Component parameter optimization, system design method and system for long-span bridge structures

Abstract

The present invention relates to the field of seismic design, and in particular to a component parameter optimization, system design method and system for a long-span bridge structure. The present invention proposes a component parameter optimization method for a long-span bridge structure, which takes the working condition safety of each component as a constraint and pursues the optimal value of the earthquake risk of the entire bridge structure. Under this goal, the optimal parameters of the components are calculated, which can not only consider the overall risk of the bridge system, but also take into account the different importance requirements of each component.

Description

Technical Field

[0001] The present invention relates to the field of earthquake-resistant design, and in particular to a component parameter optimization, system design method and system for a long-span bridge structure. Background Art

[0002] Earthquake disasters are the main risks faced by bridges and roads. They are difficult to predict and uncontrollable. Once they occur, they can cause damage and collapse of bridges at the least, or paralyze the entire road network at the worst. The probability of earthquake risk of bridges not only considers the possibility of damage to the structure at different determined strengths, but also takes into account the possibility of occurrence of determined strengths. The determination of the probability of earthquake risk of bridges involves site seismic hazard analysis, seismic vulnerability analysis and other processes. The earthquake risk of bridges is one of the important indicators for evaluating the seismic performance and reliability of bridges, and is widely used in the field of seismic analysis.

[0003] Compared with ordinary small and medium span bridges, long span bridges have complex nonlinear behaviors and a large number of bridge components. When conducting theoretical analysis on the seismic performance of long span bridges, the long span bridge is often analyzed as a whole (system vulnerability analysis). However, in engineering practice, engineers and engineering designers often pay more attention to the seismic performance of specific components. It should be noted that for long span bridges, the importance of different components is not exactly the same. For example, for cable-stayed bridges, the bridge tower is usually the most important component. Compared with bearings and piers, it should receive more attention. This difference is rarely paid attention to in the process of system seismic performance analysis. At present, long span bridges are usually equipped with seismic mitigation devices, and their parameter design should be designed to balance seismic deformation (seismic isolation device) and seismic force (column), but this is usually difficult to achieve, especially considering the difference in the importance of components. Summary of the invention

[0004] In order to solve the above-mentioned defect of difficult design of long-span bridges in the prior art, the present invention proposes a component parameter optimization method for a long-span bridge structure, which can be used to optimize the parameters of each component in a long-span bridge and facilitate the parameter design of the components in the bridge.

[0005] The present invention proposes a method for optimizing component parameters of a long-span bridge structure, comprising the following steps:

[0006] S1. Obtain the component to be optimized and the set of parameters to be optimized {x1, x2, ..., x n , …, x N}; x n Represents the nth parameter to be optimized of the component to be optimized, 1≦n≦N, N is the number of parameters to be optimized;

[0007] S2. Screening evaluation objects from all components of the bridge structure, the evaluation objects including the components to be optimized; obtaining the risk assessment model corresponding to each evaluation object and the risk assessment model corresponding to the entire bridge structure; the risk assessment model corresponding to the evaluation object is used to calculate the seismic risk of the evaluation object in combination with the parameters to be optimized of the components to be optimized, and the risk assessment model corresponding to the entire bridge structure is used to calculate the seismic risk of the entire bridge structure in combination with the parameters to be optimized of the components to be optimized;

[0008] S3. Obtain the risk threshold corresponding to each assessment object. The risk threshold of the i-th assessment object is denoted as CF i ; Establish constraints: CF i (X)≦CF i ;min(x n )≦x n ≦max(x n ), min(x n ) represents x n The lower limit of max(x n ) represents x n The upper limit of the value, min(x n ) and max(x n ) are all set values;

[0009] S4. Determine the value range of each parameter to be optimized according to the constraint conditions, and construct multiple parameter arrays based on the value range of each parameter to be optimized, each parameter array contains a value corresponding to each parameter to be optimized, and each value is within the value range of the corresponding parameter to be optimized; any two parameter arrays have at least one different value;

[0010] S5. Substitute each parameter array into the risk assessment model corresponding to the overall bridge structure, calculate the seismic risk of the overall bridge structure corresponding to each parameter array, and assign values ​​to each parameter to be optimized according to the parameter array corresponding to the minimum value of the seismic risk of the overall bridge structure.

