030] S4, load the large earthquake working condition excitation to the bridge dynamic analysis model, first calculate the horizontal displacement between the main beam and the self-centering rocking pier at this time , if , decrease , and return to step S2, if , calculate the maximum horizontal displacement of the damping dowel assembly at this time , if , increase , and return to step S3, if , go to the next step;

[0031] S5, according to the result of the bridge dynamic analysis model of step S4, analyzing the seismic response of the self-centering rocking pier, by adjusting the prestressed tendon configuration, energy dissipation bar structure and structural reinforcement design of the self-centering rocking pier, the bridge can meet the seismic demand under the condition of large earthquake.

[0032] The technical scheme of the present application has the following beneficial effects:

[0033] The recoverable function assembled bridge of the present application solves the deficiencies of traditional single damping device in bridge seismic resistance, and has the following obvious advantages: 1) by combining the damping dowel assembly and the self-centering rocking pier, the seismic resistance of the bridge under strong earthquake can be effectively improved, and the damage of the earthquake to the bridge structure can be reduced. 2) The self-centering rocking pier can quickly restore the original state of the bridge after the earthquake, reduce residual deformation, ensure the rapid recovery of the bridge function, improve the recoverability of the bridge, and reduce the post-earthquake repair workload. 3) By using the self-centering rocking pier design, the bridge can reduce the need for manual repair after the earthquake, reduce the maintenance cost and workload in the later period, and reduce the safety risk in the process of manual repair. 4) Due to the combined design of the damping dowel assembly and the self-centering rocking pier, the structure damage can be effectively reduced under multiple earthquakes, thereby improving the long-term stability and safety of the bridge and prolonging the service life of the bridge. 5) The combined design of the damping dowel assembly and the self-centering rocking pier can not only effectively cope with strong earthquakes, but also play a damping role under smaller earthquakes, and has wide adaptability.

[0034] In the recoverable function assembled bridge of the present application, the damping dowel assembly, the control assembly and the self-centering rocking pier work together to achieve three-level seismic effect. The damping dowel assembly and the self-centering rocking pier can dissipate seismic energy through elastic-plastic hysteretic deformation, and the control assembly as a key control component does not yield under various levels of earthquake, but only plays a role in limiting and preventing beam falling. When the control assembly does not produce limiting effect, the damping dowel assembly plays a major role in seismic energy dissipation, and the overall structure maintains high stiffness, which can effectively resist small and medium earthquakes; when the earthquake action is further enhanced, the displacement of the damping dowel assembly is constrained after the limiting effect of the control assembly, and the self-centering rocking pier gradually plays a major role, relying on its self-centering characteristics to bear the main energy dissipation and seismic reduction function; at the same time, the energy dissipation bar at the bottom of the self-centering rocking pier works together to enhance the overall energy dissipation capacity, thereby effectively dispersing seismic energy under strong earthquake conditions, significantly reducing structural residual deformation and post-earthquake damage, and meeting the recoverability requirements of the structure. Through this hierarchical working mode, various types of damping devices under different earthquake levels can fully play their advantages, and the seismic design goal of “no damage under small earthquake, repairable under medium earthquake, and no collapse under large earthquake” can be achieved.

[0035] In order to avoid excessive concentration of seismic energy in a single pier, the bridge in the application adopts a division type arrangement: a damping tenon assembly is arranged at the top of the ordinary pier, so that it enters the energy dissipation state under the action of moderate earthquakes, disperses and reduces the input seismic energy; a regulating assembly is arranged at the top of the self-centering rocking pier, when the seismic action further increases, the regulating assembly limits the further displacement of the damping tenon assembly and triggers the rocking mechanism of the self-centering rocking pier, so that the self-centering rocking pier plays the functions of self-centering and main energy dissipation, thereby effectively reducing the residual deformation and improving the overall seismic performance.

[0036] The self-centering rocking pier in the application does not play the rocking energy dissipation role under the action of small earthquakes, only when the regulating assembly produces the limiting effect, the self-centering rocking pier occurs rocking and participates in energy dissipation, so that the rocking mechanism is triggered when the damping tenon assembly has fully dissipated energy but has not entered the damage stage under the action of large earthquakes, thereby forming a smooth stress transition and avoiding the adverse impact effect caused by sudden stiffness mutation.

