CN110644292A

CN110644292A - Spring vibration isolator jacking method for floating slab track

Info

Publication number: CN110644292A
Application number: CN201910957109.7A
Authority: CN
Inventors: 罗雁云; 廖博; 熊永亮; 吕国生; 张天琦; 吴尚; 陈大磊
Original assignee: Shanghai Railway Academy Rail Transit Technology Co Ltd; Tongji University
Current assignee: Shanghai Railway Academy Rail Transit Technology Co Ltd; Tongji University
Priority date: 2019-10-10
Filing date: 2019-10-10
Publication date: 2020-01-03
Anticipated expiration: 2039-10-10
Also published as: CN110644292B

Abstract

The invention discloses a spring vibration isolator jacking method of a floating slab track, which is characterized in that according to the characteristic that the supporting stress of the spring vibration isolator of the floating slab track conforms to the hyperstatic principle of a structure, the supporting state of a certain point is changed to influence the stress of an adjacent support, the larger the supporting amplitude is changed, the larger the influence degree is, the farther the distance between the adjacent support points is, the smaller the influence degree is, and according to the characteristics, a gradual iteration convergence method is adopted to jack the floating slab track by the spring vibration isolator, so that the jacking height required by the floating slab track is gradually approached; through finite element analysis and calculation, the accurate control of the jacking amount is realized, the jacking sequence is established according to the mutual influence degree, the control by depending on experience accumulation of operators can be avoided, the jacking efficiency of the floating plate can be improved, the supporting uniformity of the vibration isolation spring after jacking is further improved, and the mounting quality of the floating plate is improved.

Description

Spring vibration isolator jacking method for floating slab track

Technical Field

The invention relates to the technical field of rail transit, in particular to a method for jacking a spring vibration isolator of a floating slab rail.

Background

The floating plate track has excellent vibration isolation effect, so that the floating plate track is widely applied to urban rail transit at present. The floating slab track is basically composed of a plurality of spring vibration isolators supported below a concrete track slab, and the construction method is that after cast-in-place or precast concrete slabs are placed according to requirements, special tools are applied to lift the spring vibration isolators placed below the slab one by one according to requirements, usually 1 or 2 vibration isolators are lifted simultaneously, spacers with different thicknesses can be placed on the upper portions of the springs in the lifting process to place the track slab on the spring vibration isolators according to the height, the level and the like of a track line, and the conditions of the line type, the level and the like of the track line are met.

After the spring floating slab track in an ideal state is jacked, the track structure achieves geometric conditions such as line-type elevation and the like specified by a line, and the spring vibration isolator is required to be uniformly supported and stressed, namely the counter force borne by each spring is uniform and equal. But because each floating plate track board has transferred a plurality of spring isolator, belongs to the hyperstatic structure in the structure, and the jacking of each spring isolator can produce the influence to other spring isolators, need not consider the elevation of circuit at concrete jacking in-process, also need consider the pressure that receives spring isolator simultaneously, is a more complicated operation process. At present, no uniform professional method exists in actual work, and the main purpose is to ensure the elevation of a line. Because there is certain uncertainty in jacking operation, the line elevation can be observed and controlled through a measuring instrument, the stress of the spring vibration isolator is influenced by mutual jacking, the control factors are complex and mainly performed by depending on experience accumulation of operators, and the uneven and ubiquitous supporting state of the spring is caused after the actual laying of the spring floating slab track is completed.

The spring support counter force of the floating slab track is uneven to a certain extent, although the geometric shape and position of the track can be kept to meet the line condition, when the train passes through the track, the dynamic displacement of the train running is caused to generate uneven change due to uneven support counter force, so that the stability of the train is influenced, the phenomenon is unfavorable for the vibration reduction and noise reduction performance of the track, and the safe running of the train is threatened in serious cases.

Disclosure of Invention

The invention aims to provide a spring vibration isolator jacking method for a floating slab track, which aims to solve the problems in the prior art, and can improve the jacking efficiency of a floating slab, further improve the supporting uniformity of the spring vibration isolator after jacking and improve the installation quality of the floating slab by reasonably jacking the spring vibration isolator.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a spring vibration isolator jacking method of a floating slab track, which is characterized in that according to the characteristic that the supporting stress of the spring vibration isolator of the floating slab track conforms to the hyperstatic principle of a structure, the supporting state of a certain point is changed to influence the stress of an adjacent support, the larger the supporting amplitude is changed, the larger the influence degree is, the farther the distance between the adjacent support points is, the smaller the influence degree is, and according to the characteristics, a gradual iteration convergence method is adopted to jack the floating slab track by the spring vibration isolator to gradually approach the jacking height required by the floating slab track.

