Method for closing a main girder of a cable-stayed suspension cooperative system bridge

Abstract

The application discloses a method for closing a main beam of a cable-stayed suspension cooperative system bridge, and belongs to the technical field of bridge engineering, which comprises the following steps: collecting design parameters of the bridge; designing a closure gap position according to the design parameters; respectively calculating target suspender forces of suspenders on both sides of the closure gap; after structures of the bridge except cable-stayed transition sections and suspension transition sections are constructed, hoisting the main beam of the cable-stayed transition section and the main beam of the suspension transition section to both sides of the closure gap, and respectively adjusting the suspender forces in the cable-stayed transition section and the suspension transition section to the target suspender forces; and performing closure operation of the closure gap. The method for closing the main beam of the cable-stayed suspension cooperative system bridge can not only realize rapid closure construction of the bridge structure, so as to shorten the construction period, but also can accurately adjust the closure gap and complete stress-free closure of the bridge structure, thereby providing guarantee for the stability of the bridge structure and reducing the construction cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bridge engineering, and particularly relates to a method for closing a main beam of a cable-stayed suspension cooperative system bridge. BACKGROUND

[0002] The cable-stayed suspension cooperative system is a new structural system which combines the advantages of cable-stayed bridges and suspension bridges, and can ensure a larger span of the structure and improve the overall stress performance of the structure.

[0003] The proportion of the second-phase dead load of the highway-railway combined bridge to all dead loads is relatively large, so the vertical displacement amplitude of the main beam during construction is large. For a kilometer-level cable-stayed suspension cooperative system bridge, the vertical displacement amplitude can reach several meters or even tens of meters. The main beam of the highway-railway combined bridge has large rigidity, so the range of adjustment of the beam end rotation angle and displacement is small during closure. These factors bring great difficulties to the installation and closure of the main beam of the highway-railway combined cable-stayed suspension cooperative system bridge.

[0004] The structural system of the cable-stayed suspension cooperative system bridge changes before and after closure. In order to realize stress-free closure of the main beam, it is necessary to take engineering measures to further adjust the closure gap, control the closure gap height difference and inclination angle difference, so as to realize the erection and welding requirements of the closure beam section.

[0005] The most commonly used adjustment measure for the closure gap is closure gap weight. For a 1500m-level super-long-span cable-stayed suspension cooperative system bridge, the main beam will be arched by 6-8m before the upper two dead loads, and the inclination angle difference on both sides of the closure gap in the middle of the span is large. Therefore, hundreds of tons of weight need to be pressed on both sides of the closure gap. The weight adjustment measure is costly and is not good for the stress of the structure. SUMMARY

[0006] In view of one or more of the above defects or improvement needs of the prior art, the application provides a method for closing a main beam of a cable-stayed suspension cooperative system bridge, which can not only realize rapid closure construction of the bridge structure to shorten the construction period, but also accurately adjust the closure gap and complete stress-free closure of the bridge structure, thereby providing protection for the stability of the bridge structure and reducing the construction cost.

[0007] To achieve the above purpose, the application provides a method for closing a main beam of a cable-stayed suspension cooperative system bridge, which presents the following process:

[0008] S1, collecting design parameters of the bridge;

[0009] S2, designing two closure gap positions according to the design parameters, and dividing the cable-stayed transition section and the suspension transition section on the longitudinal two sides of the closure gap respectively;

[0010] S3, calculating a first relationship curve between the suspender force on both sides of the closure gap and the closure gap height difference, and calculating a second relationship curve between the suspender force on both sides of the closure gap and the closure gap inclination angle difference.

[0011] S4, calculating a first influence matrix of the cantilever force and the height difference of the closure gap on both sides according to the first relationship curve, and calculating a second influence matrix of the cantilever force and the inclination angle difference of the closure gap on both sides according to the second relationship curve;

[0012] S5, calculating the target cantilever force of the cantilever on both sides of the closure gap according to the first influence matrix and the second influence matrix;

[0013] S6, after the construction of the bridge structure except the cable-stayed transition section and the suspension transition section, hoisting the girder of the cable-stayed transition section and the girder of the suspension transition section to the closure gap on both sides, and adjusting the cantilever force in the cable-stayed transition section and the suspension transition section to the target cantilever force respectively;

[0014] S7, performing the closure operation of the closure gap.