[0037] In addition to the purposes, features and advantages described above, the application has other purposes, features and advantages. The application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0038] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, illustrate the preferred embodiments of the application and the application will be described with reference to these drawings, but the application is not intended to be unduly limited by such embodiments. In the drawings:

[0039] Figure 1 is a structural schematic view of the recoverable function assembled bridge based on the hierarchical damping mechanism in the application;

[0040] Figure 2 is a structural schematic view of the self-centering rocking pier in the application; Figure 1 is a structural schematic view of the regulating assembly in the application;

[0041] Figure 3 is a structural schematic view of the damping tenon assembly in the application; Figure 1

[0042] Figure 4 is a schematic view of the state of the damping tenon assembly after yielding in the application; Figure 1

[0043] Figure 5 is a schematic view of the hysteresis model of the damping tenon assembly;

[0044] Figure 6 is a structural schematic view of the self-centering rocking pier in the application; Figure 1

[0045] Figure 7 ​​​is a hysteretic model schematic diagram of a self-resetting rocking pier, wherein (a) is a hysteretic model of prestressed reinforcement, (b) is a hysteretic model of energy dissipation rod, and (c) is a hysteretic model of a self-resetting rocking pier.

[0046] Wherein, 1, main beam, 2, pier support, 3, damping dowel assembly, 3.1, mounting base, 3.2, dowel body, 3.3, dowel head, 3.4, upper top plate, 3.5, mounting cavity, 4, control assembly, 4.1, limiting top plate, 4.2, movable cavity, 4.3, base plate, 4.4, rod body, 4.5, limiting block, 5, ordinary pier, 6, self-resetting rocking pier, 6.1, pier body, 6.2, energy dissipation rod, 6.3, prestressed reinforcement, 7, pile cap. DETAILED DESCRIPTION

[0047] In order to facilitate the understanding of the present application, the present application will be described more fully below, and preferred embodiments of the present application will be given. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

[0049] Embodiment:

[0050] Reference Figure 1 The embodiment provides a recoverable function fabricated bridge based on a hierarchical damping mechanism, ordinary piers 5 and self-resetting rocking piers 6 are alternately arranged along a longitudinal bridge direction, that is, a single main beam 1 is arranged on the ordinary pier 5 at one end and arranged on the self-resetting rocking pier 6 at the other end, pier supports 2 are arranged between the ordinary piers 5, the self-resetting rocking piers 6 and the main beam 1, a damping dowel assembly 3 is arranged between the ordinary pier 5 and the main beam 1, and a control assembly 4 is arranged between the self-resetting rocking pier 6 and the main beam 1.

[0051] In order to make the bridge in the embodiment achieve the effect of three-level seismic resistance, the control assembly 4 in the embodiment allows the main beam 1 and the self-resetting rocking pier 6 to have a horizontal displacement in the interval of 0-0.05H, and satisfies the following requirements:

[0052] Under the action of small earthquakes, At this time, the control assembly 4 does not produce a limiting effect, the self-resetting rocking pier 6 does not rock, and the damping dowel assembly 3 elastically deforms.

[0053] ​Under moderate earthquake action At this time, the control component 4 does not produce a limiting effect, the self-resetting swaying pier 6 still does not sway, and the shock-absorbing fastener component 3 further undergoes plastic deformation to dissipate energy.

[0054] Under the action of a major earthquake At this time, the control component 4 produces a limiting effect, and the self-resetting swaying pier 6 sways to consume energy;

[0055] in, To control the maximum allowable horizontal displacement of component 4, This refers to the horizontal displacement that occurs between the main girder 1 and the self-resetting swaying pier 6 under minor earthquake conditions. This refers to the horizontal displacement that occurs between the main girder 1 and the self-resetting swaying pier 6 under moderate earthquake conditions. This refers to the horizontal displacement that occurs between the main beam 1 and the self-resetting swaying pier 6 under the action of a major earthquake.

[0056] Specifically, any horizontal direction in this embodiment can be decomposed into two directions: along the longitudinal bridge direction and along the transverse bridge direction. That is, the horizontal displacement and horizontal force involved in this embodiment include components along the longitudinal bridge direction and along the transverse bridge direction.

[0057] Preferably, the number of shock-absorbing fastener components 3 between the ordinary pier 5 and the main beam 1, and the number of adjusting components 4 between the self-resetting swaying pier 6 and the main beam 1 can be set according to actual engineering needs.

[0058] like Figure 2 As shown, the control component 4 includes a limiting top plate 4.1 and a base assembly. The limiting top plate 4.1 is fixedly installed on the bottom surface of the main beam 1 and has a movable cavity 4.2 on it. The base assembly is fixedly installed on the upper surface of the self-resetting swing pier 6 and its upper end extends into the movable cavity 4.2.

[0059] Furthermore, the upper end of the base assembly is centrally located within the movable cavity 4.2, and the maximum horizontal distance from the upper end of the base assembly to the inner wall of the movable cavity 4.2 is [missing information]. .

