A full-scale optimization calculation method for cable force of a cable-stayed arch bridge

Abstract

This invention is a full-scale optimization calculation method for the cable force of a cable-stayed arch bridge. The specific steps are as follows: Establish a single-stage arch model; calculate the bare arch deformation under its own weight as the target tangential displacement in the slack-cable arch state; assume a set of cable sections {A}0; establish a spatial finite element model for the arch rib construction stage; input arbitrary initial cable force values ​​{T}0; and perform linear analysis to obtain the stiffness displacement {s}0 in the cantilever state and the stiffness displacement {u}0 in the slack-cable state. s}0 and tangential displacement in the loosened state {u t}0; Let the initial target value of the stiffness displacement in the slack cable state be used for state correction; tangential displacement correction; cable section correction; geometric nonlinear correction; extract the initial tension of the cable {T}0.

Description

Technical Field

[0001] This invention relates to the technical field of bridge construction, and in particular to a method for full-scale optimization calculation of cable force in a cable-stayed arch bridge. Background Technology

[0002] The cable-stayed method is a common construction method for long-span arch bridges. During the cantilever assembly of the arch rib, adjusting the cable tension can effectively control the arch rib's shape and internal forces. Therefore, determining a reasonable cable tension is the most critical issue in the construction of this type of arch bridge.

[0003] After years of development, methods for calculating the cable force of cable-stayed bridges have been developed, including the zero displacement method, the zero bending moment method, the mathematical analytical method, the fixed-length cable method, and secondary development based on the unknown load coefficient method. However, these methods have limitations, such as oversimplification of the structure, discrepancies between the target state and the actual engineering, failure to consider the effects of tangential assembly of the arch ribs and geometric nonlinearity, and cumbersome calculation processes. Summary of the Invention

[0004] This invention aims to address the shortcomings of existing technologies by providing a method for full-scale optimization calculation of cable force in cable-stayed arch bridges.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for full-scale optimization calculation of cable force in a cable-stayed arch bridge, the specific steps of which are as follows:

[0007] S1. Establish a single-stage arch model and calculate the bare arch deformation under its own weight as the target tangential displacement in the slack-cable arch state.

[0008] S2. Assuming a set of cable sections {A}0, establish a spatial finite element model for the arch rib construction stage. Input any initial cable force value {T}0, and perform linear analysis to obtain the cantilever stiffness displacement {s}0 and the slack cable stiffness displacement {u}0. s}0 and tangential displacement in the loosened state {u t}0;

[0009] S3, Let the initial target value of the stiffness displacement in the slack cable state be...

[0010] S4. Perform state correction;

[0011] S5. Perform tangential displacement correction;

[0012] S6. Perform cross-sectional correction of the cable;

[0013] S7. Perform geometric nonlinearity correction;

[0014] S8, Extract the initial tension of the buckle {T}0.

[0015] In step S4, the state correction is achieved by finding a set of cantilever state stiffness displacements {s} through difference iteration, such that the corresponding slack cable arching state stiffness displacements {u} are obtained. s} Meets the target requirements {δ} represents the allowable displacement deviation of the control point of the arch rib.

[0016] In step S4, the specific steps for state correction are as follows:

[0017] S41. Given a set of cantilever stiffness displacements {s}0 and their corresponding slack cable stiffness displacements {u}. s}0 and tangential displacement in the loosened state {u t}0;

[0018] S42. Let the target value of the stiffness displacement in the slack cable state be...

[0019] S43, Calculation

[0020] S44. Introduce the allowable displacement deviation {δ} of the arch rib control point and determine whether |{Δu s}0|≤{δ};

[0021] If not, let {s}1={s}0-{Δu s}0, using the finite element method with unknown load coefficients, calculate the slack cable stiffness displacement {u} corresponding to {s}1. s}1 and tangential displacement in the loosened state {u t}1, according to {s}0={s}1, {u s}0={u s}1, {u t}0={u t}1, Return to step S43 to continue the calculation;

[0022] If so, the status correction is complete.

