Wind-induced vibration control method for construction period of large-span cable-stayed bridge

Abstract

The invention relates to the technical field of bridge construction, and discloses a large-span cable-stayed bridge construction period wind-induced vibration control method, which comprises the steps of establishing an original finite element model of a construction state bridge structure and the like. The method disclosed by the invention is based on finite element analysis and wind tunnel test design and verifies the effectiveness of combining the temporary pier and the TMD to form a combined anti-buffeting measure to control the buffeting response and the wind-induced buffeting load in the bridge construction period, and practice proves that compared with a single anti-buffeting measure, the method has the advantages that the anti-buffeting effect is good, and the anti-buffeting effect is good. The combined anti-buffeting measure composed of the temporary piers and the TMD is applied to the bridge in the construction state, buffeting response of the bridge in the construction state can be controlled more effectively, and the safety of the bridge in the construction period and the comfort of constructors are further improved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a method for controlling wind-induced vibration of a large-span cable-stayed bridge during construction. Background Art

[0002] The contents in this section merely provide background information related to the present invention and may not constitute prior art.

[0003] As a bridge with excellent spanning capacity, the cable-stayed bridge is one of the important bridge types with long span.

[0004] At present, cable-stayed bridges are usually constructed using the cantilever construction method. Since the stiffness, frequency and damping ratio of the main beam cantilever of the cable-stayed bridge during the construction period are all lower than those in the completed bridge state, a larger flutter response will be generated under the action of natural wind than in the completed bridge state. In particular, for large-span cable-stayed bridges, due to their smaller structural stiffness and natural frequency, and the fact that they are vulnerable to typhoons in coastal areas, their designed basic wind speed is higher than other areas, so the flutter response generated under the action of natural wind is also greater, making the flutter problem of bridges one of the main control factors during design. In addition, since the construction environment in coastal areas is more complex, the construction period is longer, and the flutter impact during the construction period is more serious, accurately calculating and controlling the flutter response of large-span cable-stayed bridges during the construction period is an important factor in ensuring the safety of bridge construction and the comfort of construction workers.

[0005] At present, the anti-buffeting measures that can be used for large-span bridges mainly include: setting up temporary piers, setting up tuned mass dampers (TMD) and setting up wind-resistant cables. Summary of the invention

[0006] The inventors of the present application have discovered that, in known large-span bridges, usually only one of the three anti-vibration measures mentioned above is selected as the anti-vibration measure for the bridge. As for the method of setting up a single anti-vibration measure, it is often unable to effectively control the vibration response and wind-induced vibration load during the bridge construction period, so that the safety of the bridge construction period and the comfort of the construction workers are low.

[0007] In view of this, the purpose of the present invention is to provide a wind-induced vibration control method suitable for cable-stayed bridges, especially large-span cable-stayed bridges during the construction period. The method is designed based on finite element analysis and wind tunnel tests and verifies the effectiveness of combining temporary piers with TMDs to form a combined anti-buffeting measure to control the buffeting response and wind-induced buffeting loads during the bridge construction period.

[0008] The purpose of the present invention is achieved through the following technical solutions: The invention discloses a method for controlling wind-induced vibration during the construction period of a large-span cable-stayed bridge, the method comprising the following steps: Step S10. Establishing an original finite element model of the bridge structure under construction; Step S20. Obtain the static wind load, self-excited force and buffeting force acting on the bridge structure in the construction state, apply the acquired static wind load, self-excited force and buffeting force to the original finite element model, and perform a nonlinear time history analysis of buffeting response on the original finite element model to obtain the buffeting displacement of the cantilever end of the main beam of the bridge in the construction state under different working conditions; Step S30. Testing the wind-induced vibration response of the bridge structure under construction, and verifying the original finite element model according to the test results to obtain a target finite element model of the bridge structure under construction; Step S40: adding a combined anti-vibration measure to the target finite element model, and obtaining optimal design parameters of the combined anti-vibration measure; the combined anti-vibration measure includes a temporary pier and a TMD.

[0009] Furthermore, the optimal design parameters include an optimal setting position of the temporary pier, and an optimal mass ratio and damping ratio of the TMD.