[0060] Specifically, the base assembly includes a base plate 4.3, a rod 4.4, and a limiting block 4.5. The base plate 4.3 is disposed on the upper surface of the self-resetting swaying pier 6. One end of the rod 4.4 is disposed on the base plate 4.3, and the other end is provided with a limiting block 4.5. The limiting block 4.5 is centrally disposed in the movable cavity 4.2, and the maximum horizontal distance from the limiting block 4.5 to the inner wall of the movable cavity 4.2 is [missing information]. .

[0061] Preferably, the movable cavity 4.2 and the limiting block 4.5 (i.e. the upper end of the base assembly) are both cylindrical structures, and the limiting block 4.5 is centrally arranged in the movable cavity 4.2, so that the outer contour of the limiting block 4.5 and the inner wall contour of the movable cavity 4.2 form a concentric circle, thus ensuring that the maximum displacement of the limiting block 4.5 in any horizontal direction is equal, and guaranteeing that the bridge can achieve three-level seismic resistance under the impact of seismic forces in any direction.

[0062] It should be noted that the cylindrical structure of the movable cavity 4.2 and the limiting block 4.5 is only one of the preferred structural forms in this embodiment, and those skilled in the art can flexibly adjust the structural shape of the movable cavity 4.2 and the limiting block 4.5. For example, the movable cavity 4.2 and the limiting block 4.5 can also be spherical structures. In addition, the movable cavity 4.2 and the limiting block 4.5 do not necessarily have the same structure, such as a cylindrical structure for the movable cavity 4.2 and a spherical structure for the limiting block 4.5.

[0063] Specifically, in this embodiment, when the limiting block 4.5 is under the action of small earthquakes , under the action of medium earthquakes , and under the action of large earthquakes . In this way, it can be ensured that the limiting block 4.5 does not contact the inner wall of the movable cavity 4.2 to produce a limiting effect under the action of small and medium earthquakes, thus ensuring that only the shock dowel assembly 3 participates in seismic resistance under the action of small and medium earthquakes. On the other hand, the limiting block 4.5 will contact the inner wall of the movable cavity 4.2 to form a limiting effect under the action of large earthquakes, on the one hand, ensuring that the shock dowel assembly 3 will not continue to deform and be damaged under the action of large earthquakes, and on the other hand, allowing the self-resetting rocking pier 6 to begin to participate in energy dissipation, thus achieving the purpose of three-level seismic resistance.

[0064] Preferably, the regulating assembly 4 needs to have sufficient rigidity to ensure that the regulating assembly 4 will not yield under the action of small, medium and large earthquakes, and only serve the purpose of limiting and preventing beam falling. Steel has high strength, high rigidity and good processability, and can be the preferred material for the regulating assembly 4. Different types of steel (such as ordinary carbon steel and alloy steel) have different properties, and those skilled in the art can choose according to engineering needs.

[0065] Referring to Figures 3-5In this embodiment, the shock-absorbing tenon assembly 3 includes a mounting base 3.1, a tenon body 3.2, a tenon head 3.3, and an upper top plate 3.4. The upper top plate 3.4 is fixedly mounted on the bottom surface of the main beam 1 and has a mounting cavity 3.5 on it. The mounting base 3.1 is fixedly mounted on the upper surface of the ordinary bridge pier 5. One end of the tenon body 3.2 is mounted on the mounting base 3.1, and the other end has a tenon head 3.3. The tenon head 3.3 is centrally located in the mounting cavity 3.5, and an initial horizontal gap is left between the tenon head 3.3 and the mounting cavity 3.5. Considering the component processing and installation procedures, the initial horizontal gap Generally, it is greater than 2mm. In this embodiment, the mounting cavity 3.5 is a cylindrical cavity, and the tenon 3.3 is a spherical structure.

[0066] like Figure 4 As shown, when subjected to earthquake loads, the damping tenon assembly 3 can dissipate the earthquake energy through deformation of the tenon body 3.2, thereby reducing bridge swaying or deformation and achieving vibration damping protection for the structure. In this embodiment, the damping tenon assembly 3 undergoes elastic and plastic deformation to ensure the safety of the bridge under minor and moderate earthquakes, respectively; during normal use and under minor earthquakes, the initial horizontal gap... And the tenon body 3.2 undergoes elastic deformation to resist impact; during moderate earthquakes, the tenon body 3.2 yields and enters a plastic energy dissipation state to achieve the energy dissipation effect; during major earthquakes, since the control component 4 has been limited, the self-resetting swaying pier 6 begins to participate in energy dissipation, and the damping tenon component 3 no longer serves as the main energy dissipation component. The damping tenon component 3 only works with the control component 4 to achieve the functions of limiting and preventing beam fall.