[0023] In step S5, the tangential displacement correction is achieved by iteratively adjusting the target value of the stiffness displacement in the slack cable forming an arched state. when When {δ} is the allowable displacement deviation of the control point of the arch rib, {u s The corresponding tangential displacement of the loosened cable state {u} t Meet the target requirements

[0024] In step S5, the specific steps for tangential displacement correction are as follows:

[0025] S51. Given a set of cantilever stiffness displacements {s}0 and their corresponding slack cable stiffness displacements {u}.s}0 and tangential displacement in the loosened state {u t}0;

[0026] S52. Target value of tangential displacement under loosened cable condition.

[0027] S53, Calculation

[0028] S54. Introduce the allowable displacement deviation {δ} of the arch rib control point and determine whether...

[0029] If not, Update status correction target State correction, extracting the cantilever state stiffness displacement {s}0 and the slack cable state stiffness displacement {u} after state correction. s}0 and tangential displacement in the loosened state {u t}0, return to step S53 to continue the calculation;

[0030] If so, the tangential displacement correction is complete.

[0031] In step S6, the specific steps for correcting the cable cross-section are as follows:

[0032] S61, when |{Δu} is satisfied t}0|≤{δ}, extract the stiffness displacement {s}0 in the cantilever state and the stiffness displacement {u} in the slack cable state. s}0 and tangential displacement in the loosened state {u t}0;

[0033] S62, Extracting the maximum cable force {T} during the construction phase max}0;

[0034] S63. Introduce the allowable stress [σ] of the buckle material to determine whether...

[0035] If not, modify the section {A}0 of the ligature to make... Re-performing the linear analysis yields the stiffness displacement {s}0 in the cantilever state and the stiffness displacement {u} in the slack cable state. s}0 and tangential displacement in the loosened state {u t}0, perform state correction and tangential displacement correction, and return to step S62 to continue extraction;

[0036] If so, the cable section correction is complete.

[0037] In step S7, the specific steps for geometric nonlinear correction are as follows:

[0038] S71, Satisfaction At that time, extract the linear analysis results {s}0, {u}s}0、{u t}0;

[0039] S72. Perform geometric nonlinear analysis and extract the nonlinear analysis results {u t} non ;

[0040] S73, Calculation

[0041] S74. Introduce the allowable displacement deviation {δ} of the arch rib control point and determine whether |{Δu t}0|≤{δ};

[0042] If not, Update and fix targets State correction, extracting the cantilever state stiffness displacement {s}0 and the slack cable state stiffness displacement {u} after state correction. s}0 and tangential displacement in the loosened state {u t}0, return to step S72 to continue the geometric nonlinear analysis;

[0043] If so, the geometric nonlinear correction is complete.

[0044] The beneficial effects of the present invention are: the initial tension of the sling obtained by the method of the present invention can achieve one-time tensioning of the sling while ensuring that the stress of the sling meets the allowable stress of the material, so that the slack cable, considering the effects of tangential assembly and geometric nonlinearity, forms an arched shape that meets the target requirements. Attached Figure Description

[0045] Figure 1 This is a flowchart of the full-scale optimization algorithm in this invention;

[0046] Figure 2 This is a flowchart of the state correction process in this invention;

[0047] Figure 3 This is a flowchart of the tangential displacement correction process in this invention;

[0048] Figure 4 This is a flowchart of the cable cross-section correction process in this invention;

[0049] Figure 5 This is a flowchart of the geometric nonlinearity correction process in this invention;

[0050] Figure 6 This is a schematic diagram of the inclined cable-stayed installation in a specific embodiment;

[0051] Figure 7 This is a schematic diagram of the finite element model in a specific embodiment;

[0052] Figure 8This is a schematic diagram of the stiffness displacement in the first-round state correction of the slack cable arching state in a specific embodiment;

[0053] Figure 9 This is a schematic diagram of the tangential displacement correction for the slack cable arching state in a specific embodiment;

[0054] Figure 10 This is a schematic diagram illustrating the maximum cable force of the north bank cable after the cable section is corrected in a specific embodiment.

