阅读说明：本技术 一种斜拉桥缩尺试验模型斜拉索的安装方法 (Method for installing stay cable of cable-stayed bridge reduced scale test model ) 是由 王高新 邵婧舒 周鑫 东兆星 于 2019-11-08 设计创作，主要内容包括：本发明实施例公开了一种斜拉桥缩尺试验模型斜拉索的安装方法,根据桥梁参数,建立斜拉桥缩尺有限元模型和无拉索的斜拉桥缩尺试验模型；根据斜拉桥成桥状态要求以及所述斜拉桥缩尺有限元模型,获取斜拉桥中各斜拉索的索力张拉值；根据所述无拉索的斜拉桥缩尺试验模型和所述索力张拉值,安装斜拉索。不局限于单一期望值,能够满足不同的设计需求,计算过程简洁清晰,张拉步骤明确,每次张拉只需关注一根索的拉力信息,避免了全索张拉完成后再进行整体优化调索的复杂步骤。(The embodiment of the invention discloses a method for installing stay cables of a cable-stayed bridge reduced scale test model, which comprises the steps of establishing a cable-stayed bridge reduced scale finite element model and a cable-stayed bridge reduced scale test model without stay cables according to bridge parameters; acquiring a cable force tension value of each stay cable in the cable-stayed bridge according to the bridge-forming state requirement of the cable-stayed bridge and the scale finite element model of the cable-stayed bridge; and installing the stay cable according to the stay cable-free cable-stayed bridge reduced scale test model and the cable force tension value. The method is not limited to a single expected value, different design requirements can be met, the calculation process is simple and clear, the tensioning step is clear, the tension information of one cable only needs to be concerned in each tensioning, and the complex step of integrally optimizing and adjusting the cable after the tensioning of the whole cable is finished is avoided.)

1. A method for installing a stay cable of a cable-stayed bridge reduced scale test model is characterized by comprising the following steps:

establishing a cable-stayed bridge reduced scale finite element model and a cable-stayed bridge reduced scale test model without a stay cable according to bridge parameters;

acquiring a cable force tension value of each stay cable in the cable-stayed bridge according to the bridge-forming state requirement of the cable-stayed bridge and the scale finite element model of the cable-stayed bridge;

and installing the stay cable according to the stay cable-free cable-stayed bridge reduced scale test model and the cable force tension value.

2. The method of claim 1, wherein the establishing a finite element model of a cable-stayed bridge and a cable-less cable-stayed bridge scale test model according to the bridge parameters comprises:

determining parameters of the cable-stayed bridge after the cable-stayed bridge is subjected to scale reduction based on a bridge structure scale model similarity ratio theory by referring to a cable-stayed bridge design drawing, and establishing a cable-stayed bridge scale finite element model without stay cables;

and acquiring various parameters of the reduced scale model according to the parameters of the bridge, manufacturing and processing various members of the bridge, and establishing the cable-stayed bridge reduced scale test model without the stay cable.

3. The method of claim 1, wherein obtaining a tension value of each stay cable in the cable-stayed bridge according to the requirements of the cable-stayed bridge in a bridge forming state and the cable-stayed bridge reduced scale finite element model comprises:

according to the cable-stayed bridge reduced scale finite element model, obtaining the deflection value of each anchoring point under the action of the gravity of the bridge;

acquiring a deflection influence coefficient of the stay cable and a cable force influence coefficient of the stay cable according to the deflection value of each anchoring point under the action of the gravity of the bridge;

and acquiring tension values of the cable forces according to the requirements of the cable-stayed bridge in a bridge forming state, the deflection influence coefficient of the stay cable and the cable force influence coefficient of the stay cable.

4. The method according to claim 3, wherein the obtaining the deflection value of each anchor point under the gravity of the bridge according to the cable-stayed bridge reduced finite element model comprises:

in a cable-stayed bridge reduced scale finite element model, a dead weight G is applied to a full bridge, and the deflection value of each anchoring point under the action of the dead weight of the bridge is obtained, wherein the deflection value of the ith anchoring point of the bridge under the action of the dead weight is delta_GiAnd i is 1,2, … … and n, wherein n is the number of the anchor points.

