Bridge design method and system based on inverse analysis of displacement and stiffness by jacking

Abstract

The present invention proposes a bridge design method and system based on the inverse analysis of jacking displacement and stiffness, which belongs to the field of bridge design technology. By deriving the theoretical formula between the axial force of each span of steel box girder under the temperature change of the system after each jacking in the process of walking jacking construction, the displacement at each pier and the anti-thrust stiffness of the pier are compared, combined with the actual monitoring data of the length change of the steel box girder during the walking jacking construction process, the anti-thrust stiffness of each pier is inversely analyzed using numerical analysis software, and the curve trend of the anti-thrust stiffness changing with temperature difference under theoretical conditions is obtained, which improves the theoretical analysis of the influence of the system temperature effect on the longitudinal bridge direction during the walking jacking construction process, and provides data support for the implementation of subsequent measures such as pier stiffness adjustment and displacement release; by calculating the sparsification parameters of missing data, the adaptability to unbalanced data and data noise redundancy are stronger, which is suitable for filling missing data in the field of bridge design that is easily affected by natural factors.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge design, and in particular relates to a bridge design method and system based on jacking displacement and stiffness inversion. Background Art

[0002] The walking jacking construction method is widely used in the design and construction of long steel box girder bridges with large spans due to its advantages, such as minimal impact on the space under the bridge, uniform and reasonable stress on the beam, smooth and reliable construction, high construction precision, self-balancing jacking, and applicability to various complex working conditions. Steel box girders are increasingly widely used in the construction of long-span steel bridges in my country due to their advantages such as low deadweight, high strength, high rigidity, superior performance, and convenient construction and installation. Compared with concrete, steel has a high thermal conductivity, low specific heat capacity, and a large linear expansion coefficient, making it more susceptible to changes in ambient temperature. Furthermore, the steel box girder structure is relatively complex, and its cross-section is affected by nonlinear temperature gradients under changes in solar temperature. Therefore, the impact of temperature loads on steel structures cannot be ignored.

[0003] During the walking jacking process of the main bridge of a long steel box girder bridge, as the length of the steel box girder becomes longer and longer, the influence of system temperature changes, that is, the temperature difference between day and night, gradually increases. The temperature effect will cause relative displacement between the steel box girder, the bridge piers, and the temporary pads; and the concrete piers will change their anti-thrust stiffness due to factors such as time, temperature changes, and air humidity, and will not match the initial calculated stiffness. The above reasons may affect the safety and reliability of the jacking construction process, so it is necessary to perform inverse analysis of the jacking displacement, main bridge stiffness, etc.; in addition, due to the influence of factors such as construction conditions and monitoring equipment, the measurement data such as the length of the steel box girder may be missing, which in turn leads to inaccurate data variables during the inverse analysis. Summary of the Invention

[0004] In order to solve the above-mentioned problems existing in the prior art, the present invention proposes a bridge design method and system based on jacking displacement and stiffness inversion to improve the accuracy of inversion analysis, and ensure the safety and reliability of the jacking construction process through inversion analysis, thereby meeting the bridge design requirements.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a bridge design method based on jacking displacement and stiffness inversion, specifically comprising the following steps: Step 1): establishing a mechanical model of axial force and displacement under system temperature changes during the jacking process during bridge construction; Step 2): based on the mechanical model in Step 1), deriving the theoretical formula of the axial force and longitudinal displacement of each span of the steel box girder under system temperature changes after each jacking in the one-span, two-span and three-span step jacking construction process, and generalizing it to the case of jacking any span; Step 3): monitoring and analyzing the length monitoring data of the steel box girder during the jacking process, and using the filling method to complete the data with missing data to obtain the processed monitoring data. Measured data; Step 4): Based on the mechanical model in Step 2) and the processed monitoring data in Step 3), an inversion analysis is performed, and the numerical analysis software is used to solve the problem. The anti-thrust stiffness of each pier is inversely analyzed, and the change in the anti-thrust stiffness of each pier under temperature change is calculated; Step 5): Obtain the theoretical anti-thrust stiffness change of each pier; Step 6): According to the change in the anti-thrust stiffness of each pier and the theoretical anti-thrust stiffness change, adjust the anti-thrust stiffness of each pier: determine whether the difference between the change in the anti-thrust stiffness of the pier and the theoretical anti-thrust stiffness change exceeds a preset threshold. When the difference exceeds the preset threshold, adjust the anti-thrust stiffness of the pier. When the difference does not exceed the preset threshold, maintain the original anti-thrust stiffness of the pier unchanged.

