Method and device for calculating construction tensioning force of hybrid-composite beam cable-stayed bridge

Abstract

The invention relates to a calculation method and device for construction tensioning force of a hybrid-composite beam cable-stayed bridge, and the method comprises the following steps: building a full-bridge finite element model, and setting the last tensioning force as a designed finished bridge cable force; constructing a target formula including a stay cable force, a main beam tangential displacement and a main tower longitudinal deviation influence matrix; calculating a bridge forming state initial value and establishing an optimization objective function; forming an iterative loop calculation system; the cable force uniformity of stay cables on the two sides of the side midspan, the stress limit values of a main tower and a main beam and the pressure reserve of a transition pier and an auxiliary pier are controlled; and finally, the tensioning force of each time in the construction process is determined. The method emphasizes the consistency of finite element simulation and on-site construction, considers the shapes of a vertical curve and a horizontal curve of the bridge and the bending effect, and is suitable for bridges with various spans and curve forms; the method can effectively consider the concrete shrinkage and creep effect, is rapid in convergence, high in efficiency and wide in application range, meets multi-parameter constraint conditions, and ensures that a finished bridge state is closed with an ideal result.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and particularly to a calculation method and device for the construction tension of a hybrid-composite girder cable-stayed bridge. Background Art

[0002] In order to achieve a reasonable completed bridge state for a long-span hybrid-composite girder cable-stayed bridge, during the construction of the main girder of the hybrid-composite girder cable-stayed bridge, the cantilever erection method is often used to divide the installation of the main girder into multiple construction steps, such as: steel girder manufacturing - steel girder erection - bridge deck hoisting - wet joint pouring - movement of the bridge deck crane - multiple cable-stayed cable tensionings, etc. However, the complex conversion of the bridge structure system during the construction process may cause the displacement and internal force of the entire bridge to continuously change in a direction deviating from the ideal completed bridge state. For example, the bridge deck alignment is uneven, resulting in frequent vehicle jumping when vehicles pass through the bridge, affecting driving comfort and posing a threat to personal safety. In severe cases, the bridge may experience structural instability and collapse, causing immeasurable economic losses. To ensure the safety of the construction stage of the hybrid-composite girder cable-stayed bridge and that the internal force and alignment of the completed bridge meet the requirements of relevant specifications, it is particularly important to determine the optimal cable-stayed cable construction tension. Currently, the commonly used calculation methods for the cable-stayed cable construction tension include: the back-analysis method, the forward iteration method, and the stress-free state method, etc.

[0003] The above-mentioned cable-stayed cable construction cable adjustment methods all have their respective operational limitations and are not applicable to the calculation of the cable-stayed cable construction tension of the hybrid-composite girder cable-stayed bridge. For example, when the construction tension obtained by the back-analysis method is used for forward calculation, due to the influence of the time effect of concrete shrinkage and creep and the inability to ensure that the disassembled units are in a stress-free state, the calculation result at the completed bridge stage is often not closed compared with the ideal completed bridge state; when the forward iteration method calculates the cable-stayed cable construction tension according to the actual construction process of the bridge, it usually cannot consider the influence relationships between the cable-stayed cables and the main girder, between the cable-stayed cables and the main tower, and between the main girder and the main tower, as well as the overall safety of the bridge structure; the stress-free state method can only be used for the calculation of steel structure bridges and has certain limitations in the scope of use. Summary of the Invention

[0004] Aiming at the above deficiencies, the present invention provides a calculation method and calculation device for the construction tension of a hybrid-composite girder cable-stayed bridge, which can solve the problems of large limitations in the scope of use and low optimization calculation efficiency existing in the commonly used calculation methods for the cable-stayed cable construction tension.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A calculation method for the construction tension of a hybrid-composite girder cable-stayed bridge includes the following steps:

[0007] S1. Establish a full-bridge finite element construction model, determine the tensile force of the stay cables in the finite element construction model, and set the last tensile force as the designed in-service cable force;

[0008] S2. Establish an objective formula for the control parameters of the hybrid-composite girder cable-stayed bridge composed of the influence matrix formula in the finite element construction model;

[0009] Calculate the influence matrix of the stay cable force, the tangential displacement of the main girder, and the longitudinal deviation of the main tower of the hybrid-composite girder cable-stayed bridge;

[0010] S3. Calculate the initial values of the stay cable force, the tangential displacement of the main girder, and the longitudinal deviation of the main tower of the hybrid-composite girder cable-stayed bridge in the in-service state;

[0011] Establish an objective function composed of the tensile force of the stay cables, the in-service cable force of the stay cables, the tangential displacement of the main girder, and the variables of the longitudinal deviation of the main tower;

[0012] Set multi-parameter constraint control conditions for the parameters in the objective function, and establish an optimization control equation for the optimized objective function;

[0013] S4. Establish an iterative loop calculation system composed of the objective function, the multi-parameter constraint control conditions, and the optimization control equation;

[0014] S5. Control the uniformity of the change in the stay cable force between the adjacent stay cables on both sides of the side and middle spans of the hybrid-composite girder cable-stayed bridge;

[0015] Control the tensile and compressive stresses of the main tower and the main girder of the hybrid-composite girder cable-stayed bridge so that they do not exceed the allowable limit values;

[0016] Control the transition piers and auxiliary piers of the hybrid-composite girder cable-stayed bridge to have sufficient reserve pressure;

[0017] S6. Calculate and determine the tensile force of each stay cable during the construction process of the hybrid-composite girder cable-stayed bridge.

[0018] Furthermore, the last tensile force of each stay cable in the full-bridge finite element construction model is taken as the designed in-service cable force, and the intermediate tensile force of each stay cable is taken as one fraction of the number of times of the designed in-service cable force.

[0019] Furthermore, in step S2, the target value [B i of the control parameters in the full-bridge finite element construction model is equal to:

[0020] [B i = [C]·[X] + [B0];

[0021] Among them, [C] is the influence matrix in the full-bridge finite element construction model, [X] is the adjustment vector in the full-bridge finite element construction model, [B0] is the current state of the control parameters in the full-bridge finite element construction model, and the target value [B i of the control parameters in the full-bridge finite element construction model is equal to the difference between the current state [B0] and the adjusted vector [B];

[0022] Among them, the influence matrix [C] refers to the degree of influence of the adjustment vector on the adjusted vector. The adjustment vector [X] refers to that adjusting certain parameter variables can achieve specific structural adjustment goals, and the adjusted vector [B] refers to the target adjustment value achieved by changing the parameter variables in the adjustment vector [X].

[0023] Furthermore, in step S2, the cable force influence matrix of the stay cables is composed of the influence vectors {S ij}, which is the influence on the in-service cable force of the j-th stay cable when the final tension of the i-th stay cable changes;

[0024] The influence matrix of the tangent displacement of the main girder The tangent displacements of the main girder at the n connection and anchorage points of the main girder corresponding to the n stay cables are taken as the in-service tangent displacements of the main girder. It is composed of the influence vectors {W ij}, which is the influence on the tangent displacement of the j-th anchorage point when the final tension of the i-th stay cable changes;

[0025] The influence matrix of the longitudinal deviation of the main tower One longitudinal deviation point at the top of the main tower and one at the midpoint of the tower limb are taken as the in-service longitudinal deviation points of the main tower. It is composed of the influence vectors {T ij}, which is the influence on the longitudinal deviation point of the j-th main tower when the final tension of the i-th stay cable changes.

