Rail structure-ultra-long-span bridge space coupling static model construction method

Abstract

The application provides a track structure-ultra-large-span bridge space coupling static model construction method. The method comprises the following steps: establishing an ultra-large-span bridge and approach bridge finite element model, the modeling objects comprising a beam body, a bridge tower, a bridge deck slab, a bridge pier support, a main cable and a suspender or a stay cable, and the bridge tower and the bridge deck slab are simplified modeled according to the influence degree of the bridge components on the seamless track on the bridge; a ballast track structure finite element model is established, the modeling objects comprising a steel rail, a fastener, a sleeper and a track bed; temperature, wind, vehicle and other loads are applied to the track structure-ultra-large-span bridge space coupling static model, and the stress deformation law of the track is studied. The track-bridge coupling model established based on the modeling idea of reasonably simplifying the bridge model and refining the track model can accurately reflect the influence of the particularity of the bridge structure on the mechanical properties of the seamless track thereon, the model improves the modeling efficiency and reduces the error rate in the modeling process on the premise of ensuring the accuracy of the calculation results.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of interaction between bridge and track structure, and particularly relates to a track structure-ultra-large-span bridge space coupling static model construction method. BACKGROUND

[0002] With the improvement of bridge design and construction level, in order to adapt to the complex topography of China, ultra-large-span bridges are gradually applied to the lower foundation of high-speed railways. Compared with ordinary bridges, the ultra-large-span bridge structure system is relatively flexible, is easily affected by various loads and has extremely strong nonlinearity of deformation. After the seamless line is laid on the bridge, the interaction relationship between the beam and the track and the stress deformation of the line will be quite different from those of the ordinary line-bridge structure. In order to accurately reflect the influence of the spatial deformation of the ultra-large-span bridge in the complex environment on the seamless line thereon, a line-bridge space coupling static model suitable for analyzing the interaction between the ultra-large-span bridge and the track structure needs to be considered and proposed.

[0003] At present, the research method about the interaction between the ultra-large-span bridge and the track in the prior art does not focus on the influence of the particularity of the bridge structure on the seamless line thereon, so the ultra-large-span bridge is simplified as a continuous beam bridge for simulation, and a set of modeling method and research idea for the seamless line on the continuous beam and simply supported beam bridge is still used to analyze the mechanical properties of the seamless line on the ultra-large-span bridge.

[0004] However, with more and more ultra-large-span railway bridges being put into operation, many problems that cannot be solved by the existing research methods and theories have appeared in actual engineering. The disadvantages of the research method about the interaction between the ultra-large-span bridge and the track in the prior art include that these methods are only applicable to the analysis of the beam-track interaction of the seamless line on the small-span bridge, are difficult to be applied to the ultra-large-span bridge-line structure, and it is urgent to establish a more refined track structure-ultra-large-span bridge space coupling static model considering the geometric nonlinearity of large deformation of the bridge to carry out research.

[0005] However, because the focus of the research is the stress deformation of the seamless line on the bridge, the model of the ultra-large-span bridge does not need to build every component of the bridge very carefully. In order to improve the modeling efficiency and reduce the error rate, the modeling process of the bridge components which have little influence on the beam-track interaction can be appropriately and reasonably simplified without affecting the accuracy of the calculation results of the seamless line on the bridge. For the track structure which is the focus of attention, a refined modeling method needs to be considered.

[0006] Therefore, for the analysis of the beam-track interaction between the ultra-large-span bridge and the track structure, a modeling method which is efficient and can accurately reflect the influence of the particularity of the ultra-large-span bridge structure on the spatial static mechanical properties of the seamless line on the bridge is required. SUMMARY

[0007] The application provides a track structure-ultra-large-span bridge space coupling statics model construction method to provide a reliable research basis for mechanical analysis of a seamless line on an ultra-large-span bridge.

[0008] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme.

[0009] The processing flow of the track structure-ultra-large-span bridge space coupling statics model construction method provided by the embodiment of the application comprises the following steps.