[0006] Furthermore, the filling method includes: step S31: initializing the memory, and storing the length monitoring data into a one-dimensional data sample in the memory; step S32: detecting the position of the missing data in the current one-dimensional data sample and defining a position detection matrix idx with the same length as the one-dimensional data sample, returning 1 when there is missing data and assigning it to the corresponding position in the position detection matrix, otherwise returning 0 and assigning it to the corresponding position in the position detection matrix; step S33: based on the position of the missing data, calculating the sparsification parameters of the missing data; step S34: generating a random sample based on the sparsification parameters of the missing data; step S35: performing data filling processing on the missing values ​​based on the random sample to obtain processed monitoring data.

[0007] Furthermore, in step S33, based on the position of the missing data, the sparsification parameter of the missing data is calculated, specifically:

[0008] ;

[0009] Where Spar represents the sparsification parameter of missing data, max() represents the maximum value function, L represents the length of one-dimensional data samples, sum() represents the summation function, and idx represents the position detection matrix.

[0010] Furthermore, the random sample is generated in step S34, specifically:

[0011] ;

[0012] Where rndsmp represents a random sample, prod[] represents the array element multiplication function, betarnd() represents the function for generating Beta distribution random numbers, Data1 represents the first element of the non-missing element sequence in the one-dimensional data sample, Data2 represents the sum of the remaining elements in the non-missing element sequence in the one-dimensional data sample after removing the first element, sum[] represents the summation function, and randg(Spar) represents the generation of Gamma distribution random numbers with shape parameter Spar.

[0013] Furthermore, in step S35, data filling processing is performed on the missing values ​​based on the random sample, specifically, the mean of the random sample rndsmp is used as the filling reference value, and for each missing value, the filling reference value is multiplied by the adjustment coefficient as the final filling value to fill the missing value data.

[0014] Furthermore, in step 1), the walking jacking construction model of the long steel box girder is taken as the research object, and a mechanical model of the axial force and displacement under the temperature change of the jacking process system is established. The jacking direction is from left to right, the leftmost end is a fixed hinge support, and the remaining supports are all movable hinge supports.

[0015] In addition, the present invention also proposes a bridge design system based on jacking displacement and stiffness inversion, which is used to execute the above-mentioned bridge design method based on jacking displacement and stiffness inversion, including a data acquisition unit, a model construction unit and a numerical analysis unit, the data acquisition unit is connected to the numerical analysis unit, and the model construction unit is connected to the numerical analysis unit; the data acquisition unit is used to monitor and analyze the length monitoring data of the steel box girder during the jacking process, the model construction unit is used to establish a mechanical model of axial force and displacement under temperature changes of the jacking process system and derive theoretical formulas, and the numerical analysis unit is used to perform inversion analysis.

[0016] The beneficial technical effects of the present invention compared with the prior art are:

[0017] (1) The present invention derives a theoretical formula between the axial force of each span of steel box girders under system temperature changes after each jacking process, the displacement at each pier, and the pier anti-thrust stiffness, and combines the actual monitoring data of the steel box girder length changes during the walking jacking construction process. The numerical analysis software is used to perform an inverse analysis on the anti-thrust stiffness of each pier, and the curve trend of the anti-thrust stiffness changing with temperature difference under theoretical conditions is obtained, which improves the theoretical analysis of the influence of the system temperature effect on the longitudinal bridge direction during the walking jacking construction process; through the inverse analysis of the jacking displacement and stiffness, the pier anti-thrust stiffness under a certain temperature change is calculated, thereby providing data support for the implementation of subsequent measures such as pier stiffness adjustment and displacement release, thereby improving the safety and reliability of bridge design and jacking construction process;

[0018] (2) The present invention calculates the sparsification parameters of missing data during data filling. Compared with the mean filling method or mode filling method in the prior art, the present invention has stronger adaptability to unbalanced data and data noise redundancy. It is suitable for filling missing data in the field of bridge design that is easily affected by natural factors, and objectively ensures the accuracy of inversion analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0020] Figure 1 This is a simplified calculation model diagram of the pushing process of the present invention;