[0055] Figure 11 This is a schematic diagram illustrating the correction of the number of steel strands in the north bank cable section in a specific embodiment;

[0056] Figure 12 This is a schematic diagram illustrating the modification of the safety factor of the north bank cable section in a specific embodiment;

[0057] Figure 13 This is a schematic diagram illustrating the maximum cable force of the south bank cable after the cable section is corrected in a specific embodiment;

[0058] Figure 14 This is a schematic diagram illustrating the correction of the number of steel strands in the south bank cable section in a specific embodiment;

[0059] Figure 15 This is a schematic diagram illustrating the modification of the safety factor of the south bank cable section in a specific embodiment;

[0060] Figure 16 This is a schematic diagram of the tangential displacement of the cable section in the arched state after the cable slack is corrected in a specific embodiment;

[0061] Figure 17 This is a schematic diagram of the tangential displacement in the slack cable arching state after geometric nonlinear correction in a specific embodiment;

[0062] Figure 18 This is a schematic diagram illustrating the geometric nonlinear correction of the safety factor for the north bank cable in a specific embodiment;

[0063] Figure 19 This is a schematic diagram illustrating the geometric nonlinear correction of the safety factor for the south bank cable in a specific embodiment;

[0064] Figure 20 This is a schematic diagram of the tension force of the north bank cable during a single tensioning operation in a specific embodiment.

[0065] Figure 21 This is a schematic diagram of the tension force of the south bank cable during a single tensioning operation in a specific embodiment.

[0066] Figure 22 This is a comparison chart of displacement calculation results using different calculation methods in a specific embodiment;

[0067] Figure 23 This is a comparison chart of the calculation results of the tension cable force of the north bank cable under different calculation methods in a specific embodiment;

[0068] Figure 24 This is a comparison chart of the calculation results of the single tension cable force of the south bank cable using different calculation methods in a specific embodiment;

[0069] The following will describe in detail, with reference to the accompanying drawings, embodiments of the present invention. Detailed Implementation

[0070] The principles and features of the present invention are described below with reference to the accompanying drawings. The embodiments given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0071] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0072] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0073] Algorithm Theory:

[0074] The influence matrix method describes the impact of changes in the control vector on the response vector using the influence matrix of the structure. For the calculation of the cable-stayed arch bridge construction process, the specific method is to establish an equilibrium equation between the initial tension of the cable and the displacement of the control points of the arch rib, and then solve for the initial tension of the cable based on the target displacement.

[0075] {s} = [M]{T} + {d};

[0076] {T}=[M] -1 ({s}-{d});

[0077] In the formula:

[0078] {T} is the initial tension vector of the sling;

[0079] {s} is the total displacement vector of the control points of the arch rib;

[0080] [M] is the influence matrix of each cable tension unit force on the displacement of the arch rib control point;

[0081] {d} is the displacement vector of the control point of the arch rib caused by the self-weight and constant dead load ({d} remains unchanged when the structural stiffness and dead load remain unchanged).

[0082] The influence matrix method is based on the principle of linear superposition of structures, so it cannot take into account the effects of tangential assembly displacement of the arch rib and geometric nonlinearity. At the same time, since the influence matrix method cannot calculate the arch rib displacement caused by the construction stage after all the cable tensioning is completed (such as the closing stage and the cable removal stage), the cable force calculated by it cannot make the arch displacement after the cable is loosened meet the target requirements.

[0083] Therefore, the present invention sets an intermediate target. Establish the stiffness displacement {s} in the cantilever state and the tangential displacement {u} in the slack cable arch state. t The mathematical relationship between} is based on the tangential displacement target of the slack cable arch state. The over-difference iterative method calculates a set of cantilever stiffness displacements {s}, and the corresponding tangential displacements {u} in the slack cable arching state are obtained. t} Satisfy the target requirements, that is The initial tension {T} at this point is the tension force of the cable during the first tensioning stage, as detailed below:

[0084] A method for full-scale optimization calculation of cable tension in a cable-stayed arch bridge, see [link to relevant documentation]. Figure 1 The specific steps are as follows:

[0085] S1. Establish a single-stage arch model and calculate the bare arch deformation under its own weight as the target tangential displacement in the slack-cable arch state.