[0015] As a further preferred embodiment of the present application, the calculation of the first relationship curve and the second relationship curve is realized by constructing a finite element model of the bridge structure, and calculating the first relationship curve and the second relationship curve according to the finite element model.

[0016] As a further preferred embodiment of the present application, the calculation of the first influence matrix comprises the following steps:

[0017] S41, the height difference when the cantilever force on one side of the closure gap is 0 is obtained by calculating the corresponding height difference of the closure gap when the cantilever force on the other side changes according to the first relationship curve;

[0018] S42, the height difference when the cantilever force on both sides of the closure gap is not 0 is obtained by calculating the height difference when the cantilever force on the first side corresponds to the cantilever force on the second side being 0 according to the first relationship curve, and correspondingly calculating the height difference when the cantilever force on the second side corresponds to the cantilever force on the first side being 0 according to the first relationship curve, and then adding the two height differences and subtracting the height difference when the cantilever force on both sides of the closure gap is 0.

[0019] As a further preferred embodiment of the present application, the calculation of the second influence matrix comprises the following steps:

[0020] S43, the inclination angle difference when the cantilever force on one side of the closure gap is 0 is obtained by calculating the corresponding inclination angle difference of the closure gap when the cantilever force on the other side changes according to the first relationship curve;

[0021] S44, the inclination difference when the crane forces on both sides of the closure gap are not 0, the inclination difference when the first side crane force corresponds to the second side crane force being 0 is calculated according to the first relationship curve respectively, and correspondingly, the inclination difference when the second side crane force corresponds to the first side crane force being 0 is calculated according to the first relationship curve respectively, and the two inclination differences are added and then subtracted by the inclination difference when the crane forces on both sides of the closure gap are 0.

[0022] As a further preferred embodiment of the present application, the calculation of the target crane force is as follows: in the first influence matrix and the second influence matrix, the crane forces on both sides of the closure gap corresponding to the height difference and the inclination difference respectively crossing 0 when the crane force changes are marked respectively; by comparing the marked areas of the first influence matrix and the second influence matrix, a marked overlapping area is selected, and the target crane force of the crane on both sides of the closure gap is determined according to the overlapping area.

[0023] As a further preferred embodiment of the present application, the main girder of the cable-stayed transition section and the main girder of the suspension transition section are hoisted to the closure gap at the same time.

[0024] As a further preferred embodiment of the present application, the bridge includes a bridge tower and a main cable.

[0025] As a further preferred embodiment of the present application, the main girder of the cable-stayed transition section is hoisted from the bridge tower to the closure gap in sequence by a bridge deck crane.

[0026] As a further preferred embodiment of the present application, the main girder of the suspension transition section is hoisted from the midspan to the closure gap in sequence by a cable crane.

[0027] As a further preferred embodiment of the present application, the closure operation adjusts the width of the closure gap by using the traction closure or the push-pull low-temperature closure to complete the closure.

[0028] The above improved technical features can be combined with each other as long as they do not conflict with each other.

[0029] Overall, compared with the prior art, the above technical solutions conceived by the present application have the following beneficial effects:

[0030] (1) The main girder closure method of the cable-stayed suspension cooperative system bridge of the present application accurately divides the two closure gap positions according to the bridge design parameters, and calculates the relationship curves between the crane forces on both sides of the closure gap and the height difference and the inclination difference respectively, and then obtains the influence matrix between the crane forces on both sides of the closure gap and the height difference and the inclination difference. The accurate calculation of the crane forces of the transition sections on both sides of the closure gap is realized, and the stress-free closure of the closure gap is effectively realized when the closure is closed, the structural stability of the entire bridge structure is ensured, the construction process of the bridge closure is effectively simplified, the counterweight design on both sides of the bridge is cancelled, the construction cost is greatly reduced on the premise of shortening the construction period.