[0021] Figure 2 This is a calculation model diagram of the basic structure of a push-up span of the present invention;

[0022] Figure 3 This is a calculation model diagram of the basic structure of two spans of jacking in the present invention;

[0023] Figure 4 This is a calculation model diagram of the three-span basic structure of the jacking method of the present invention;

[0024] Figure 5 This is a calculation model diagram of the n-span basic structure of the jacking of the present invention;

[0025] Figure 6 A simplified flow chart of the bridge design method based on jacking displacement and stiffness inversion of the present invention;

[0026] Figure 7 The figure is a simplified flow chart of the completion method of the present invention. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] The following first describes the concepts involved in this application with reference to the accompanying drawings. It should be noted that the following description of each concept is intended only to make the content of this application easier to understand and does not limit the scope of protection of this application. At the same time, the embodiments and features in the embodiments of this application can be combined with each other unless there is a conflict. The following detailed description of this application will be made with reference to the accompanying drawings and in conjunction with the embodiments.

[0029] The bridge design method based on jacking displacement and stiffness inversion proposed in this invention is combined with the appendix of the specification. Figure 6 , specifically including the following steps: Step 1): Establish a mechanical model of axial force and displacement under temperature changes of the system during the jacking process during bridge construction;

[0030] As the instruction manual Figure 1 As shown, the pushing direction is from left to right (A→B→C...), where the leftmost end (end A) is a fixed hinge support, and the remaining supports (end B, end C...) are all movable hinge supports. The overall temperature rise of the main bridge (steel box girder) is t0, the linear expansion coefficient of steel is α, the tensile stiffness of the steel box girder is EA, and the bending stiffness of the concrete pier is EI i (i = 1, 2, 3, …, n), with the spacing between each jacking attempt being l. To analyze the temperature effects at each support of the steel box girder caused by the overall temperature fluctuation during the jacking process, it is necessary to calculate the axial force in each span of the steel box girder and the displacement along the jacking direction (longitudinal bridge direction) at each pier of the main bridge after each jacking attempt. This requires solving the general formula for the axial force and displacement after n jacking attempts. Since only the longitudinal displacement of the steel box girder is considered, that is, only the axial tensile stiffness EA of the steel box girder is considered, and its longitudinal bending stiffness EI is not considered, the steel box girder can be treated as a tie rod, simplifying the calculation model to a truss structure.

[0031] Step 2): Based on the mechanical model in step 1), derive the theoretical formulas for the axial force and longitudinal displacement of the steel box girder of each span under the temperature change of the system after each jacking in the one-span, two-span, and three-span walking jacking construction process, and generalize them to the case of jacking any span;

[0032] First, analyze the mechanical model in step 1): Figure 2 The one-span structure is a statically indeterminate structure. The right direction is the positive direction. Assuming that the AB rod is in compression, its internal force is X1, and the horizontal displacement under temperature load is Δ1t , the flexibility coefficient is δ 11 , the force method equation and its solution are as follows:

[0033] ;

[0034] ;

[0035] Where α is the linear expansion coefficient of steel; t0 is the overall temperature rise of the steel box girder; l is the first jacking distance; h is the height of the concrete pier; EA is the tensile stiffness of the steel box girder; EI1 is the bending stiffness of the pier; k1 is the anti-thrust stiffness of the pier, k1=3EI1 / h 3 Then we can get the axial force of the AB rod (axial force of the beam) F N1 for:

[0036] ;

[0037] The horizontal displacement of point B (longitudinal displacement of the beam) Δ1 can be obtained through the bending deformation of the BC rod:

[0038] ;

[0039] Where M1 is the first-level intermediate variable.

