Method for determining hydration heat temperature field of concrete-filled steel tube arch bridge

Abstract

The application provides a method for determining a hydration heat temperature field of a steel pipe concrete arch bridge, which comprises the following steps: S1, collecting environmental parameters of a target steel pipe concrete arch bridge; S2, determining a maximum value t max and a minimum value t min of a circumferential temperature of an interface of the steel pipe concrete arch bridge based on the environmental parameters; and S3, determining a circumferential temperature field of the steel pipe concrete and a radial temperature field of the steel pipe concrete based on the maximum value t max and the minimum value t min of the circumferential temperature of the interface of the arch bridge. Through the method, the circumferential temperature field and the radial temperature field of the steel pipe concrete can be determined by combining the environmental parameters of the steel pipe concrete arch bridge and the hydration heat of the steel pipe concrete, so that the accuracy of the temperature field calculation is ensured, accurate data support is provided for the structural stability analysis of the steel pipe concrete arch bridge, and the method is suitable for any arch bridge and has high adaptability.

Description

Technical Field

[0001] This invention relates to a method for determining the temperature field of a building, and more particularly to a method for determining the hydration heat temperature field of a steel-concrete composite arch bridge. Background Technology

[0002] Concrete-filled steel tube arch bridges have advantages such as high load-bearing capacity, mature design theory and construction technology, high structural rigidity, excellent dynamic performance, and good durability. Compared with long-span bridges such as suspension and cable-stayed bridges, they are less expensive. Therefore, concrete-filled steel tube arch bridges are widely used.

[0003] The structural stability of steel-concrete composite arch bridges is affected by temperature. In existing technologies, temperature field studies of steel-concrete composite arch bridges often use a single evaluation factor, such as a single reference environmental factor or a single reference to the heat of hydration. This results in a large deviation between the temperature field of the concrete arch bridge and the actual temperature field, causing great interference to the operation and maintenance of steel-concrete composite arch bridges and thus affecting the structural stability of steel-concrete composite arch bridges. Moreover, existing methods can only be applied to the specific environment of the target arch bridge, which has great limitations.

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

[0005] In view of this, the purpose of this invention is to provide a method for determining the hydration heat temperature field of a concrete-filled steel tube arch bridge. This method can combine the environmental parameters of the concrete-filled steel tube arch bridge with its own hydration heat to determine the circumferential and radial temperature fields of the concrete-filled steel tube, thereby ensuring the accuracy of the temperature field calculation. This provides accurate data support for the structural stability analysis of the concrete-filled steel tube arch bridge and is adaptable to any arch bridge, demonstrating strong adaptability.

[0006] This invention provides a method for determining the hydration heat temperature field of a steel-concrete composite arch bridge, comprising:

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

[0008] S2. Determining the maximum circumferential temperature t at the interface of a steel-concrete composite arch bridge based on environmental parameters. max and the minimum value t min ;

[0009] S3. Maximum t based on the circumferential temperature at the arch bridge interface max and the minimum value t min The circumferential temperature field and radial temperature field of steel-concrete composite tubular ...

[0010] Furthermore, the circumferential temperature field of concrete-filled steel tubular structures was determined using the following method:

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

[0012] t = Asinθ + B;

[0013] Wherein, the curve takes the horizontal direction of the section of the steel pipe concrete as the abscissa, takes the vertical direction of the section of the steel pipe concrete as the ordinate and establishes a coordinate system with the steel pipe concrete as the center, θ represents the included angle between the line connecting the point on the interface of the steel pipe concrete to the origin of the coordinate system and the negative half axis of the coordinate system;

[0014] Determine the coefficient B:

[0015]

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

[0017] Determine the coefficient A:

[0018] When 0° < θ ≤ 180°:

[0019] A = t max -B;

[0020] When 180° < θ ≤ 360°:

[0021] A = B-t min ;

[0022] The circumferential temperature field of the steel pipe concrete is:

[0023]

[0024]

[0025] Further, the maximum value t max and the minimum value t min of the circumferential temperature of the interface of the steel pipe concrete arch bridge are determined according to the following method:

[0026]

[0027] Wherein: t w is the ambient temperature of the steel pipe concrete arch bridge, I max is the peak value of the solar radiation intensity, I min is the amplitude value of the solar radiation intensity; h f is the air convection heat transfer coefficient of the environment of the steel pipe concrete arch bridge.

[0028] Further, the radial temperature field of the steel pipe concrete is determined by the following method:

[0029] The temperature field in the horizontal diameter direction of the steel pipe concrete is:

[0030]

[0031] In the late night and early morning period, the radial temperature field of the steel pipe concrete section except the horizontal diameter direction is:

[0032] T2 is the temperature at a set radial depth;

[0033] In the afternoon period, the radial temperature field of the steel pipe concrete section except the horizontal diameter direction is:

[0034]

[0035] Wherein, x is the steel pipe concrete temperature influence depth coefficient, and x>2, D is the inner diameter of the steel pipe, T is the steel pipe concrete section radial evaluation point temperature, l is the distance between the evaluation point and the sunny side interface of the steel pipe concrete; T4 is the first inflection point value of the temperature radially downward from the sunny side interface of the steel pipe concrete in the afternoon period, and T5 is the second inflection point value of the temperature radially downward from the sunny side interface of the steel pipe concrete in the afternoon period.

