CN-121834999-B - Fulcrum elevation determination method and device for steel truss girder pushing construction

CN121834999BCN 121834999 BCN121834999 BCN 121834999BCN-121834999-B

Abstract

The application relates to a method and a device for determining the elevation of a fulcrum in pushing construction of a steel truss girder, the current counter force of the sliding block is checked in real time through the finite element simulation covering pushing full construction working condition, and the sliding block with the exceeding counter force is subjected to targeted adjustment only. And calculating the actual elevation adjustment amount by means of the quantitative corresponding relation between the unit elevation adjustment amount and the unit adjustment counter force, and controlling the counter force of each sliding block within the target counter force range. Through the dynamic optimization adjustment of the elevation of the sliding blocks under each working condition, the stress transmission path of the steel truss girder is more reasonable, the problem that the counter force of the temporary pier is overlarge and an individual fulcrum in the pushing of the heavy steel truss girder is effectively solved, and therefore materials for the temporary pier are saved. The flow constructed by the method takes finite element calculation as a core basis, abandons a subjective judgment mode depending on construction experience, and outputs a slider elevation adjustment strategy scheme for constructors to directly refer to and execute.

Inventors

DONG CHUANGWEN
ZENG GUODONG
LI CHUANXI
TAN LIXIN
WU YUXIAN
LIU CHENGHONG
FENG ZHENG

Assignees

长沙理工大学
佛山市交通科技有限公司
广西大学
保利长大工程有限公司

Dates

Publication Date: 20260512
Application Date: 20260316

Claims (9)