[0040] The situation of pushing two spans is as shown in the attached manual. Figure 3 As shown in the figure, this structure is twice statically indeterminate and can be solved using the horizontal displacement coordination condition of the common endpoint of the horizontal and vertical members. The right direction is the positive direction, and each member is in compression (the AB and BC members are both in compression, with their internal forces being X1 and X2 respectively. The same applies to the following cases). There are two ways to express the horizontal displacement of point C, the common endpoint of the BC and CE members: the horizontal displacement of point C caused by the bending moment of the CE member Δ C ; The horizontal displacement Δ' of point C caused by the axial forces of rods BC and AB (compression is negative) and the temperature change of rod BC (overall temperature increase is positive) C , the two expressions are calculated as follows:

[0041] ;

[0042] Where α is the linear expansion coefficient of steel; t0 is the overall temperature rise of the steel box girder; l is the first push spacing; h is the height of the concrete pier; EA is the tensile stiffness of the steel box girder; EI2 is the bending stiffness of the pier; k2 is the anti-thrust stiffness of the pier, k2=3EI2 / h 3 , M CE is a first-level intermediate variable, F NBC and F NAB are the axial forces of the corresponding rods.

[0043] Similarly, the horizontal displacement of point B, the common endpoint of rods AB and BD, can also be expressed in two ways: the horizontal displacement of point B caused by the bending moment of rod BD, Δ B ; The horizontal displacement Δ' of point B caused by the axial force of rod AB (compression is negative) and the temperature change of rod AB (overall temperature increase is positive) B , the two expressions are calculated as follows:

[0044] ;

[0045] Combined Δ C =Δ' C With Δ B =Δ' B And simplifying it, we can get the system of two linear equations:

[0046] ;

[0047] remember In the above formula, m1 is the first secondary intermediate variable, which can be solved to obtain the axial force of the AB rod and the BC rod (the axial force of the first and second span beams) F N1 、F N2 They are:

[0048] ;

[0049] Therefore, the horizontal displacements of points B and C (longitudinal displacements of the first and second span beams) Δ1 and Δ2 are:

[0050] .

[0051] The situation of pushing three spans is as follows Figure 4 As shown, this structure is a cubically indeterminate structure. Similar to the two-span jacking case, the solution is based on the horizontal displacement coordination condition for the shared endpoints of the horizontal and vertical members. The horizontal displacements of point D, the shared endpoint of the CD and DG members, point C, the shared endpoint of the BC and CF members, and point B, the shared endpoint of the AB and BE members, can be expressed in two ways and calculated as follows:

[0052] ;

[0053] Combined Δ D =Δ' D , Δ C =Δ' C , Δ B =Δ' B Three forms, and remember , then solve the above three-variable linear equations to obtain the axial forces F of the first, second and third span beams N1 、F N2 、F N3 The longitudinal displacements of the beam Δ1, Δ2, and Δ3 are:

[0054] ;

[0055] Push n span structure as shown in the instruction manual Figure 5 As shown in the figure, the structure is an n-order hyperstatic structure. Combining the derivation process and results of the two cases of jacking two spans and three spans, the axial force F of the i-th (i=1,2,3,……,n) span beam can be obtained by inductive solution. Ni The longitudinal displacement of the beam Δ i They are:

[0056] ;

[0057] ;

[0058] Where EA is the tensile stiffness of the steel box girder, α is the linear expansion coefficient of the steel, l is the spacing between each jacking, M represents the first-level intermediate variable, j represents the first-level intermediate variable number, i represents the span beam number, M i represents the i-th level intermediate variable, M i-1 represents the i-1th level intermediate variable, M j represents the jth level intermediate variable, M n Represents the nth level intermediate variable, M n-1 Indicates the n-1th level intermediate variable, m n represents the nth secondary intermediate variable, k n It represents the anti-thrust stiffness of the nth pier, and n represents the number of thrust spans.

[0059] Step 3): Monitor and analyze the length monitoring data of the steel box girder during the jacking process, and use the filling method to fill in the missing data to obtain the processed monitoring data; Figure 6-7 The filling method includes: step S31: initializing the memory, and storing the length monitoring data into a one-dimensional data sample in the memory; step S32: detecting the position of the missing data in the current one-dimensional data sample and defining a position detection matrix idx with the same length as the one-dimensional data sample, returning 1 when there is missing data and assigning it to the corresponding position in the position detection matrix, otherwise returning 0 and assigning it to the corresponding position in the position detection matrix; it can be understood that idx is a one-dimensional data sequence with a value of 0 or 1; step S33: calculating the sparsification parameter of the missing data based on the position of the missing data; step S34: generating a random sample based on the sparsification parameter of the missing data; step S35: performing data filling processing on the missing values ​​based on the random sample to obtain processed monitoring data.