[0031] (2) The method for closing the main girder of the cable-stayed suspension cooperative system bridge according to the application accurately obtains the height difference and the inclination angle difference corresponding to the actual change of the crane force of the other side of the closure gap when the crane force of one side of the closure gap is 0 by using the first relationship curve and the second relationship curve, and accurately calculates the first influence matrix and the second influence matrix by using the data of the first relationship curve and the second relationship curve, so as to quickly determine the target crane force of the crane on the two sides of the closure gap when the height difference and the inclination angle difference meet the design requirements, so that the crane force can be accurately and quickly adjusted during the hoisting of the cable-stayed transition section main girder and the suspension transition section main girder, and the stress-free closure of the closure gap is quickly realized.

[0032] (3) The method for closing the main girder of the cable-stayed suspension cooperative system bridge according to the application has simple construction process, high reliability, and wide application, and the first relationship curve and the second relationship curve between the crane forces on the two sides of the closure gap and the height difference and the inclination angle difference are accurately constructed by using the finite element model, and then the first influence matrix and the second influence matrix on the two sides of the closure gap are accurately derived, so that the crane forces of the cranes corresponding to the cable-stayed transition section and the suspension transition section on the two sides of the closure gap during the closure of the closure gap are accurately obtained, and the stress-free closure of the closure gap is ensured. By using the simultaneous construction mode of the cable-stayed transition section and the suspension transition section, the construction period can be greatly shortened, and the use of counterweight during the closure of the bridge can be effectively reduced. Under the premise of ensuring the stress structure of the bridge body, the construction cost is significantly reduced, especially for large-span bridge structures, which has excellent economic benefits and promotion value. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a flowchart of the method for closing the main girder of the cable-stayed suspension cooperative system bridge according to the application;

[0034] Figure 2 is a bridge body structure diagram of the method for closing the main girder of the cable-stayed suspension cooperative system bridge according to the application;

[0035] Figure 3 is a first relationship curve diagram of the method for closing the main girder of the cable-stayed suspension cooperative system bridge according to the application;

[0036] Figure 4 is a second relationship curve diagram of the method for closing the main girder of the cable-stayed suspension cooperative system bridge according to the application;

[0037] Figure 5 is a first influence matrix diagram of the method for closing the main girder of the cable-stayed suspension cooperative system bridge according to the application;

[0038] Figure 6 is a second influence matrix diagram of the method for closing the main girder of the cable-stayed suspension cooperative system bridge according to the application;

[0039] Figure 7is a suspension end suspender force and height difference relationship curve schematic diagram of a main girder closure method of a cable-stayed suspension cooperative system bridge in the application;

[0040] Figure 8 is a cable-stayed end suspender force and height difference relationship curve schematic diagram of a main girder closure method of a cable-stayed suspension cooperative system bridge in the application;

[0041] Figure 9 is a suspension end suspender force and inclination difference relationship curve schematic diagram of a main girder closure method of a cable-stayed suspension cooperative system bridge in the application;

[0042] Figure 10 is a cable-stayed end suspender force and inclination difference relationship curve schematic diagram of a main girder closure method of a cable-stayed suspension cooperative system bridge in the application.

[0043] In all the drawings, the same reference signs refer to the same technical features, specifically:

[0044] 1, cable-stayed transition section; 11, cable-stayed transition section suspender; 2, suspension transition section; 21, suspension transition section suspender; 3, closure gap; 4, bridge tower; 5, main cable. DETAILED DESCRIPTION

[0045] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0046] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0047] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can include at least one of the features explicitly or implicitly. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0048] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0049] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0050] Embodiment:

[0051] As shown in Figures 1-6 The main girder closure method of the cable-stayed suspension cable cooperative system bridge in the preferred embodiment of the present application not only can realize the rapid closure construction of the bridge structure to shorten the construction period, but also can realize the accurate adjustment of the closure gap 3, complete the stress-free closure of the bridge structure, provide protection for the stability of the bridge structure, and reduce the construction cost.