[0026] Furthermore, in step S3, an objective function is established, which consists of the cable tension variable [x] of the stay cables and the corresponding cable force variable [S i of the stay cables, the tangent displacement variable [W i of the main girder, and the longitudinal deviation variable [T i of the main tower in the completed state of concrete shrinkage and creep of the in-service structure. Specifically:

[0027]

[0028] Among them, the parameter variables [x0], [S0], [W0], and [T0] are respectively the initial iteration values of the cable tension of the stay cables and the corresponding initial iteration values of the cable force of the stay cables, the initial iteration value of the tangent displacement of the main girder, and the initial iteration value of the longitudinal deviation of the main tower in the in-service state. Their values are taken as the results of the previous iteration calculation in each round of iterative loop calculation;

[0029] The parameter variable [x iis the target value of the tensile force after the i-th round of iterative calculation, [S i is the target value of the cable force of the stay cable corresponding to the completed bridge state after the i-th round of iterative calculation, [W i is the target value of the tangent displacement of the main girder corresponding to the completed bridge state after the i-th round of iterative calculation, and [Ti] is the target value of the longitudinal deviation of the main tower corresponding to the completed bridge state after the i-th round of iterative calculation.

[0030] Furthermore, the multi-parameter constraint control conditions for setting the upper and lower limit ranges of the cable force variable [S i , the tangent displacement variable [W i , and the longitudinal deviation variable [T i of the stay cable in the completed state of concrete shrinkage and creep of the bridge for the objective function are as follows:

[0031]

[0032] Furthermore, an optimization control equation for the optimization objective function is established using the least squares method theory:

[0033] F(x) = ||[C]·[X] - ([B i - [B0])|| 2 = min.

[0034] Furthermore, the specific iterative loop calculation system composed of the objective function, multi-parameter constraint control conditions, and optimization control equation is as follows:

[0035] When calculating the value of the parameter variable [x] in the objective function, it starts with the unit 1. Calculate the corresponding target values [S i , [W i , and [T i of the parameter variable [x i , and input the results into the multi-parameter constraint control conditions to determine whether the three constraint control conditions are satisfied. If not, first return to the objective function equation to continue taking new values of the parameter variable [x] for iterative calculation. This result is then input into the multi-parameter constraint control conditions again to determine whether the three constraint control conditions are satisfied. Repeat this cycle until one or more of the constraint control conditions in the multi-parameter constraint control conditions are satisfied. At this time, enter the optimization control equation to optimize the parameter variable [x] using the least squares method. The new variable [x] then returns to the objective function equation and the constraint control conditions to continue the iterative loop calculation. If the target value still does not satisfy the constraint conditions, continue to return to the optimization control equation to optimize the iterative loop calculation using the least squares method.

[0036] Furthermore, in step S6, under the limiting conditions of step S5, find the optimal solution [x 优 of the tensile force of the stay cable, and the values of the other intermediate tensile forces of each stay cable are the optimal solution [x优 One over the number of times.

[0037] The present invention also provides a calculation device for the construction tension of a hybrid - composite girder cable - stayed bridge, including:

[0038] A basic information calculation module, which is used to establish a finite - element construction model of the whole bridge, determine the tension of the stay cables in the finite - element construction model, set the last - time tension as the designed in - bridge cable force, and calculate the initial values of the stay - cable force, the tangent displacement of the main girder, and the longitudinal deviation of the main tower in the completed - bridge state of the hybrid - composite girder cable - stayed bridge;

[0039] A linear superposition principle calculation module, which is used to calculate the influence matrix of the stay - cable force, the tangent displacement of the main girder, and the longitudinal deviation of the main tower of the hybrid - composite girder cable - stayed bridge;

[0040] An objective - function intelligent calculation module, which is used to establish an objective formula for the control parameters of the hybrid - composite girder cable - stayed bridge composed of the influence - matrix formula in the finite - element construction model, and calculate and establish an objective function composed of the variables of the stay - cable tension, the in - bridge cable force of the stay cable, the tangent displacement of the main girder, and the longitudinal deviation of the main tower;

[0041] A parameter constraint and intelligent adjustment calculation module, which is used to set multi - parameter constraint control conditions for the parameters in the objective function, establish an optimization control equation for the optimized objective function, and establish an iterative loop calculation system composed of the objective function, the multi - parameter constraint control conditions, and the optimization control equation;

[0042] A result automatic judgment calculation module, which is used to realize controlling the uniformity of the change in the stay - cable force between the adjacent stay cables on both sides of the side and middle spans of the hybrid - composite girder cable - stayed bridge, controlling that the tensile and compressive stresses of the main tower and the main girder of the hybrid - composite girder cable - stayed bridge do not exceed the allowable limit values, and controlling that the transition piers and auxiliary piers of the hybrid - composite girder cable - stayed bridge have sufficient reserve pressure; and calculating and determining the tension of each time during the construction process of the stay cables of the hybrid - composite girder cable - stayed bridge.

[0043] Compared with the prior art, the beneficial effects of the present invention are:

[0044] 1. The present invention emphasizes the consistency between the finite - element construction calculation simulation and the on - site cantilever erection construction process, simulates the vertical curve and horizontal curve shapes of the actual bridge, and considers the influence of the vertical bending and horizontal bending effects on the bridge cantilever erection construction process, and is applicable to the calculation of the construction tension of any curve form and span - size hybrid - composite girder cable - stayed bridge;

[0045] 2. Compared with the traditional technical methods for calculating the construction tension of stay cables, the present invention can consider the concrete shrinkage and creep effects that are closely related to time, and the calculation results at the completed bridge stage are closed to the ideal completed bridge state; it can also consider the influence relationships among the stay cables, main tower and main girder, and has fast iterative calculation efficiency, good use effect and wide application scope.

[0046] 3. The initial value of the calculation of the stay cable tension of the present invention is taken as the designed stay cable force at the completed bridge. From the optimized value of the calculation initial value, the iterative loop calculation system can converge rapidly, and a solution for the construction tension of the hybrid-composite girder cable-stayed bridge that satisfies the multi-parameter constraint control conditions can be found without going through cumbersome steps in the calculation process.

[0047] 4. The calculation of the stay cable tension of the present invention takes the stay cable force under the completed bridge, the tangent displacement of the main girder and the longitudinal deviation of the main tower as multi-parameter constraint control conditions. From the optimized value of the constraint control conditions, the iterative loop calculation system can converge rapidly, and an optimal solution for the construction tension of the hybrid-composite girder cable-stayed bridge that satisfies the requirements of uniform stay cable forces in the side and middle spans, safe tower and girder stresses, and a certain pressure reserve for the piers can be found.

[0048] 5. The calculation method for the construction tension of the hybrid-composite girder cable-stayed bridge of the present invention can make the stay cable forces of the finished cables in the side and middle spans of the whole bridge uniform and the deviations are within the error range, ensure that the stresses of the finished cables do not exceed the requirements of their material strength, reduce fatigue damage, and extend the service life of the finished cables; after the bridge is completed, there is no need for secondary cable adjustment, reducing the tensioning times of the finished cables of the whole bridge, shortening the construction period of the whole bridge, and greatly improving the local economic benefits.

[0049] 6. The calculation method for the construction tension of the hybrid-composite girder cable-stayed bridge of the present invention can make the elevation deviations of the main girder after the bridge is completed within the error range, ensure that the alignment of the whole bridge is smooth and fluent, the curve is smooth without sharp corners, the top surface is flat and straight, and it is coordinated with the plane alignment of the approach bridge. At the same time, the continuity and balance of each alignment element are maintained, avoiding phenomena such as sudden changes and vehicle jumping on the whole bridge deck when the vehicle is traveling.

[0050] 7. The calculation method for the construction tension of the hybrid-composite girder cable-stayed bridge of the present invention can make the side span stay cable force larger than the middle span stay cable force after the bridge is completed, ensure that the longitudinal deviation of the main tower is pre-deviated towards the side span, and resist the tendency of the main tower to deflect towards the middle span when the vehicle is traveling, so as to achieve the effect of "tower straight" during the normal operation of the bridge.

[0051] 8. The calculating device for the construction tension of the hybrid-composite girder cable-stayed bridge of the present invention can calculate the construction tension of the hybrid-composite girder cable-stayed bridge, facilitating the engineering technicians at the construction site to calculate the optimal solution of the construction tension of any hybrid-composite girder cable-stayed bridge with any curve form and span size. Most of the calculation work is handed over to the calculating device to automatically adjust the cables, eliminating the need for manual repeated adjustment and calculation. By simplifying the complex, the optimization calculation efficiency of the construction tension of the stay cables is greatly improved, and the technical level of engineering technicians is also enhanced, having certain engineering application value and significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments.