[0010] Furthermore, the process of obtaining the optimal setting position of the temporary pier includes: setting the temporary pier at different positions away from the cantilever end of the main beam of the bridge under construction and performing calculations to obtain the position with the minimum extreme value of the vertical vibration displacement response under different construction conditions. The position with the minimum extreme value of the vertical vibration displacement response is the optimal layout position of the temporary pier.

[0011] Furthermore, the optimal mass ratio and damping ratio of the TMD is obtained by minimizing the power amplification factor DAF get; Among them, the power amplification factor DAF The expression is as follows:

[0012] In the above formula: ; ; ; ; in, F represents the time-varying wind load; is the mass ratio of TMD, is the damping ratio of the bridge, is the damping ratio of TMD; It is the ratio of the circular frequency of the simple harmonic load to the natural frequency of the bridge.

[0013] Further, in step S40, the vibration frequency of the TMD is close to or the same as the first-order vertical frequency of the bridge structure in the construction state.

[0014] Further, in step S20, the buffeting force is calculated by the following process: Obtaining a buffeting force time history and a fluctuating wind speed time history of the bridge structure under construction; The acquired time history data of the buffeting force time history and the fluctuating wind speed time history are transformed by using a fast Fourier transform technique to obtain a buffeting force power spectrum and a fluctuating wind speed power spectrum; Obtaining a frequency domain equivalent aerodynamic admittance function of the buffeting force according to the buffeting force power spectrum and the pulsating wind speed power spectrum; According to the wind speed spectrum and the frequency domain equivalent aerodynamic admittance function of the buffeting force, a buffeting force power spectrum considering the influence of aerodynamic admittance is obtained; The buffeting force time history in the time domain can be obtained by transforming the buffeting force power spectrum considering the influence of aerodynamic admittance from the frequency domain to the time domain.

[0015] Furthermore, the calculation formula of the buffeting force power spectrum considering the influence of aerodynamic admittance is: ; ; ; In the above three formulas, , , They represent respectively the buffeting drag spectrum function, buffeting lift force spectrum function and buffeting lift moment spectrum function considering the influence of aerodynamic admittance; is the air density; U is the incoming wind speed; B is the width of the main beam; , , are the drag coefficient, lift coefficient and lift moment coefficient respectively; , , are the derivative of the drag coefficient, the derivative of the lift coefficient, and the derivative of the lift moment coefficient, respectively. , , The frequency domain equivalent aerodynamic admittance functions representing buffeting drag, buffeting lift and buffeting lift moment respectively; , Respectively Kaimal Spectrum and Panofsky Score.

[0016] Further, in step S30, verifying the original finite element model according to the test results specifically includes: Testing the wind-induced vibration response of the bridge structure under construction to obtain the buffeting displacement of the cantilever end of the main beam of the bridge under construction under different working conditions of the bridge structure under construction, and comparing the obtained buffeting displacement data with the buffeting displacement data obtained after performing buffeting response nonlinear time history analysis on the original finite element model in step S20; If the comparison result meets the preset standard data, the original finite element model is directly used as the target finite element model; otherwise, the original finite element model is modified until the target finite element model is obtained.

[0017] Furthermore, the method further comprises the steps of: Step S50. Apply the combined anti-bounce measures to the bridge structure under construction according to the optimal design parameters, and conduct a wind-induced vibration response test on the bridge structure under construction to which the combined anti-bounce measures are applied through an aeroelastic model wind tunnel test, so as to verify the effectiveness of the combined anti-bounce measures based on the test results.

[0018] Furthermore, in step S50, the process of verifying the effectiveness of the combined anti-vibration measure according to the test result includes: Wind-induced vibration response tests are performed on the bridge structure under construction to which the combined anti-vibration measures are applied and the bridge structure under construction to which the combined anti-vibration measures are not applied, respectively, to obtain test data; then, the test data of the bridge structure under construction to which the combined anti-vibration measures are applied is compared with the test data of the bridge structure under construction to which the combined anti-vibration measures are not applied.