[0086] S2. Assuming a set of cable sections {A}0, establish a spatial finite element model for the arch rib construction stage. Input any initial cable force value {T}0, and perform linear analysis to obtain the cantilever stiffness displacement {s}0 and the slack cable stiffness displacement {u}0. s}0 and tangential displacement in the loosened state {u t}0;

[0087] S3, Let the initial target value of the stiffness displacement in the slack cable state be...

[0088] S4. Perform state correction;

[0089] S5. Perform tangential displacement correction;

[0090] S6. Perform cross-sectional correction of the cable;

[0091] S7. Perform geometric nonlinearity correction;

[0092] S8, Extract the initial tension of the buckle {T}0.

[0093] In step S4, the state correction is achieved by finding a set of cantilever state stiffness displacements {s} through difference iteration, such that the corresponding slack cable arching state stiffness displacements {u} are obtained. s} Meets the target requirements {δ} represents the allowable displacement deviation of the control point of the arch rib.

[0094] See the status correction process. Figure 2 The specific steps are as follows:

[0095] S41. Given a set of cantilever stiffness displacements {s}0 and their corresponding slack cable stiffness displacements {u}. s}0 and tangential displacement in the loosened state {u t}0;

[0096] S42. Let the target value of the stiffness displacement in the slack cable state be...

[0097] S43, Calculation

[0098] S44. Introduce the allowable displacement deviation {δ} of the arch rib control point and determine whether |{Δu s}0|≤{δ};

[0099] If not, let {s}1={s}0-{Δu s}0, using the finite element method with unknown load coefficients, calculate the slack cable stiffness displacement {u} corresponding to {s}1. s}1 and tangential displacement in the loosened state {u t}1, according to {s}0={s}1, {u s}0={u s}1, {u t}0={u t}1, Return to step S43 to continue the calculation;

[0100] If so, the status correction is complete.

[0101] In step S5, the tangential displacement correction is achieved by iteratively adjusting the target value of the stiffness displacement in the slack cable forming an arched state. when Time (achieved through state correction), {δ} is the allowable deviation of the arch rib control point displacement, {u s The corresponding tangential displacement of the loosened cable state {u} t} Meets the target requirements

[0102] See the tangential displacement correction procedure. Figure 3 The specific steps are as follows:

[0103] S51. Given a set of cantilever stiffness displacements {s}0 and their corresponding slack cable stiffness displacements {u}. s}0 and tangential displacement in the loosened state {u t}0;

[0104] S52. Given the target value of tangential displacement in the slack cable state (displacement of the bare arch during a single frame drop).

[0105] S53, Calculation

[0106] S54. Introduce the allowable displacement deviation {δ} of the arch rib control point and determine whether |{Δu t}0|≤{δ};

[0107] If not, Update status correction target State correction, extracting the cantilever state stiffness displacement {s}0 and the slack cable state stiffness displacement {u} after state correction. s}0 and tangential displacement in the loosened state {u t}0, return to step S53 to continue the calculation;

[0108] If so, the tangential displacement correction is complete.

[0109] In step S6, since the cable force is unknown at the beginning of the solution, it is necessary to assume the cross section of the cable. After the final cable force is obtained, the cross section is adjusted so that the maximum stress of the cable meets the allowable stress requirements of the material.

[0110] The influence matrix [M] is derived based on the structural stiffness. Adjusting the cable section will cause changes in the structural stiffness, which in turn will cause changes in the influence matrix [M], ultimately leading to changes in the initial tension of the cable solved by the influence matrix method. Therefore, cable section correction is required.

[0111] See the procedure for correcting the cross-section of the cable. Figure 4 The specific steps are as follows:

[0112] S61, when |{Δu} is satisfied t}0|≤{δ}, extract the stiffness displacement {s}0 in the cantilever state and the stiffness displacement {u} in the slack cable state. s}0 and tangential displacement in the loosened state {u t}0;

[0113] S62, Extracting the maximum cable force {T} during the construction phase max}0;

[0114] S63. Introduce the allowable stress [σ] of the buckle material to determine whether...