[0060] In step S33, the sparsification parameters of the missing data are calculated based on the position of the missing data, specifically:

[0061] ;

[0062] Where Spar represents the sparsification parameter for missing data, max() represents the maximum value function, L represents the length of the one-dimensional data sample, sum() represents the summation function, idx represents the position detection matrix, and sum(idx) specifically represents the number of missing data. By calculating the above non-negative sparsification parameter, local sparsity control is achieved, which improves adaptability to imbalanced data and data noise redundancy.

[0063] The random sample is generated in step S34, specifically:

[0064] ;

[0065] Where rndsmp represents a random sample, prod[] represents the array element multiplication function, betarnd() represents the function for generating Beta distribution random numbers, Data1 represents the first element of the non-missing element sequence in the one-dimensional data sample, Data2 represents the sum of the remaining elements in the non-missing element sequence in the one-dimensional data sample after removing the first element, sum[] represents the summation function, and randg(Spar) represents the generation of Gamma distribution random numbers with shape parameter Spar.

[0066] In step S35, missing values ​​are filled based on the random sample. Specifically, the mean of the random sample rndsmp is used as a filling reference value, and for each missing value, the filling reference value is multiplied by an adjustment coefficient to obtain the final filling value. The adjustment coefficient is set to reduce the overlap of Beta-distributed random numbers and Gamma-distributed random numbers, thereby reducing the deviation between the filled data and the actual data.

[0067] The following demonstrates the results of missing value filling, based on monitoring and analysis of steel box girder length data from the jacking process of a Yellow River Bridge. During this monitoring and analysis of the steel box girder length data, missing girder length data were found at some pier locations, as shown in Table 1. This table presents the length monitoring data for the four spans (Pier 57# to Pier 62#) following the completion of the jacking process, from 2:00 PM on April 6th (ambient temperature 12°C) to 7:00 AM on April 7th (ambient temperature 5°C), under the influence of a 7°C temperature drop during the day and night. Due to factors such as construction conditions and monitoring equipment, data for Pier 58# is missing. The data for Pier 57# represents the mileage or total girder length of the two spans (Pier 57# and Pier 58#). The corresponding girder length change data also represents the total girder length change for both spans. Since the walking jacking construction of the steel box girder of this project has been completed, it is impossible to conduct on-site measurements to update the beam length change data. In addition, the location of the missing data in the subsequent sets of data is the same pier number (Pier 58#), and it is impossible to use data from other dates to fit and fill in the missing data. Therefore, the missing data can only be filled in using the existing data at other piers in this group. A more obvious consequence of this filling method is that the error cannot be controlled.

[0068] Table 1 Beam length measured data

[0069]

[0070] For this set of data, namely the missing data at Pier 58, the measured girder length change data is required as a variable in the subsequent inversion calculation. Therefore, the data completion method of the present invention is applied to complete the data for the two expected target values: the steel box girder length data or the steel box girder length change data. After data completion, the girder length data for all five piers and four spans are obtained. Based on this data, the girder length change data for all pier locations can be obtained, as shown in Table 2 below.

[0071] Table 2 Beam length supplement data table

[0072]

[0073] Step 4): Based on the mechanical model in step 2) and the processed monitoring data in step 3), an inversion analysis is performed, and the solution is obtained using numerical analysis software. The anti-thrust stiffness of each pier is inversely analyzed, and the change in the anti-thrust stiffness of each pier under temperature change is calculated; Step 5): Obtain the theoretical anti-thrust stiffness change of each pier; Step 6): According to the change in the anti-thrust stiffness of each pier and the theoretical anti-thrust stiffness change, the anti-thrust stiffness of each pier is adjusted, specifically, judging whether the difference between the change in the anti-thrust stiffness of the pier and the theoretical anti-thrust stiffness change exceeds a preset threshold, and adjusting the anti-thrust stiffness of the pier by increasing the pad height when the above difference exceeds the preset threshold, and maintaining the original anti-thrust stiffness of the pier unchanged when the above difference does not exceed the preset threshold, thereby meeting the safety and reliability requirements of the bridge design and jacking construction process.