[0019] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects: The method disclosed in the present invention is based on finite element analysis and wind tunnel test design and verifies the effectiveness of combining temporary piers with TMD to form a combined anti-vibration measure to control the vibration response and wind-induced vibration load of the bridge during construction. Practice has proved that compared with a single anti-vibration measure, applying the combined anti-vibration measure composed of temporary piers and TMD to the bridge under construction can more effectively control the vibration response of the bridge under construction, thereby further improving the safety of the bridge during the construction period and the comfort of the construction workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flow chart of a method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge provided by an embodiment of the present invention; Figure 2 The schematic diagram of the layout of the combined anti-buffeting measures applied to the bridge under construction; Figure 3This is the maximum stress curve of the tower bottom at different temporary pier positions under the maximum double cantilever construction state of the bridge. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described in conjunction with specific implementation methods below. The same figure marks in the accompanying drawings represent the same components. It should be noted that the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Compared to the embodiments shown in the drawings, feasible embodiments within the scope of the present invention may have fewer components, other components not shown in the drawings, different components, differently arranged components, or differently connected components, etc. In addition, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0023] An embodiment of the present invention discloses a method for controlling wind-induced vibration during the construction period of a large-span cable-stayed bridge. The method is designed based on finite element analysis and aeroelastic model wind tunnel tests and verifies the effectiveness of combining temporary piers with TMDs to form a combined anti-buffeting measure to control the buffeting response and wind-induced buffeting load during the bridge construction period.

[0024] like Figure 1 As shown, the control method disclosed in this embodiment may include the following steps: Step S10: Establishing an original finite element model of the bridge structure under construction, wherein the bridge structure under construction refers to the structure of the bridge during the construction period, and the original finite element model of the structure can be established according to the design parameters and construction plan data of the bridge.

[0025] Step S20. Obtain the static wind load, self-excited force and buffeting force acting on the bridge structure in the construction state, apply the obtained static wind load, self-excited force and buffeting force to the original finite element model, and perform a nonlinear time-history analysis of the buffeting response of the original finite element model to obtain the buffeting displacement of the cantilever end of the main beam of the bridge in the construction state under different working conditions.

[0026] In step S20, the static wind load acting on the bridge structure under construction can be defined by the static three-force in the wind axis coordinate system, and the static three-force includes static wind resistance, static wind lift and static wind lift moment. The calculation formula of the static wind load acting on the bridge structure under construction is as follows: ; ; ; In the above three formulas, a is the incoming wind attack angle; , , The incoming wind angle of attack a Under the condition, the static wind resistance, static wind lift and static wind lift moment of the main beam in the wind axis coordinate system; is the air flow pressure, where is the air density, U is the incoming wind speed; H , B , L are the height, width and length of the main beam respectively; , , are the drag coefficient, lift coefficient and lift moment coefficient respectively.

[0027] In step S20, the self-excited forces acting on the bridge structure under construction include self-excited drag, self-excited lift and self-excited pitch torque. The calculation formula of the self-excited forces acting on the bridge structure under construction is as follows: ; ; ; In the above three formulas, , , are the self-excited drag, self-excited lift and self-excited pitching torque acting on the bridge structure under construction; is the air density; U is the incoming wind speed; B is the width of the main beam; K is the dimensionless reduced frequency, and , is the circular frequency of vibration; , , is the dimensionless inverse of flutter, which can be obtained through forced vibration test, where i =1,2,3,4,5,6; P is the horizontal displacement; h is the vertical displacement; a is the twist angle; is the horizontal speed; is the vertical speed, is the torsion angular velocity.

[0028] In step S20, the buffeting force acting on the bridge structure under construction includes buffeting resistance, buffeting lift force and buffeting lift moment. The buffeting force acting on the bridge structure under construction can be calculated by the following process: In the aeroelastic model wind tunnel test, the pressure measurement method is used to obtain the aerodynamic admittance function of the buffeting force of the main beam section.