[0010] Step S1: establishing an ultra-large-span bridge and approach bridge finite element model, the modeling objects comprising a beam body, a bridge tower, a bridge deck, a bridge pier support, a main cable and a suspender or a cable-stayed cable, and the bridge tower and the bridge deck are reasonably simplified according to the influence degree of the bridge components on the seamless line on the bridge, and the step comprises:

[0011] S11: each chord in the stiffening beam of the ultra-large-span bridge is simulated by an Euler-Bernoulli beam element considering shear deformation, is modeled according to the actual section properties, the section area and the moment of inertia of the rod are considered, and the connected rods are rigidly connected;

[0012] S12: the orthotropic bridge deck is simplified into a rectangular plate according to the stiffness equivalence principle, is simulated by a shell element, and the section parameters calculated according to the equivalence principle are simulated;

[0013] S13: the bridge tower is simulated by a mass point, a point connected with the cable / cable and the main beam and a mass point located at the lower part of the main beam are established, the mass point is rigidized, and the mass point at the lower part of the main beam is fixed.

[0014] S14: the main cable and the suspender of the suspension bridge or the cable-stayed cable of the cable-stayed bridge is simulated by a rod element only subjected to tension and considering initial strain, and is modeled according to the actual structure properties;

[0015] S15: the approach bridges located on both sides of the main bridge are simulated by beam elements, are modeled according to the actual section properties, and the section area, the moment of inertia and the turning moment parameters of the beam body are considered;

[0016] S16: the longitudinal, transverse and vertical constraint actions of the bridge pier support on the beam body are simulated by linear spring elements, one end of the linear spring element is connected with the beam body, and the other end is fixed.

[0017] S17: for the ultra-large-span bridge belonging to a semi-floating system, the main beam and the lower transverse beam of the bridge tower are linearly spring-constrained in the transverse and vertical directions, and are connected by a damper in the longitudinal direction, and the longitudinal damper is simulated by a nonlinear spring.

[0018] S18: the beam ends of the main beam are fully constrained, and the anchoring side of the back cable is fully constrained.

[0019] Step S2: a refined ballast track structure finite element model is established, modeling objects include steel rail, fastener, sleeper and ballast bed, and the step comprises:

[0020] S21: the steel rail is simulated by using ironwood Xike beam unit, is modeled according to actual section properties, the section area, moment of inertia and torsional bending moment parameters of the steel rail are considered, and the nodes at both ends of the steel rail are all constrained;

[0021] S22: the fastener is simulated by using three-way spring unit, the vertical and lateral supports are selected to be linear spring units, the longitudinal resistance of the fastener is simulated by using nonlinear spring unit, one end of the fastener spring is connected with the node of the steel rail, and the other side is connected with the node of the sleeper;

[0022] S23: the sleeper is simulated by using Euler-Bernoulli beam unit, is modeled according to actual section properties, the nodes of the sleeper are connected with the nodes of the fastener spring and the nodes of the ballast bed spring at the same time;

[0023] S24: the mechanical properties of the ballast bed are simulated by using three-way spring unit, the vertical support is simulated by using linear spring unit, the lateral and longitudinal constraints are all considered to be nonlinear spring constraints, one end of the spring is connected with the node of the sleeper, and the other end is connected with the node of the steel arm;

[0024] S25: the thickness of the ballast bed is simulated by using steel arm, one end of the steel arm is connected with the spring node in step S24, and the other end is connected with the bridge deck slab.

[0025] Step S3: the temperature, wind, vehicle and other complex environmental loads are applied to the track structure-super-long-span bridge space coupling statics model, and the stress deformation law of the bridge and the track is researched.

[0026] Further, the equivalent schematic diagram of the orthotropic bridge deck slab in the simplified modeling method adopted by the present application is as shown in Figure 2 The rectangular bridge deck slab model simplified by the orthotropic bridge deck slab structure adopted by the present application is as shown in Figure 3 The simplified modeling of the orthotropic bridge deck slab in step S12 is according to the following steps:

[0027] The section parameters are calculated according to the equivalent stiffness principle:

[0028]

[0029]

[0030] Wherein, E is the elastic modulus of the original model, I yy is the vertical stiffness of the original model, E * is the elastic modulus of the equivalent model, is the vertical stiffness of the equivalent model, B is the section width, H * is the section height of the equivalent model, Izz is the lateral stiffness of the original model, is the lateral stiffness of the equivalent model;

[0031] The cross-section height and elastic modulus of the equivalent rectangular section can be calculated from formula (1) (2), and the density of the equivalent model is calculated from the following formula according to the equivalent mass principle:

[0032] M = pAl = p * A * l (3)

[0033] Wherein, M is the unit length mass, p is the density of the original model, A is the cross-sectional area of the original model, l is the unit length, p * is the density of the equivalent model, A * is the cross-sectional area of the equivalent model;

[0034] The specific parameters of the orthotropic bridge deck equivalent to the rectangular bridge deck are calculated through the above steps.