[0074] The inversion process usually includes the establishment of a model containing a set of nonlinear equations, actual data observation and model optimization solution. For the mathematical model solution of nonlinear programming problems such as the above nonlinear equations, the idea of ​​optimization problem can be used to interactively optimize the problem and solve the nonlinear equations, so that the simulation results are most consistent with the actual observed data. For the nonlinear equations that need to be solved this time, the linear expansion coefficient of steel α, the tensile stiffness of steel box beam EA, the bending stiffness of concrete pier EI i (i=1,2,3,……,n)and the ejection distance l are known variables, and the displacement Δi(i=1,2,3,……,n)and the temperature change t are defined. The displacement Δ and m(m=k iThe relationship f(Δ m) between l / EA) consists of elementary functions and is relatively easy to create, transform, and modify. Therefore, a problem-based solution can be used. Problem-based solution is similar to linear programming and integer programming. First, the optimization problem is constructed using variables and expressions. This means that the unknown variable is defined as an optimization variable to describe the problem objective and constraints. The objective function in the problem object is defined as an expression in the named variables. An optimization problem object is then created and the objective expression and constraints are defined within it. The constraints of the optimization problem are then defined as comparisons of named variables or expressions. Finally, an initial point is given and the optimization problem is solved. For piers 57# to 62# (pier 62# is a fixed support and the others are sliding supports), based on 32 sets of monitored data, the displacement caused by temperature changes during the jacking of the fifth and sixth spans and the relationship between the anti-thrust stiffness are used for inverse calculation. The specific solution steps for the nonlinear equation group for the jacking of the five spans are as follows: (1) define five displacements (d1, d2, d3, d4, d5) and the temperature change (t); (2) use optimvar to define X as a five-element optimization variable. The optimization variable is a symbolic variable used to describe the problem objective and constraints; (3) define the objective function in the problem object as an expression in the named variable, that is, create four equations (eq1, eq2, eq3, eq4, eq5) as optimization equation expressions after deforming the nonlinear equation group to be solved; (4) use optimproblem to create an optimization problem object. The problem object is a container in which the objective expression and constraints are defined. In this problem, use eqnproblem to create an equation problem where the left and right sides of the equation are equal. (5) Define the optimization problem constraints as comparisons of named variables or expressions, that is, place four equations into the problem and compare the left and right sides of the five equations to ensure equality. (6) Use show to examine the problem. (7) Given an initial point ([0,0,0,0,0]), use solve to begin solving the problem. (8) Use disp to view the solution points. The results of the inverse calculation of the anti-thrust stiffness based on the above method and data are shown in Table 3 below.

[0075] Table 3 Stiffness inversion calculation results

[0076]

[0077] By analyzing the curve graph of anti-thrust stiffness and time during a period of jacking suspension and combining it with the day and night temperature changes during this period, it can be found that when the temperature difference between day and night is not large (the maximum temperature difference is 15°C), the integrated anti-thrust stiffness of the piers and pads will not change much. On dates with relatively large temperature differences, control measures such as increasing the anti-thrust stiffness (increasing the pad height) or performing longitudinal displacement release (installing slides) can be taken at piers with greater stiffness to reduce the impact of the system temperature effect and improve the safety and reliability of the walking jacking construction process.

[0078] In addition, the present invention also proposes a bridge design system based on jacking displacement and stiffness inversion, which is used to execute the above-mentioned bridge design method based on jacking displacement and stiffness inversion, including a data acquisition unit, a model construction unit and a numerical analysis unit, the data acquisition unit is connected to the numerical analysis unit, and the model construction unit is connected to the numerical analysis unit; the data acquisition unit is used to monitor and analyze the length monitoring data of the steel box girder during the jacking process, the model construction unit is used to establish a mechanical model of axial force and displacement under temperature changes of the jacking process system and derive theoretical formulas, and the numerical analysis unit is used to perform inversion analysis.

[0079] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present invention, and do not impose any form of limitation on the implementation methods of the technology of the present invention. Any person skilled in the art may make slight changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as technologies or embodiments that are essentially the same as the present invention.