1. The fulcrum elevation determining method for the pushing construction of the steel truss girder is characterized by comprising the following steps of: Determining target counter force of the sliding blocks on each temporary pier according to the construction working condition of pushing of the steel truss girder ; Checking the current counter force of each sliding block from the initial working condition through simulating each construction working condition of pushing of the steel truss girder by finite elements ; If working conditions are met Is of the order of (a) Is the current reaction force of (a) Exceeding the target reaction force Starting the elevation adjustment of the sliding block; given slider Unit elevation adjustment amount Then, carrying out finite element calculation again to obtain new unit adjustment counter force of each sliding block, wherein if the working condition is that Is a single slider of (a) Is the current reaction force of (a) Exceeding the target reaction force Given a slider Unit elevation adjustment amount After that, calculate the slider The corresponding temperature load is , wherein, Is under the working condition of Lower slide block Is used for the length of the unit of (a), The temperature expansion coefficient of the material of the sliding block; to the slide block The unit applying a temperature load Carrying out finite element calculation again to obtain new unit adjustment counter force of each sliding block ; Adjusting the reaction force according to the unit And unit elevation adjustment amount The corresponding relation between the two is obtained to obtain the current counter force Adjust to be less than or equal to the target counter force The actual elevation adjustment amount of (2) is ; Adjusting slide block according to actual elevation adjustment quantity After the current elevation of the steel truss girder, continuously executing the subsequent construction working conditions of pushing the steel truss girder, and circularly checking the current counter force of each sliding block And outputting the slide block elevation adjustment strategy scheme until all the construction working conditions are executed.
2. The method for determining the elevation of a fulcrum in pushing construction of a steel truss girder according to claim 1, wherein the slider is adjusted according to an actual elevation adjustment amount After the current elevation of (2), further comprising: carrying out finite element calculation again to obtain actual adjustment reaction force after the elevation of each sliding block fulcrum in the working condition is adjusted; if the actual adjustment reaction force is smaller than or equal to the target reaction force Continuing to execute the subsequent construction working conditions; If the actual adjustment reaction force is greater than the target reaction force According to the current reaction force of each sliding block In the case, the step of starting the slider elevation adjustment is cyclically executed until the actual adjustment reaction force is smaller than or equal to the target reaction force 。
3. The method for determining the elevation of a fulcrum in pushing construction of a steel truss girder according to claim 1, wherein a given slider is Unit elevation adjustment amount Then, the finite element calculation is carried out again to obtain new unit adjustment counter force of each sliding block, and the current counter force is adjusted to be smaller than or equal to the target counter force according to the corresponding relation between the unit adjustment counter force and the unit elevation adjustment amount Comprises: If working conditions are met At least two sliders of (a) Is the current reaction force of (a) Exceeding the target reaction force Then each overrun slide block is individually given in turn Unit elevation adjustment amount Calculating the temperature load corresponding to each sliding block as , wherein, Is under the working condition of Sliding block Is used for the length of the unit of (a), The temperature expansion coefficient of the material of the sliding block; for each overrun slide block in turn The unit applying a temperature load Carrying out finite element calculation again to obtain new unit adjustment counter force of each sliding block ; Adjusting the reaction force according to the unit Establishing an influence matrix of the counter-force increment Wherein the matrix is affected Elements of (2) Is defined as ; Adjusting the reaction force according to the unit And unit elevation adjustment amount The corresponding relation between the two is obtained to obtain the current counter force Adjust to be less than or equal to the target counter force Actual elevation adjustment of (2) The relation of (2) is that 。
4. The method for determining the elevation of a fulcrum in pushing construction of a steel truss girder according to claim 3, wherein the unit elevation adjustment amount is Is-10 mm.
5. A method for determining the elevation of a fulcrum in pushing construction of a steel truss girder according to any one of claims 1 to 3, wherein the target reaction force of the slider on each temporary pier is determined according to the construction condition of the pushing of the steel truss girder Comprising: counting the maximum counter force of each sliding block under different construction working conditions when the weight of the steel truss girder is supported by each sliding block And statistics of each slider when the steel truss girder weight is all supported by each slider Final reaction force under last construction condition Target reaction force Satisfy the following requirements 。
6. The method for determining the elevation of a fulcrum in pushing construction of a steel truss girder according to claim 5, wherein the target reaction force , wherein, 0.8-0.95.
7. A method for determining the elevation of a fulcrum in pushing construction of a steel truss girder according to any one of claims 1 to 3, wherein the construction condition of pushing the steel truss girder comprises: the working condition 1 is that a front walking machine and a rear walking machine are controlled to synchronously lift the steel truss girder according to the target vertical jacking force so as to enable all sliding blocks to be unloaded; working condition 2, controlling the forward extension of the walking machine by a pushing stroke to push the steel truss girder forward by a pushing stroke, and controlling the retraction of a vertical top oil cylinder of the walking machine to a run-out state; The working condition 3 is that the walking machine is controlled to reset; Working conditions 4, namely circularly executing working conditions 1 to 3 until the sliding block moves to a position close to the walking machine positioned in front; Controlling each walking machine to jack up the steel truss girder until each sliding block and the steel truss girder are emptied, stopping the machine, resetting the empty sliding blocks, and adjusting the height of the upper backing plate of the sliding blocks according to the sliding block elevation adjustment strategy scheme; and 6, circularly executing the working conditions 1-5 until pushing is in place.
8. The method for determining the elevation of a fulcrum in pushing construction of a steel truss girder according to claim 7, wherein the slider is adjusted according to an actual elevation adjustment amount Comprises: If working conditions are met Comprises an idle sliding block resetting procedure, and the sliding block is adjusted according to the actual elevation adjustment quantity Is at working condition Finish the process under the condition of The no-load slide block resetting procedure is not included, then under the working condition Under the working condition that the immediately previous working procedure comprises the no-load sliding block resetting procedure, the sliding block is adjusted according to the actual elevation adjustment quantity Is a current elevation of (c).
9. A fulcrum elevation determining device for steel truss girder pushes away in construction, its characterized in that, fulcrum elevation determining device includes: the target reaction force determining module is used for determining target reaction forces of the sliding blocks on each temporary pier according to the construction working conditions of pushing of the steel truss girder ; The finite element analysis module is used for simulating each construction working condition of the pushing of the steel truss girder through finite elements and checking the current counter force of each sliding block from the initial working condition; The judging module is used for judging the condition of the condition Is of the order of (a) Is the current reaction force of (a) Exceeding the target reaction force Starting the elevation adjustment of the sliding block; elevation adjusting module for working condition Is a single slider of (a) Is the current reaction force of (a) Exceeding the target reaction force Given a slider Unit elevation adjustment amount After that, calculate the slider The corresponding temperature load is , wherein, Is under the working condition of Lower slide block Is used for the length of the unit of (a), The temperature expansion coefficient of the material of the sliding block; to the slide block The unit applying a temperature load Carrying out finite element calculation again to obtain new unit adjustment counter force of each sliding block ; The calculation module is used for adjusting the counter force according to the unit And unit elevation adjustment amount The corresponding relation between the two is obtained to obtain the current counter force Adjust to be less than or equal to the target counter force The actual elevation adjustment amount of (2) is ; The circulation execution module is used for adjusting the sliding block according to the actual elevation adjustment quantity After the current elevation of the slide blocks, continuing to execute the subsequent construction working conditions of pushing the steel truss girder, and circularly checking the current counter force of each slide block until all the construction working conditions are executed; the scheme output module is used for outputting a slide block elevation adjustment strategy scheme.