[0035] Further, in the step S13, the influence of the geometric nonlinearity factor is considered, and the strain of the main cable and the suspension cable or the stay cable after the bridge is adjusted until the vertical displacement of the main beam is close to 0.

[0036] Further, in the step S21, the arrangement of the rail expansion joint at the end of the beam of the super-long-span railway bridge is considered, the joint is achieved by the mutual displacement of the basic rail and the pointed rail to disperse the longitudinal force, and the essence is a broken rail behavior. In the static calculation of the joint, the broken rail is simulated to simulate the influence law of the joint on the seamless line on the super-long-span bridge.

[0037] Further, in the step S21, in order to reduce the boundary effect, the steel rails of the approach bridge on both sides are extended outward by 150m.

[0038] Further, in the step S22, the fastener resistance parameters and the line resistance parameters in the step S23 are referred to the current specification or the measured value.

[0039] Further, the step S3 comprises

[0040] S31: selecting modeling parameters according to engineering practice;

[0041] S32: based on the track structure-super-long-span bridge space coupling statics modeling method, coupling the finite element model of the super-long-span bridge and the approach bridge and the finite element model of the ballast track structure together, and establishing a track structure-super-long-span bridge statics analysis model by using a finite element software;

[0042] S33: load temperature, wind, train, highway vehicle, brake, etc. to the track structure- super large span bridge space coupling statics model for operation, extract the calculation results of the rail, analyze the stress deformation law of the track structure under the influence of complex environmental load.

[0043] It can be seen from the technical solutions provided by the above-mentioned application that the modeling method of the super large span bridge and the track structure interaction provided by the application not only considers the influence of the particularity of the super large span bridge structure on the mechanical properties of the seamless track thereon, but also can reasonably simplify the modeling process of the super large span bridge, and more finely model the track structure which is the focus, so as to realize the establishment of the high-efficiency, accurate and reasonable track structure-super large span bridge space coupling statics model, and provide a reliable research basis for the mechanical analysis of the super large span bridge seamless track.

[0044] Additional aspects and advantages of the application will be described in the following description, which will become apparent from the description, or will be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0046] Figure 1 A track structure-super large span bridge space coupling statics model construction method flowchart provided by the embodiment of the application;

[0047] Figure 2 An equivalent schematic diagram of the orthotropic bridge deck in the simplified modeling method adopted by the application;

[0048] Figure 3 A rectangular bridge deck model simplified by the orthotropic bridge deck structure in the application adopting the stiffness equivalence principle;

[0049] Figure 4 A cable-stayed bridge tower model simplified by the particle method in the application;

[0050] Figure 5 A ballast track structure model schematic diagram provided by the embodiment of the application;

[0051] Figure 6 A super large span suspension bridge seamless track space coupling whole model schematic diagram provided by the embodiment of the application;

[0052] Figure 7Verification result of the correctness of the bridge deck model simplification method;

[0053] Figure 8 Verification result of the correctness of the bridge tower model simplification method;

[0054] Figure 9 Temperature deflection force diagram caused by vertical deformation of the bridge;

[0055] Figure 10 Vertical deformation of the bridge and lateral deformation of the steel rail under the action of the highway load;

[0056] Figure 11 Peak value diagram of the steel rail braking force under various braking force conditions;

[0057] Figure 12 Distribution diagram of the steel rail longitudinal force under the train braking force condition;

[0058] Figure 13 Lateral deformation diagram of the bridge under the action of the lateral wind load;

[0059] Figure 14 10m chord rail irregularity diagram under the action of the lateral wind load.

[0060] Legend:

[0061] 1, steel rail; 2, fastener; 3, sleeper; 4, ballast; 5, ballast thickness (rigid arm); 6, main beam; 7, suspender; 8, main cable; 9, damper; 10, bridge tower; 11, auxiliary pier; 12, transition pier; 13, expansion device; 14, expansion adjuster; 15-1, movable support; 15-2, fixed support. DETAILED DESCRIPTION

[0062] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are for the purpose of explanation only, and cannot be interpreted as a limitation on the present application.