[0053] Figure 1 It is a schematic flow chart of the calculation method for the construction tension of the hybrid-composite girder cable-stayed bridge in the present invention.

[0054] Figure 2 It is a schematic diagram of the calculating device based on the calculation method for the construction tension of the hybrid-composite girder cable-stayed bridge in the present invention.

[0055] Figure 3 It is a data transfer relationship diagram between modules in the calculating device.

[0056] Figure 4 It is an exemplary elevation layout diagram of the hybrid-composite girder cable-stayed bridge.

[0057] Figure 5 It is an exemplary three-dimensional spatial effect diagram of the hybrid-composite girder cable-stayed bridge.

[0058] Figure 6 It is an effect diagram of the cable forces of the completed bridge controlled by constraints in the 1st to 6th round iterative calculations in the example.

[0059] Figure 7 It is an effect diagram of the tangent displacement of the main girder of the completed bridge controlled by constraints in the 1st to 6th round iterative calculations in the example.

[0060] Figure 8 It is an effect diagram of the longitudinal deviation of the main tower of the completed bridge controlled by constraints in the 1st to 6th round iterative calculations in the example. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0062] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0063] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0064] Please refer to Figure 1 , on the one hand, a preferred embodiment of the present invention provides a calculation method for the construction tension of a hybrid-composite girder cable-stayed bridge. The method includes the following steps:

[0065] S1. Establish a full-bridge finite element construction model, determine the tension of the stay cables in the finite element construction model, and set the tension of the last cable tensioning as the designed in-service cable force.

[0066] Establish a full-bridge finite element construction model that guides the on-site real-bridge cantilever erection construction and simulates the shape of the real bridge. The finite element construction model is a three-dimensional space model of the full-bridge finite element construction.

[0067] Establish a three-dimensional space model of the full-bridge finite element construction that guides the on-site bridge cantilever erection construction through finite element analysis and calculation software, that is, establish the full-bridge finite element construction model. The finite element construction model includes structural stiffness information (stay cables, main girders, main towers, piers, and caissons, etc.), boundary condition information (internal boundaries and external boundaries, etc.), and construction load action information (self-weight, second-stage, prestress load, stay cable tension, concrete shrinkage and creep, and other temporary loads, etc.). And the full-bridge finite element construction model should simulate the vertical curve and horizontal curve shapes of the on-site real bridge, and at the same time ensure that the definition of the construction stage in the full-bridge finite element construction model is completely consistent with the construction process of the on-site real-bridge cantilever erection process.

[0068] In a preferred embodiment, the finite element calculation is to simulate the actual shape of the bridge - considering the influence of the elevation bending and plane bending effects on the finite element calculation of the bridge, not limited to the finite element calculation of straight bridges, but also including the finite element calculation of curved bridges.

[0069] In a preferred embodiment, in the full-bridge finite element construction model, the construction stages must be established according to the actual construction procedures determined on-site, so as to accurately and effectively guide each cantilever erection construction step at the construction site to be carried out in accordance with the designed target state of the completed bridge.

[0070] Determine the tensile force of the stay cables in the full-bridge finite element construction model, and the last tensile force is the designed stay cable force of the completed bridge, that is, determine the tensile force of the stay cables in the finite element construction model, and set the last tensile force as the designed stay cable force of the completed bridge.

[0071] The last tensile force (i.e., the final tensile force) of each stay cable in the full-bridge finite element construction model takes the designed stay cable force of the completed bridge (the tensile force here is the adjustment vector in step S2), and the intermediate tensile force of each stay cable takes one over the number of times of the designed stay cable force of the completed bridge. For example, if the stay cables are tensioned m times during the construction process, the first tensile force of the stay cable is The second tensile force is And so on, and the final tensile force is the designed stay cable force of the completed bridge. It should be noted that in the present invention, the last tensioning (i.e., the final tensile force) of each stay cable in the full-bridge finite element construction model refers to the last tensioning (i.e., the final tensile force) of the stay cable corresponding to the current steel beam segment during the cantilever erection construction process before the full-bridge closure, not the overall tensioning of all stay cables after the full-bridge closure.

[0072] S2. Establish a target formula for the control parameters of the hybrid-composite girder cable-stayed bridge composed of the influence matrix formulas in the finite element construction model; calculate the influence matrices of the cable forces of the stay cables, the tangential displacements of the main girder, and the longitudinal displacements of the main tower of the hybrid-composite girder cable-stayed bridge.

[0073] S21. Establish a target formula for the control parameters of the hybrid-composite girder cable-stayed bridge composed of the influence matrix formulas in the finite element construction model.

[0074] It is known that the structure of the hybrid-composite girder cable-stayed bridge satisfies the principle of linear superposition, then the influence matrix [C], the adjustment vector [X], and the adjusted vector [B] in the full-bridge finite element construction model can establish the following equation:

[0075] [C]·[X]=[B]; (1)

[0076] And the difference between the target value [B i of the control parameters (cable forces of the stay cables, tangential displacements of the main girder, and longitudinal displacements of the main tower) in the full-bridge finite element construction model and the current state [B0] is equal to the adjusted vector [B], that is:

[0077] [B] = [B i - [B0]; (2)

[0078] By combining Equation (1) and Equation (2), it can be seen that the target values of the control parameters (cable forces of stay cables, tangential displacements of the main girder, and longitudinal displacements of the main tower) in the full-bridge finite element construction model [B i are equal to:

[0079] [B i = [C]·[X] + [B0]; (3)

[0080] Among them, the influence matrix [C] in Equation (1) refers to the degree of influence of the adjusted vector on the vector to be adjusted. The adjusted vector [X] means that by adjusting certain parameter variables, a specific structural adjustment goal can be achieved. The vector to be adjusted [B] refers to the target adjustment value achieved by changing the parameter variables in the adjusted vector [X], such as the cable forces of stay cables, tangential displacements of the main girder, and longitudinal displacements of the main tower corresponding to the completion of concrete shrinkage and creep of the completed bridge, etc.

[0081] It should be noted that the control parameter - the cable force of the stay cable in Equation (2) and Equation (3) refers to the cable force corresponding to the completion of concrete shrinkage and creep of the completed bridge, rather than the tension force of the stay cable during the construction process. The main difference between the two is that the former is the vector to be adjusted and the latter is the adjusted vector; the control parameter - the tangential displacement of the main girder in Equation (2) and Equation (3) refers to the cumulative displacement of the completed bridge after the new beam segment is assembled along the tangent of the existing cantilever beam segment during the installation of the steel girder, rather than the cumulative displacement of the completed bridge during the cantilever construction of the prestressed concrete beam. The main difference between the two is that during the cantilever construction of the steel girder, the new beam segment is assembled along the tangent direction of the old beam segment, while during the construction of the concrete beam, no tangent assembly is required; the control parameter - the longitudinal displacement of the main tower in Equation (2) and Equation (3) refers to the displacement of the main tower in the longitudinal direction of the bridge corresponding to the completion of concrete shrinkage and creep of the completed bridge, rather than the displacement in other directions.

[0082] S22. Calculate the influence matrices of the cable forces of the stay cables, the tangential displacements of the main girder, and the longitudinal displacements of the main tower of the hybrid - composite girder cable - stayed bridge.