[0029] Specifically, several pressure measuring holes are arranged on the surface of the bridge structure in the construction state to measure the pressure distribution on any cross section of the bridge main beam, and the buffeting force time history is obtained by integrating the pressure signal. The calculation formula of the buffeting force time history is as follows: ; ; ; In the above three formulas, , , They are respectively the buffeting resistance time history, buffeting lift time history and buffeting lift moment time history of the main beam per unit length relative to the torsion center in the body axis coordinate system; L i For the i Integration length of the point; a i For the i The angle between the internal normal of the point and the horizontal plane of the bridge deck; X i and Y i Respectively i The horizontal and vertical distances between the point and the bridge axis.

[0030] At the same time, the fluctuating wind speed time history can be obtained by measuring, for example, a fluctuating anemometer. On the basis of obtaining the buffeting force time history and the fluctuating wind speed time history, the time history data of the obtained buffeting force time history and the fluctuating wind speed time history are transformed using the fast Fourier transform (FFT) technology to obtain the corresponding power spectrum, that is, the buffeting force power spectrum and the fluctuating wind speed power spectrum. Among them, the buffeting force power spectrum includes the buffeting resistance spectrum, the buffeting lift force spectrum and the buffeting lift moment spectrum, and the fluctuating wind speed power spectrum includes the lateral fluctuating wind speed spectrum and the vertical fluctuating wind speed spectrum.

[0031] The frequency domain equivalent aerodynamic admittance function of the buffeting force is obtained according to the buffeting force power spectrum and the fluctuating wind speed power spectrum. The expression of the frequency domain equivalent aerodynamic admittance function of the buffeting force is as follows: ; ; ; In the above three formulas, , , It can be understood as the frequency domain equivalent aerodynamic admittance that takes into account the buffeting force under the combined action of the lateral fluctuating wind speed and the vertical fluctuating wind speed. Specifically, the three represent the frequency domain equivalent aerodynamic admittance functions of the buffeting resistance, buffeting lift and buffeting lift moment respectively; , , represent respectively the buffeting drag spectrum, buffeting lift force spectrum and buffeting lift moment spectrum obtained through the above wind tunnel test; , They respectively represent the lateral fluctuating wind speed spectrum and the vertical fluctuating wind speed spectrum obtained through the above wind tunnel test; combined with the above, , , are the drag coefficient, lift coefficient and lift moment coefficient respectively; , , They are the derivative of the drag coefficient, the derivative of the lift coefficient, and the derivative of the lift moment coefficient, respectively.

[0032] Furthermore, by substituting the wind speed spectrum and the frequency domain equivalent aerodynamic admittance function of the buffeting force into the following formula, the buffeting force power spectrum considering the influence of aerodynamic admittance can be obtained. Kaimal Spectrum and Panofsky Spectrum. Among them, the buffeting force power spectrum considering the influence of aerodynamic admittance also includes the buffeting resistance spectrum, buffeting lift force spectrum and buffeting lift moment spectrum. The calculation formula of the buffeting force power spectrum considering the influence of aerodynamic admittance is as follows: ; ; ; In the above three formulas, , , They represent respectively the buffeting drag spectrum function, buffeting lift force spectrum function and buffeting lift moment spectrum function considering the influence of aerodynamic admittance; is the air density; U is the incoming wind speed; B is the width of the main beam; combined with the above, , , are the drag coefficient, lift coefficient and lift moment coefficient respectively; , , are the derivative of the drag coefficient, the derivative of the lift coefficient, and the derivative of the lift moment coefficient, respectively. , , The frequency domain equivalent aerodynamic admittance functions representing buffeting drag, buffeting lift and buffeting lift moment respectively; , Respectively Kaimal Spectrum and Panofsky Score.

[0033] in, Kaimal The spectrum is expressed as: ; Panofsky The spectrum is expressed as: ; In the above two formulas, f are similarity law coordinates, and ,in, n is the frequency of incoming pulsating wind, z is the height from the ground, U ( z ) is the height z The average wind speed at is the friction velocity, which is related to the roughness of the ground, and ,in, k ≈0.4, The roughness of the ground.

[0034] On this basis, the above-mentioned buffeting force power spectrum considering the influence of aerodynamic admittance is transformed from the frequency domain to the time domain, and the buffeting force time history in the time domain can be obtained, that is, the buffeting force acting on the bridge structure under construction can be obtained. And the obtained buffeting force time history in the time domain can provide the necessary conditions for the time domain analysis of buffeting.

