Method for determining long-term temperature field of concrete-filled steel tube arch bridge considering environmental factors

Abstract

The present invention provides a method for determining the long-term temperature field of a steel tube concrete arch bridge considering environmental factors, comprising the following steps: S1. collecting environmental parameters of a target steel tube concrete arch bridge; S2. determining the maximum circumferential temperature t of the steel tube concrete arch bridge interface based on the environmental parameters. max and the minimum value t min ; S3. Based on the maximum circumferential temperature of the arch bridge interface t max and the minimum value t min The long-term circumferential temperature field of the steel tube concrete interface and the long-term radial temperature field of the steel tube concrete can be determined; the environmental parameters of the steel tube concrete arch bridge and its own hydration heat can be combined to determine the long-term circumferential and cross-sectional radial temperature fields of the steel tube concrete, thereby ensuring the accuracy of the temperature field calculation, providing accurate data support for the structural stability analysis of the steel tube concrete arch bridge, and can be adapted to any arch bridge with strong adaptability.

Description

Technical Field

[0001] The present invention relates to a method for determining a building temperature field, and in particular to a method for determining a long-term temperature field of a steel tube concrete arch bridge taking environmental factors into consideration. Background Art

[0002] Steel tube concrete arch bridges have the advantages of high bearing capacity, mature design theory and construction technology, high structural rigidity, superior dynamic performance, and good durability. Compared with large-span bridge types such as suspension and cable-stayed bridges, they have lower costs; therefore, steel tube concrete arch bridges are widely used.

[0003] The structural stability of steel tube concrete arch bridges is affected by temperature. In the existing technology, the temperature field research of steel tube concrete arch bridges often adopts a single evaluation factor, such as a single reference environmental factor or a single reference hydration heat effect. As a result, the temperature field of the concrete arch bridge deviates greatly from the actual temperature field, which greatly interferes with the operation and maintenance of the steel tube concrete arch bridge, thereby affecting the structural stability of the steel tube concrete arch bridge. Moreover, the existing method can only be used in the specific environment of the target arch bridge, which has great limitations.

[0004] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for determining the long-term temperature field of a steel tube concrete arch bridge taking environmental factors into consideration. The method can combine the environmental parameters of the steel tube concrete arch bridge with its own hydration heat to jointly determine the long-term temperature field of the circumferential and cross-sectional radial directions of the steel tube concrete, thereby ensuring the accuracy of the temperature field calculation, providing accurate data support for the structural stability analysis of the steel tube concrete arch bridge, and being adaptable to any arch bridge with strong adaptability.

[0006] The present invention provides a method for determining the long-term temperature field of a steel tube concrete arch bridge taking environmental factors into consideration, which is characterized by comprising the following steps:

[0007] S1. Collect environmental parameters of the target concrete-filled steel tube arch bridge;

[0008] S2. Determine the maximum circumferential temperature t of the steel tube concrete arch bridge interface based on environmental parameters max and the minimum value t min ;

[0009] S3. Based on the maximum circumferential temperature of the arch bridge interface t max and the minimum value t min Determine the long-term circumferential temperature field of the steel tube concrete interface and the long-term radial temperature field of the steel tube concrete; where:

[0010] The long-term circumferential temperature field of the steel tube concrete interface is determined by the following method:

[0011] Determine the circumferential temperature distribution curve of the steel tube concrete interface:

[0012] t=A sinθ+B;

[0013] The curve takes the horizontal direction of the steel tube concrete section as the horizontal axis, the vertical axis perpendicular to the horizontal direction of the steel tube concrete section as the vertical axis, and the steel tube concrete as the center of the circle to establish a coordinate system. θ represents the angle between the line connecting the point on the steel tube concrete interface to the coordinate origin in this coordinate system and the negative half axis of the horizontal axis of the coordinate system.