[0052] Specifically, as shown in Figure 1 The method comprises the following steps:

[0053] S1, collecting the design parameters of the bridge;

[0054] Preferably, the design parameters include bridge span, bridge tower 4 position, bridge tower 4 height and the like.

[0055] S2, designing two closure gap 3 positions according to the design parameters, and dividing the cable-stayed transition section 1 and the suspension transition section 2 on the longitudinal two sides of the closure gap 3 respectively; preferably, the closure gap is arranged between the cable-stayed section and the suspension section, or the closure gap is arranged in the suspension section.

[0056] S3, calculating the first relationship curve between the suspension force on both sides of the closure gap 3 and the height difference of the closure gap 3, and calculating the second relationship curve between the suspension force on both sides of the closure gap 3 and the inclination angle difference of the closure gap 3;

[0057] The relative height difference is a relative height difference in a vertical direction between opposite ends of the cable-stayed transition section 1 and the suspension transition section 2. The inclination angle difference is an included angle between two top surfaces of the opposite ends of the cable-stayed transition section 1 and the suspension transition section 2.

[0058] S4, calculating a first influence matrix of the height difference of the closure gap 3 and the suspender force on the two sides of the closure gap 3 according to the first relationship curve, and calculating a second influence matrix of the inclination angle difference of the closure gap 3 and the suspender force on the two sides of the closure gap 3 according to the second relationship curve;

[0059] S5, calculating the target suspender force of the suspender force on the two sides of the closure gap 3 according to the first influence matrix and the second influence matrix;

[0060] S6, after the structures of the bridge except the cable-stayed transition section 1 and the suspension transition section 2 are constructed, hoisting the girder of the cable-stayed transition section 1 and the girder of the suspension transition section 2 to the two sides of the closure gap 3, and adjusting the suspender force in the cable-stayed transition section 1 and the suspension transition section 2 to the target suspender force respectively;

[0061] S7, performing the closure operation of the closure gap 3.

[0062] Further, as shown in Figure 3 , 4 In the preferred embodiment of the present application, in step S3, the first relationship curve between the suspender force on the two sides of the closure gap 3 and the height difference of the closure gap 3 and the second relationship curve between the suspender force on the two sides of the closure gap 3 and the inclination angle difference of the closure gap 3 are mainly obtained by constructing a finite element model of the entire bridge structure and by analyzing the finite element model of the bridge structure. Of course, the calculation of the first relationship curve and the second relationship curve is not limited to the finite element analysis, and the mechanical analysis of the bridge structure can also be used. It is worth mentioning that in Figure 3 , 4 In the cable-stayed transition section 11 and the suspension transition section 2, the suspender force curve of the cable-stayed transition section 11 and the suspender force curve of the suspension transition section 2 are respectively a square curve with a label and a curve with a circle.

[0063] More specifically, in one preferred embodiment of the present application, the first relationship curve is preferably a curve formed by calculating the change of the height difference with the suspender force on the other side when the suspender force on one side of the closure gap 3 is 0. That is, in the first relationship curve, there are two curves, one of which is a curve formed by setting the suspender force of the cable-stayed transition section 11 on one side of the closure gap 3 to 0 and the height difference changes with the suspender force of the suspension transition section on the other side of the closure gap 3; the other is a curve formed by setting the suspender force of the suspension transition section 21 on one side of the closure gap 3 to 0 and the height difference changes with the suspender force of the cable-stayed transition section 11 on the other side of the closure gap 3.