[0063] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is further understood that the terms "comprise" (or comprise), "comprises" (or comprises) and "comprising" (or comprising) when used in this specification, specify the presence of stated features, integers, steps, operations, elements, or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. It is further understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements can be present. In addition, the word "connected" or "coupled" as used herein can include wirelessly connected or coupled. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0064] It is to be understood that the terms so used are intended to encompass the terms defined in a broad sense as well as in a narrow sense, unless otherwise defined specifically herein. It is further understood that the use of relational terms such as "first," "second," and the like, if any, are used solely to distinguish one from another entity or action without necessarily implying a relationship or order between the entities or actions so distinguished, unless otherwise specifically stated.

[0065] For the purpose of clarity, the present application will be further explained in connection with the attached figures as follows, which are presented solely for the purpose of illustration and are not intended to limit the scope of the present application in any way.

[0066] Embodiment One:

[0067] A flow chart of a method for constructing a track structure-super-long-span bridge spatial coupling statics model according to an embodiment of the present application is shown in FIG. 1, which includes the following steps: Figure 1

[0068] Step S1: Establishing a finite element model of a super-long-span bridge and an approach bridge, the modeling objects including a beam body, a tower, a bridge deck, a pier support, a stay cable or a main cable, and a suspender, and the tower and the bridge deck are reasonably simplified modeled according to the influence degree of the bridge components on the seamless track thereon.

[0069] Step S2: Establishing a refined ballast track structure finite element model, the modeling objects including a rail, a fastener, a sleeper, and a track bed.

[0070] Step S3: Applying temperature, wind, vehicle, and other complex environmental loads to the track structure-super-long-span bridge spatial coupling statics model, and studying the stress deformation law of the track.

[0071] The above steps are performed in the following sub-steps by taking an (84+84+1092+84+84) m super-long-span suspension bridge of a high-speed railway as an example.​

[0072] Figure 4 The tower model of the cable-stayed bridge and the suspension bridge is simplified by using the particle method for the present application.

[0073] The stiffening girder of the suspension bridge is established:

[0074] A segment of the stiffening girder is first established, and then the entire stiffening girder structure is obtained by copying the segment. The members constituting the stiffening girder are simulated by using Euler-Bernoulli beam elements, the actual cross-sectional properties such as cross-sectional area and moment of inertia of each member are assigned to the beam elements, and rigid connections are used between the members.

[0075] The deck slab of the suspension bridge is established:

[0076] The orthotropic deck slab is simplified into a rectangular slab by using the equivalent stiffness principle, the upper and lower deck slabs are simulated by using shell elements, and the actual parameters of the orthotropic deck slab are converted into the equivalent parameters and assigned to the shell elements.

[0077] The tower of the suspension bridge is established:

[0078] A number of key nodes are selected to construct the tower model, the nodes D1 and D2 at the ends of the upper cross beam of the tower, the nodes D3 at the ends of the lower cross beam, the node D4 at the middle of the lower cross beam, the nodes D5 and D6 at the points ±15 m from the middle of the lower cross beam, and the node D7 at the midpoint of the line connecting the two points at the bottom of the tower are selected, each node is simulated by using a mass point, and the node D7 is the master node, and all the mass points are rigidly processed.

[0079] The main cable and the suspender of the suspension bridge are established:

[0080] The main cable and the suspender are simulated by using the bar element that only bears tension and does not bear compression, the corresponding cross-sectional parameters of the main cable and the suspender are assigned, an initial strain value is assigned to the main cable element and the suspender element, and the two ends of the main cable are coupled and connected with the end points of the upper cross beams of the north and south towers in the longitudinal, transverse and vertical directions.

[0081] The approach bridges on both sides are established:

[0082] The approach bridges are simulated by using the beam element, the modeling is performed according to the actual cross-sectional properties, the cross-sectional area, the moment of inertia and the turning moment parameters of the beam body are considered, and the top surface needs to be kept at the same height as the main girder of the suspension bridge.

[0083] The pier support is established:

[0084] For the movable support, a linear spring element is established to simulate the horizontal and vertical stiffness of the pier, and the horizontal and vertical movements of the beam body are constrained, for the fixed support, a linear spring element is established to simulate the longitudinal, horizontal and vertical stiffness of the pier, and the longitudinal, horizontal and vertical movements of the beam body are constrained. The spring is connected to the beam body at one end and is fixed at the other end.

[0085] The constraint between the beam and the tower is established:

[0086] Linear spring simulation bridge tower to the main beam of the horizontal, vertical constraints, spring connection main beam and bridge tower lower beam, spring one end and mass point D5 / D6 connected, the other end and the main beam bottom node connected; longitudinal damping connection, longitudinal damper using nonlinear spring simulation.