[0083] Take one tower in the full-bridge finite element construction model of a hybrid-composite girder cable-stayed bridge for analysis. If a tower has n stay cables, then by modifying the construction adjustment vector - the final tension of each stay cable (the final tension of each stay cable is increased by 100 kN separately, that is, when the final tension of the current stay cable is increased by 100 kN, the final tensions of other stay cables remain unchanged), a total of n calculations are made, and the three influence matrices [C] of the stay cable forces, the tangent displacement of the main girder, and the longitudinal deviation of the main tower under the corresponding completed stage of concrete shrinkage and creep of the hybrid-composite girder cable-stayed bridge are obtained as: [S], [W], and [T], respectively. That is, when 1 construction adjustment vector [X] - the final tension of each stay cable changes individually (the tension increment is calculated as 100 kN, and the other intermediate tensions are taken according to step S1 and remain unchanged), it causes changes in the influence vectors of cable forces, tangent displacements, and longitudinal deviations, and thus the influence matrices corresponding to the completed bridge state are formed in sequence, which are respectively:

[0084] Influence matrix of stay cable forces: The influence matrix [S] of the completed bridge cable forces of a total of n stay cables of one tower is composed of the influence vectors {S ij}, which is defined as the influence on the completed bridge cable force of the j-th stay cable when the final tension of the i-th stay cable changes;

[0085] Influence matrix of the tangent displacement of the main girder: The tangent displacements at the n connection and anchorage points of the main girder corresponding to n stay cables of the main girder are taken. The influence matrix [W] of the tangent displacements of a total of n main girder positions of one tower is composed of the influence vectors {W ij}, which is defined as the influence on the tangent displacement of the j-th anchorage point when the final tension of the i-th stay cable changes;

[0086] Influence matrix of the longitudinal deviation of the main tower: One longitudinal deviation point at the top of the tower and one at the midpoint of the tower limb are taken for the main tower. The influence matrix [T] of the longitudinal deviations of a total of 2 main tower positions of one tower is composed of the influence vectors {T ij}, which is defined as the influence on the longitudinal deviation point of the j-th main tower position when the final tension of the i-th stay cable changes.

[0087] S3. Calculate the initial values of the stay cable forces, the tangent displacement of the main girder, and the longitudinal deviation of the main tower under the completed bridge state of the hybrid-composite girder cable-stayed bridge; establish an objective function composed of the stay cable tension and the variables of the stay cable completed bridge force, the tangent displacement of the main girder, and the longitudinal deviation of the main tower; set multi-parameter constraint control conditions for the parameters in the objective function, and establish an optimization control equation for the optimized objective function.

[0088] S31. Calculate the initial values of the stay cable forces, the tangent displacement of the main girder, and the longitudinal deviation of the main tower under the completed bridge state of the hybrid-composite girder cable-stayed bridge.

[0089] In the full-bridge finite element construction model, the initial value of the final tension of each stay cable is denoted as [x0], and its value is taken as the designed in-service cable force. The other intermediate tensile forces of each stay cable are determined according to step S1. After the finite element construction model is calculated by the finite element analysis software, the initial value of the stay cable force [S0], the initial value of the tangential displacement of the main girder [W0], and the initial value of the longitudinal deviation of the main tower [T0] corresponding to the completed state of concrete shrinkage and creep of the in-service bridge are obtained. It should be noted that the parameter variables [x0], [S0], [W0], and [T0] obtained in this step are the initial values for the first-round iterative loop calculation in the objective function of formula 4 in step S32, that is, in the first-round iterative loop calculation, the four parameter variables [x0], [S0], [W0], and [T0] are all constant initial values; however, in a new round of iterative loop calculation, the optimized result of the previous round should be taken as the initial value for the new iterative loop calculation. Through tens of thousands of iterative calculations, the present invention has found that taking the designed in-service cable force as the initial value [x0] of the final tension of the stay cable in the first-round iterative loop calculation can enable the iterative loop calculation system in step S4 to converge quickly and solve a set of solutions that meet the requirements of the in-service state.

[0090] S32. Establish an objective function composed of the tensile force of the stay cable and the variables of the in-service cable force of the stay cable, the tangential displacement of the main girder, and the longitudinal deviation of the main tower.

[0091] Establish an objective function composed of the stay cable tensile force variable [x] and the stay cable force variable [S i corresponding to the completed state of concrete shrinkage and creep of the in-service bridge, the main girder tangential displacement variable [W i , and the main tower longitudinal deviation variable [T i as follows:

[0092]

[0093] Among them, when calculating the value of the parameter variable [x] in formula 4, the value of 1 is taken at the beginning, and during the iterative calculation, trial values are taken in an increasing or decreasing trend (either positive or negative) until the iterative calculation converges.

[0094] The parameter variables [S i , [W i , and [T i in formula 4 are the cable force influence matrix, the main girder tangential displacement influence matrix, and the main tower longitudinal deviation influence matrix corresponding to the in-service state in step S2, respectively.

[0095] The parameter variables [x0], [S0], [W0], and [T0] in formula 4 are the initial values of the stay cable tensile force iteration and the initial values of the stay cable force iteration, the main girder tangential displacement iteration, and the main tower longitudinal deviation iteration corresponding to the in-service state, respectively. In each round of iterative loop calculation, their values are taken as the results of the previous round of iterative calculation.

[0096] The parameter variable [x i in Equation 4 is the target value of the tensile force after the i-th round of iterative calculation, and [S i is the target value of the stay cable force in the completed bridge state corresponding to the i-th round of iterative calculation, and [W i is the target value of the tangent displacement of the main girder in the completed bridge state corresponding to the i-th round of iterative calculation, and [Ti] is the target value of the longitudinal deviation of the main tower in the completed bridge state corresponding to the i-th round of iterative calculation.

[0097] S33. Set multi-parameter constraint control conditions for the parameters in the objective function, and establish an optimization control equation for the optimization objective function.

[0098] Set the multi-parameter constraint control conditions for the upper and lower limit ranges of the stay cable force variable [S i , the tangent displacement variable [W i , and the longitudinal deviation variable [T i of the main tower in the completed bridge state of the concrete shrinkage and creep completion state for the objective function in step S32:

[0099]

[0100] Among them, the definitions of the parameter variables [S i , [W i , and [T i in Equation 5 are the same as those in step S32 above.

[0101] The bar above / below the control parameter variable in Equation 5 represents the upper / lower limit of the parameter variable. For example, S i represents the lower limit of the parameter variable, while represents the upper limit of the parameter variable. The specific values can be determined comprehensively according to design requirements, specification requirements, and iterative loop calculation results, etc.

[0102] Equation 5 does not need to constrain whether the stay cable meets the requirements of the material strength of its finished cable, that is, whether it exceeds its stress limit. Here, the constraint control is the deviation range condition of the stay cable force in the completed bridge state. As long as the deviation range of the stay cable force does not exceed the requirements in the design and specifications, the stay cable naturally meets the requirements of the material strength of its finished cable, that is, the stress does not exceed the limit.

[0103] The parameter variable [W i in Equation 5 requires that the tangent displacement of the main girder is close to 0 in the state of completed concrete shrinkage and creep in the completed bridge, and it is a smooth and flowing curve, and the appearance of sharp corners is avoided.

[0104] For hybrid-composite girder cable-stayed bridges, the design and specifications require that the target value of the stay cable force [S iThat is, the upper and lower limits of the completed bridge cable force are ±5%; the target value of the tangent displacement of the main girder [W i is controlled between -3 and 3 cm in the concrete beam part and between -6 and 6 cm in the composite beam part; the target value of the longitudinal deviation of the main tower [T i requires the main tower to deform towards the side span and is controlled between -10 and 0 cm; however, the parameter constraint control conditions are not limited to this, and dynamic adjustment should also be made according to the results of the iterative loop calculation.

[0105] Since the present invention takes the designed completed bridge cable force as the initial value of the final tension of each stay cable, denoted as [x0], the deviations of the obtained completed bridge parameters variables [S0], [W0], and [T0] compared with the constraint control conditions will be relatively large. Therefore, when determining the control parameter values, the constraint method should start from a single control parameter and be constrained from a large range to a small range, and when modifying a single control parameter, the values of the other two control parameters remain unchanged.