[0035] Step S30. Using methods such as aeroelastic model wind tunnel test, the wind-induced vibration response of the bridge structure under construction is tested, and the original finite element model is verified according to the test results to verify the accuracy of the original finite element model, thereby obtaining a target finite element model of the bridge structure under construction.

[0036] Among them, the wind-induced vibration response of the bridge structure under construction is tested, and the original finite element model is verified according to the test results, which specifically includes: testing the wind-induced vibration response of the bridge structure under construction through an aeroelastic model wind tunnel test to obtain the flutter displacement of the cantilever end of the main beam of the bridge under construction under different working conditions of the bridge structure under construction, and comparing the obtained flutter displacement data with the flutter displacement data obtained after performing a nonlinear time-history analysis of the flutter response of the original finite element model in step S20 to determine whether the established original finite element model is accurate and effective.

[0037] Among them, if the comparison result meets the preset standard data, it means that the established original finite element model is accurate and valid, then the original finite element model can be directly used as the target finite element model and enter step S40; otherwise, the original finite element model is corrected until the original finite element model passes the accuracy verification to obtain the target finite element model and enter step S40.

[0038] For example, the inventors of the present application obtained, through actual experiments, partial buffeting displacement data of the bridge structure under construction in the wind tunnel test and its original finite element model under the design base wind speed of 46.1 m / s. The results are shown in Table 1 below.

[0039] Table 1 Table of buffeting displacement data of the middle tower of the bridge structure under construction in the state of maximum double cantilever construction

[0040] It can be seen from Table 1 that the buffeting displacement obtained after the buffeting calculation of the original finite element model of the bridge structure under construction is compared with the buffeting displacement obtained after the bridge structure under construction is tested in the wind tunnel test. The errors of the buffeting displacements of the two meet the preset standard data, which proves the accuracy and effectiveness of the original finite element model of the proposed bridge structure under construction. At this time, the original finite element model can be directly used as the target finite element model.

[0041] Step S40. Based on the accuracy of the original finite element model verified in step S30 and the target finite element model obtained, a combined anti-vibration measure is added to the target finite element model, and optimal design parameters of the combined anti-vibration measure are obtained.

[0042] In this embodiment, combined with Figure 2 As shown in Figure 1, the combined anti-bounce measures include temporary piers and TMDs. The optimal design parameters include the optimal layout of temporary piers and the optimal mass ratio and damping ratio of TMDs.

[0043] Specifically, when adding temporary piers, temporary piers should be set up at different positions away from the cantilever end of the main beam of the bridge under construction and calculations should be performed to obtain the position where the maximum stress at the bottom of the tower is the smallest under different construction conditions, and the position where the maximum stress at the bottom of the tower is the smallest should be used as the optimal layout position of the temporary piers.

[0044] For example, considering that the vibration response of the bridge is the largest under the maximum double cantilever construction state, this embodiment studies the influence of the temporary pier position on the vibration response of the bridge structure based on the maximum double cantilever construction state. Among them, the temporary pier is used to constrain the vertical and lateral displacement of the main beam. For example, when the maximum cantilever length is 356.25m, 9 temporary pier arrangement schemes 1 to 9 are used to arrange the temporary piers. Schemes 1 to 9 are 1 / 6 (59.375m), 1 / 5 (71.25m), 1 / 4 (89.0625m), 1 / 3 (118.75m), 1 / 2 (178.125m), 2 / 3 (237.5m), 3 / 4 (267.1875m), 4 / 5 (285m), and 5 / 6 (296.875m), respectively; in the above values, the numbers in brackets represent the distance between the temporary pier and the center of the middle tower, and the fraction represents the ratio of the distance to the maximum cantilever length of 356.25m. Combined with Figure 3 It can be seen that in the absence of temporary piers, the maximum stress at the bottom of the tower is basically constant. In the case of temporary piers, the maximum stress at the bottom of the tower is significantly reduced, and as the distance between the temporary piers and the mid-tower gradually increases, the maximum stress at the bottom of the tower shows a trend of gradually decreasing first and then increasing slightly, and in Scheme 7 (that is, the distance between the temporary piers and the mid-tower is 267.1875m), the maximum stress at the bottom of the tower is at the minimum value. Therefore, the location of the temporary pier in Scheme 7 can be used as the optimal location for the temporary pier.