[0014] Coefficient of determination B:

[0015]

[0016] Wherein, a is the ratio of the peak value of the positive half cycle to the peak value of the negative half cycle of the temperature distribution curve;

[0017] Coefficient of determination A:

[0018] When 0°<θ≤180°:

[0019] A=t max -B;

[0020] When 180°<θ≤360°:

[0021] A=Bt min ;

[0022] The circumferential temperature field of concrete-filled steel tube is:

[0023]

[0024]

[0025] The long-term radial temperature field of concrete-filled steel tubes is determined by the following method:

[0026]

[0027] Where: x is the temperature influence depth coefficient of the steel tube concrete, and x>2, D is the inner diameter of the steel tube, T is the temperature of the radial point to be evaluated in the steel tube concrete section, l is the distance between the point to be evaluated and the sunny side interface of the steel tube concrete; T3 is the temperature at the set radial depth.

[0028] Furthermore, the maximum circumferential temperature of the steel tube concrete arch bridge interface t is determined according to the following method: max and the minimum value t min :

[0029]

[0030] Where: t w is the ambient temperature of the steel tube concrete arch bridge, I max is the peak solar radiation intensity, I min is the solar radiation intensity amplitude; h f is the air convection heat transfer coefficient of the steel tube concrete arch bridge environment.

[0031] The beneficial effects of the present invention are as follows: Through the present invention, the environmental parameters of the steel tube concrete arch bridge and its own hydration heat can be combined to jointly determine the long-term temperature field conditions of the circumferential and cross-sectional radial directions of the steel tube concrete, thereby ensuring the accuracy of the temperature field calculation, providing accurate data support for the structural stability analysis of the steel tube concrete arch bridge, and being adaptable to any arch bridge with strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0033] Figure 1 Flowchart of the present invention.

[0034] Figure 2 It is a schematic diagram of the circumferential temperature distribution curve of the steel tube concrete interface of the present invention.

[0035] Figure 3 It is a schematic diagram of the radial temperature field distribution of the steel tube concrete cross section of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below:

[0037] The present invention provides a method for determining the long-term temperature field of a steel tube concrete arch bridge taking environmental factors into consideration, which is characterized by comprising the following steps:

[0038] S1. Collect environmental parameters of the target concrete-filled steel tube arch bridge;

[0039] S2. Determine the maximum circumferential temperature t of the steel tube concrete arch bridge interface based on environmental parameters max and the minimum value t min ;

[0040] S3. Based on the maximum circumferential temperature of the arch bridge interface t max and the minimum value t min Determine the long-term circumferential temperature field of the steel tube concrete interface and the long-term radial temperature field of the steel tube concrete; where:

[0041] The long-term circumferential temperature field of the steel tube concrete interface is determined by the following method:

[0042] Determine the circumferential temperature distribution curve of the steel tube concrete interface:

[0043] t=A sinθ+B;

[0044] The curve is established with the horizontal direction of the steel tube concrete section as the horizontal axis, the vertical axis perpendicular to the horizontal direction of the steel tube concrete section as the vertical axis, and the steel tube concrete as the center of the circle. θ represents the angle between the line connecting the point on the steel tube concrete interface to the coordinate origin in the coordinate system and the negative semi-axis of the horizontal axis of the coordinate system. The temperature distribution curve is determined by fitting using an existing method. The fitting method is a prior art and will not be described in detail here.

[0045] Coefficient of determination B:

[0046]

[0047] Wherein, a is the ratio of the peak value of the positive half cycle to the peak value of the negative half cycle of the temperature distribution curve;

[0048] Coefficient of determination A:

[0049] When 0°<θ≤180°:

[0050] A=t max -B;

[0051] When 180°<θ≤360°:

[0052] A=Bt min ;

[0053] The circumferential temperature field of concrete-filled steel tube is:

[0054]

[0055]

[0056] The long-term radial temperature field of concrete-filled steel tubes is determined by the following method:

[0057]

[0058] Where: x is the temperature influence depth coefficient of the steel tube concrete, and x>2, D is the inner diameter of the steel tube, T is the temperature of the radial point to be evaluated in the steel tube concrete section, l is the distance between the point to be evaluated and the sunny side interface of the steel tube concrete; T3 is the temperature at the set radial depth.