5. The method as claimed in claim 4, wherein the obtaining the deflection influence coefficient of the stay cable according to the deflection value of each anchor point under the gravity of the bridge comprises:

installing a first stay cable in a finite element model of a cable-stayed bridge reduced scale, and applying any initial tension W₁The cable force after the first cable is retracted is obtained as

Then, sequentially installing the stay cables in the cable-stayed bridge reduced-scale finite element model, and respectively applying any initial tension W to the stay cables_mSequentially obtaining the cable force of each stay cable after retractionAnd the deflection value of each anchoring point under the load of the dead weight of the bridge and the tension cable force

6. The method according to claim 4, wherein the obtaining of the influence coefficient of the cable force of the stay cable according to the deflection value of each anchor point under the gravity of the bridge comprises:

installing the mth cable in the cable-stayed bridge reduced scale finite element model and applying any initial tension W_mTo obtain

7. The method of claim 3, wherein obtaining the tension values according to the requirements of the cable-stayed bridge in the bridge-forming state, the deflection influence coefficient of the stay cable and the cable force influence coefficient of the stay cable comprises:

if the cable-stayed bridge is in a bridge-forming state and the deflection value of a certain anchoring point is required to be a determined value, establishing n deflection equations and acquiring tension values of all cable forces;

if the cable-stayed bridge is in a bridge-forming state and requires that the cable force of each stayed cable is equal and is a determined value, establishing m cable force equations and obtaining tension values of the cable force;

and if the cable-stayed bridge is in a bridge-forming state, requiring that the deflection value of a certain anchoring point is a certain determined value and requiring that the cable force of each stayed cable is equal and is a certain determined value, combining the deflection equation and the cable force equation to obtain the cable force values.

8. The method of claim 1, wherein installing a stay cable based on the cable-less cable-stayed bridge scale test model and the cable force tension value comprises:

and sequentially installing a stay cable and a cable force sensor of each cable in the cable-stayed bridge reduced scale test model without the stay cable, and adjusting the cable force to the cable force tensioning value.

Technical Field

The invention relates to the field of stay cable installation, in particular to a method for installing a stay cable of a cable-stayed bridge scale test model.

Background

The cable-stayed bridge is a bridge with a main beam directly pulled on a bridge tower by a plurality of guys, and is a structural system formed by combining a pressure-bearing tower, the pulled guys and a bending-bearing beam body. Modern cable-stayed bridges occupy an important position in modern bridge structures due to their large spanning capacity, good technical and economic indicators and aesthetic value. The stay cable is an important load-bearing component on the cable-stayed bridge and is responsible for transmitting the load of the main beam to the bridge tower, and whether the force value of the stay cable is properly set will influence the accuracy of the cable-stayed bridge scale test model.

In the existing modeling of a cable-stayed bridge scale model, a stay cable force tensioning method comprises a rigid support beam continuous method, a zero displacement method, a bending moment square sum minimum method, a bending energy minimum method and the like. The methods have the problems of profound basic theory and complex calculation process, and are difficult to master and apply by bridge engineering technicians. In addition, bridge engineering technicians expect that optimization results with different expected values can be achieved in the process of optimizing the stay cable force, however, the methods are generally limited to a single expected value at present.

Disclosure of Invention

The embodiment of the invention provides a method for installing a stayed cable of a cable-stayed bridge scale test model, which is not limited to a single expected value, can meet different design requirements, has simple and clear calculation process and definite tensioning steps, only needs to pay attention to the tension information of one cable during each tensioning, and avoids the complex step of integrally optimizing and adjusting the cable after the whole cable is tensioned.

In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:

in a first aspect, the embodiment of the invention provides a method for installing a stay cable of a cable-stayed bridge reduced scale test model, which comprises the steps of establishing a cable-stayed bridge reduced scale finite element model and a cable-stayed bridge reduced scale test model without the stay cable according to bridge parameters; acquiring a cable force tension value of each stay cable in the cable-stayed bridge according to the bridge-forming state requirement of the cable-stayed bridge and the scale finite element model of the cable-stayed bridge; and installing the stay cable according to the stay cable-free cable-stayed bridge reduced scale test model and the cable force tension value.

With reference to the first aspect, as a first achievable mode, determining parameters of the cable-stayed bridge after being scaled down based on a bridge structure reduced scale model similarity ratio theory by referring to a cable-stayed bridge design drawing, and establishing a cable-stayed bridge scaled finite element model without stay cables; and acquiring various parameters of the reduced scale model according to the parameters of the bridge, manufacturing and processing various members of the bridge, and establishing the cable-stayed bridge reduced scale test model without the stay cable.

With reference to the first implementable manner of the first aspect, as a second implementable manner, obtaining a deflection value of each anchoring point under the action of gravity of the bridge according to the reduced-scale finite element model of the cable-stayed bridge;

acquiring a deflection influence coefficient of the stay cable and a cable force influence coefficient of the stay cable according to the deflection value of each anchoring point under the action of the gravity of the bridge; and acquiring tension values of the cable forces according to the requirements of the cable-stayed bridge in a bridge forming state, the deflection influence coefficient of the stay cable and the cable force influence coefficient of the stay cable.