Preferably, finite element stress analysis calculation is carried out on the spring vibration isolator, and a control value of the spring vibration isolator for jacking displacement of the floating slab track is provided.

Preferably, according to a jacking value obtained by stress analysis and calculation, a gradual iterative convergence method is adopted to perform jacking gradual approximation, a jacking program starts to approximate from two ends of a floating slab track to the middle part, the jacking height of the floating slab is based on the elevation required by the floating slab track, and the jacking error of each group of spring vibration isolators is smaller than 0.5mm from low to high, so that the design requirements are gradually met.

Preferably, when the spring vibration isolator performs displacement jacking on the floating plate rail, the stress of the spring vibration isolator is monitored, and the final stress value of the spring vibration isolator is controlled to be the average value of the stress of all the spring vibration isolators in the previous cyclic jacking process.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention provides a method for jacking a spring vibration isolator of a floating slab track, aiming at the mechanical characteristics of a spring vibration isolator support of the floating slab track, and the influence rule of each supporting point change on the adjacent supporting points are calculated and analyzed, a corresponding jacking method is provided, the jacking sequence and amplitude are set according to the stress characteristics and the mutual influence of the change of the statically indeterminate structure, a gradual approaching route is adopted, the method is to carry out scientific calculation on the stress change of the structure, particularly to fully utilize the mutual relation between the displacement and the stress of the hyperstatic structure of the plate support, and adopt the iterative successive approximation principle in mathematics to realize the double control of the displacement and the stress, the jacking device has the advantages that the jacking can be completed through two cycles, and the traditional self-jacking by manpower can be completed through more than 5 jacking cycles; the method has the advantages that the jacking precision is high, the method is provided on the basis of the stress characteristics and the change rule of the statically indeterminate structure of the floating plate, iteration gradual approximation is adopted, the jacking sequence is established according to the mutual influence degree, the influence degree of jacking at a certain point on other points is improved, the jacking precision is guaranteed through iteration convergence, control is not needed to be carried out through accumulated experience of operators, the precision can be controlled through an operation program, particularly, elevation and pressure double control of the floating plate spring vibration isolator in the jacking process is realized, the stress precision of the twice circulating spring vibration isolator can be controlled within an error range of 200kg, the elevation precision can be controlled to be about 0.3mm, and the method is greatly higher than that of the traditional method and is only used for controlling the elevation precision to be 1 mm. However, in the conventional method, because the elevation control and the stress control are often influenced mutually and cannot be considered at the same time when the spring vibration isolator is operated, the stress control is generally not required in the operation, the stress of the floating slab spring vibration isolator after the actual laying is often uneven, even the suspension phenomenon of the individual spring vibration isolator is found, so that the vibration reduction effect of the floating slab track is influenced by different degrees, which is also a problem often appeared in the current floating slab track, and the problem can be fundamentally solved after the method is adopted.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic structural view of a floating plate track with a spring isolator according to the present invention;

FIG. 2 is a schematic perspective view of a floating plate having a plurality of spring isolators positioned at the bottom thereof according to the present invention;

FIG. 3 is a finite element model of a floating plate with a plurality of spring isolators, respectively, at the bottom of the floating plate according to the present invention;

FIG. 4 is a pressure curve diagram of the spring vibration isolator during the lifting process of the floating slab in the invention;

FIG. 5 is a graph of a difference between the elevation of the upper surface of the floating plate at the jacking point and the design elevation during jacking of the spring isolator of the present invention;

in the figure: the vibration isolator comprises a spring isolator 1-I, a spring isolator 2-II, a spring isolator 3-III, a spring isolator 4-IV, a spring isolator 5-V, a spring isolator 6-VI, a spring isolator 7-VII, a spring isolator 8-eight, a spring isolator 9-ninth, a spring isolator 10-tenth and a floating plate 11.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a method for jacking a spring vibration isolator of a floating slab track, which aims to solve the problems in the prior art.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

The basic principle of the invention is to set a targeted jacking program according to the stress principle of the floating plate track spring vibration isolator, thereby realizing the purposes of improving the jacking effect and improving the supporting uniformity. The floating plate structure belongs to a multipoint support plate system in mechanics, the multipoint supported plate structure belongs to a statically indeterminate structure in mechanics, according to the statically indeterminate theory, the support change of each point can affect adjacent points, if a certain point support point is lifted, the support force of other adjacent points can be reduced, the change amplitude is related to the rigidity of the floating plate and the spring and the arrangement of the support points and also related to the mutual positions of lifting fulcrums, according to calculation, the lifting of the floating plate by a certain point spring for 2mm can reduce the stress of the adjacent point spring vibration isolator by about one third, the height can also rise by about 0.7mm, the lifting of a certain point spring for 1mm can reduce the stress of the adjacent point spring vibration isolator by about one fourth, the height can also rise by about 0.3mm, the influence of the factors is considered, the position order and amplitude control of the lifting fulcrums are reasonably arranged, the jacking is gradually approached to reach the design height, and a better jacking effect can be realized.