[0106] Establish an optimization control equation for the optimization objective function, specifically, use the least squares method theory to establish an optimization control equation for the optimization objective function:

[0107] F(x) = ||[C]·[X] - ([B i - [B0])|| 2 = min; (6)

[0108] The meaning of the influence matrix [C] in Equation 6 is the same as that in step S2.

[0109] The adjustment vector [B i in Equation 6 respectively refers to the adjusted vector - the iterative target value [S i of the stay cable force corresponding to the completed bridge state, the iterative target value [W i of the tangent displacement of the main girder, and the iterative target value [T i of the longitudinal deviation of the main tower. Its value will change continuously in each round of iterative loop calculation until an ultimate tensile force target value that meets the constraint control conditions is obtained through the convergence of the iterative loop calculation.

[0110] The adjustment vector [B0] in Equation 6 respectively refers to the adjusted vector - the initial value [S0] of the stay cable force, the initial value [W0] of the tangent displacement of the main girder, and the initial value [T0] of the longitudinal deviation of the main tower corresponding to the completed bridge state. Its meaning is the same as the description in the above steps and remains unchanged in each round of iterative loop calculation.

[0111] The maximum number of iterations of the optimization control equation F(x) in Equation 6 is set to 10,000 times, and the minimum convergence tolerance value is set to 0.00001.

[0112] If the iterative loop calculation in Formula 6 does not converge, return to the previous step (set multi-parameter constraint control conditions for the parameters in the objective function) and appropriately adjust the parameter variables [S i , [W i , and [T i . Also, return to step S32 for iterative loop calculation and adjust until Formula 6 converges. Note that the upper and lower limit ranges of the parameter variables [S i , [W i , and [T i must meet the design and specification requirements.

[0113] S4. Establish an iterative loop calculation system composed of an objective function, multi-parameter constraint control conditions, and an optimization control equation.

[0114] As can be seen from step S3, the present invention establishes an objective function composed of a construction adjustment vector [x], an influence matrix [C], and a controlled vector [B], etc., and sets multi-parameter constraint control conditions for the upper and lower limit ranges of the controlled vector [B] in the objective function, forming an iterative loop calculation system after optimizing the objective function using the least squares method. This system stops calculating until the optimized iterative loop calculation equation converges, thereby obtaining a set of solutions for the cable tension [x].

[0115] Among them, in the preferred embodiment of the present invention, the objective function is:

[0116]

[0117] The constraint control conditions are:

[0118]

[0119] Use the least squares method theory to establish an optimization control equation for optimizing the objective function:

[0120] F(x) = ||[C]·[X] - ([B i - [B0])|| 2 = min; (9)

[0121] The calculation logic of this iterative loop calculation system is: First, when calculating the value of the parameter variable [x] in the objective function of Formula 7, take the unit 1 at the beginning, and then calculate the corresponding target values [S i , [W i , and [T i corresponding to the parameter variable [x i, this result will be used to determine in Equation 8 whether the three constraint control conditions are met. If not, it will return to Equation 7 to continue obtaining a new value of the parameter variable [x] for iterative calculation. This result will continue to be used to determine in Equation 8 whether the three constraint control conditions are met. This process will repeat in a loop until one or more of the constraint control conditions in Equation 8 are satisfied. At this point, it will enter Equation 9 for optimizing iterative loop calculation of the equation to optimize the parameter variable [x] through the least squares method. The new variable [x] will then return to Equations 7 and 8 to continue iterative loop calculation. If the target value still does not meet the constraint conditions, it will continue to return to Equation 9 for optimizing iterative loop calculation through the least squares method.

[0122] When determining the constraint control conditions, the value should be taken according to the deviation result calculated from the iterative initial value, and the constraint method should start from a single control parameter and be carried out from a large range to a small range. When modifying a single control parameter, the values of the other two control parameters remain unchanged. The iterative calculation result after each modification of the constraint control conditions serves as the initial value for the next iterative loop calculation. This modification form facilitates the convergence of the iterative calculation system.

[0123] S5. Control the uniformity of the cable force changes of adjacent stay cables on both sides of the side and middle spans of the hybrid-composite girder cable-stayed bridge; control the tensile and compressive stresses of the main tower and main girder of the hybrid-composite girder cable-stayed bridge not to exceed the allowable limit values; control the transition piers and auxiliary piers of the hybrid-composite girder cable-stayed bridge to have sufficient reserve pressure.

[0124] S51. Control the uniformity of the cable force changes of adjacent stay cables on both sides of the side and middle spans of the hybrid-composite girder cable-stayed bridge.

[0125] Strictly control the limit values of the cable force of a set of stay cables obtained in Step S4 for the stay cables on both sides of the side and middle spans with the same label. The cable force of the stay cables calculated in Step S4 meets the requirements of the constraint control conditions for the corresponding as-built cable force, indicating that the finished cables also meet the requirements of the material strength. On this basis, it is also necessary to ensure the uniformity of the cable force changes of adjacent stay cables on both sides of the side and middle spans with the same label during the construction process of the main girder, that is, the difference between adjacent cable forces should not be too large, and it is required that the cable force of the stay cables on the side span is greater than that on the middle span, and the difference between the cable force of the stay cables on the side span and that on the middle span with the same label does not exceed 1500 kN (i.e., the cable force of the side span stay cable - the cable force of the middle span stay cable ≤ 1500 kN). If the obtained set of cable force solutions [x] of the stay cables does not meet the limit requirements, then adjust the constraint control conditions of the as-built cable force in Step S4, and re-iterate and calculate in a loop to determine whether it meets the requirement that the limit value of the cable force of the stay cables on both sides of the side and middle spans with the same label is ≤ 1500 kN until the cable force solution [x] of the stay cables is obtained and enter the subsequent steps.

[0126] S52. Control the tensile and compressive stresses of the main tower and main girder of the hybrid-composite girder cable-stayed bridge not to exceed the allowable limit values.

[0127] From the solution [x] of the cable tension of the cable-stayed bridge during the cantilever erection construction process that satisfies the multi-parameter constraint control conditions and the cable tension limit requirements on both sides of the mid-span of the side, after substituting it into the full-bridge finite element construction model and running to obtain the analysis results, check whether the principal tower compression and tension stresses and the main girder compression and tension stresses (the top and bottom plate stresses of the steel main girder and precast bridge deck of the mid-span composite beam and the top and bottom plate stresses of the cast-in-place concrete beam of the side span) during the cantilever erection construction process of the full bridge exceed the allowable values of the specifications and design. If they exceed the limit, adjust the multi-parameter constraint control conditions in step S4 (note that the adjustment of the parameter variable range must meet the requirements of the design, specifications, and iterative loop calculation results), re-iterate the loop calculation, and then judge whether the stress safety requirements of the principal tower and the main girder are met until the cable tension solution [x] is obtained and proceed to the subsequent steps.

[0128] S53. Control the sufficient pressure reserved by the transition piers and auxiliary piers of the hybrid-composite beam cable-stayed bridge to avoid the bearing pads from becoming disengaged.

[0129] From the solution [x] of the cable tension of the cable-stayed bridge during the cantilever erection construction process that satisfies the multi-parameter constraint control conditions, the uniform change of the cable force of the cable-stayed cables, and the stress requirements of the principal tower and the main girder, after substituting it into the full-bridge finite element construction model and running to obtain the analysis results, check whether the bearing reactions of the transition piers and auxiliary piers show "negative reactions", that is, the phenomenon of tension, which means that the bearing pads are in a disengaged state, the main girder does not act on the bearing pads, and the bearing pads are not in a normal working state. It is required that the transition piers and auxiliary piers should reserve sufficient pressure under the action of the dead load of the completed bridge to avoid the phenomenon of the bearing pads becoming disengaged. If the phenomenon of the bearing pads becoming disengaged appears in the obtained set of cable tension solutions [x], adjust the multi-parameter constraint control conditions in step S4, re-iterate the loop calculation, and then judge whether the bearing pads show "negative reactions". If the bearing pads are not disengaged, this solution is the optimal solution [x] of the cable tension of the cable-stayed bridge during the cantilever erection construction process. 优 .