[0067] Figure 5 This is the hysteresis model of the shock-absorbing latch assembly 3 in this embodiment. In the figure, segment oa represents the initial gap of the shock-absorbing latch assembly 3. slope This represents the stiffness of the damping tenon assembly before yielding. In segment 0a, the tenon 3.3 does not contact the inner wall of the mounting cavity 3.5, and the damping tenon assembly is in the free clearance stage. After entering segment ab, the tenon 3.3 contacts the inner wall of the mounting cavity 3.5 and plays a restraining role, and the damping tenon assembly enters the elastic working stage. When point b is reached, the tenon 3.2 begins to yield, and the subsequent segments bcdefg exhibit the plastic energy dissipation stage.

[0068] Preferably, in order for the bridge in this embodiment to achieve a three-level seismic resistance effect, the overall structure of the bridge must be designed to ensure that the horizontal force and horizontal displacement borne by the damping latch assembly 3 under minor and moderate earthquakes meet the following conditions:

[0069] Under the action of small earthquake, the horizontal force borne by the damping dowel assembly 3 is less than the elastic limit bearing capacity thereof;

[0070] Under the action of medium earthquake, the horizontal force borne by the damping dowel assembly 3 is greater than or equal to the elastic limit bearing capacity thereof and less than or equal to the horizontal limit displacement corresponding to the horizontal yielding force thereof; times the horizontal limit displacement corresponding to the horizontal yielding force thereof;

[0071] Under the action of large earthquake, the horizontal force borne by the damping dowel assembly 3 is less than or equal to the horizontal limit displacement corresponding to the horizontal yielding force thereof.

[0072] Under the action of small earthquake, the horizontal displacement of the damping dowel assembly 3 is satisfies: ;

[0073] Under the action of medium earthquake, the horizontal displacement of the damping dowel assembly 3 is satisfies: ;

[0074] Under the action of large earthquake, the horizontal displacement of the damping dowel assembly 3 is satisfies: ;

[0075] wherein, is the initial horizontal gap of the damping dowel assembly, is the horizontal yielding displacement of the damping dowel assembly, is the horizontal limit displacement of the damping dowel assembly, is an adjustment coefficient, ; in the embodiment, the adjustment coefficient is set to ensure that only the damping dowel assembly participates in energy dissipation under the action of medium earthquake and the damping dowel assembly will not be damaged under the action of medium earthquake, and in the embodiment, = 0.8.

[0076] For the damping dowel assembly 3, the principle that the damping dowel assembly remains elastic under the action of small earthquake and starts to plastically deform under the action of medium earthquake is adopted to determine the yielding force of the damping dowel assembly, instead of considering the horizontal force borne by the damping dowel assembly under the action of a PGA value (peak ground acceleration) of earthquake. Because, by simultaneously considering the deformation state of the damping dowel assembly 3 under the action of small earthquake and medium earthquake, the multi-level fortification target based on performance in the Chinese railway seismic code can be achieved; in addition, the deformation size of the damping dowel assembly is affected by multiple factors, such as the stiffness of the damping dowel assembly, the waveform of the seismic wave and the micro-cracks of the structure, etc., which make the deformation state of the damping dowel assembly 3 uncertain. Therefore, by limiting the horizontal force borne by the damping dowel assembly under the action of small earthquake to be less than the elastic limit bearing capacity thereof, the horizontal force borne by the damping dowel assembly under the action of medium earthquake to be greater than or equal to the elastic limit bearing capacity thereof and less than or equal to the horizontal limit displacement corresponding to the horizontal yielding force thereof, and the horizontal force borne by the damping dowel assembly under the action of large earthquake to be less than or equal to the horizontal limit displacement corresponding to the horizontal yielding force thereof, the deformation state of the damping dowel assembly 3 can be ensured to be within the range of the elastic limit bearing capacity thereof under the action of small earthquake, the elastic limit bearing capacity thereof under the action of medium earthquake and the horizontal limit displacement corresponding to the horizontal yielding force thereof under the action of large earthquake. The horizontal yield force corresponding to the horizontal ultimate displacement of the self-centering rocking bridge pier 6 is calculated by the following formula:

[0077] Preferably, the self-centering rocking bridge pier 6 is not limited to the structural form of the embodiment, and the self-centering rocking bridge pier (or self-centering rocking bridge pier) in the prior art can be used in the embodiment.