With reference to the first implementable manner of the first aspect, as a third implementable manner, in the reduced-scale finite element model of the cable-stayed bridge, a dead weight G is applied to the full bridge, and a deflection value of each anchor point under the action of the dead weight of the bridge is obtained, wherein the deflection value of the ith anchor point of the bridge under the action of the dead weight is Δ_GiAnd i is 1,2, … … and n, wherein n is the number of the anchor points.

With reference to the first implementable manner of the first aspect, as a fourth implementable manner, a first stay cable is installed in the cable-stayed bridge reduced-scale finite element model, and any initial tension W is applied₁The cable force after the first cable is retracted is obtained as

And the deflection value of each anchoring point under the load of the dead weight of the bridge and the tension cable force

Obtaining the influence coefficient of the first cable tension on the deflection of each anchoring point

Sequentially installing the stay cables in the finite element model of the cable-stayed bridge reduced scale, and respectively applying any initial tension W to the stay cables_mSequentially obtaining the cable force of each stay cable after retraction

And the deflection value of each anchoring point under the load of the dead weight of the bridge and the tension cable force

Obtaining the influence coefficient of the tensioning of the second to the mth cables on the deflection of each anchoring point

m represents the corresponding serial number of the installed stay cable, and m is more than 1.

With reference to the first implementable manner of the first aspect, as a fifth implementable manner, the mth cable is installed in the cable-stayed bridge reduced-scale finite element model and any initial tension W is applied_mTo obtain

The cable force value of the jth cable under the self weight of the bridge and the tension cable force load after the mth cable is tensioned is shown, j is 1,2,3, … … and m-1,

the cable force value after the jth cable is tensioned and retracted is shown, and the influence coefficient of the mth cable tensioning on the cable force of the front (m-1) stay cables is obtained

And the influence coefficient of the mth cable tension on the jth stayed cable force is shown.

With reference to the first implementable manner of the first aspect, as a sixth implementable manner, if the cable-stayed bridge is in a bridged state and the deflection value of a certain anchoring point is required to be a certain value, n deflection equations are established, and tension values of each cable force are obtained; if the cable-stayed bridge is in a bridge-forming state and requires that the cable force of each stayed cable is equal and is a determined value, establishing m cable force equations and obtaining tension values of the cable force; and if the cable-stayed bridge is in a bridge-forming state, requiring that the deflection value of a certain anchoring point is a certain determined value and requiring that the cable force of each stayed cable is equal and is a certain determined value, combining the deflection equation and the cable force equation to obtain the cable force values.

With reference to the first implementable manner of the first aspect, as a seventh implementable manner, in the cable-less cable-stayed bridge reduced scale test model, the stay cables and the cable force sensors of each cable are sequentially installed, and the cable force is adjusted to the cable force tension value.

The method for installing the stay cable of the cable-stayed bridge scale test model provided by the embodiment of the invention is not limited to a single expected value, can meet different design requirements, is simple and clear in calculation process and clear in tensioning step, only needs to pay attention to the tension information of one cable during each tensioning, and avoids the complex step of integrally optimizing and adjusting the cable after the whole cable is tensioned. Compared with the prior art, in the implementation of the invention, a cable-stayed bridge reduced scale finite element model and a cable-free cable-stayed bridge reduced scale test model are established according to bridge parameters; acquiring a cable force tension value of each stay cable in the cable-stayed bridge according to the bridge-forming state requirement of the cable-stayed bridge and the scale finite element model of the cable-stayed bridge; and installing the stay cable according to the stay cable-free cable-stayed bridge reduced scale test model and the cable force tension value.

The method is characterized in that the bridge forming state of the cable-stayed bridge without the stay cable is taken as an initial state, the stay cables are installed and tensioned one by one under the state, and each tensioning only needs to pay attention to the tension information of the stay cable, and the influence of the cable tensioning on the cable force of other stay cables and the deflection of each anchoring point is not needed. After the full cable force is tensioned according to the target value, the cable force values and the deflection of the anchoring points naturally reach the design expected value, three conditions expected by technicians are considered when the cable force is solved, the cable force is not limited to a single expected value any more, and different design requirements can be met. The method has the advantages that the calculation process is simple and clear, the tensioning step is clear, only the tension information of one cable needs to be concerned in each tensioning, and the complex step of integrally optimizing and adjusting the cable after the whole cable is tensioned is avoided.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a flow chart of an embodiment of the present invention.

FIG. 2 is another flow chart of an embodiment of the present invention.