[0130] S6. Calculate and determine the cable tension of each time during the cable-stayed cable construction process of the hybrid-composite beam cable-stayed bridge.

[0131] The cable tension of the cable-stayed bridge during the cantilever erection construction process obtained from step S5 should not only meet the requirements that the cable forces of the cable-stayed cables are uniform and the deviation is within the allowable range of the design and specifications at the completion stage of the concrete shrinkage and creep of the corresponding completed bridge, the tangent displacement of the main girder is close to a straight line state, and the longitudinal deviation of the principal tower deflects towards the side span, but also meet the requirements of the stress safety of the principal tower and the main girder during the cantilever erection construction process of the full bridge and no negative reactions occur in the transition piers and auxiliary piers. This solution is the optimal solution [x] of the cable tension. 优 . Furthermore, the values of the cable tensions of each other intermediate stage of each cable-stayed cable are obtained as the optimal solution [x] of the cable tension. 优One over the number of times, that is, if the stay cables are tensioned 3 times during the construction process (in this invention, the overall tension adjustment of all stay cables of the whole bridge is not required), then the first tension of the stay cable is the optimal solution [x 优 of The second tension of the stay cable is the optimal solution [x 优 of The intermediate tension value of the stay cable here is an empirical value, and the actual value should be finally adjusted and determined according to the stress state of the top and bottom plates of the main girder during the actual construction process of the cable-stayed bridge. So far, the construction tensions of the stay cables of the hybrid-composite girder cable-stayed bridge have been all solved, that is, the calculation of the construction tensions of the hybrid-composite girder cable-stayed bridge is realized.

[0132] On the other hand, please refer to Figure 2 and Figure 3 , this invention also provides a calculation device for the construction tensions of a hybrid-composite girder cable-stayed bridge, which mainly includes:

[0133] Basic information calculation module, which is used to establish a finite element construction model of the whole bridge, determine the tensions of the stay cables in the finite element construction model, set the last tension as the designed in-service cable force, and calculate the initial values of the stay cable forces, the tangent displacement of the main girder, and the longitudinal deviation of the main tower in the in-service state of the hybrid-composite girder cable-stayed bridge.

[0134] Through this module, the basic information of the finite element construction model of the hybrid-composite girder cable-stayed bridge considering the shapes of the bridge vertical curve and horizontal curve can be calculated - the cable forces [S0], the tangent displacement [W0] of the main girder, and the longitudinal deviation [T0] of the main tower in the in-service concrete completion shrinkage and creep stage calculated and analyzed based on the final tension [x0] of the stay cable as the designed in-service cable force.

[0135] Linear superposition principle calculation module, which is used to calculate the influence matrices of the stay cable forces, the tangent displacement of the main girder, and the longitudinal deviation of the main tower of the hybrid-composite girder cable-stayed bridge.

[0136] Through this module, the influence matrices formed by the change of the target value influence vector caused by a unit change in the final tension of each stay cable can be calculated, which are respectively: the stay cable force influence matrix [S], the tangent displacement influence matrix [W] of the main girder, and the longitudinal deviation influence matrix [T] of the main tower.

[0137] Objective function intelligent calculation module, which is used to establish the objective formula of the control parameters of the hybrid-composite girder cable-stayed bridge composed of the influence matrix formulas in the finite element construction model, and calculate and establish the objective function composed of the variables of the stay cable tensions, the in-service cable forces of the stay cables, the tangent displacement of the main girder, and the longitudinal deviation of the main tower.

[0138] Through this module, the formula [x i= 100·[x] + [x0] and [B] including the dependent variable i = [C]· X + [B0] and the objective function is composed of. When starting to calculate the iterative independent variable [x], it takes the unit 1 and tries to calculate the value in an increasing or decreasing trend (both positive and negative numbers are acceptable). [x] in the module can automatically change to any value, and the change rate can also be set manually until the iterative calculation converges.

[0139] The parameter constraint and intelligent adjustment calculation module is used to set multi-parameter constraint control conditions for the parameters in the objective function, establish an optimization control equation for optimizing the objective function, and establish an iterative loop calculation system composed of the objective function, multi-parameter constraint control conditions, and optimization control equation.

[0140] Through this module, the upper and lower limit ranges of the cable forces [S], the tangent displacement [W] of the main girder, and the longitudinal deviation [T] of the main tower of the stay cables in the completed state of shrinkage and creep of the bridge deck concrete can be set. The values can be adjusted and modified manually according to design requirements, specification requirements, and actual needs of the iterative loop calculation results, etc.; and in the module, the most core optimization iterative loop calculation system formed by the least squares method is also established. The maximum number of iterations of its control equation is set to 10,000 times, and the minimum convergence tolerance value is set to 0.00001.

[0141] The result automatic judgment calculation module is used to realize controlling the uniformity of the cable force changes of the adjacent stay cables on both sides of the side and middle spans of the hybrid-composite girder cable-stayed bridge, controlling that the tensile and compressive stresses of the main tower and main girder of the hybrid-composite girder cable-stayed bridge do not exceed the allowable limit values, and controlling that the transition piers and auxiliary piers of the hybrid-composite girder cable-stayed bridge have sufficient pressure reserves; and calculating and determining the tensile force of each stay cable during the construction process of the hybrid-composite girder cable-stayed bridge.

[0142] Three judgment conditions can be established through this module, namely the cable force uniformity requirement for the side and middle span sides of the same label, the stress safety requirement for the main tower and main girder, and the requirement that the transition piers and auxiliary piers have a certain pressure reserve; the cable force uniformity range, the main tower and main girder stress range, and the pressure range of the transition piers and auxiliary piers can be set manually in the module; the module will also prompt which requirement is not met, and people can go to modify the control constraint conditions in the "parameter constraint and adjustment calculation module" accordingly. For example, if the cable force uniformity does not meet the requirement, then modify the upper and lower limit ranges of the cable force [S] variable in the "parameter constraint and adjustment calculation module".

[0143] Among them, the objective function intelligent calculation module and the parameter constraint and intelligent adjustment calculation module as well as the parameter constraint and intelligent adjustment calculation module and the result automatic judgment calculation module can transfer data to each other and perform iterative cycle calculations to obtain the optimal solution for the tensioning force of the inclined cable construction; the result automatic judgment calculation module can transfer data to the objective function intelligent calculation module for iterative calculation, and if the objective function intelligent calculation module wants to return to the result automatic judgment calculation module for calculation, it must pass through the parameter constraint and intelligent adjustment calculation module to reach the result automatic judgment calculation module; the objective function intelligent calculation module can transfer data to the basic information calculation module.

[0144] The following is a specific exemplary implementation example of the present invention, please refer to Figure 4 and Figure 5 The span combination of a double-tower double-cable-plane hybrid-composite beam cable-stayed bridge is (51+89+400+89+51)m. The vertical curve of the bridge is located on the longitudinal slope of the -1.2% straight slope section, and the horizontal curve is located on the straight line. The bridge adopts a semi-floating system, with tower-beam separation and tower-pier consolidation. The cable-stayed cable adopts a 7mm diameter parallel steel wire finished cable, which is a double-cable-plane arrangement. There are 128 finished cables in the whole bridge, and a tower has a total of 32 finished cables with different lengths of cable-stayed cables on both sides of the large and small pile numbers. The side span of the main beam is 62m long and is a π-shaped concrete cast-in-place beam. The secondary side span and the middle span are both steel-concrete composite beams, using the double-sided main box form, with a central beam height of 3.0m and a total width of 31.5m. The main tower adopts a reinforced concrete diamond-shaped cable tower. The cast-in-place section of the side span of the main beam of the whole bridge adopts full-span bracket construction, the secondary side span and the middle span are both constructed by cantilever assembly of the bridge deck crane, and the main tower adopts climbing formwork construction.