[0078] As shown in Figure 6 , the self-centering rocking bridge pier 6 includes a pier body 6.1, a energy dissipation member 6.2 and a prestressed tendon 6.3. The self-centering rocking bridge pier 6 is arranged on the pile cap 7; the self-centering rocking bridge pier 6 is the prior art in the art, so the self-centering rocking bridge pier 6 is not described in detail in the embodiment.

[0079] Specifically, the self-centering rocking bridge pier 6 relies on the rocking and self-centering characteristics of the structure to absorb seismic energy and restore the original position through the synergistic effect of the prestressed tendon 6.3 and the energy dissipation member 6.2. The self-centering rocking bridge pier 6 releases seismic energy through the rotation of the rocking interface, and at the same time, consumes seismic energy through the deformation of the energy dissipation member 6.2, thereby reducing the permanent damage of the bridge structure caused by the earthquake.

[0080] Figure 7 For the hysteretic model of the self-centering rocking bridge pier 6, in Figure 7 (a), the oa segment corresponds to the initial elastic stage of the prestressed tendon 6.3, the ac segment corresponds to the secondary elastic stage of the prestressed tendon 6.3, and the b and d points correspond to the characteristic points in the loading and unloading processes, respectively. Because it is still in the elastic stage, there is no yield displacement. In Figure 7 (b), the ob segment represents that the energy dissipation member 6.2 is in the elastic stage, and the bcd segment represents that the energy dissipation member 6.2 is in the plastic energy dissipation stage. In Figure 7 (c), the oa segment represents that the self-centering rocking bridge pier 6 is in the elastic stage, and the abcd segment represents that the self-centering rocking bridge pier 6 enters the plastic energy dissipation stage.

[0081] Further, the bending moment of the self-centering rocking bridge pier 6 is composed of the energy dissipation bending moment and the self-centering bending moment, wherein the energy dissipation bending moment can be calculated by the product of the axial force of a single energy dissipation member and the arm, and the self-centering bending moment is provided by the gravity of the upper structure (i.e. the main beam), the self-weight of the pier body and the axial force of the prestressed tendon. In order to consider the second-order effect of gravity, the following method is used to calculate the contribution of the self-weight of the structure to the restoring moment in the embodiment , and the expression is as follows:

[0082]

[0083] Wherein, is the gravity of the self-centering rocking bridge pier. is the bottom section width of the self-centering rocking bridge pier; is the height of the self-centering rocking bridge pier; is the uplift rotation angle of the self-centering rocking bridge pier; is the gravity of the superstructure above the self-centering rocking bridge pier.

[0084] restoring moment contributed by the prestressed tendon is:

[0085]

[0086] wherein, is the elastic modulus of the prestressed tendon; is the cross-sectional area of the prestressed tendon; is the length of the prestressed tendon; is the initial prestress, which is 12% of the gravity of the pier.

[0087] Therefore, the self-centering moment of the self-centering rocking bridge pier 6 is:

[0088]

[0089] Further, in order to prevent the pier from collapsing, the energy dissipation rod 6.2 needs to meet the following conditions: when the self-centering rocking bridge pier 6 begins to rock and dissipate energy under the action of a major earthquake, the energy dissipation rod immediately enters a plastic state and will not be completely destroyed under the action of a major earthquake.

[0090] Further, in this embodiment, the energy dissipation rod 6.2 and the damping dowel assembly 3 are arranged in a replaceable form, so that the function recovery of the bridge damping system can be realized. It should be noted that the self-centering rocking bridge pier is not limited to Figure 6 the structure shown in the figure, and the self-centering rocking bridge pier structure involved in the field can be used in the damping scheme of this embodiment.

[0091] Further, the pier support 2 is prior art in the field, and the pier support 2 will not be described in detail in this embodiment.

[0092] The minor earthquake, the moderate earthquake and the major earthquake mentioned in this embodiment have clear regulations in the field and are common knowledge in the field, so they will not be described in detail in this embodiment.

[0093] The principle of the recoverable function assembly type bridge in this embodiment to realize three-level seismic resistance is:

[0094] Under the action of a minor earthquake , the limiting block 4.5 in the regulating assembly 4 is not in contact with the inner wall of the movable cavity 4.2, the regulating assembly 4 does not produce a limiting effect, the self-resetting swing pier 6 does not swing under the action of its own weight and the prestressed tendon, the tenon head 3.3 of the damping tenon assembly 3 is in contact with the inner wall of the mounting cavity 3.5 to produce a limiting effect, and the tenon body 3.2 is elastically deformed to resist impact;

[0095] When a medium earthquake acts , the limiting block 4.5 in the regulating assembly 4 is still not in contact with the inner wall of the movable cavity 4.2, the regulating assembly 4 does not produce a limiting effect, the self-resetting swing pier 6 still does not swing under the action of its own weight and the prestressed tendon, and the tenon body 3.2 further plastically deforms to dissipate energy;

[0096] When a large earthquake acts , the limiting block 4.5 in the regulating assembly 4 is in contact with the inner wall of the movable cavity 4.2, the regulating assembly 4 produces a limiting effect, at this time, the tenon body 3.2 of the damping tenon assembly 3 does not further plastically deform, the self-resetting swing pier 6 swings to dissipate energy, and at this time, the regulating assembly 4 and the damping tenon assembly 3 both have the effects of limiting and preventing the beam from falling.