[0059] In this embodiment, the maximum circumferential temperature t of the steel tube concrete arch bridge interface is determined according to the following method: max and the minimum value t min :

[0060]

[0061] Where: t w is the ambient temperature of the concrete-filled steel tube arch bridge, I max is the peak value of solar radiation intensity, I min is the amplitude of solar radiation intensity; h f is the convective heat transfer coefficient of the air in the environment of the concrete-filled steel tube arch bridge.

[0062] As Figure 3 shown: Among them, T1 represents the temperature of the interface on the sunny side of the concrete-filled steel tube, that is, at the position where point A is located. When moving radially inward from point A, its temperature will gradually decrease. When it decreases to a certain extent, that is Figure 3 when the depth in reaches D / x, that is, after reaching B, as its depth increases, the temperature will not change. The internal temperature field is determined by the hydration heat and is all T3. T2 is the temperature of the interface on the shady side, that is Figure 3 at the position where point D is located in. In the long run, when moving radially inward from point D, its temperature gradually decreases, from T2 to T3. Among them, T2 < T1. Then, within the depth range from the interface of the concrete-filled steel tube to D / x, its temperature field is affected by the internal hydration heat and the external temperature. Then, the temperature at any point in this area (such as Figure 3 the short range of AB and the range of CD in) is calculated by the above long-term radial temperature field formula. T2 and T1 are calculated through the long-term circumferential temperature field.

[0063] Among them, x and T3 are determined by the existing finite element simulation method, which belongs to the existing technology and will not be elaborated here.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for determining the long-term temperature field of a steel tube concrete arch bridge considering environmental factors, characterized by: The following steps are involved: S1. Collect environmental parameters of the target concrete-filled steel tube arch bridge; S2. Determine the maximum circumferential temperature t of the steel tube concrete arch bridge interface based on environmental parameters max and the minimum value t min ; S3. Based on the maximum circumferential temperature of the arch bridge interface t max and the minimum value t min Determine the long-term circumferential temperature field of the steel tube concrete interface and the long-term radial temperature field of the steel tube concrete; where: The long-term circumferential temperature field of the steel tube concrete interface is determined by the following method: Determine the circumferential temperature distribution curve of the steel tube concrete interface: t=A sinθ+B; The curve takes the horizontal direction of the steel tube concrete section as the horizontal axis, the vertical axis perpendicular to the horizontal direction of the steel tube concrete section as the vertical axis, and the steel tube concrete as the center of the circle to establish a coordinate system. θ represents the angle between the line connecting the point on the steel tube concrete interface to the coordinate origin in this coordinate system and the negative half axis of the horizontal axis of the coordinate system. Coefficient of determination B: Wherein, a is the ratio of the peak value of the positive half cycle to the peak value of the negative half cycle of the temperature distribution curve; Coefficient of determination A: When 0°<θ≤180°: A=t max -B; When 180°<θ≤360°: A=B-t min ; The circumferential temperature field of concrete-filled steel tube is: The long-term radial temperature field of concrete-filled steel tubes is determined by the following method: Where: x is the temperature influence depth coefficient of the steel tube concrete, and x>2, D is the inner diameter of the steel tube, T is the temperature of the radial point to be evaluated in the steel tube concrete section, l is the distance between the point to be evaluated and the sunny side interface of the steel tube concrete; T3 is the temperature at the set radial depth.

2. The method for determining the long-term temperature field of a steel tube concrete arch bridge considering environmental factors according to claim 1 is characterized by: The maximum circumferential temperature t of the interface of the steel tube concrete arch bridge is determined according to the following method: max and the minimum value t min : Where: t w is the ambient temperature of the steel tube concrete arch bridge, I max is the peak solar radiation intensity, I min is the solar radiation intensity amplitude; h f is the air convection heat transfer coefficient of the steel tube concrete arch bridge environment.

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