[0064] Correspondingly, the second relationship curve is also preferably a curve formed by calculating the inclination angle difference when the cable force of the one side of the closure gap 3 is 0 and the cable force of the other side changes. That is, in the second relationship curve, there are two curves, one of which is a curve formed by setting the cable force of the cable-stayed transition section cable 11 on one side of the closure gap 3 to 0 and the inclination angle difference changes with the cable force of the suspension cable section cable on the other side of the closure gap 3; the other is a curve formed by setting the cable force of the suspension cable transition section cable 21 on one side of the closure gap 3 to 0 and the inclination angle difference changes with the cable force of the cable-stayed transition section cable 11 on the other side of the closure gap 3.

[0065] Further, as shown in the preferred embodiment of the present application, in step S4, the calculation of the first influence matrix includes the following steps: Figure 5 、 6

[0066] S41, the height difference when the cable force of one side of the closure gap 3 is 0 is calculated by using the first relationship curve to calculate the corresponding closure gap 3 height difference when the cable force of the other side changes.

[0067] S42, the height difference when the cable force of both sides of the closure gap 3 is not 0 is calculated by calculating the height difference when the first side cable force corresponds to the second side cable force being 0 according to the first relationship curve, and correspondingly, the height difference when the second side cable force corresponds to the first side cable force being 0 according to the first relationship curve, and then adding the two height differences and subtracting the height difference when the cable force of both sides of the closure gap 3 is 0.

[0068] In actual use, according to the first relationship curve, the closure gap 3 height difference corresponding to the change of the other side in sequence when the cable force of one side of the closure gap 3 is 0 can be directly obtained, and then the data of the first row and the first column in the first influence matrix can be accurately obtained. The other data in the first influence matrix is calculated by calculating the height difference when the cable force of the cable-stayed transition section cable 11 corresponds to the cable force of the suspension cable transition section cable 21 being 0 according to the first relationship curve, and correspondingly, the height difference when the cable force of the suspension cable transition section cable 21 corresponds to the cable force of the cable-stayed transition section cable 11 being 0 according to the first relationship curve, and then adding the two height differences and subtracting the height difference when the cable force of both sides of the closure gap 3 is 0. Thus, the first influence matrix is accurately calculated. It is worth mentioning that in the Figure 5 , the cable force unit is KN, and the middle height difference unit is millimeter.

[0069] Correspondingly, in step S4, the calculation of the second influence matrix includes the following steps:

[0070] S43, the inclination angle difference when the cable force of one side of the closure gap 3 is 0 is calculated by using the first relationship curve to calculate the corresponding closure gap 3 inclination angle difference when the cable force of the other side changes.

[0071] ​S44, the inclination difference when the forces of the two side suspender ropes of the closure gap 3 are not 0, the inclination difference when the force of the first side suspender rope corresponds to the force of the second side suspender rope being 0 is calculated according to the first relationship curve, and correspondingly, the inclination difference when the force of the second side suspender rope corresponds to the force of the first side suspender rope being 0 is calculated according to the first relationship curve, and the two inclination differences are added and then the inclination difference when the forces of the two side suspender ropes of the closure gap 3 are 0 is subtracted to obtain.

[0072] The use method thereof in actual use is similar to that of the first influence matrix, and will not be described herein. It is worth mentioning that in the first influence matrix and the second influence matrix, the unit of the suspender rope force is KN, and the unit of the intermediate inclination difference is degree. Figure 6

[0073] Further, in the preferred embodiment of the present application, in step S5, the calculation of the target suspender rope force includes the following steps:

[0074] S51, in the first influence matrix and the second influence matrix, the forces of the two side suspender ropes of the closure gap 3 when the height difference and the inclination difference respectively cross 0 are marked respectively;

[0075] As shown in the first influence matrix and the second influence matrix, the points crossing 0 refer to the contents in the black boxes in the two figures. Figure 5 6

[0076] S52, comparing the marked areas of the first influence matrix and the second influence matrix, selecting the overlapping area, and determining the target suspender rope force of the two side suspender ropes of the closure gap 3 according to the overlapping area.

[0077] Preferably, the target suspender rope force is the suspender rope force of the cable-stayed transition section suspender rope 11 and the suspender rope force of the suspension transition section suspender rope 21.