[0045] When adding TMD, TMD is arranged on the bridge deck at the cantilever end of the main beam of the bridge under construction. As a known passive control device, TMD adjusts its own mass and stiffness to make its frequency close to or the same as the natural frequency of the bridge structure, so as to produce a response in the opposite direction of the bridge structure vibration when the bridge structure vibrates, so as to achieve the effect of offsetting the vibration energy. Among them, the core components of the known TMD include mass blocks, springs and dampers. The joint action of these components can achieve frequency tuning and energy dissipation, and ultimately achieve the purpose of controlling bridge vibration.

[0046] By arranging the TMD at the cantilever end of the main beam of the bridge under construction, the variability of the bridge during the construction process is fully considered. As the construction progresses, the mass and stiffness of the bridge will gradually increase, which will cause the vibration characteristics of the bridge to change accordingly. In order to adapt to this frequency change, the TMD used must have a certain degree of adjustability so that the frequency of the TMD can dynamically match the real-time vibration frequency of the bridge.

[0047] Specifically, during the construction period, the vibration mass of the bridge will increase as the construction progresses, and the natural frequency of the bridge will decrease, which requires the vibration mass of the TMD to also increase so that the natural frequency of the TMD can be reduced synchronously. In actual operation, as the construction progresses, the natural frequency of the TMD can be reduced synchronously with the natural frequency of the bridge by keeping the stiffness of the TMD spring unchanged and increasing the mass of the TMD to adapt to the changes in the vibration characteristics of the bridge structure, thereby achieving a continuous and stable vibration suppression effect. This dynamic adjustment capability enables the TMD to maintain a good vibration reduction effect at different construction stages, providing effective protection for wind resistance safety during the bridge construction period.

[0048] The inventors of the present application have discovered that, generally, the fluttering vertical internal force of a bridge under construction when fluttering occurs will account for more than 90% of the total vertical internal force (that is, the fluttering vertical internal force + the static wind vertical internal force), and the fluttering vertical internal force of the bridge under construction in the first-order vertical bending vertical vibration mode accounts for more than 90% of the total fluttering vertical internal force of the bridge under construction in all orders of vertical bending vertical vibration modes. Therefore, the total vertical internal force of the bridge under construction can be effectively controlled by only making the vibration frequency of the TMD close to or the same as the first-order vertical frequency of the bridge structure under construction.

[0049] Among them, the dynamic characteristics of the bridge structure under construction can be analyzed to obtain the first twenty natural frequency information of the main beam at different construction stages, and then the first-order vertical frequency mentioned above can be obtained from the first twenty natural frequency information.

[0050] Furthermore, when the bridge structure under construction is subjected to wind load, it is assumed that the wind load is a simple harmonic load, that is, the wind load expression is assumed to be: ;in, F represents the time-varying wind load; F 0 is the amplitude of wind load; w is the circular frequency of the simple harmonic load; t is time. At the same time, let the static displacements of the bridge and TMD under construction be and , the motion differential equation of the bridge-TMD in the construction state can be derived as follows: ; In the above formula, is the generalized quality of the bridge; is the quality of TMD; , are the damping coefficients of the bridge and TMD, respectively; , are the stiffness of the bridge and TMD, respectively.

[0051] Also available: ; ;in, , are the natural frequencies of the bridge and TMD respectively; and: ; ; ; ;in, is the mass ratio of TMD, is the damping ratio of the bridge, is the damping ratio of TMD.

[0052] Therefore, the dynamic amplification factor is introduced DAF , we can derive DAF The expression is as follows: ; In the above formula: ; ; ; ;in, is the ratio of the circular frequency of the simple harmonic load to the natural frequency of the bridge, that is, .