[0011] Preferably, the risk assessment model for the i-th assessment object is:

[0012]

[0013] Where X represents the set of parameters to be optimized, X = {x1, x2, ..., x n , …, x N}; CF i (X) represents the earthquake risk of the i-th assessment object; a0 (i) 、a p (i) 、a pp (i) and a pq (i)are the coefficients of the risk assessment model for the i-th assessment object; k represents the set coefficient in the disaster curve, and k is used to represent the earthquake intensity of the region; x p represents the pth parameter to be optimized, x q represents the qth parameter to be optimized, 1≦p≦N, 1≦q≦N.

[0014] Preferably, a0 (i) 、a p (i) 、a pp (i) and a pq (i) Obtained through data fitting.

[0015] Preferably, the overall risk assessment model of the bridge structure is:

[0016]

[0017] Where X represents the set of parameters to be optimized, X = {x1, x2, ..., x n , …, x N}; OF(X) represents the overall earthquake risk of the bridge structure; a0 (Sys) 、a p (Sys) 、a pp (Sys) and a pq (Sys) are all model coefficients; k represents the set coefficient in the disaster curve, and k is used to represent the earthquake intensity in the region; x p represents the pth parameter to be optimized, x q represents the qth parameter to be optimized, 1≦p≦N, 1≦q≦N.

[0018] Preferably, a0 (Sys) 、a p (Sys) 、a pp (Sys) and a pq (Sys) Obtained through data fitting.

[0019] Preferably, the component to be optimized is: a bridge tower, a support or an earthquake mitigation device.

[0020] Preferably, the evaluation objects include: bridge towers, bearings and earthquake mitigation devices.

[0021] The present invention also proposes a component parameter optimization system for a long-span bridge structure, which is used to carry the component parameter optimization method for the long-span bridge structure mentioned above, so as to facilitate the promotion of the parameter optimization method.

[0022] The present invention provides a component parameter optimization system for a long-span bridge structure, comprising a memory in which a computer program is stored. When the computer program is executed, it is used to implement the component parameter optimization method for the long-span bridge structure.

[0023] Preferably, it also includes a processor, which is connected to the memory and is used to execute the computer program to implement the component parameter optimization method of the long-span bridge structure.

[0024] The present invention also proposes a system design method for a long-span bridge structure, which uses the above-mentioned component parameter optimization method for the long-span bridge structure to obtain the parameters of each important component, ensure the working safety of each component, and thus ensure the reliability of the overall design scheme of the bridge.

[0025] The present invention proposes a system design method for a long-span bridge structure, comprising the following steps:

[0026] SA1. Obtain components to be optimized and components to be evaluated in the bridge structure;

[0027] SA2. Execute the component parameter optimization method of the long-span bridge structure for each component to be optimized, and obtain the value assignment of each parameter to be optimized of each component to be optimized.

[0028] The advantages of the present invention are:

[0029] (1) The present invention proposes a method for optimizing the component parameters of a long-span bridge structure, which takes the working safety of each component as a constraint and pursues the optimal value of the seismic risk of the entire bridge structure. Under this goal, the optimal parameters of the components are calculated, which can consider both the overall risk of the bridge system and the different importance requirements of each component.

[0030] (2) The parameter optimization method proposed in the present invention is suitable for optimizing the parameters of each component in the bridge structure, and the calculation is simple and easy to implement. The implementation of the present invention is conducive to ensuring the seismic performance of each bridge component while ensuring the overall seismic performance of the bridge structure, thereby ensuring the safety of the bridge, extending the service life of the bridge, and avoiding the scrapping of the entire bridge structure due to damage to individual components.

[0031] (3) The risk assessment model provided in the present invention adopts the k value to take into account the earthquake characteristics of different regions, which is conducive to optimizing parameters in combination with regional characteristics and achieving a balance between performance and cost in bridge design.

[0032] (4) In the present invention, a template of the risk assessment model is given, which facilitates obtaining the model coefficients through data fitting, thereby ensuring accurate assessment of the seismic risks of the bridge structure as a whole and each component, laying a foundation for the accuracy of parameter optimization.

[0033] (5) The system design method for the long-span bridge structure provided by the present invention does not interfere with each other when optimizing the parameters of individual components, and the system design is simpler and more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flow chart of a parameter optimization method for a long-span bridge structure provided by the present invention;

[0035] Figure 2 A three-dimensional diagram of the risk assessment model for the bridge tower;

[0036] Figure 3 Provide a three-dimensional diagram of the risk assessment model for the bearing;

[0037] Figure 4 A three-dimensional diagram of the risk assessment model for viscous dampers;

[0038] Figure 5 It is a schematic diagram of the parameter allowable range;

[0039] Figure 6 Schematic diagram of the parameter optimization process. DETAILED DESCRIPTION

[0040] Example: Parameter optimization method for earthquake mitigation device of long-span bridge structure

[0041] The earthquake mitigation device in this embodiment is a viscous damper. This embodiment uses the viscous damper of a component of a long-span bridge structure as a component to be optimized to explain the component parameter optimization method of the long-span bridge structure provided by the present invention. Figure 1 shown.