[0145] This example uses the calculation method for the construction tension force of the hybrid-combined beam cable-stayed bridge described in the present invention to analyze and explain. Since the vertical curve of the cable-stayed bridge in this example is located on the longitudinal slope of the -1.2% straight slope section, the two towers are not symmetrically arranged along the middle span, and the two towers should be taken separately for analysis when calculating the construction tension force of the cable-stayed cable of the entire bridge. Since the analysis technology methods of the two towers are consistent, they are not displayed one by one. Only the cable-stayed cable of the main tower on the small pile number side is taken for analysis. The calculation method for the construction tension force of the cable-stayed cable of the main tower on the large pile number side is consistent with that of the small pile number side, and can be directly referenced.

[0146] (1) According to step S1, the initial value of the final tension of each cable of the main tower on the small pile side is a column vector: [x0] = [5321, 5237, 5263, 5186, 5086, 4869, 4553, 4127, 3795, 3588, 3366, 3197, 2954, 2725, 2490, 2252, 2363, 2568, 2737, 2963, 3227, 3464, 3678, 3869, 4099, 4478, 4717, 4869, 4891, 4749, 4644, 4672] T。

[0147] (2) According to step S2, the three influence matrices [S], [W], and [T] of the cable forces of the stay cables, the tangent displacement of the main girder, and the longitudinal deviation of the main tower on the small-stake-number side at the completion stage of the concrete shrinkage and creep of the completed bridge are as follows (only partial contents of the influence matrices are listed due to space limitations):

[0148] Influence matrix of stay cable force:

[0149]

[0150] Influence matrix of tangent displacement of main girder:

[0151]

[0152] Influence matrix of longitudinal deviation of main tower:

[0153]

[0154] (3) According to step S3, the initial values [S0], [W0], and [T0] of the cable forces of the stay cables, the tangent displacement of the main girder, and the longitudinal deviation of the main tower in the corresponding completed-bridge state obtained under the final tension of the stay cables on the small-stake-number side are as follows:

[0155] Initial value of the cable force of the stay cable in the completed bridge: [x0] = [6222, 5998, 5868, 5592, 5307, 4886, 4377, 3788, 3313, 3104, 2981, 3329, 2732, 2346, 2060, 1974, 2148, 2282, 2512, 2891, 3341, 3765, 3677, 3762, 3879, 4297, 4665, 5016, 5235, 5153, 5046, 5049] T (unit: kN), and the deviation of the cable force in the completed bridge is within 20%.

[0156] Initial value of the tangent displacement of the main girder in the completed bridge: [W0] = [5, 10, 15, 20, 22, 21, 19, 14, 7, -11, -7, 271, 143, 45, -15, -37, 23, 96, 214, 382, 607, 891, 1237, 1649, 2129, 2678, 3293, 3969, 4703, 5489, 6324, 7201] T (unit: mm), and the deviation range of the tangent displacement of the main girder in the completed bridge is between -37 and 7201 mm.

[0157] Initial value of the longitudinal deviation of the main tower in the completed bridge: [T0] = [-66, -44]T (Unit: mm). The longitudinal deviation range of the main tower of the completed bridge is -66 to -44 mm towards the side span.

[0158] (4) According to Step S3 and Step S4, as well as the requirements of design, specifications, and relevant experience, the multi-parameter constraint control conditions for the upper and lower limit ranges of the cable forces [S], the tangential displacement [W] of the main girder, and the longitudinal deviation [T] of the main tower in the completed state after concrete shrinkage and creep are as follows:

[0159]

[0160] For hybrid-composite girder cable-stayed bridges, the target value of the cable force of the stay cables [S i , that is, the upper and lower limit ranges of the cable forces in the completed bridge are ±5%; the target value of the tangential displacement [W i is controlled between -6 and 6 cm; the target value of the longitudinal deviation [T i requires the main tower to deform towards the side span and is controlled between -10 and 0 cm.

[0161] Table 1 Constraint control conditions of this example

[0162] Iterative calculation Controlling cable force Controlled displacement / mm Controlled tower deviation / mm Remarks The 1st round ±20％ ±60 -100，0 Controlled displacement The 2nd round ±10％ ±60 -100，0 Controlling cable force The 3rd round ±7％ ±60 -100，0 Controlling cable force The 4th round ±5％ ±60 -100，0 Controlling cable force The 5th round ±5％ ±60 -100，0 Uniformity of cable force control The 6th round ±5％ ±20 -100，0 Uniformity of cable force control and alignment

[0163] (5) According to Step S5 and Step S6 and comprehensively considering Step S3 and Step S4, the adjustment process of the constraint control conditions in this example is as shown in Table 1 above. Since the deviation of the tangential displacement of the main girder in the completed bridge is relatively large, in the first round of iterative calculation, only the tangential displacement of the main girder in the completed bridge is constrained to be within ±60 mm, and the constraints of the other two parameters remain in the original range; in the 2nd to 4th rounds of iterative calculation, only the cable forces in the completed bridge are constrained to be within ±10%, ±7%, and ±5% respectively, and the constraints of the other two parameters remain in the original range; due to the uneven cable tensions of the stay cables in the side and middle spans in the results of the 4th round of iterative calculation, in the 5th round of iterative calculation, it is necessary to constrain the cable tensions of the stay cables in the side and middle spans and require the cable tension in the side span to be greater than that in the middle span. Only the range of the tangential displacement of the main girder needs to be slightly adjusted, and the constraints of the other two parameters remain in the original range; in the results of the 5th round of iterative calculation, the cable tensions of the stay cables in the side and middle spans are still uneven and the alignment is not smooth. In the 6th round of iterative calculation, the range of the tangential displacement of the main girder is fine-tuned again to ensure that the cable tension in the side span is greater than that in the middle span and the alignment is smooth, and the constraints of the other two parameters remain in the original range, which can be referred to Figures 6 to 8 . If the cable tension solution [x] calculated in the 6th round of iterative calculation results in uniform cable tensions in the completed bridge and meets the requirements of the stress safety of the main tower and main girder during the cantilever erection construction process of the entire bridge, and no negative reaction forces occur at the transition piers and auxiliary piers, then this solution is the optimal solution [x 优 of the cable tensions of the stay cables during the cantilever erection construction process of the hybrid-composite girder cable-stayed bridge, specifically [x 优= [4700, 4641, 4721, 4757, 4758, 4693, 4319, 3792, 3551, 3396, 3057, 2452, 2217, 2120, 2298, 2396, 2342, 2083, 2060, 2031, 2011, 2119, 2571, 2648, 2911, 3235, 3355, 3510, 3560, 3368, 3632, 3992] T , during the process, the first tensile force of the stay cable is taken as 0.5 times of the optimal solution of [x 优 . Thus, the construction tensile forces of all the stay cables of the hybrid-composite girder cable-stayed bridge have been solved completely.

[0164] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the said claims.

Claims

1. A calculation method for the construction tension of a hybrid-composite girder cable-stayed bridge, characterized in that It includes the following steps: S1. Establish a full-bridge finite element construction model, determine the tensile force of the stay cables in the finite element construction model, and set the last tensile force as the designed in-service cable force; S2. Establish an objective formula for the control parameters of the hybrid-composite girder cable-stayed bridge composed of the influence matrix formula in the finite element construction model; Calculate the influence matrix of the stay cable force, the tangent displacement of the main girder, and the longitudinal deviation of the main tower of the hybrid-composite girder cable-stayed bridge; S3. Calculate the initial values of the stay cable force, the tangent displacement of the main girder, and the longitudinal deviation of the main tower of the hybrid-composite girder cable-stayed bridge in the in-service state; Establish an objective function composed of the tensile force of the stay cables, the in-service cable force of the stay cables, the tangent displacement of the main girder, and the longitudinal deviation of the main tower; Set multi-parameter constraint control conditions for the parameters in the objective function, and establish an optimization control equation for optimizing the objective function; S4. Establish an iterative loop calculation system composed of the objective function, the multi-parameter constraint control conditions, and the optimization control equation; S5. Control the uniformity of the change in the stay cable force between the adjacent stay cables on both sides of the side and middle spans of the hybrid-composite girder cable-stayed bridge; Control the tensile and compressive stresses of the main tower and the main girder of the hybrid-composite girder cable-stayed bridge so that they do not exceed the allowable limit values; Control the hybrid-composite girder cable-stayed bridge to have sufficient pressure reserved at the transition piers and auxiliary piers; S6. Calculate and determine the tensile force for each time during the construction of the stay cables of the hybrid-composite girder cable-stayed bridge.