[0053] The inventors of this application have studied and proved that when evaluating the vibration reduction effect of TMD, the power amplification factor DAF It can well reflect the vibration reduction of TMD. And from the above analysis, we can know that the parameter , F, , , All of them have an important influence on the vibration reduction effect of TMD. Among them, the dynamic amplification factor DAF is taken as the performance target. When the given frequency ratio and the damping ratio of the bridge under construction When TMD has the best mass ratio and damping ratio By minimizing the power amplification factor DAF To obtain, that is, we only need to let the power amplification factor DAF Minimum, the best mass ratio of TMD can be obtained and damping ratio .

[0054] Step S50. By adding a combined anti-vibration measure to the target finite element model in step S40, the optimal design parameters of the combined anti-vibration measure are obtained, that is, the optimal setting position of the temporary pier and the optimal mass ratio of the TMD. and damping ratio Afterwards, the combined anti-buffeting measures were applied to the bridge structure under construction according to the optimal design parameters, and the wind-induced vibration response test of the bridge structure under construction with the combined anti-buffeting measures was carried out through an aeroelastic model wind tunnel test to verify the effectiveness of the combined anti-buffeting measures based on the test results.

[0055] Specifically, in step S50, when conducting the aeroelastic model wind tunnel test, wind-induced vibration response tests are performed on the bridge structure under construction to which the combined anti-vibration measures are applied and the bridge structure under construction to which the combined anti-vibration measures are not applied (for example, only one anti-vibration measure among the combined anti-vibration measures, such as a temporary pier, is applied) to obtain test data; subsequently, the test data of the bridge structure under construction to which the combined anti-vibration measures are applied is compared with the test data of the bridge structure under construction to which the combined anti-vibration measures are not applied, so as to intuitively see the effectiveness of the combined anti-vibration measures.

[0056] The test data may include a ratio of the buffeting internal force to the total buffeting internal force, and a ratio of the first-order vertical bending vertical buffeting internal force to the buffeting internal force.

[0057] Specifically, this embodiment obtains the comparison results of the buffeting internal force of the bridge tower under the middle tower cross beam when a single temporary pier is added to the bridge structure under construction with or without TMD by conducting an aeroelastic model wind tunnel test. The comparison results are shown in Table 2 below.

[0058] Table 2 Comparison results of buffeting internal forces of single temporary pier with and without TMD

[0059] It can be seen from Table 2 that, compared with the bridge structure under construction without the combined anti-buffeting measures (that is, only temporary piers are set without TMD), the bridge structure under construction with the combined anti-buffeting measures consisting of temporary piers and TMD has smaller ratios of the buffeting internal force to the total buffeting internal force, and smaller ratios of the first-order vertical bending vertical buffeting internal force to the buffeting internal force. This indicates that adding the combined anti-buffeting measures can more effectively control the buffeting response of the bridge under construction, so as to further improve the safety of the bridge during the construction period and the comfort of the construction workers.

[0060] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling wind-induced vibration during the construction period of a long-span cable-stayed bridge, characterized in that: The method comprises the following steps: Step S10. Establishing an original finite element model of the bridge structure under construction; Step S20. Obtain the static wind load, self-excited force and buffeting force acting on the bridge structure in the construction state, apply the acquired static wind load, self-excited force and buffeting force to the original finite element model, and perform a nonlinear time history analysis of buffeting response on the original finite element model to obtain the buffeting displacement of the cantilever end of the main beam of the bridge in the construction state under different working conditions; Step S30. Testing the wind-induced vibration response of the bridge structure under construction, and verifying the original finite element model according to the test results to obtain a target finite element model of the bridge structure under construction; Step S40: adding a combined anti-vibration measure to the target finite element model, and obtaining optimal design parameters of the combined anti-vibration measure; the combined anti-vibration measure includes a temporary pier and a TMD.

2. The method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge according to claim 1, characterized in that: The optimal design parameters include the optimal setting position of the temporary pier, and the optimal mass ratio and damping ratio of the TMD.