Description

Fulcrum elevation determination method and device for steel truss girder pushing construction Technical Field The application relates to the technical field of bridge pushing construction, in particular to a method and a device for determining fulcrum elevation in steel truss girder pushing construction. Background The steel truss girder has the remarkable advantages of strong bearing capacity, large spanning capacity, easiness in realizing double-deck bridge deck arrangement and the like, and is widely applied to large-span bridge engineering. The pushing method is used as one of the core construction methods of the steel truss bridge, and becomes a preferable construction scheme in various bridge projects by virtue of the characteristics of high construction speed, low requirements on sites and small influence on surrounding environments. At present, a mainstream walking pushing method in steel truss girder pushing construction comprises various forms, however, no matter which walking pushing mode is adopted, the problem of reasonable setting of the fulcrum elevation of a girder body is faced, the setting of the fulcrum elevation directly influences the stress state of a pushing pier, the problem is particularly prominent in heavy steel truss girder construction with larger pushing weight, if the fulcrum elevation is improperly set, the stress overload of the pushing pier is easily caused, and potential safety hazards such as structural deformation, stability reduction and the like are further caused, so that the construction quality and the progress are influenced. In order to solve the above-mentioned problem, for example, patent application CN118814649a proposes a technology for adjusting the height of a support to optimize the pushing support reaction force, by raising the height of a shoveling pad of a sliding block fulcrum of an adjacent temporary support of a concrete pier, and simultaneously lowering the height of the shoveling pad of the sliding block fulcrum of a support at the side of the pier, the pushing construction support reaction force of the support at the side of the pier is lowered. In order to obtain accurate supporting counter force of each bracket, a finite element method beam unit model is established, finite element analysis is carried out aiming at different shoveling pad adjusting working conditions, and then an optimal shoveling pad adjusting scheme is obtained. However, the technology only provides the thought of optimizing the supporting reaction force through the shoveling pad height adjustment, a specific shoveling pad adjustment scheme acquisition method is not explicitly provided, and the problems of uneven supporting point reaction force and overlarge temporary pier stress in the pushing of the heavy steel truss girder are difficult to fundamentally solve. In summary, the existing steel truss girder walking pushing construction technology has obvious defects in the aspect of fulcrum elevation setting, and the existing improvement technology lacks a concrete scheme capable of falling to the ground, so that a technology capable of accurately and efficiently determining a fulcrum shoveling pad adjustment scheme is required to be developed so as to optimize the fulcrum reaction distribution in the heavy steel truss girder pushing process, reduce the pushing pier stress, ensure the construction safety and structural stability and meet the actual engineering construction requirements. Disclosure of Invention In view of the above, it is necessary to provide a method and apparatus for determining the elevation of a fulcrum point in pushing construction of a steel truss girder. The fulcrum elevation determining method for the pushing construction of the steel truss girder comprises the following steps: Determining target counter force of the sliding blocks on each temporary pier according to the construction working condition of pushing of the steel truss girder ; Checking the current counter force of each sliding block from the initial working condition through simulating each construction working condition of pushing of the steel truss girder by finite elements; If working conditions are met Is of the order of (a)Is the current reaction force of (a)Exceeding the target reaction forceStarting the elevation adjustment of the sliding block; given slider Unit elevation adjustment amountThen, carrying out finite element calculation again to obtain new unit adjustment counter force of each sliding block; Obtaining the current counter force according to the corresponding relation between the unit adjustment counter force and the unit elevation adjustment amount Adjust to be less than or equal to the target counter forceIs an actual elevation adjustment amount; Adjusting slide block according to actual elevation adjustment quantity And (3) continuously executing the subsequent construction working conditions of pushing the steel truss girder, and circularly checking the current counter