Based on the principle, the invention provides a method for jacking the spring vibration isolator of the floating slab track, which is characterized in that according to the condition that the supporting stress of the spring vibration isolator of the floating slab track conforms to the structural hyperstatic principle characteristic, the change of the supporting state of a certain point can affect the stress of adjacent supporting points, the larger the change of the supporting amplitude is, the larger the influence degree is, the farther the distance between the adjacent supporting points is, the smaller the influence degree is, and according to the characteristics, a gradual iteration convergence method is adopted to jack the floating slab track by the spring vibration isolator, so that the jacking height required by the floating slab track is gradually approached.

Specifically, finite element stress analysis and calculation are carried out on the spring vibration isolator, and a control value of the spring vibration isolator for jacking displacement of the floating slab track is provided; according to the jacking value obtained by the stress analysis and calculation, adopting a gradual iterative convergence method to carry out jacking gradual approximation, wherein the jacking program is to approach from the two ends of the floating slab track to the middle part, the jacking height of the floating slab is based on the elevation required by the floating slab track, and the jacking error of each group of spring vibration isolators is smaller than 0.5mm from low to high, so as to gradually meet the design requirement; when the spring vibration isolator performs displacement jacking on the floating plate rail, stress of the spring vibration isolator is monitored, and the final stress value of the spring vibration isolator is controlled to be the average value of the stress of all the spring vibration isolators in the previous cycle jacking process.

Taking a common concrete floating slab with the length of 6 meters as an example for explanation, fig. 2 is a schematic view of a three-dimensional structure of a floating slab which is already preliminarily installed, and with reference to fig. 2, the concrete jacking steps are as follows:

(1) according to the orbital elevation of floating slab, the jacking is located spring isolator 1, No. two spring isolator 2, No. three spring isolator 3 and No. four spring isolator 4 of 11 four angle departments of floating slab, and the jacking height is about being less than design elevation (the orbital jacking height of the required floating slab of design) 3mm, and hydraulic pressure jacking device pressure when every some jacking of record.

(2) The jacking height is about less than 2mm of the designed elevation, the display pressure in the hydraulic jacking device is recorded when the two points are jacked, and the pressure at the moment is slightly lower than the pressure of the first spring vibration isolator 1, the second spring vibration isolator 2, the third spring vibration isolator 3 and the fourth spring vibration isolator 4.

(3) And continuing to lift the rest 4 seven spring vibration isolators 7, eight spring vibration isolators 8, nine spring vibration isolators 9 and ten spring vibration isolators 10, wherein the lifting height is about 2mm of the design elevation, is slightly higher than the lifting height of the five spring vibration isolators 5 and the six spring vibration isolators 6, and the pressure is displayed in the hydraulic lifting device during the four-point lifting.

(4) Averaging all jacking point recorded pressure values, accurately jacking, wherein the operation sequence is the same as that of the previous time, jacking a first spring vibration isolator 1, a second spring vibration isolator 2, a third spring vibration isolator 3 and a fourth spring vibration isolator 4 which are positioned at four corners of a floating slab 11, the jacking height is about 0.5mm lower than the design elevation, checking the jacking pressure to be about the average value of the jacking pressure values of all the previous vibration isolation springs, jacking a fifth spring vibration isolator 5 and a sixth spring vibration isolator 6, the jacking height to be about 0.3mm lower than the design elevation, and checking the jacking pressure to be about the average value of all the jacking pressure values of all the previous vibration isolation springs; and finally, jacking the rest 4 seven-spring vibration isolators 7, eight-spring vibration isolators 8, nine-spring vibration isolators 9 and ten-spring vibration isolators 10, wherein the jacking height is about the designed elevation, and the checking jacking pressure is about the average value of the jacking pressure values of all the previous vibration isolation springs. And finishing the jacking of the floating plate spring vibration isolator according to the steps.