[0097] In normal use, the horizontal gap between the limiting block 4.5 in the regulating assembly 4 and the inner wall of the movable cavity 4.2 and the horizontal initial gap between the tenon head 3.3 of the damping tenon assembly 3 and the mounting cavity 3.5 meet the movement requirements of the bridge in normal use.

[0098] The embodiment also provides a design method of the above-mentioned recoverable function assembled bridge based on a hierarchical damping mechanism, and the method specifically comprises the following steps:

[0099] S1, a bridge dynamic analysis model is established, and the initial stiffness , the horizontal initial gap , the post-yield stiffness , the horizontal yield displacement and the horizontal ultimate displacement of the damping tenon assembly 3 are set, and the stiffness and the maximum horizontal movable displacement of the regulating assembly 4 are set, wherein the stiffness meets the requirement that the regulating assembly 4 does not yield under the action of a small earthquake, a medium earthquake and a large earthquake;

[0100] S2, a small earthquake working condition excitation is loaded on the bridge dynamic analysis model, the horizontal displacement between the main girder 1 and the self-resetting swing pier 6 is first calculated, if , the stiffness is increased, the horizontal displacement is recalculated, and if then the maximum horizontal displacement of the shock-absorbing tenon assembly 3 at this time is calculated , if then the value of k is increased and the calculation is re-performed , if then the next step is entered;

[0101] S3, the bridge dynamic analysis model is loaded with the medium earthquake working condition excitation, and the horizontal displacement between the main girder 1 and the self-centering rocking pier 6 at this time is calculated , if then the value of k is increased and the calculation is re-performed , if then the maximum horizontal displacement of the shock-absorbing tenon assembly 3 at this time is calculated , if then the value of k is decreased and the process returns to step S2, if then the value of k is increased and the calculation is re-performed , if then the next step is entered, is an adjustment coefficient;

[0102] S4, the bridge dynamic analysis model is loaded with the large earthquake working condition excitation, and the horizontal displacement between the main girder 1 and the self-centering rocking pier 6 at this time is calculated , if then the value of k is decreased and the process returns to step S2, if then the maximum horizontal displacement of the shock-absorbing tenon assembly 3 at this time is calculated , if then the value of k is increased and the process returns to step S3, if then the next step is entered;

[0103] S5, according to the results of the bridge dynamic analysis model in step S4, the seismic response of the self-centering rocking pier 6 is analyzed, and by adjusting the prestressed tendon configuration, energy dissipation bar structure and structural reinforcement design of the self-centering rocking pier 6, the bridge satisfies the seismic requirements under the large earthquake working condition.

[0104] Further, in actual design, the seismic effects of the bridge in the longitudinal direction and the transverse direction need to be considered at the same time, so in actual design, steps S1-S5 need to be performed under the excitation of the seismic working condition in the longitudinal direction and the transverse direction (i.e. the seismic effects of the bridge under the action of small earthquakes, medium earthquakes and large earthquakes in the longitudinal direction need to be verified, and the seismic effects of the bridge under the action of small earthquakes, medium earthquakes and large earthquakes in the transverse direction also need to be verified) to ensure that the bridge can cope with seismic action from different directions.

[0105] The design method in the embodiment can well guide those skilled in the art to apply the recoverable function assembly type bridge based on the hierarchical damping mechanism in the embodiment, provide a basis for confirming the key parameters of the damping dowel assembly and the regulating assembly for those skilled in the art, and facilitate the bridge seismic scheme in the embodiment to be widely applied and popularized.