[0087] Establish the rail:

[0088] According to the actual project to select the rail section shape, using iron wood Xin Ke beam unit modeling. With fastener spacing 0.6m as the unit length, first establish the length of 0.6m rail model, then copy the rail model, get the whole bridge rail model and rail on the interval 0.6m distribution of nodes, the approach bridge rail to extend 150m outward.

[0089] Establish the sleeper:

[0090] The rail node below the establishment of sleeper node, using beam element to simulate the sleeper, the sleeper parameters are assigned to the beam element.

[0091] Establish the fastener:

[0092] Fastener using three-dimensional spring element simulation, vertical and horizontal support selected linear spring element, vertical and horizontal stiffness of 60kN / mm, fastener longitudinal resistance using nonlinear spring element simulation, the value of reference to the current specification, fastener spring one end and rail node connected, the other side and sleeper node connected.

[0093] Establish the ballast bed:

[0094] Figure 5 The ballast bed of the mechanical properties of the three-dimensional spring element simulation, vertical support using linear spring element simulation, vertical stiffness of 120kN / mm, the horizontal and longitudinal constraints are considered as nonlinear spring constraint, the horizontal resistance of 12kN / root, the longitudinal resistance reference to the current specification, spring one end and sleeper node connected, the other end and steel arm node connected; the thickness of the ballast bed using steel arm simulation, steel arm one end and ballast spring node connected, the other end and the deck connected.

[0095] Establish the boundary conditions:

[0096] The bridge beam end is fully constrained; the back cable anchoring side is fully constrained; the main node in the bridge tower mass point is fully constrained; the rail end node is fully constrained.

[0097] Adjust the strain of the main cable and suspender after the bridge is built:

[0098] The model is only subjected to the gravity load, the strain of the main cable and the suspender calculated is given to each rod unit, and calculation is carried out again, and the cycle is repeated until the vertical displacement of the main beam under the action of gravity is close to 0, and thus the adjustment of the strain value of the main cable and the suspender after the bridge is completed is completed.

[0099] Verification of the correctness of the bridge deck panel model simplification method:

[0100] Figure 6 A large-span suspension bridge spatial coupling integral model diagram on the bridge is provided for the embodiment of the application. The track structure-large-span bridge spatial coupling static model before and after the simplification of the orthotropic bridge deck panel is compared and analyzed, and the calculation condition is that the cable structure is cooled by 30 DEG C. Figure 7 The rail longitudinal force diagrams of the two calculation models under the action of temperature are shown in the above calculation results. It is concluded from the above calculation results that under the action of temperature load, the calculation results of the two models before and after the simplification are very close, compared with the model before the simplification of the bridge deck panel, the modeling process of the simplified model is simpler, the error rate is smaller, and the calculation speed is faster. Therefore, for the calculation model of the large-span bridge seamless line, the orthotropic bridge deck panel can be simplified by the stiffness equivalent principle.

[0101] Verification of the correctness of the bridge tower model simplification method:

[0102] The track structure-large-span bridge spatial coupling static model after the simplification of the bridge tower is compared and analyzed, and the calculation condition is that the bridge tower is cooled by 25 DEG C. Figure 8 The rail longitudinal force diagrams of the two calculation models under the action of temperature are shown in the above calculation results. It is concluded from the above calculation results that under the action of temperature load, the calculation results of the two models before and after the simplification are very close, compared with the model before the simplification of the bridge deck panel, the modeling process of the simplified model is simpler, the error rate is smaller, and the calculation speed is faster. Therefore, for the calculation model of the large-span bridge seamless line, the orthotropic bridge deck panel can be simplified by the stiffness equivalent principle.

[0103] Load application:

[0104] In this example, the track structure-large-span bridge spatial coupling static model is established based on the above, the rail additional force analysis under the action of temperature and the beam-rail interaction analysis under the action of highway load effect, train braking force and transverse wind load are carried out.

[0105] Temperature load action

[0106] In this example, three working conditions of the main cable and the suspender cooling by 10 DEG C, 20 DEG C and 30 DEG C are taken as examples, the influence of the temperature change of the main cable and the suspender on the beam-rail interaction relationship is explored, the rail longitudinal additional force caused by the vertical deformation of the bridge under the action of temperature is calculated, and the change law is as follows Figure 9 .