Fig. 3 is a diagram of an example of installation of the embodiment of the present invention.

FIG. 4 is a diagram of an example of an installation algorithm according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, those skilled in the art can obtain the embodiments without any inventive step in advance, and the embodiments are within the protection scope of the present invention.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In the embodiment of the invention, a cable-stayed bridge reduced scale finite element model and a cable-stayed bridge reduced scale test model without a stay cable are established according to bridge parameters; acquiring a cable force tension value of each stay cable in the cable-stayed bridge according to the bridge-forming state requirement of the cable-stayed bridge and the scale finite element model of the cable-stayed bridge; according to the cable-stayed bridge scale test model without the stay cable and the cable force tensioning value, the stay cable is installed, the single expected value is not limited, different design requirements can be met, the calculation process is simple and clear, the tensioning step is clear, the tension information of one cable only needs to be concerned in each tensioning, and the complex step of integrally optimizing and adjusting the cable after the whole cable is tensioned is avoided.

The embodiment of the invention provides a method for installing a stay cable of a cable-stayed bridge reduced scale test model, which comprises the following steps of:

s110, establishing a cable-stayed bridge reduced scale finite element model and a cable-stayed bridge reduced scale test model without a stay cable according to the bridge parameters.

And determining parameters of the cable-stayed bridge after the cable-stayed bridge is subjected to scale reduction based on a bridge structure scale model similarity ratio theory by referring to a cable-stayed bridge design drawing, and establishing a cable-stayed bridge scale finite element model without stay cables.

And determining various parameters of the cable-stayed bridge after the cable-stayed bridge is subjected to scale reduction, such as geometric dimension, density, elastic modulus, rigidity and the like based on a bridge structure scale model similarity ratio theory by referring to a cable-stayed bridge design drawing. The similarity referred to herein means the ratio of the physical quantities corresponding to the model and prototype, and generally, the similarity of the physical quantities related to the structural performance is mainly as follows: similar geometry, similar load, similar mass, similar stiffness, similar time, etc. Firstly, determining a geometric scale ratio according to drawings, test conditions, test purposes and the like, determining a model material meeting the structural volume-weight similarity ratio, and then determining a statics similarity relation and a dynamics similarity relation between the model and a prototype so as to design an ideal model. When the sizes of the bridge tower and the main beam of the scale model are designed, the design is strictly designed according to the geometric similarity ratio, but if the model manufacturing and testing conditions cannot simultaneously meet a plurality of similar relations, the similar relation with large influence on the structure needs to be preferentially met. If the rigging is difficult to design according to the geometric similarity ratio due to the limitation of the geometric similarity ratio, a scheme that the number of model guys is half less than that of a prototype can be adopted. In engineering practice, because a reduced-scale model test is limited by a test site, a scale, a cost and the like, compared with a prototype structure test, the reduced-scale model test can reduce the test scale and reduce the requirements on materials and equipment, and therefore, a reduced-scale (similar model) test is mostly adopted in a general research test.

After determining each parameter, establishing a cable-stayed bridge scale finite element model without stay cables by using MIDAS, namely regarding the structural state without the stay cables as an initial state, and installing the tensioning stay cables one by one in the initial state and calculating the influence coefficient of each stay cable on the deflection of an anchoring point and the force of other stay cables in subsequent calculation. Referring to the existing bridge finite element modeling method, a bridge tower is simulated by a solid unit, and a main beam is simulated by a beam unit. The bottom of the bridge tower is consolidated; the two ends of the main beam are hinged and constrained, and the main beam and the bridge tower are subjected to node coupling treatment at the support position, namely the main beam and the bridge tower are subjected to displacement coupling in the transverse bridge direction and the vertical bridge direction at the support position.

And acquiring various parameters of the reduced scale model according to the parameters of the bridge, manufacturing and processing various members of the bridge, and establishing the cable-stayed bridge reduced scale test model without the stay cable.

And S120, acquiring a cable tension value of each stay cable in the cable-stayed bridge according to the bridge forming state requirement of the cable-stayed bridge and the cable-stayed bridge reduced scale finite element model.

As shown in fig. 2, S120 includes:

and S1201, acquiring the deflection value of each anchoring point under the action of the gravity of the bridge according to the cable-stayed bridge reduced scale finite element model.

In a cable-stayed bridge reduced scale finite element model, a dead weight G is applied to a full bridge, and the deflection value of each anchoring point under the action of the dead weight of the bridge is obtained, wherein the deflection value of the ith anchoring point of the bridge under the action of the dead weight is delta_GiAnd i is 1,2, … … and n, wherein n is the number of the anchor points.