[0106] By applying the technical scheme in the embodiment, the following effects are achieved:

[0107] The recoverable function assembly type bridge in the embodiment solves the deficiencies of the traditional single damping device in bridge seismic resistance, and through the cooperative work of the damping dowel assembly 3, the regulating assembly 4 and the self-centering rocking pier 6, three-level seismic effects are achieved. The damping dowel assembly 3 and the self-centering rocking pier 6 can both consume seismic energy through elastic-plastic hysteretic deformation, and the regulating assembly 4, as a key regulating component, does not yield under the action of each level of earthquake, but only plays a role in limiting and preventing the beam from falling. When the regulating assembly 4 does not produce a limiting effect, the damping dowel assembly plays a major role in seismic energy dissipation, and the overall structure maintains a high stiffness, which can effectively resist the action of small and medium earthquakes; when the seismic action is further increased, the displacement of the damping dowel assembly is constrained after the regulating assembly 4 produces a limiting effect, and the self-centering rocking pier 6 gradually plays a major role, relying on its self-centering characteristics to bear the main energy dissipation and seismic reduction functions; at the same time, the energy dissipation bars arranged at the bottom of the self-centering rocking pier work cooperatively to enhance the overall energy dissipation capacity, thereby effectively dispersing seismic energy under strong earthquake conditions, significantly reducing structural residual deformation and post-earthquake damage, and at the same time meeting the recoverability requirements of the structure. Through this hierarchical working mode, different types of damping devices under different earthquake levels can fully exert their advantages, and the seismic design goal of "no damage under small earthquakes, repairable under medium earthquakes, and not falling under large earthquakes" can be achieved.

[0108] In order to avoid excessive concentration of seismic energy on a single pier, the bridge in the embodiment adopts a division type arrangement: the damping dowel assembly is arranged on the top of the ordinary pier 5 to make it enter the energy dissipation state under the action of medium earthquakes, thereby dispersing and reducing the input seismic energy; the regulating assembly 4 is arranged on the top of the self-centering rocking pier 6, and when the seismic action is further increased, the regulating assembly 4 limits the further displacement of the damping dowel assembly and triggers the rocking mechanism of the self-centering rocking pier, so that the self-centering rocking pier plays the self-centering and main energy dissipation functions, thereby effectively reducing residual deformation and improving overall seismic performance.

[0109] The self-centering rocking pier in the embodiment does not play a rocking energy dissipation role under the action of small earthquakes, and only when the regulating assembly 4 produces a limiting effect does the self-centering rocking pier 6 rock and participate in energy dissipation, so that the rocking mechanism is triggered when the damping dowel assembly has fully dissipated energy but has not yet entered the damage stage under the action of strong earthquakes, thereby forming a smooth stress transition and avoiding the adverse impact effect caused by sudden stiffness mutation.

[0110] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A recoverable function assembled bridge based on a hierarchical shock absorption mechanism, characterized in that, Ordinary piers (5) and self-resetting rocking piers (6) are alternately arranged along the longitudinal direction of the bridge, and pier supports (2) are arranged between the ordinary piers (5), the self-resetting rocking piers (6) and the main girder (1), damping tenon assemblies (3) are further arranged between the ordinary piers (5) and the main girder (1), and regulating assemblies (4) are further arranged between the self-resetting rocking piers (6) and the main girder (1); The control assembly (4) allows the horizontal displacement of the girder (1) with respect to the self-centering rocking pier (6) in the interval ​ When small earthquake acts, At this time, the regulating assembly (4) does not produce limiting effect, the self-resetting swing pier (6) does not swing, and the damping dowel assembly (3) is elastically deformed. Under the action of a medium earthquake, At this time, the regulating assembly (4) does not produce limiting effect, the self-resetting rocking pier (6) still does not rock, and the damping dowel assembly (3) further plastically deforms to dissipate energy. Under the action of a large earthquake, At this time, the control assembly (4) produces a limiting effect, and the self-resetting rocking pier (6) starts to rock and dissipate energy. wherein, is the maximum horizontal displacement allowed by the governing assembly (4), is the horizontal displacement between the main girder (1) and the self-centering rocking pier (6) under the action of small earthquakes, is the horizontal displacement between the main girder (1) and the self-centering rocking pier (6) under the action of medium earthquakes, is the horizontal displacement between the main girder (1) and the self-centering rocking pier (6) under the action of large earthquakes.

2. The resilient functional assembled bridge based on hierarchical shock absorption mechanism according to claim 1, characterized in that, The regulating assembly (4) comprises a limiting top plate (4.1) and a base assembly, the limiting top plate (4.1) is fixedly arranged on the bottom surface of the main girder (1) and is provided with a movable cavity (4.2) thereon, and the base assembly is fixedly arranged on the upper end surface of the self-resetting rocking pier (6) and extends into the movable cavity (4.2) at the upper end thereof; The upper end of the base assembly is centrally arranged in the movable cavity (4.2), and the maximum horizontal distance from the upper end of the base assembly to the inner wall of the movable cavity (4.2) is .