[0042] In this embodiment, the parameter to be optimized of the viscous damper is first defined as the damping coefficient C d and velocity index a, and determine the bridge towers, bearings and viscous dampers in the bridge structure as evaluation objects.

[0043] In this embodiment, firstly, C is obtained by software simulation. d The seismic risks faced by the bridge tower, bearing, viscous damper and the bridge structure as a whole when and take different values ​​within the value range are obtained respectively by data fitting.

[0044] In this embodiment, software simulation and data fitting are performed in combination with a large-span bridge structure in a certain area, and the risk assessment model corresponding to the bridge tower is finally obtained as follows:

[0045]

[0046] The risk assessment model corresponding to the bearing is:

[0047]

[0048] The risk assessment model corresponding to the viscous damper is:

[0049]

[0050] The overall risk assessment model of the bridge structure is:

[0051]

[0052] Among them, 1.926 is the seismic intensity in the area where the bridge is located, which is set by field experts according to relevant standards.

[0053] In this embodiment, the risk assessment models corresponding to the bridge tower, support and viscous damper are respectively as follows: Figure 2 , Figure 3 , Figure 4 shown.

[0054] In this embodiment, the risk threshold of the bridge tower is set by the domain experts as CF1=0.32, the risk threshold of the support is set as CF2=0.43, and the risk threshold of the viscous damper is set as CF3=0.43.

[0055] In this embodiment, the risk threshold of the bridge tower, the risk threshold of the support, the risk threshold of the viscous damper and the risk threshold of the entire bridge structure are combined. d The value range of and the value range of a construct C d The value constraints of and a are as follows:

[0056]

[0057] Combined with the above constraints, C d The value range of a is as follows Figure 5 shown.

[0058] A specific analysis shows that the overall seismic risk of the bridge structure is very insensitive to the velocity index a of the viscous damper, so in this embodiment, a is set to a commonly used constant of 0.3. Figure 5 It can be seen that when a = 0.3, the C corresponding to the bridge tower d The value range is C d Minimum value range.

[0059] Combining the risk assessment model and risk threshold corresponding to the bridge tower, it can be seen that when a=0.3, 0.52≤C d ≤0.66. In this embodiment, in combination with the parameter optimization method provided by the present invention, the C value that can minimize the earthquake risk of the entire bridge structure is selected in the interval [0.52, 0.66]. d value, get Cd =0.66, at this time the earthquake risk of the bridge tower is less than the corresponding risk threshold of 0.32.

[0060] In the existing method, the parameters of each component are determined only according to the earthquake risk of the entire bridge structure. In this embodiment, according to the existing technology, it can be determined that when C d When =0.78, the earthquake risk of the entire bridge structure is the smallest, but the earthquake risk of the bridge tower exceeds the risk threshold, and the bridge tower area is in a dangerous condition.

[0061] In this embodiment, by comparing the parameter optimization method provided by the present invention with the traditional method for finding the minimum seismic risk of the entire bridge structure, it can be seen that the parameters found by the method of the present invention are slightly different from those found by the traditional method in terms of the seismic risk of the entire bridge structure. Even if the parameter value range obtained according to the constraint conditions includes the parameter point corresponding to the minimum seismic risk of the entire bridge structure, the present invention can obtain the same result as the traditional method. However, the present invention can always ensure that each evaluation object can achieve a seismic risk less than the corresponding risk threshold, that is, each evaluation object can work under safe conditions, thereby ensuring the working safety of all components of the bridge structure and avoiding uncertain risks caused by local damage.

[0062] In this way, through the application of the present invention, when designing a large-span bridge structure, the method provided by the present invention can be used to optimize each component that needs to be optimized, such as components that are prone to damage, one by one, thereby ensuring that the components in the bridge structure can all work under safe conditions and ensuring the earthquake resistance of the overall bridge structure.