Assuming that the cable-stayed bridge needs to stretch n stay cables in total, the anchoring points of the stay cables on the main beam are respectively marked as D₁、D₂、D₃......D_n-1、D_nWherein the anchoring point of the ith stay cable on the main beam is D_i，i＝1、2、……、n。

In a cable-stayed bridge reduced scale finite element model, a dead weight G is applied to a full bridge, and a solution D is obtained under the action of the dead weight of the bridge₁、D₂、D₃......D_n-1、D_nThe deflection value of each point is obtained by the automatic operation and analysis of the model_G1、Δ_G2、Δ_G3......Δ_G(n-1)、Δ_GnWherein the deflection value of the i-th anchoring point of the bridge under the self-weight is delta_Gi，i＝1、2、……、n。

S1202, acquiring a deflection influence coefficient and a cable force influence coefficient of the stay cable according to the deflection value of each anchoring point under the action of the gravity of the bridge.

Solving the first cable tension pair D₁、D₂、D₃......D_n-1、D_nThe deflection influence coefficient of each anchoring point.

Installing a first stay cable in a finite element model of a cable-stayed bridge reduced scale, wherein the stay cable is simulated by adopting a truss unit and applying any initial tension W₁The operation analysis shows that the rope force of the first rope after retraction isAnd the deflection value of each anchoring point under the load of the dead weight of the bridge and the tension cable force

The influence coefficient of the tension of the first cable on the deflection of each anchoring point can be obtained

Wherein

Showing the deflection value of the ith anchoring point under the self weight of the bridge and the load of the tension cable force after the first guy cable is tensioned,

and (3) showing the influence coefficient of the tensioning of the first cable on the deflection of the ith anchoring point, wherein i is 1,2,3, … …, n.

Further installing a second cable in the finite element model of the cable-stayed bridge reduced scale, wherein the stay cable is simulated by adopting a truss unit and applying any initial tension W₂And calculating the influence coefficient of the second cable tensioning on the deflection of each anchoring point and the influence coefficient of the first cable force.

The influence coefficient of each point deflection is calculated as follows: installing a second cable in the cable-stayed bridge reduced scale finite element model and applying any initial tension W₂The operation analysis shows that the cable force after the retraction of the second cable is

And the deflection value of each anchoring point under the load of the dead weight of the bridge and the tension cable force

The influence coefficient of the second cable tension on the deflection of each anchoring point can be obtained

Wherein

Showing the deflection value of the ith anchoring point under the self weight of the bridge and the load of the tension cable force after the second cable is tensioned,

and (3) showing the influence coefficient of the second cable tensioning on the flexibility of the ith anchoring point, wherein i is 1,2,3, … … and n.

Wherein the first root force influence coefficient is calculated as follows: installing a second cable in the cable-stayed bridge reduced scale finite element model and applying any initial tension W₂Then, the operation analysis obtains the cable force value of the first cable under the load of the self weight of the bridge and the tension cable force

The influence coefficient of the second cable after being tensioned on the first cable force can be obtained

And analogizing in sequence, installing the mth cable in the cable-stayed bridge reduced scale finite element model, wherein the stay cable is simulated by adopting the truss unit, and applying any initial tension W_mAnd the influence coefficient of the mth cable force on the deflection of each anchoring point and the influence coefficient of the previous (m-1) cable force are obtained through operation analysis.

The influence coefficient of the deflection of each anchoring point is calculated as follows: installing the mth cable in the cable-stayed bridge reduced scale finite element model and applying any initial tension W_mThe operation analysis shows that the cable force of the mth cable after retraction is

And the deflection value of each anchoring point under the load of the dead weight of the bridge and the tension cable force

The deflection influence coefficient of the mth cable tensioning on each anchoring point can be obtained

Wherein

Showing the deflection value of the ith anchoring point under the self weight of the bridge and the load of the tension cable force after the mth cable is tensioned,

and (3) showing the influence coefficient of the mth cable tensioning on the flexibility of the ith anchoring point, wherein i is 1,2,3, … … and n.

Wherein the front (m-1) ropeThe force impact coefficient is calculated as follows: installing the mth cable in the cable-stayed bridge reduced scale finite element model and applying any initial tension W_mAnd the operation analysis obtains the cable force value of the front (m-1) stay cables under the load of the self weight of the bridge and the tension cable forceThe influence coefficients of the m-th cable tension on the cable force of the front (m-1) stay cables are respectively obtained

Wherein

Showing the cable force value of the jth cable under the self weight of the bridge and the tension cable force load after the mth cable is tensioned,the value of the cable force after the jth stay cable is tensioned and retracted is shown,

the influence coefficient of the mth cable tension on the jth stay cable force is shown, where j is 1,2,3, … …, (m-1).