2. The calculation method of the construction tensile force of the hybrid-composite girder cable-stayed bridge according to claim 1, characterized in that the last tensile force of each stay cable in the full-bridge finite element construction model is taken as the designed in-service cable force, and the intermediate tensile force of each stay cable is taken as one over the number of times of the designed in-service cable force.

3. The calculation method of the construction tensile force of the hybrid-composite girder cable-stayed bridge according to claim 1, characterized in that In step S2, the target value of the control parameter in the full-bridge finite element construction model [B i is equal to: [B i = [C]·[X]+[B0]; where [C] is the influence matrix in the full-bridge finite element construction model, [X] is the adjustment vector in the full-bridge finite element construction model, [B0] is the current state of the control parameters in the full-bridge finite element construction model, and the difference between the target value [B i of the control parameters in the full-bridge finite element construction model and the current state [B0] is equal to the adjusted vector [B]; wherein, the influence matrix [C] refers to the influence degree formed by the adjustment vector on the adjusted vector, the adjustment vector [X] refers to adjusting certain parameter variables to achieve a specific structural adjustment goal, and the adjusted vector [B] refers to the target adjustment value achieved by changing the parameter variables in the adjustment vector [X].

4. The calculation method of the construction tensile force of the hybrid-composite girder cable-stayed bridge according to claim 3, characterized in that In step S2, the cable force influence matrix of the stay cables is composed of the influence vectors {S ij}, which represents the influence on the in-service cable force of the j-th stay cable when the final tension of the i-th stay cable changes. Influence matrix of tangent displacement of main girder The tangent displacement of the main girder at the n connection and anchorage points between the main girder and the stay cables corresponding to n stay cables of the main girder when the bridge is completed is composed of the influence vectors {W ij}, which is the influence on the tangent displacement of the j-th anchorage point when the final tension of the i-th stay cable changes; Longitudinal deviation influence matrix of the main tower For the longitudinal deviation points of the main tower at the top of the tower and the midpoint of the tower limb respectively when the bridge is completed, it is composed of the influence vector {T ij}, which is the influence on the longitudinal deviation point j of the main tower when the final tension of the i-th stay cable changes.

5. The calculation method of the construction tensile force of the hybrid-composite girder cable-stayed bridge according to claim 4, characterized in that In step S3, an objective function is established, which consists of the cable tension variable [x] of the stay cables and the corresponding cable force variables [S i of the stay cables in the completed state of concrete shrinkage and creep of the completed bridge, the tangent displacement variable [W i of the main girder, and the longitudinal deviation variable [T i of the main tower. Specifically, it is as follows: wherein, the parameter variables [x0], [S0], [W0], [T0] are respectively the iterative initial values of the stay cable tensile force and the iterative initial values of the stay cable force, the tangent displacement of the main girder, and the longitudinal deviation of the main tower in the corresponding in-service state, and their values are taken as the results of the previous round of iterative calculation in each round of iterative loop calculation; The parameter variable [x i is the target value of the tensile force after the i-th round of iterative calculation, [S i is the target value of the cable force of the stay cable corresponding to the completed bridge state after the i-th round of iterative calculation, [W i is the target value of the tangent displacement of the main girder corresponding to the completed bridge state after the i-th round of iterative calculation, and [Ti] is the target value of the longitudinal deviation of the main tower corresponding to the completed bridge state after the i-th round of iterative calculation.

6. The calculation method of the construction tensile force of the hybrid-composite girder cable-stayed bridge according to claim 5, characterized in that Set the objective function to the multi-parameter constraint control conditions for the upper and lower limit ranges of the cable force variable [S i of the stay cables at the completion state of the shrinkage and creep of the bridge concrete, the tangent displacement variable [W i of the main girder, and the longitudinal deviation variable [T i of the main tower as follows:

7. The calculation method of the construction tensile force of the hybrid-composite girder cable-stayed bridge according to claim 6, characterized in that establish an optimization control equation for the optimization objective function by using the least squares method theory: F(x) = ||[C]·[X] - ([B i - [B0])|| 2 = min。 8. The calculation method of the construction tensile force of the hybrid-composite girder cable-stayed bridge according to claim 7, characterized in that Specifically, an iterative loop calculation system consisting of an objective function, multi-parameter constraint control conditions, and an optimization control equation is established as follows: When calculating the value of the parameter variable [x] in the objective function, the unit 1 is taken at the beginning, and the objective value corresponding to the parameter variable [x i , [S i , [W i , and [T i are input into the multi-parameter constraint control conditions to determine whether the three constraint control conditions are satisfied. If not, return to the objective function equation first to continue taking new values of the parameter variable [x] for iterative calculation. This result is continuously input into the multi-parameter constraint control conditions to determine whether the three constraint control conditions are satisfied. Repeat this loop until one or more of the constraint control conditions in the multi-parameter constraint control conditions are satisfied. At this time, enter the optimization control equation to optimize the parameter variable [x] by the least squares method. The new variable [x] returns to the objective function equation and the constraint control conditions to continue the iterative loop calculation. If the objective value still does not satisfy the constraint conditions, continue to return to the optimization control equation to optimize the iterative loop calculation by the least squares method.

9. The calculation method of the construction tension of the hybrid-composite girder cable-stayed bridge according to claim 1, characterized in that: In step S6, under the limiting conditions of step S5, the optimal solution of the cable tension of the stay cable is obtained [x 优 , and the value of the other intermediate cable tensions of each stay cable is one over the number of times of the optimal solution of the cable tension of the stay cable [x 优 .

10. A calculating device for the construction tension of a hybrid-composite girder cable-stayed bridge, characterized in that It includes: A basic information calculation module, which is used to establish a full-bridge finite element construction model, determine the tension of the stay cables in the finite element construction model, set the tension of the last cable as the designed in-service cable force, and calculate the initial values of the stay cable forces, the tangent displacement of the main girder, and the longitudinal deviation of the main tower in the in-service state of the hybrid-composite girder cable-stayed bridge; A linear superposition principle calculation module, which is used to calculate the influence matrices of the stay cable forces, the tangent displacement of the main girder, and the longitudinal deviation of the main tower of the hybrid-composite girder cable-stayed bridge; An objective function intelligent calculation module, which is used to establish an objective formula for the control parameters of the hybrid-composite girder cable-stayed bridge composed of the influence matrix formulas in the finite element construction model, and calculate and establish an objective function composed of the variables of the stay cable tension, the in-service cable force of the stay cable, the tangent displacement of the main girder, and the longitudinal deviation of the main tower; A parameter constraint and intelligent adjustment calculation module, which is used to set multi-parameter constraint control conditions for the parameters in the objective function, establish an optimization control equation for optimizing the objective function, and establish an iterative loop calculation system composed of the objective function, multi-parameter constraint control conditions, and the optimization control equation; A result automatic judgment calculation module, which is used to achieve the uniformity of controlling the change of the stay cable forces on both sides of the adjacent side and middle spans of the hybrid-composite girder cable-stayed bridge, controlling that the tensile and compressive stresses of the main tower and the main girder of the hybrid-composite girder cable-stayed bridge do not exceed the allowable limit values, and controlling that the transition piers and auxiliary piers of the hybrid-composite girder cable-stayed bridge have sufficient reserve pressure; and calculating and determining the tension of each stay cable during the construction process of the hybrid-composite girder cable-stayed bridge.

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