3. The resilient functional assembled bridge based on hierarchical shock absorption mechanism according to claim 2, characterized in that, The base assembly comprises a base plate (4.3), a shaft (4.4) and a limiting stopper (4.5), the base plate (4.3) is arranged on the upper end surface of the self-resetting rocking pier (6), one end of the shaft (4.4) is arranged on the base plate (4.3), and the other end of the shaft (4.4) is provided with the limiting stopper (4.5), the limiting stopper (4.5) is arranged in the middle of the movable cavity (4.2), and the maximum horizontal distance from the limiting stopper (4.5) to the inner wall of the movable cavity (4.2) is .

4. The resilient functional assembled bridge based on hierarchical shock absorption mechanism according to claim 3, characterized in that, The movable cavity (4.2) and the limiting block (4.5) are one of a cylindrical structure and a spherical structure.

5. The recoverable function assembled bridge based on the hierarchical damping mechanism according to claim 1, characterized in that: Under the action of small earthquake, the horizontal displacement of the damping tenon assembly (3) satisfies: ; Under the action of a medium earthquake, the horizontal displacement of the shock-absorbing tenon assembly (3) satisfies: ; Under the action of a large earthquake, the horizontal displacement of the shock-absorbing dowel assembly (3) satisfies: ; wherein the horizontal initial gap of the shock-absorbing dowel assembly, the horizontal yield displacement of the shock-absorbing dowel assembly, the horizontal ultimate displacement of the shock-absorbing dowel assembly, is an adjustment factor.

6. The recoverable function assembled bridge based on the hierarchical damping mechanism according to claim 5, characterized in that: Under the action of small earthquakes, the horizontal force borne by the damping tenon assembly (3) is less than the elastic limit bearing capacity thereof; Under the action of a medium earthquake, the horizontal force borne by the damping dowel assembly (3) is greater than or equal to the elastic limit bearing capacity thereof and less than or equal to the horizontal limit displacement corresponding to the horizontal yielding force of the elastic limit bearing capacity thereof times. Under the action of large earthquakes, the horizontal force borne by the damping tenon assembly (3) is less than or equal to the horizontal yield force corresponding to the horizontal limit displacement thereof.

7. The resilient functional assembled bridge based on hierarchical shock absorption mechanism according to claim 6, characterized in that, the adjustment coefficient .

8. The resilient functional assembled bridge based on hierarchical shock absorption mechanism according to any one of claims 1-7, characterized in that, The regulating assembly (4) needs to satisfy that it does not yield under the action of small earthquakes, medium earthquakes and large earthquakes.

9. A design method of a recoverable function assembly type bridge based on a hierarchical shock absorbing mechanism according to any one of claims 1 to 8, characterized in that, Comprise: S1, a bridge dynamic analysis model is established, and initial stiffness of the shock-absorbing tenon assembly (3) is set , horizontal initial gap , post-yield stiffness , horizontal yield displacement and horizontal ultimate displacement , at the same time, stiffness of the regulating assembly (4) and maximum horizontal movement displacement allowed by the regulating assembly (4) are set, wherein the stiffness satisfies that the regulating assembly (4) does not yield under the action of small earthquakes, medium earthquakes and large earthquakes. S2, load the small earthquake working condition excitation to the bridge dynamic analysis model, first calculate the horizontal displacement between the main girder (1) and the self-resetting rocking pier (6) at this time , if , then increase , and then recalculate , if , then calculate the maximum horizontal displacement of the shock-absorbing tenon assembly (3) at this time , if , then increase , and then recalculate , if , then go to the next step; S3, load the bridge dynamic analysis model with the near-fault excitation, first calculate the horizontal displacement between the main girder (1) and the self-centering rocking pier (6) at this time , if , then increase , and then recalculate , if , then calculate the maximum horizontal displacement of the shock-absorbing dowel assembly (3) at this time , if , then decrease , and then return to step S2, if , then increase the value of , and then recalculate , if , then go to the next step , is an adjustment coefficient; S4, load the large earthquake working condition excitation on the bridge dynamic analysis model, first calculate the horizontal displacement between the main girder (1) and the self-resetting rocking pier (6) at this time , if , then reduce , and then return to step S2, if , then calculate the maximum horizontal displacement of the shock-absorbing dowel assembly (3) at this time , if , then increase , and then return to step S3, if , then proceed to the next step; S5. According to the results of the bridge dynamic analysis model in step S4, analyze the seismic response of the self-resetting rocking pier (6), and by adjusting the prestressed tendon configuration, energy dissipation bar structure and structural reinforcement design of the self-resetting rocking pier (6), make the bridge satisfy the seismic demand under the large earthquake working condition.

Images