[0115] If not, modify the section {A}0 of the ligature to make... Re-performing the linear analysis yields the stiffness displacement {s}0 in the cantilever state and the stiffness displacement {u} in the slack cable state. s}0 and tangential displacement in the loosened state {u t}0, perform tangential displacement correction (including state correction), and return to step S62 to continue extraction;

[0116] If so, the cable section correction is complete.

[0117] In step S7, for long-span arch bridges, the large cantilever of the arch rib and the length of the cable tie during assembly cause significant deformation under load. This large deformation leads to changes in structural stiffness, causing the load and displacement to no longer conform to a linear relationship, i.e., geometric nonlinearity of the structure. This paper, through case analysis, finds that the impact of geometric nonlinearity on long-span arch bridges cannot be ignored and must be considered in the calculation process; therefore, geometric nonlinearity correction is necessary.

[0118] See the geometric nonlinearity correction process. Figure 5 The specific steps are as follows:

[0119] S71, Satisfaction At that time, extract the linear analysis results {s}0, {u} s}0、{u t}0;

[0120] S72. Perform geometric nonlinear analysis and extract the nonlinear analysis results {u t} non ;

[0121] S73, Calculation

[0122] S74. Introduce the allowable displacement deviation {δ} of the arch rib control point and determine whether |{Δu t}0|≤{δ};

[0123] If not, Update and fix targets State correction (linear analysis), extracting the cantilever state stiffness displacement {s}0 and the slack cable state stiffness displacement {u} after state correction. s}0 and tangential displacement in the loosened state {u t}0, return to step S72 to continue the geometric nonlinear analysis;

[0124] If so, the geometric nonlinear correction is complete. Specific Implementation Example 1:

[0126] This major bridge is a mid-span steel box arch bridge. The main bridge is 612m long, with a clear span of 570m and a clear rise of 126.67m, resulting in a rise-to-span ratio of 1 / 4.5. The angle between the arch plane and the vertical plane is 8° inward, and the arch axis follows a multiple parabola. The standard cross-section of the arch ribs is a chamfered steel box, 5.5m wide, with the height gradually decreasing from 12m at the arch foot to 8m at the arch crown. Two horizontal beams and ten horizontal steel box braces are installed between the two arch ribs.

[0127] The single arch rib is divided into 47 lifting segments: 23 cantilever segments on the south and north banks, and one arch crown closure segment. Segments G1 to G3 at the arch foot are installed using scaffolding; segments G4 to G23 are each equipped with a pair of cable-stayed cantilever assemblies, resulting in a total of 40 pairs of cable-stayed ties for each arch rib. The steel box arch uses Q420qD steel, and the cable-stayed ties are made of Φ15.24 steel strand (fy = 1860MPa).

[0128] Due to site topographical constraints, the cable anchors are arranged asymmetrically. The north bank anchor is 62.5m from the arch foot, and the south bank anchor is 66.5m from the arch foot. The different cable lengths and inclination angles on both banks result in different cable forces. For details on the cable-stayed system, please refer to [link / reference needed]. Figure 6 .

[0129] The structural analysis software Midas Civil 2022 was used, with the arch rib and tie cables simulated using beam and truss elements, respectively. This paper only studies the tie cable force, neglecting the influence of the tie tower and back cable. The connection between the tie cable and the tie tower is simplified to a fixed end, and the arch foot is fixed throughout the construction of the arch rib, also simulated using a fixed-end simulation. The initial cross-section of the tie cables consisted of 15 Φ15.24 steel strands (A≈51.7mm2), with an initial tension of 1000kN. The calculation used the displacement of the bare arch under its own weight during a single scaffolding drop as the target tangential displacement in the slack cable state. The finite element model can be found here. Figure 7 .

[0130] 1. Initial status correction:

[0131] Figure 8 This is the calculation process for the first round of state correction. It can be seen that after four iterations, the stiffness and displacement of the slack cable arch state can meet the target requirements, and the displacement difference is less than 1mm.

[0132] 2. Tangential displacement correction:

[0133] Depend on Figure 9 It can be seen that after the first round of state correction, the tangential displacement of the slack cable arched state is still quite different from the target. However, after three rounds of tangential displacement correction, the slack cable arched state can meet the target requirements, and the displacement difference is less than 2mm.