3. The method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge according to claim 2, characterized in that: The process of obtaining the optimal setting position of the temporary pier includes: setting the temporary pier at different positions away from the cantilever end of the main beam of the bridge under construction and performing calculations to obtain the position where the maximum stress at the bottom of the tower is the minimum under different construction conditions. The position where the maximum stress at the bottom of the tower is the minimum is the optimal arrangement position of the temporary pier.

4. The method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge according to claim 2, characterized in that: The optimal mass and damping ratio of the TMD is obtained by minimizing the power amplification factor DAF get; Among them, the power amplification factor DAF The expression is as follows: ； In the above formula: ; ; ; ; in, F represents the time-varying wind load; is the mass ratio of TMD, is the damping ratio of the bridge, is the damping ratio of TMD; It is the ratio of the circular frequency of the simple harmonic load to the natural frequency of the bridge.

5. The method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge according to claim 1, characterized in that: In step S40, the vibration frequency of the TMD is the same as the first-order vertical frequency of the bridge structure under construction.

6. The method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge according to claim 1, characterized in that: In step S20, the buffeting force is calculated by the following process: Obtaining a buffeting force time history and a fluctuating wind speed time history of the bridge structure under construction; The acquired time history data of the buffeting force time history and the fluctuating wind speed time history are transformed by using a fast Fourier transform technique to obtain a buffeting force power spectrum and a fluctuating wind speed power spectrum; Obtaining a frequency domain equivalent aerodynamic admittance function of the buffeting force according to the buffeting force power spectrum and the pulsating wind speed power spectrum; According to the wind speed spectrum and the frequency domain equivalent aerodynamic admittance function of the buffeting force, a buffeting force power spectrum considering the influence of aerodynamic admittance is obtained; The buffeting force time history in the time domain can be obtained by transforming the buffeting force power spectrum considering the influence of aerodynamic admittance from the frequency domain to the time domain.

7. The method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge according to claim 6, characterized in that: The calculation formula of the buffeting force power spectrum considering the influence of aerodynamic admittance is: ； ； ； In the above three formulas, , , They represent respectively the buffeting drag spectrum function, buffeting lift force spectrum function and buffeting lift moment spectrum function considering the influence of aerodynamic admittance; is the air density; U is the incoming wind speed; B is the width of the main beam; , , are the drag coefficient, lift coefficient and lift moment coefficient respectively; , , are the derivative of the drag coefficient, the derivative of the lift coefficient, and the derivative of the lift moment coefficient, respectively. , , The frequency domain equivalent aerodynamic admittance functions representing buffeting drag, buffeting lift and buffeting lift moment respectively; , Respectively Kaimal Spectrum and Panofsky Score.

8. The method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge according to claim 1, characterized in that: In step S30, verifying the original finite element model according to the test results specifically includes: Testing the wind-induced vibration response of the bridge structure under construction to obtain the buffeting displacement of the cantilever end of the main beam of the bridge under construction under different working conditions of the bridge structure under construction, and comparing the obtained buffeting displacement data with the buffeting displacement data obtained after performing buffeting response nonlinear time history analysis on the original finite element model in step S20; If the comparison result meets the preset standard data, the original finite element model is directly used as the target finite element model; otherwise, the original finite element model is modified until the target finite element model is obtained.

9. The method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge according to claim 1, characterized in that: Also includes the steps: Step S50. Apply the combined anti-bounce measures to the bridge structure under construction according to the optimal design parameters, and conduct a wind-induced vibration response test on the bridge structure under construction to which the combined anti-bounce measures are applied through an aeroelastic model wind tunnel test, so as to verify the effectiveness of the combined anti-bounce measures based on the test results.

10. The method for controlling wind-induced vibration during construction of a long-span cable-stayed bridge according to claim 9, characterized in that: In step S50, the process of verifying the effectiveness of the combined anti-vibration measure according to the test result includes: Wind-induced vibration response tests are performed on the bridge structure under construction to which the combined anti-vibration measures are applied and the bridge structure under construction to which the combined anti-vibration measures are not applied, respectively, to obtain test data; then, the test data of the bridge structure under construction to which the combined anti-vibration measures are applied is compared with the test data of the bridge structure under construction to which the combined anti-vibration measures are not applied.

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