S1203, acquiring tension values of the cable forces according to the requirements of the cable-stayed bridge in a bridge forming state, the deflection influence coefficient of the stay cable and the cable force influence coefficient of the stay cable.

If the cable-stayed bridge is in a bridge-forming state and the deflection value of a certain anchoring point is required to be a determined value, establishing n deflection equations and acquiring tension values of all cable forces;

when the cable-stayed bridge is in a bridge forming state, if the bending value of the ith anchoring point expected by a designer is H_iAccordingly, n deflection equations are established as follows:

if the cable-stayed bridge is in a bridge-forming state and requires that the cable force of each stayed cable is equal and is a determined value, establishing m cable force equations and obtaining tension values of the cable force;

when the cable-stayed bridge is in a bridge forming state, if a designer expects that all cable forces are C, m cable force equations are established according to the C cable force equations as follows:

wherein X_qAnd (5) setting the q-th cable to be a target cable force value after tensioning is finished, wherein q is 1,2,3, … … and m.

And if the cable-stayed bridge is in a bridge-forming state, requiring that the deflection value of a certain anchoring point is a certain determined value and requiring that the cable force of each stayed cable is equal and is a certain determined value, combining the deflection equation and the cable force equation to obtain the cable force values.

Solving the cable force value can be divided into three cases:

a. if the designer only cares that the deflection value of the ith anchoring point of the cable-stayed bridge is H in the bridge forming state_iAnd simultaneously establishing n deflection equations, and solving each cable force value by using an elimination method. The elimination method is a problem solving method for solving a problem by transforming a plurality of elements in a relational expression for a limited time and eliminating some elements in the relational expression. The elimination method mainly comprises substitution elimination, addition and subtraction elimination, integral elimination, exchange elimination, structural elimination, factorial decomposition elimination, constant elimination, proportional property elimination, etc.;

b. if the designer only cares that the cable forces of the cable-stayed bridge are equal and are all C when the cable-stayed bridge is in the bridge forming state, combining m cable force equations, and solving each cable force value by using a null method;

c. if the designer cares about the two conditions of a and b, the deflection and the cable force equation are simultaneously established, and the cable force values are solved by a multivariate linear regression method. Linear regression is a statistical analysis method that utilizes regression analysis in mathematical statistics to determine the interdependent quantitative relationships between two or more variables, and is widely used. The regression analysis, which includes only one independent variable and one dependent variable and the relationship between them can be approximately expressed by a straight line, is called unitary linear regression analysis. If two or more independent variables are included in the regression analysis and there is a linear relationship between the dependent variable and the independent variable, it is called a multiple linear regression analysis. In fact, a phenomenon is often associated with multiple factors, and predicting or estimating a dependent variable from an optimal combination of multiple independent variables is more efficient and more practical than predicting or estimating with only one independent variable. The multiple linear regression can be applied to various fields of mathematics, economics, finance and the like, and required data are used for prediction or analysis of correlation among various influencing factors.

And S130, installing a stay cable according to the stay cable-free cable-stayed bridge scale test model and the cable force tension value.

Establishing a cable-stayed bridge reduced scale test model without stay cables, and installing and tensioning each stay cable according to a cable force target value:

①, according to each parameter of the scale model, processing each component of the bridge, and establishing a cable-stayed bridge scale test model without stay cables;

② installing the first stay cable and its cable force sensor, tensioning, and regulating cable force to target value X₁；

③ installing a second stay cable and its cable force sensor, tensioning, and regulating cable force to target value X₂；

……

④ repeating the steps, installing the nth cable and its cable force sensor, tensioning, and adjusting the cable force to the target value X_n

The following describes the technical solution of the present invention by way of an example.

This example is a double tower single plane cable stayed bridge that uses four stay cables to validate the method discussed in this patent.

(1) Determining various parameters of the cable-stayed bridge, such as geometric dimension, density, elastic modulus, rigidity and the like after the cable-stayed bridge is subjected to scale reduction based on a bridge structure scale model similarity ratio theory by referring to a cable-stayed bridge design drawing;

after determining all the parameters, establishing a cable-stayed bridge reduced scale finite element model without the stay cable by using MIDAS. The bridge tower is simulated by a solid unit, and the main beam is simulated by a beam unit. The bottom of the bridge tower is consolidated; the two ends of the main beam are hinged and constrained, and the main beam and the bridge tower are subjected to node coupling treatment at the support position, namely the main beam and the bridge tower are subjected to displacement coupling in the transverse bridge direction and the vertical bridge direction at the support position.