[0134] Each tangential displacement correction includes 1 to 3 state corrections, with the number of state corrections decreasing as the number of tangential displacement corrections increases.

[0135] 3. Correction of the cable cross-section:

[0136] Figures 10-15 These are the main calculation results during the correction of the cable section.

[0137] According to the specifications, the safety factor of the cable material (Φ15.24 steel strand) should be greater than 2. After the tangential displacement correction, some cables no longer met the requirements, and the safety factors of each cable were extremely uneven. Therefore, the cable cross-section was adjusted for the first time, and the safety factors after adjustment were all within the range of 2.1-2.4. Because the range and magnitude of the first adjustment to the cable cross-section were large, the structural stiffness changed significantly, and the displacement of the rib control points deviated from the target value. Therefore, the cable cross-section was corrected to bring the displacement back to the target state. After the cable cross-section correction, the cable force changed, and the safety factor of some cables again did not meet the requirements. Therefore, the cable cross-section was adjusted for the second time, and the safety factors of the cables after adjustment were all within the range of 2.1-2.4. However, because the range and magnitude of the second adjustment to the cable cross-section were small, the displacement changes of the arch rib control points were all less than 1mm, which still met the target requirements, and no further correction of the cable cross-section was needed. The cable cross-section correction was thus completed.

[0138] 4. Geometric nonlinearity correction:

[0139] Depend on Figure 17 It can be seen that, considering the influence of geometric nonlinearity, the maximum change in arch crown displacement is approximately 14 mm, with a variation range of about 15.6%, and its impact can no longer be ignored. After geometric nonlinearity correction, the displacements of the arch rib control points all meet the target requirements. Since the difference in cable tension before and after correction is not significant, the safety factor of the cable after correction still meets the requirements, and no adjustment of the cable section is required. The safety factor is shown in [reference needed]. Figures 18-19 .

[0140] 5. Initial tension of the cable during the first tensioning:

[0141] The initial tension of the tension cable calculated by the full-scale optimization algorithm is shown below. Figures 20-21 It can be seen that:

[0142] (1) The tension of the cable generally increases from the arch foot to the arch crown, which is consistent with the stress characteristics of a cable-stayed arch bridge;

[0143] (2) Due to the self-weight load of the crossbeam or cross brace, the cable tension at the corresponding arch rib changes abruptly and increases to varying degrees compared with the adjacent segments.

[0144] (3) The angle between the arch top cable and the horizontal plane is small (about 9°), and the influence coefficient of the cable force on the vertical displacement of the arch rib is small, resulting in the maximum cable force at the arch top.

[0145] 6. Comparison of different calculation methods:

[0146] The algorithm of this invention is compared with the improved positive mounting iterative method in the literature "Research on Calculation Method of Cable-stayed Cable Force of Long-span Steel-concrete Composite Arch Bridge". The calculation results are shown in [the original text]. Figures 22-24 .

[0147] It can be seen that the arch rib displacement of both methods can meet the target requirements. However, the cable force results calculated in the literature are greatly affected by the initial cable force value. Since the arch bridge in this embodiment adopts a box girder and cross bracing, its weight is concentrated on the corresponding arch rib stage, resulting in a significant increase in the cable force of the cable in this arch rib stage compared with the adjacent segment. If the initial cable force in the literature method is taken as 1000kN, it is difficult to obtain satisfactory results. In addition, the literature method requires the interaction and iteration of the cable adjustment module and finite element software, which makes the calculation process cumbersome and fails to consider the influence of geometric nonlinearity. Many problems limit its application.

[0148] This invention proposes a full-scale optimization calculation method for the cable force of cable-stayed arch bridges based on the influence coefficient method and the difference iteration method, which can meet the following requirements:

[0149] (1) No simplification or assumptions are required for the structure. The actual structural stiffness and influence matrix are used in the calculation process, and the calculation results are true and reliable.

[0150] (2) The calculation method is simple and easy to implement. It can be achieved through commonly used commercial structural finite element analysis software. There is no need to write a separate tuning module, which greatly simplifies the calculation process.