[0078] Further preferably, in the preferred embodiment of the present application, if there are multiple groups in the overlapping area, it is judged whether they are within the design threshold, and preferably, the design threshold is that the absolute value of the height difference is not greater than 3 centimeters, and the absolute value of the inclination difference is not greater than 0.172°.

[0079] In addition, in one preferred embodiment of the present application, the relationship between the suspender rope force and the closure gap height difference and the relationship between the suspender rope force and the closure gap inclination difference can also be fitted to quickly determine the accurate value of the target suspender rope force or determine the approximate interval of the target suspender rope force.

[0080] In a specific embodiment, the relationship curves between the suspender rope force and the closure gap height and the relationship curves between the suspender rope force and the closure gap inclination difference are constructed by the finite element model constructed in the past closure gap design and by the finite element model, that is, the relationship curves between the suspender rope force and the closure gap height difference of the suspension section suspender rope and the relationship curves between the suspender rope force and the closure gap inclination difference of the cable-stayed section suspender rope as shown in the first influence matrix and the second influence matrix, that is, the relationship curves between the suspender rope force and the closure gap height difference of the suspension section suspender rope and the relationship curves between the suspender rope force and the closure gap inclination difference of the cable-stayed section suspender rope as shown in the first influence matrix and the second influence matrix. Figures 7-10 Figure 7 In a specific embodiment, the relationship curves between the suspender rope force and the closure gap height and the relationship curves between the suspender rope force and the closure gap inclination difference are constructed by the finite element model constructed in the past closure gap design and by the finite element model, that is, the relationship curves between the suspender rope force and the closure gap height difference of the suspension section suspender rope and the relationship curves between the suspender rope force and the closure gap inclination difference of the cable-stayed section suspender rope as shown in the first influence matrix and the second influence matrix, that is, the relationship curves between the suspender rope force and the closure gap height difference of the suspension section suspender rope and the relationship curves between the suspender rope force and the closure gap inclination difference of the cable-stayed section suspender rope as shown in the first influence matrix and the second influence matrix.​​​​Figure 8 the relationship curve between the cable force of the different pairs of suspension cable end suspender and the closure gap height shown in FIG. 2, such as Figure 9 the relationship curve between the cable force of the different pairs of suspension cable end suspender and the closure gap inclination difference shown in FIG. 3, such as Figure 10 the relationship curve between the cable force of the different pairs of suspension cable end suspender and the closure gap inclination difference shown in FIG. 3, such as

[0081] And through the above relationship curve, the fitting relationship between the cable force of the cable segment suspender, the cable force of the cable segment suspender and the closure gap height, the closure gap inclination difference respectively is determined, and each fitting relationship is as follows:

[0082] According to the relationship curve between the cable force of the suspension cable end suspender and the closure gap height, a first fitting formula is fitted, and the first fitting formula is preferably:

[0083]

[0084] Wherein, c1 is the closure gap height corresponding to the suspension cable end suspender force of 0; a1 is a parameter related to the bridge structure system and the main beam stiffness; y1 is the dependent variable, i.e. the closure gap height; x1 is the independent variable, i.e. the cable force of the suspension cable end suspender.

[0085] According to the relationship curve between the cable force of the suspension cable end suspender and the closure gap height, a first fitting formula is fitted, and the first fitting formula is preferably:

[0086] y2=a2x2+c2

[0087] Wherein, c2 is the closure gap height corresponding to the suspension cable end suspender force of 0; a2 is a parameter related to the bridge structure system and the main beam stiffness; y2 is the dependent variable, i.e. the closure gap height; x2 is the independent variable, i.e. the cable force of the suspension cable end suspender.

[0088] According to the relationship curve between the cable force of the suspension cable end suspender and the closure gap height, a first fitting formula is fitted, and the first fitting formula is preferably:

[0089]

[0090] Wherein, is the closure gap inclination difference corresponding to the suspension cable end suspender force of 0; is a parameter related to the bridge structure system and the main beam stiffness; is the dependent variable, i.e. the closure gap inclination difference; x1 is the independent variable, i.e. the cable force of the suspension cable end suspender.