(2) The cable-stayed bridge needs to stretch 4 stay cables, and the anchoring points of the stay cables on the main beam are respectively marked as D₁、D₂、D₃、D₄. Applying dead weight G to the full bridge, and solving D under the action of dead weight of the bridge₁、D₂、D₃、D₄And (3) the deflection value of each point is obtained by running and analyzing: delta_G1＝-0.00022m、Δ_G2＝-0.00022m、Δ_G3＝-0.00392m、Δ_G4-0.00392m, wherein the i-th anchor point of the bridge has a deflection value Δ under its own weight_Gi，i＝1、2、3、4。

(3) ① solving for a first cable stretch pair D₁、D₂、D₃、D₄The deflection influence coefficient of each anchoring point.

Installing a first stay cable in the finite element model, wherein the stay cable is simulated by adopting a truss unit, applying an initial tension of 60N, and obtaining a cable force value after the first cable is retracted through running analysis

And the deflection value of each anchoring point under the load of the self weight of the bridge and the tension cable force:

the influence coefficient of the first cable tension on the deflection of each anchoring point can be obtained:

wherein

Showing the deflection value of the ith anchoring point under the self weight of the bridge and the load of the tension cable force after the first guy cable is tensioned,

and (3) showing the influence coefficient of the tensioning of the first cable on the deflection of the ith anchoring point, wherein i is 1,2,3 and 4.

② installing a second cable in the finite element model, wherein the stayed cable is simulated by truss unit and applying initial tension 60N, calculating the influence coefficient of the second cable tension on the deflection of each anchoring point and the influence coefficient of the first cable tension.

The influence coefficient of the deflection of each anchoring point is calculated as follows: after a second cable is installed in the finite element model and initial tension of 60N is applied, running analysis is carried out to obtain a cable force value after the second cable is retracted

And the deflection value of each anchoring point under the self weight of the bridge and the load of the tension cable force:

the deflection influence coefficient of the second cable tension on each anchoring point can be obtained:

wherein the content of the first and second substances,showing the deflection value of the ith anchoring point under the self weight of the bridge and the load of the tension cable force after the second cable is tensioned,

and (3) showing the influence coefficient of the second cable tensioning on the flexibility of the ith anchoring point, wherein i is 1,2,3 and 4.

Wherein, the influence coefficients of the first two cable forces are calculated as follows: installing a second cable in the finite element model and applying an initial tension of 60N, and obtaining a cable force value of the first cable under the load of the self weight of the bridge and the tension cable force through running analysis

The influence coefficient of the second cable after being tensioned on the first cable force can be obtained

③ a third cable is further installed in the finite element model, wherein the stayed cable is simulated by the truss unit and is applied with initial tension of 60N, and the influence coefficient of the third cable tension on the deflection of each anchoring point and the influence coefficient of the first two cable forces are calculated.

The influence coefficient of the deflection of each anchoring point is calculated as follows: after a third cable is installed in the finite element model and initial tension of 60N is applied, running analysis is carried out to obtain a third cable loopValue of cable force after shrinkage

And the deflection value of each anchoring point under the load of the dead weight of the bridge and the tension cable force

The influence coefficient of the third cable tension on the deflection of each anchoring point can be obtained:

wherein

Showing the deflection value of the ith anchoring point under the self weight of the bridge and the load of the tension cable force after the third cable is tensioned,

and (3) showing the influence coefficient of the third cable tensioning on the flexibility of the ith anchoring point, wherein i is 1,2,3 and 4.

The influence coefficients of the first two cable forces are calculated as follows: installing a third cable in the finite element model and applying an initial tension of 60N, and obtaining a cable force value of the first cable under the load of the self weight of the bridge and the tension cable force through running analysisCable force value of the second cableThe influence coefficient of the third cable to the first two cable forces after being tensioned can be obtained

Wherein

The influence coefficient of the j-th cable force after the third cable is tensioned is shown, and j is 1 and 2.

④ installing a fourth cable in the finite element model, wherein the stayed cable is simulated by truss unit and applying initial tension 60N, calculating the influence coefficient of the fourth cable tension on the deflection of each anchoring point and the influence coefficients of the first three cables.

The influence coefficient of each point deflection is calculated as follows: after a fourth cable is installed in the finite element model and initial tension of 60N is applied, running analysis is carried out to obtain a cable force value after the fourth cable is retracted

And the deflection value of each anchoring point under the load of the dead weight of the bridge and the tension cable force

The influence coefficient of the fourth cable tension on the deflection of each anchoring point can be obtained:

wherein

Showing the deflection value of the ith anchoring point under the self weight of the bridge and the load of the tension cable force after the fourth cable is tensioned,

and (3) showing the influence coefficient of the tensioning of the fourth rope on the flexibility of the ith anchoring point, wherein i is 1,2,3 and 4.