The following describes an implementation process of the present invention by way of example with reference to fig. 4 and 5, where fig. 4 and 5 are a pressure curve of a spring of a vibration isolator during a jacking process of a floating slab and a curve of a difference between an elevation of an upper surface of the floating slab at a jacking point and a design elevation, and fig. 1, 2, 3, and 4 in the two figures represent a first spring vibration isolator, a second spring vibration isolator, a third spring vibration isolator, and a fourth spring vibration isolator, respectively; 5. 6 respectively represents a fifth spring vibration isolator and a sixth spring vibration isolator; 7. 8, 9 and 10 respectively represent a seven-spring vibration isolator, an eight-spring vibration isolator, a nine-spring vibration isolator and a ten-spring vibration isolator; the jacking process is simulated by a finite element model, as shown in fig. 3, the model can simulate a floating plate unit plate with the thickness of 300mm and the length of 6000mm, the longitudinal interval of the spring vibration isolator is 1200mm, the mass of the floating plate 11 is 10800kg, the model sequentially lifts by controlling the vertical displacement of the spring vibration isolator to simulate the jacking process of the floating plate, and the concrete jacking steps are as follows:

(1) the jacking height is about 3.5mm below the design elevation, and after the jacking is completed, the jacking force of recording four points is about 2700 kg.

(2) Jacking a fifth spring vibration isolator 5 and a sixth spring vibration isolator 6 which are positioned in the middle of the floating slab 11, wherein the jacking height is about 2mm lower than the designed elevation, and recording that the display pressure in the hydraulic jacking device is about 1800kg when the two points are jacked;

(3) and continuously jacking the rest 4 seven-spring vibration isolators 7, the eight-spring vibration isolator 8, the nine-spring vibration isolator 9 and the ten-spring vibration isolator 10, wherein the jacking height is about 1mm lower than the design elevation, and the display pressure in the hydraulic jacking device is about 1100kg when the 4-point jacking is recorded.

(4) Calculating the jacking average pressure to obtain the average jacking pressure of 1080 kg; carrying out accurate jacking, jacking a first spring vibration isolator 1, a second spring vibration isolator 2, a third spring vibration isolator 3 and a fourth spring vibration isolator 4 which are positioned at four corners of a floating slab 11, wherein the jacking height is about 0.6mm lower than the design elevation, the jacking pressure at the moment is 1470kg, the requirement of the checking regulation is met, further jacking a fifth spring vibration isolator 5 and a sixth spring vibration isolator 6 in the middle of the floating slab, the jacking height is about 0.4mm lower than the design elevation, the checking jacking pressure is about 1300kg, the checking requirement is met, finally jacking the rest 4 seventh spring vibration isolators 7, eighth spring vibration isolators 8, ninth spring vibration isolators 9 and tenth spring vibration isolators 10, the jacking height is about the design elevation, the checking jacking pressure is about 1050kg, and the checking requirement is met; and after the completion, performing elevation check on the whole floating plate unit, finishing jacking after no error exists, and repeating the steps if the error exceeds the standard. In fig. 4 and 5, after the floating slab is finally lifted, the lifting pressure of each spring tends to be equal, and the displacement of the lifting point approaches to the elevation. Thus, the lifting of the floating plate spring vibration isolator is accurately finished.

The principle and the implementation mode of the invention are explained by applying specific examples, and the description of the above examples is only used for helping understanding the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In summary, this summary should not be construed to limit the present invention.

Claims

1. A spring vibration isolator jacking method of a floating slab track is characterized by comprising the following steps: the jacking method is characterized in that according to the characteristic that the supporting stress of the spring vibration isolator of the floating slab track conforms to the structural hyperstatic principle, the supporting state of a certain point is changed to influence the stress of the adjacent support, the larger the supporting amplitude is changed, the larger the influence degree is, and the farther the distance between the adjacent support points is, the smaller the influence degree is, and according to the characteristics, a gradual iterative convergence method is adopted to jack the spring vibration isolator to the floating slab track to gradually approach the jacking height required by the floating slab track.

2. The method of jacking a spring isolator of a floating plate track of claim 1, wherein: and carrying out finite element stress analysis and calculation on the spring vibration isolator, and providing a control value of the spring vibration isolator to the jacking displacement of the floating slab track.

3. The method of jacking a spring isolator of a floating plate track of claim 2, wherein: and (3) according to the jacking value obtained by the stress analysis and calculation, adopting a gradual iterative convergence method to perform jacking gradual approximation, wherein the jacking procedure is to approach from the two ends of the floating slab track to the middle part, the jacking height of the floating slab is based on the elevation required by the floating slab track, and gradually reaches the design requirement from low to high by taking the jacking error of each group of spring vibration isolators to be less than 0.5mm as a control target.

4. The method of claim 3, wherein the spring isolator jacking method comprises: and when the spring vibration isolator performs displacement jacking on the floating slab track, monitoring the stress of the spring vibration isolator, and controlling the final stress value of the spring vibration isolator to be the average value of the stress of all the spring vibration isolators in the previous cycle jacking process.