[0063] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for optimizing component parameters of a long-span bridge structure, characterized in that: The following steps are involved: S1. Obtain the component to be optimized and the set of parameters to be optimized {x1, x2, ..., x n , …, x N }; x n Represents the nth parameter to be optimized of the component to be optimized, 1≦n≦N, N is the number of parameters to be optimized; S2. Screening evaluation objects from all components of the bridge structure, the evaluation objects including the components to be optimized; obtaining the risk assessment model corresponding to each evaluation object and the risk assessment model corresponding to the entire bridge structure; the risk assessment model corresponding to the evaluation object is used to calculate the seismic risk of the evaluation object in combination with the parameters to be optimized of the components to be optimized, and the risk assessment model corresponding to the entire bridge structure is used to calculate the seismic risk of the entire bridge structure in combination with the parameters to be optimized of the components to be optimized; S3. Obtain the risk threshold corresponding to each assessment object. The risk threshold of the i-th assessment object is denoted as CF i ; Establish constraints: CF i (X)≦CF i ;min(x n )≦x n ≦max(x n ), min(x n ) represents x n The lower limit of max(x n ) represents x n The upper limit of the value, min(x n ) and max(x n ) are all set values; S4. Determine the value range of each parameter to be optimized according to the constraint conditions, and construct multiple parameter arrays based on the value range of each parameter to be optimized, each parameter array contains a value corresponding to each parameter to be optimized, and each value is within the value range of the corresponding parameter to be optimized; any two parameter arrays have at least one different value; S5. Substitute each parameter array into the risk assessment model corresponding to the overall bridge structure, calculate the seismic risk of the overall bridge structure corresponding to each parameter array, and assign values ​​to each parameter to be optimized according to the parameter array corresponding to the minimum value of the seismic risk of the overall bridge structure.

2. The component parameter optimization method of a long-span bridge structure according to claim 1, characterized in that: The risk assessment model for the i-th assessment object is: Where X represents the set of parameters to be optimized, X = {x1, x2, ..., x n , …, x N }; CF i (X) represents the earthquake risk of the i-th assessment object; a0 (i) 、a p (i) 、a pp (i) and a pq (i) are the coefficients of the risk assessment model for the i-th assessment object; k represents the set coefficient in the disaster curve, and k is used to represent the earthquake intensity of the region; x p represents the pth parameter to be optimized, x q represents the qth parameter to be optimized, 1≦p≦N, 1≦q≦N.

3. The component parameter optimization method of a long-span bridge structure according to claim 2, characterized in that: a0 (i) 、a p (i) 、a pp (i) and a pq (i) Obtained through data fitting.

4. The component parameter optimization method of a long-span bridge structure according to claim 1, characterized in that: The overall risk assessment model of the bridge structure is: Where X represents the set of parameters to be optimized, X = {x1, x2, ..., x n , …, x N }; OF(X) represents the overall earthquake risk of the bridge structure; a0 (Sys) 、a p (Sys) 、a pp (Sys) and a pq (Sys) are all model coefficients; k represents the set coefficient in the disaster curve, and k is used to represent the earthquake intensity in the region; x p represents the pth parameter to be optimized, x q represents the qth parameter to be optimized, 1≦p≦N, 1≦q≦N.

5. The component parameter optimization method of a long-span bridge structure according to claim 4, characterized in that: a0 (Sys) 、a p (Sys) 、a pp (Sys) and a pq (Sys) Obtained through data fitting.

6. The component parameter optimization method of a long-span bridge structure according to claim 1, characterized in that: The components to be optimized are: bridge towers, bearings or earthquake mitigation devices.

7. The component parameter optimization method of a long-span bridge structure according to claim 1, characterized in that: The assessment objects include: bridge towers, bearings and seismic mitigation devices.

8. A component parameter optimization system for a long-span bridge structure, characterized in that: It comprises a memory, in which a computer program is stored, and when the computer program is executed, it is used to implement the component parameter optimization method of the long-span bridge structure as described in any one of claims 1-6.

9. The component parameter optimization system for a long-span bridge structure according to claim 8, characterized in that: It also includes a processor, which is connected to the memory and is used to execute the computer program to implement the component parameter optimization method of the long-span bridge structure as described in any one of claims 1-6.

10. A system design method for a long-span bridge structure, characterized in that: The following steps are involved: SA1. Obtain components to be optimized and components to be evaluated in the bridge structure; SA2. Execute the component parameter optimization method for the long-span bridge structure as described in any one of claims 1 to 6 for each component to be optimized, and obtain the value assignment of each parameter to be optimized of each component to be optimized.

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