The influence coefficients of the first three cable forces are calculated as follows: installing a fourth cable in the finite element model and applying an initial tension of 60N, and obtaining the force values of the first three cables under the load of the self weight of the bridge and the tension cable force through running analysisCable force value of the second cableCable force value of the third cable

The influence coefficient of the fourth cable on the forces of the first three cables after being tensioned can be obtained

WhereinThe force value of the jth cable after the fourth cable is tensioned is shown,

the influence coefficient of the tensile force of the fourth cable on the j-th cable is shown, and j is 1,2, and 3.

(4) When the cable-stayed bridge is in a bridge forming state, if a designer expects a midspan deflection value of 0.005m, the deflection values of other anchoring points are set according to a parabola,

wherein

The designer's expected value for the ith anchor point deflection is shown, i is 1,2,3,4.

From this, 4 deflection equations were established as follows:

-0.00022+1.83×10^-5X₁+2.42×10^-6X₂+1.40×10^-5X₃+(-8.49×10^-6)X₄

＝0.00217

-0.00022+2.50×10^-6X₁+1.77×10^-5X₂+(-4.89×10^-6)X₃+1.53×10^-5X₄

＝0.00217

-0.00392+(-3.33×10^-6)X₁+(-4.03×10^-6)X₂+4.66×10^-5X₃+3.03×10^-5X₄

＝0.00495

-0.00392+(-4.16×10^-6)X₁+(-3.22×10^-6)X₂+4.23×10^-5X₃+3.56×10^-5X₄

＝0.00495

wherein X_qAfter the q-th cable is tensionedQ is 1,2,3,4.

(5) And (3) combining 4 deflection equations, and solving each cable force value by using an elimination method:

X₁＝70.67N、X₂＝68.63N、X₃＝131.55N、X₄＝107.31N

(6) ①, according to the parameters of the reduced scale model determined in the step (1), making and processing each component of the bridge, and establishing a cable-stayed bridge reduced scale test model without stay cables, as shown in fig. 3;

② installing the first stay cable and its cable force sensor, tensioning, and regulating cable force to target value X₁＝70.67N；

③ installing a second stay cable and its cable force sensor, tensioning, and regulating cable force to target value X₂＝68.63N；

④ installing a second stay cable and its cable force sensor, tensioning, and regulating cable force to target value X₃＝131.55N；

⑤ installing the fourth stay cable and its cable force sensor, tensioning, and regulating cable force to target value X₄＝107.31N。

(7) And checking whether the deflection of each anchoring point after the bridge is formed is in accordance with the expectation or not, as shown in figure 4,

wherein

And the deflection value of the ith anchoring point after the bridge is expressed, i is 1,2,3 and 4.

The method for installing the stay cable of the cable-stayed bridge scale test model provided by the embodiment of the invention is not limited to a single expected value, can meet different design requirements, is simple and clear in calculation process and clear in tensioning step, only needs to pay attention to the tension information of one cable during each tensioning, and avoids the complex step of integrally optimizing and adjusting the cable after the whole cable is tensioned. Compared with the prior art, in the implementation of the invention, a cable-stayed bridge reduced scale finite element model and a cable-free cable-stayed bridge reduced scale test model are established according to bridge parameters; acquiring a cable force tension value of each stay cable in the cable-stayed bridge according to the bridge-forming state requirement of the cable-stayed bridge and the scale finite element model of the cable-stayed bridge; and installing the stay cable according to the stay cable-free cable-stayed bridge reduced scale test model and the cable force tension value.

The method is characterized in that the bridge forming state of the cable-stayed bridge without the stay cable is taken as an initial state, the stay cables are installed and tensioned one by one under the state, and each tensioning only needs to pay attention to the tension information of the stay cable, and the influence of the cable tensioning on the cable force of other stay cables and the deflection of each anchoring point is not needed. After the full cable force is tensioned according to the target value, the cable force values and the deflection of the anchoring points naturally reach the design expected value, three conditions expected by technicians are considered when the cable force is solved, the cable force is not limited to a single expected value any more, and different design requirements can be met. The method has the advantages that the calculation process is simple and clear, the tensioning step is clear, only the tension information of one cable needs to be concerned in each tensioning, and the complex step of integrally optimizing and adjusting the cable after the whole cable is tensioned is avoided.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.