[0151] (3) The arched state after the cable is loosened is the target, which is consistent with the control target of the actual construction process;

[0152] (4) Fully consider the effects of tangential assembly, geometric nonlinearity, and cable cross-section on structural displacement;

[0153] The method in this invention solves for the initial tension of the sling, which can achieve one-time tensioning of the sling while ensuring that the stress of the sling meets the allowable stress of the material. This allows the slack cable to form an arch shape that meets the target requirements, taking into account the effects of tangential assembly and geometric nonlinearity.

[0154] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or direct application to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A full-scale optimization calculation method for cable force of a cable-stayed arch bridge, characterized in that, The specific steps are as follows: S1, establish a one-time frame into an arch model, calculate the deformation of the bare arch under the action of self weight as the tangential displacement target of the loose cable arch ; S2, assuming a set of cable cross-sections , establish the spatial finite element model of arch-rib construction stage, input arbitrary initial cable force value , linear analysis to obtain cantilever state stiffness displacement , loose cable state stiffness displacement and loose cable state tangential displacement ; S3, set the slack cable state stiffness displacement initial target value as ; S4, state correction, find a set of state stiffness displacement of the cantilever through difference iteration , so that the corresponding loose cable becomes an arch state stiffness displacement to meet the target requirements , arch rib control point displacement allowable deviation; S5, tangential displacement correction is performed, and the slack cable is continuously adjusted to the arch cable state stiffness displacement target value through difference iteration When , The displacement allowance of the control point of the arch rib The corresponding tangential displacement of the slack cable Satisfies the target requirement ; S6, the cable section correction is performed; The specific steps are as follows: S61, when satisfied , extract cantilever state stiffness displacement , slack cable state stiffness displacement and slack cable state tangential displacement ; S62, extracting the maximum cable force in the construction phase ; S63, introducing a tether material allows stress , determining whether ; If no, modify the cross section of the cable Make , re-linear analysis to get the stiffness displacement of the cantilever state , stiffness displacement of the slack cable state and tangential displacement of the slack cable state , state correction, tangential displacement correction, return to step S62 to continue extraction; If yes, the cable section correction is completed; S7, the geometric nonlinear correction is performed; The specific steps are as follows: S71, meet linear analysis results , ; S72, performing geometric non-linear analysis, extracting non-linear analysis result ; S73, compute ; S74, introduce the vault rib control point displacement allows deviation , determine whether ; If no, let , update the correction target , state correction, extract the state stiffness displacement of the cantilever after the state correction , the slack cable state stiffness displacement and the slack cable state tangential displacement , return to step S72 to continue the geometric nonlinear analysis; If yes, the geometric nonlinear correction is completed; S8, extracting the initial tension of the cable .

2. The full-scale optimization calculation method for cable force of a cable-stayed arch bridge according to claim 1, characterized in that, In step S4, the specific steps of the state correction are as follows: S41, knowing a set of cantilever state stiffness displacements and their corresponding slack cable state stiffness displacements and slack cable state tangential displacements ; S42, set the slack cable state stiffness displacement target value as ; S43, calculate ; S44, introducing the displacement allowance of the control point of the arch rib , judging whether ; If no, let , the finite element software unknown load coefficient method to solve, calculate The corresponding loose cable state stiffness displacement And loose cable state tangential displacement According to , , , return to step S43 to continue calculation; If yes, the state correction is completed.

3. The full-scale optimization calculation method for cable force of a cable-stayed arch bridge according to claim 2, characterized in that, In step S5, the specific steps of the tangential displacement correction are as follows: S51, known set of cantilever state stiffness displacements and their corresponding slack cable state stiffness displacements and slack cable state tangential displacements ; S52, tangential displacement target value of known slings status ; S53, compute ; S54, introduce the arch rib control point displacement allows deviation , determine whether ; If no, let , update the state correction target , state correction, extract the state stiffness displacement of the cantilever after state correction , the slack cable state stiffness displacement and the slack cable state tangential displacement , return to step S53 to continue calculation. If yes, the tangential displacement correction is completed.

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