[0091] According to the relationship curve between the cable force of the suspension cable end suspender and the closure gap height, a first fitting formula is fitted, and the first fitting formula is preferably:

[0092]

[0093] wherein, is the closure gap inclination difference corresponding to the situation that the cable-stayed end suspender force is 0; is a parameter related to the bridge structure system and the main girder stiffness; is the dependent variable, i.e. the closure gap inclination difference; x2 is the independent variable, i.e. the suspender force of the cable-stayed end suspender.

[0094] Then, the closure gap difference and inclination difference equation set is constructed, specifically as follows:

[0095]

[0096] wherein, d is the gap between the cable-stayed section and the suspension section when hoisted to the closure section, d * is the inclination difference between the cable-stayed section and the suspension section when hoisted to the closure section.

[0097] In actual closure gap design, only the finite element model of the closure bridge is needed, and for each fitting formula or two sets of independent variable and dependent variable values, a and c in the fitting formula can be obtained. Then, the first fitting formula, the second fitting formula, the third fitting formula, and the fourth fitting formula are brought into the closure gap difference and inclination difference equation set, and the target suspender force of the suspension section and the cable-stayed section when d and d * are both 0 is solved through the closure gap difference and inclination difference equation set.

[0098] Of course, the theoretical range of the target suspender force can also be obtained through the above calculation, and then the specific value is determined in the influence matrix to improve the calculation rate.

[0099] Further preferably, in the bridge tower 4 construction process, the structures of the bridge other than the cable-stayed transition section 1 and the suspension transition section 2 include the bridge tower 4, the anchorage, the side pier, the auxiliary pier and foundation, the cable-stayed cable, the suspender, and the main cable 5.

[0100] In step S6, the main girder of the cable-stayed transition section 1 and the main girder of the suspension transition section 2 are hoisted at the same time, i.e. in the bridge construction project, the cable-stayed transition section 1 main girder can be hoisted from the longitudinal two sides of the bridge tower 4 to the middle at the same time, and at the same time, the suspension transition section 2 is set from the midspan, thereby greatly improving the construction progress of the bridge structure.

[0101] More specifically, in step S6, the main girder of the cable-stayed transition section 1 is hoisted from the bridge tower 4 to the closure gap 3 in sequence by the bridge deck crane. Further preferably, the main girder of the suspension transition section 2 is hoisted from the midspan to the closure gap 3 in sequence by the cable crane.

[0102] Further, in the preferred embodiment of the present application, in step S7, the closure operation adopts the method of pulling closure or pushing closure to adjust the width of the closure gap 3 to complete the closure. Of course, according to the adjustment state of the closure gap, if the closure gap state is good after the girder hoisting, the closure can be directly performed.

[0103] In addition, in another preferred embodiment of the present application, after the closure of the girder, the construction of the secondary dead load is adjusted, and the stay cables and the sling are adjusted to be the bridge cable force.

[0104] The girder closure method of the cable-stayed suspension cable cooperation system bridge in the present application has simple construction process, high reliability, and wide application. The first relationship curve and the second relationship curve between the hoisting force of the hoisting rod on both sides of the closure gap 3 and the height difference and the inclination difference are accurately constructed by using the finite element model, and then the first influence matrix and the second influence matrix on both sides of the closure gap 3 are accurately derived, and the hoisting force of the hoisting rod corresponding to the setting of the cable-stayed transition section 1 and the suspension cable transition section 2 on both sides of the closure gap 3 during the closure is accurately obtained, and then the stress-free closure of the closure gap 3 is ensured. By using the method of simultaneous construction of the cable-stayed transition section 1 and the suspension cable transition section 2, the construction period can be greatly shortened, and the use of counterweight during the closure process of the bridge can be effectively reduced. Under the premise of ensuring the stress structure of the bridge body, the construction cost is significantly reduced, especially for large-span bridge structures, which has excellent economic benefits and promotion value.