[0080] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of this application, they can also make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. The bridge design method based on jacking displacement and stiffness inversion is characterized by: The specific steps include: Step 1): Establish a mechanical model of axial force and displacement under temperature changes in the jacking process during bridge construction; Step 2): Based on the mechanical model in step 1), derive the theoretical formula of the axial force and longitudinal displacement of each span of the steel box girder under the temperature change of the system after each jacking in the N-span step jacking construction process, where N is an arbitrary positive integer; Step 3): Monitor and analyze the length monitoring data of the steel box girder during the jacking process, and use the filling method based on the sparse parameters of the missing data to complete the missing data to obtain the processed monitoring data; Step 4): Based on the mechanical model in step 2) and the processed monitoring data in step 3), an inverse analysis is performed, and numerical analysis software is used to solve the problem. The anti-thrust stiffness of each bridge pier is inversely analyzed to calculate the change in the anti-thrust stiffness of each bridge pier under temperature changes; Step 5): Obtain the theoretical anti-thrust stiffness change of each pier; Step 6): According to the change in the anti-thrust stiffness of each pier and the change in the theoretical anti-thrust stiffness, the anti-thrust stiffness of each pier is adjusted: determine whether the difference between the change in the anti-thrust stiffness of the pier and the change in the theoretical anti-thrust stiffness exceeds a preset threshold. When the difference exceeds the preset threshold, the anti-thrust stiffness of the pier is adjusted. When the difference does not exceed the preset threshold, the original anti-thrust stiffness of the pier is maintained unchanged.

2. The bridge design method based on jacking displacement and stiffness inversion according to claim 1 is characterized in that: The filling method comprises the following steps: Step S31: Initialize the memory and store the length monitoring data into a one-dimensional data sample in the memory; Step S32: Detect the position of missing data in the current one-dimensional data sample and define a position detection matrix idx with the same length as the one-dimensional data sample. When there is missing data, return 1 and assign it to the corresponding position in the position detection matrix; otherwise, return 0 and assign it to the corresponding position in the position detection matrix. Step S33: Calculating the sparsification parameters of the missing data based on the location of the missing data; Step S34: generating random samples based on the sparsification parameters of the missing data; Step S35: performing data completion processing on the missing values ​​based on the random sample to obtain processed monitoring data.

3. The bridge design method based on jacking displacement and stiffness inversion according to claim 2 is characterized in that: In step S33, the sparsification parameters of the missing data are calculated based on the position of the missing data, specifically: ； Where Spar represents the sparsification parameter of missing data, max() represents the maximum value function, L represents the length of one-dimensional data samples, sum() represents the summation function, and idx represents the position detection matrix.

4. The bridge design method based on jacking displacement and stiffness inversion according to claim 3 is characterized in that: The random sample is generated in step S34, specifically: ； Where rndsmp represents a random sample, prod[] represents the array element multiplication function, betarnd() represents the function for generating Beta distribution random numbers, Data1 represents the first element of the non-missing element sequence in the one-dimensional data sample, Data2 represents the sum of the remaining elements in the non-missing element sequence in the one-dimensional data sample after removing the first element, sum[] represents the summation function, and randg(Spar) represents the generation of Gamma distribution random numbers with shape parameter Spar.

5. The bridge design method based on jacking displacement and stiffness inversion according to claim 4 is characterized in that: In step S35, the missing values ​​are filled based on the random sample. Specifically, the mean of the random sample rndsmp is used as the filling reference value, and for each missing value, the filling reference value is multiplied by the adjustment coefficient as the final filling value to fill the missing value data.

6. The bridge design method based on jacking displacement and stiffness inversion according to claim 1 is characterized in that: In step 1), the walking jacking construction model of the long steel box girder is taken as the research object, and a mechanical model of the axial force and displacement under the temperature change of the jacking process is established. The jacking direction is from left to right, the leftmost end is a fixed hinge support, and the remaining supports are all movable hinge supports.

7. A bridge design system based on jacking displacement and stiffness inversion, for executing the bridge design method based on jacking displacement and stiffness inversion according to any one of claims 1 to 6, characterized in that: It includes a data acquisition unit, a model building unit and a numerical analysis unit, the data acquisition unit is connected to the numerical analysis unit, and the model building unit is connected to the numerical analysis unit; the data acquisition unit is used to monitor and analyze the length monitoring data of the steel box girder during the jacking process, the model building unit is used to establish a mechanical model of axial force and displacement under temperature changes in the jacking process system and derive theoretical formulas, and the numerical analysis unit is used to perform inverse analysis.

Images