[0107] From Figure 9It can be seen that the values of the longitudinal additional force of the steel rail at the bridge tower are 50.4, 100.6 and 150.6 kN respectively, and the values of the longitudinal additional force of the steel rail at the midspan are -55.2, -110.3 and -165.2 kN respectively. It can be seen that, under the action of temperature, the bridge will produce a large vertical deformation, thereby causing the relative displacement between the bridge and the long steel rail to produce a longitudinal additional force.

[0108] Highway load effect

[0109] In this example, the differences in the displacement and additional force of the steel rail caused by different highway load arrangements are considered, and the 1-8 lane arrangement conditions of the highway lane are calculated. In the calculation, the highway load is loaded on the main bridge of the bridge. The highway load is loaded according to the highway-Ⅰclass lane load, and the transverse reduction and longitudinal reduction of multiple lanes are considered. The steel rail transverse deformation and bridge vertical deformation under each condition are shown in Figure 10 .

[0110] It can be seen from Figure 10 that, under the action of the highway load, the beam structure produces deflection. When the upper highway bridge deck is fully loaded with 8 lanes, the maximum vertical displacement of the bridge is 0.36 m, which occurs at the midspan of the bridge. In the range from the bridge tower to the beam end, the bridge has a weak upward arch, which can be basically ignored. Compared to the symmetrical arrangement of the highway lane load about the bridge deck center axis, when the highway lane load is offloaded, it will have a relatively obvious influence on the transverse displacement of the steel rail, with a maximum of 2.48 mm, which occurs at the midspan of the bridge. However, the transverse displacement caused by the offloading has a weak influence on the track irregularity.

[0111] Train braking force

[0112] In this example, the braking load adopts the ZK standard live load, and the braking rate is 0.164. The braking additional force at different loading positions is calculated by considering that the train brakes from the left side and the double lines are loaded simultaneously. The peak value of the steel rail braking force when the braking load acts on different positions of the whole bridge is shown in Figure 11 . It can be seen from the figure that, when the braking load gradually moves from the left end of the main beam to the right end of the main beam, the peak value of the braking force first increases and then decreases. When the loading position is close to the regulator laying position, the peak value of the steel rail braking force changes greatly. When the loading position is closer to the midspan of the main beam, the steel rail braking force is greater. The peak values of the braking pressure and the pulling force appear at the head and tail of the loading position respectively. Two working conditions are applied. Working condition 1: the starting point of the braking load acts on the left side of the bridge tower (0, 400 m) of the main beam; working condition 2: the starting point of the braking load acts on the midspan (546 m, 946 m) of the main beam. The steel rail longitudinal force is shown in Figure 12 .

[0113] It can be seen from Figure 12It can be seen from the analysis that the peak rail braking force in both working conditions appears at the head and tail of the load, and the braking force is anti-symmetrically distributed about the center of the load. For working condition 1, the peak rail braking pressure appears at the head of the load, which is 43.78 kN, and the peak braking tension appears at the tail of the load, which is 42.09 kN. For working condition 2, the distribution law of the braking force is the same as that of working condition 1, and only the position of the peak braking force is different. The peak braking pressure is 45.31 kN, and the peak braking tension is 42.78 kN.

[0114] Apply lateral wind load

[0115] In this example, for the lateral wind load, only the beam-rail interaction problem caused by the wind pseudo-static force is studied, and the stress and deformation law of the super-long-span bridge seamless track under the action of the lateral wind load is studied. The wind force perpendicular to the track direction is applied to the bridge, and the value is determined according to the “Highway Bridge Wind Resistance Design Specification”. The wind speed of the railway bridge surface in the operation stage is considered as V1 = 20 m / s, V2 = 25 m / s, and V3 = 30 m / s. Three working conditions are calculated to analyze the influence law of the wind speed on the deformation of the beam and the rail and the stress of the rail. The calculation results show that the influence of the lateral wind load on the deformation of the main beam is mainly the lateral deformation, and the vertical deformation and the torsion angle of the main beam are basically close to 0. The lateral deformation of the bridge under different wind speeds is shown in Figure 13 The track irregularity value of the track under the condition of the wind speed of 30 m / s is calculated by using the 10 m chord method, and the calculation results are shown in Figure 14

[0116] It can be seen from Figure 13 that the lateral deformation is symmetrically distributed about the midspan, and the maximum offset of the main bridge plane is at the midspan. When the wind speed is 20 m / s, 25 m / s, and 30 m / s, the lateral offset at the midspan is 0.50 m, 0.78 m, and 1.12 m, respectively. The lateral deformation of the bridge will drive the track to deform correspondingly, so that the track on the bridge will produce relatively significant track irregularity. It can be seen from Figure 14 that the track irregularity value of the whole bridge track is less than the specification limit, and the irregularity value at the beam end is also small because the torsion angle is very small. The sudden change value of the track irregularity appears at the north and south main towers and the auxiliary bridge piers of the side span, and the fluctuation peak value appears at the auxiliary bridge piers because of the sudden change of the lateral stiffness, which reaches 0.44 mm. The whole main span interval presents a change law that the irregularity value gradually decreases from the bridge tower to the midspan section, and relatively severe fluctuations appear near the midspan section.