[0105] Those skilled in the art will readily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for closing a main span of a cable-stayed catenary- stayed hybrid bridge, characterized in that, The process is shown as follows: S1, collecting the design parameters of the bridge; S2, designing two closure gap positions according to the design parameters, and dividing the cable-stayed transition section and the suspension transition section on the longitudinal sides of the closure gap respectively; S3, calculating a first relationship curve between the suspension forces on both sides of the closure gap and the closure gap height difference, and calculating a second relationship curve between the suspension forces on both sides of the closure gap and the closure gap inclination difference; S4, calculating a first influence matrix of the suspension forces on both sides of the closure gap and the closure gap height difference according to the first relationship curve, and calculating a second influence matrix of the suspension forces on both sides of the closure gap and the closure gap inclination difference according to the second relationship curve; S4 includes the following steps: S41, the closure gap height difference when the suspension force on one side of the closure gap is 0 is calculated by using the first relationship curve to calculate the corresponding closure gap height difference when the suspension force on the other side of the closure gap changes; S42, the closure gap height difference when the suspension forces on both sides of the closure gap are not 0 is calculated by using the first relationship curve to calculate the closure gap height difference when the suspension force on the first side corresponds to the suspension force on the second side being 0, and correspondingly, using the first relationship curve to calculate the closure gap height difference when the suspension force on the second side corresponds to the suspension force on the first side being 0, and then adding the two height differences and subtracting the closure gap height difference when the suspension forces on both sides of the closure gap are 0; S43, the closure gap inclination difference when the suspension force on one side of the closure gap is 0 is calculated by using the first relationship curve to calculate the corresponding closure gap inclination difference when the suspension force on the other side of the closure gap changes; S44, the closure gap inclination difference when the suspension forces on both sides of the closure gap are not 0 is calculated by using the first relationship curve to calculate the closure gap inclination difference when the suspension force on the first side corresponds to the suspension force on the second side being 0, and correspondingly, using the first relationship curve to calculate the closure gap inclination difference when the suspension force on the second side corresponds to the suspension force on the first side being 0, and then adding the two inclination differences and subtracting the closure gap inclination difference when the suspension forces on both sides of the closure gap are 0; S5, calculating the target suspension force of the suspension on both sides of the closure gap according to the first influence matrix and the second influence matrix; The calculation of the target suspension force is shown as follows: In the first influence matrix and the second influence matrix, the suspension forces on both sides of the closure gap when the height difference and the inclination difference respectively cross 0 corresponding to the change of the suspension force are marked respectively; By comparing the marked areas of the first influence matrix and the second influence matrix, the target suspension force of the suspension on both sides of the closure gap is selected in the overlapping area, and the target suspension force of the suspension on both sides of the closure gap is determined according to the overlapping area; S6, after the construction of the structure of the bridge except the cable-stayed transition section and the suspension transition section, hoisting the girder of the cable-stayed transition section and the girder of the suspension transition section to both sides of the closure gap, and adjusting the suspension force in the cable-stayed transition section and the suspension transition section to the target suspension force respectively; S7, performing the closure operation of the closure gap.

2. The method of claim 1, wherein, The calculation of the first relationship curve and the second relationship curve is shown as follows: constructing a finite element model of the bridge structure, and calculating the first relationship curve and the second relationship curve according to the finite element model.

3. The method of claim 1 or 2, wherein, The girder of the cable-stayed transition section and the girder of the suspension transition section are hoisted to the closure gap at the same time.

4. The method of claim 1 or 2, wherein, The bridge includes a tower, a main cable, a stay cable and a suspension.

5. The method of claim 4, wherein, The main girder of the cable-stayed transition section is hoisted from the bridge tower to the closure gap by a bridge deck crane.

6. The method of claim 4, wherein, The main girder of the suspension cable transition section is hoisted from the midspan to the closure gap by a cable crane.

7. The method of claim 2, 5, or 6, wherein, The closure operation adopts direct closure, traction closure or push-together low-temperature closure.

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