[0117] In summary, compared with the conventional analysis method, the embodiment of the present application considers the influence of the particularity of the super-long-span bridge structure on the stress and deformation of the seamless track thereon, and can more accurately reflect the complex interaction relationship between the super-long-span bridge and the track structure.

[0118] ​Compared with the existing super-long-span bridge-seamless line space coupling static model, the influence degree of each component of the bridge on the stress characteristics of the seamless line on the bridge is considered, the bridge tower and the orthotropic bridge deck are simplified, the modeling efficiency is greatly improved, the error rate in the modeling process is reduced, and the model analysis speed is accelerated.

[0119] Compared with the existing ballast track-bridge space coupling static model, the track structure which is more concerned in the study of the seamless line on the bridge is modeled more finely, and the force transmission law of the seamless line on the bridge can be more truly and accurately reflected.

[0120] The technical scheme disclosed by the application can fully consider the complex beam-rail interaction relationship of the super-long-span railway bridge, accurately and efficiently realize the calculation and analysis of the super-long-span seamless line on the bridge, and has a broad application prospect.

[0121] Those skilled in the art can understand that the drawings are only schematic diagrams of an embodiment, and the modules or flows in the drawings are not necessarily necessary for implementing the application.

[0122] From the above description of the embodiments, those skilled in the art can clearly understand that the application can be implemented by means of software and the necessary general hardware platform. Based on such understanding, the technical scheme of the application can be embodied in the form of a software product, which can be stored in a storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the method described in each embodiment or some parts of the embodiments of the application.

[0123] Each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other, and each embodiment mainly describes the difference from other embodiments. Especially, since the device or system embodiment is basically similar to the method embodiment, it is described more simply, and the related parts can be referred to the part of the method embodiment. The device and system embodiments described above are only schematic, and the units described as separate components can be or can not be physically separated, and the components displayed as units can be or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. According to the actual needs, some or all of the modules can be selected to achieve the purpose of the embodiment. Those skilled in the art can understand and implement without creative labor.

[0124] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any changes or replacements within the technical scope disclosed by the present application, which can be easily thought by those skilled in the art, should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for constructing a spatial coupling static model of a track structure-ultra-long span bridge, characterized in that, The application relates to a method for simulating the coupling of a track structure and a super-long-span bridge. The method comprises the following steps: S1: a finite element model of a super-long-span bridge and an approach bridge is established, the modeling objects include a beam body, a tower, a bridge deck, a pier support, main cables and hangers or stay cables, and the tower and the bridge deck are simplified according to the influence degree of the bridge components on the seamless track; S2: a finite element model of a ballast track structure is established, the modeling objects include a steel rail, a fastener, a sleeper and a track bed; S3: a track structure-super-long-span bridge space coupling static model is established based on the finite element model of the super-long-span bridge and the approach bridge and the finite element model of the ballast track structure, environmental loads are applied to the track structure-super-long-span bridge space coupling static model, and the stress deformation law of the bridge and the track is researched; The step S1 specifically comprises the following steps: S11: each chord of the super-long-span bridge stiffening beam is simulated by an Euler-Bernoulli beam element considering shear deformation, the modeling is performed according to actual section properties, the section area and the moment of inertia of the rod are considered, and the connected rods are rigidly connected; S12: the orthotropic bridge deck is simplified into a rectangular plate according to the stiffness equivalence principle, is simulated by a shell element, and the section parameters calculated according to the equivalence principle are simulated; S13: the tower is simulated by a mass point, points connected with the cables / cables, the main beam and a mass point located at the lower part of the main beam are established, the mass point is rigidized, and the mass point at the lower part of the main beam is fixed; S14: the main cables and hangers of the suspension bridge or the stay cables of the cable-stayed bridge are simulated by rod elements only subjected to tension and not subjected to compression and considering initial strain, and the modeling is performed according to actual structure properties; S15: the approach bridges located at the two sides of the main bridge are simulated by beam elements, the modeling is performed according to actual section properties, the section area, the moment of inertia and the turning moment parameters of the beam body are considered; S16: the longitudinal, transverse and vertical constraint actions of the pier support on the beam body are simulated by linear spring elements, one end of the linear spring element is connected with the beam body, and the other end is fixed; S17: for the super-long-span bridge belonging to a semi-floating system, the main beam and the lower transverse beam of the tower are linearly spring-constrained in the transverse and vertical directions and are connected by a damper in the longitudinal direction, and the longitudinal damper is simulated by a nonlinear spring; S18: the main beam end is fully constrained, and the back cable anchoring side is fully constrained; The step S2 specifically comprises the following steps: S21: the steel rail is simulated by an ironwood element, the modeling is performed according to actual section properties, the section area, the moment of inertia and the torsional bending moment parameters of the steel rail are considered, and all the nodes at the two ends of the steel rail are constrained; S22: the fastener is simulated by a three-way spring element, the vertical and transverse supports are simulated by linear spring elements, the longitudinal resistance of the fastener is simulated by a nonlinear spring element, one end of the fastener spring is connected with a steel rail 1 node, and the other end is connected with a sleeper node; S23: the sleeper is simulated by an Euler-Bernoulli beam element, the modeling is performed according to actual section properties, and the sleeper node is connected with the fastener spring node and the track bed spring node; S24: the mechanical properties of the ballast track bed are simulated by a three-way spring element, the vertical support is simulated by a linear spring element, the transverse and longitudinal constraints are considered as nonlinear spring constraints, one end of the spring is connected with the sleeper node, and the other end is connected with the steel arm node. S25: the thickness of the ballast bed is simulated by a steel arm, one end of the steel arm is connected with a spring node, and the other end is connected with the bridge deck.

2. The method of claim 1, wherein, The orthotropic bridge deck in the step S12 is simplified into a rectangular plate according to the stiffness equivalence principle, is simulated by a shell element, and is simulated according to the cross-section parameters calculated by the equivalence principle, including: The cross-section parameters are calculated according to the equivalent stiffness principle: where E is the elastic modulus of the original model, I yy is the vertical stiffness of the original model, E * is the elastic modulus of the equivalent model, is the vertical stiffness of the equivalent model, B is the cross-sectional width, H * is the cross-sectional height of the equivalent model, I zz is the lateral stiffness of the original model, is the lateral stiffness of the equivalent model; The cross-section height and the elastic modulus of the equivalent rectangular cross-section are calculated by the formula (1) (2), and the density of the equivalent model is calculated by the following formula according to the equivalent mass principle: M = pAl = p * A * l (3) where M is the mass per unit length, p is the original model density, A is the original model cross-sectional area, l is the unit length, p * is the equivalent model density, A * is the equivalent model cross-sectional area; The specific parameters of the orthotropic bridge deck equivalent to the rectangular bridge plate are calculated through the above steps.

3. The method of claim 1, wherein, The step S13 further includes adjusting the strain or elastic modulus of the main cable 8 and the sling 7 after the bridge is completed until the vertical displacement of the main beam is close to 0.

4. The method of claim 1, wherein, The step S21 further includes considering the arrangement of the rail expansion joint at the beam end in the super-long-span railway bridge, the rail expansion joint at the beam end realizes the dispersion of the longitudinal force by the mutual displacement of the basic rail and the pointed rail, and the joint is simulated as a broken rail in the static calculation of the joint to simulate the influence law of the joint on the seamless line on the super-long-span bridge.

5. The method of claim 1, wherein, The step S21 further includes that the steel rails of the two side approach bridges each extend outward by 150m.

6. The method of claim 1, wherein, The fastener resistance parameters in the step S22 and the line resistance parameters in the step S23 refer to the current specification or the measured values.

7. The method according to any one of claims 1 to 6, characterized in that, The step S3 specifically includes: S31: selecting modeling parameters according to engineering practice; S32: based on the track structure-super-long-span bridge space coupling statics model construction method, a track structure-super-long-span bridge statics analysis model is established by using a finite element software; S33: temperature, wind, train, highway vehicle, and braking load are applied to the track structure-super-long-span bridge space coupling statics model for operation, the calculation results of the steel rail are extracted, and the stress and deformation law of the track structure under the influence of complex environmental loads is analyzed.

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