[0036] The beneficial effects of the present application are: through the present application, the circumferential and sectional radial temperature field of the steel pipe concrete can be determined by combining the environmental parameters of the steel pipe concrete arch bridge and the hydration heat itself, so as to ensure the accuracy of the temperature field calculation, the structural stability analysis of the steel pipe concrete arch bridge provides accurate data support, and it can be adapted to any arch bridge, and has strong adaptability. BRIEF DESCRIPTION OF DRAWINGS

[0037] The present application will be further described below in combination with the drawings and examples:

[0038] Figure 1 The flowchart of the present application.

[0039] Figure 2 The steel pipe concrete interface circumferential temperature distribution curve diagram of the present application.

[0040] Figure 3 The steel pipe concrete hydration heat temperature field radial distribution schematic diagram in the late night and early morning period.

[0041] Figure 4 The steel pipe concrete hydration heat temperature field radial distribution schematic diagram in the afternoon period. DETAILED DESCRIPTION

[0042] The present application will be further described below in combination with the drawings and examples:

[0043] The present application provides a kind of to determine the method of steel pipe concrete arch bridge hydration heat temperature field, comprising:

[0044] S1. Collecting the environmental parameters of the target steel pipe concrete arch bridge;

[0045] S2. Determining the maximum value t max and the minimum value t min of the circumferential temperature of the interface of the steel pipe concrete arch bridge based on the environmental parameters;

[0046] S3. Determining the circumferential temperature field of the steel pipe concrete and the radial temperature field of the steel pipe concrete based on the maximum value t max and the minimum value t min of the circumferential temperature of the interface of the arch bridge, through the above method, the circumferential and cross-sectional radial temperature fields of the steel pipe concrete can be determined by combining the environmental parameters of the steel pipe concrete arch bridge and the hydration heat of the steel pipe concrete, so as to ensure the accuracy of the temperature field calculation, the structural stability analysis of the steel pipe concrete arch bridge provides accurate data support, and it is suitable for any arch bridge and has strong adaptability.

[0047] In this embodiment, the circumferential temperature field of the steel pipe concrete is determined by the following method:

[0048] Determine the circumferential temperature distribution curve of the interface of the steel pipe concrete:

[0049] t=A sinθ+B (1);

[0050] Wherein, the curve takes the horizontal direction of the section of the steel pipe concrete as the abscissa, takes the vertical direction of the section of the steel pipe concrete as the ordinate, and establishes a coordinate system with the steel pipe concrete as the center, and θ represents the included angle between the line connecting the point on the interface of the steel pipe concrete to the origin of the coordinate system and the negative half axis of the coordinate system; wherein, the determination of the temperature distribution curve is fitted by using the existing method, and the fitting method is the prior art, which will not be described here;

[0051] Determine the coefficient B:

[0052]

[0053] Wherein, a is the ratio of the positive half peak value to the negative half peak value of the temperature distribution curve;

[0054] Determine the coefficient A:

[0055] When 0°<θ≤180°:

[0056] A=t max -B (3);

[0057] When 180°<θ≤360°:

[0058] A=B-t min (4);

[0059] The circumferential temperature field of the steel pipe concrete is:

[0060]

[0061]

[0062] In the embodiment, the maximum value t of the circumferential temperature of the steel pipe concrete arch bridge interface is determined according to the following method max and the minimum value t min :

[0063]

[0064] Wherein: t w is the ambient temperature of the steel pipe concrete arch bridge, I max is the peak value of the solar radiation intensity, I min is the amplitude value of the solar radiation intensity; h f is the air convection heat transfer coefficient of the environment of the steel pipe concrete arch bridge; t max represents the maximum value of the temperature on the sunny side, t min is the minimum value of the temperature on the sunny side, and the solar radiation intensity is the smallest, when the period of deep night or early morning, I max and I min are both 0; on the summer solstice day, the solar normal steel pipe concrete section is at the top, and the sunny side of the bottom of the steel pipe concrete can also be considered as I min 0.

[0065] In the embodiment, the radial temperature field of the steel pipe concrete is determined by the following method:

[0066] The temperature field in the horizontal diameter direction of the steel pipe concrete is:

[0067]

[0068] In the period of deep night and early morning, the radial temperature field except the horizontal diameter direction of the steel pipe concrete section is:

[0069] T2 is the temperature at the set radial depth;

[0070] In the period of the afternoon, the radial temperature field except the horizontal diameter direction of the steel pipe concrete section is:

[0071]

[0072] Where x is the temperature influence depth coefficient of steel-concrete composite, and x>2; D is the inner diameter of the steel pipe; T is the radial temperature of the steel-concrete composite section to be evaluated; l is the distance between the evaluation point and the sun-facing interface of the steel-concrete composite; T4 is the first inflection point value of the temperature radially downward from the sun-facing side of the steel-concrete composite interface during the afternoon period; and T5 is the second inflection point value of the temperature radially downward from the sun-facing side of the steel-concrete composite interface during the afternoon period.

[0073] like Figure 3 As shown: Figure 3 This diagram illustrates the radial temperature distribution of a steel-concrete composite section during late night or early morning. T1 represents the temperature at the interface between the steel and concrete sections. Since the interface temperature is the same during late night or early morning (i.e., points A and D have the same temperature), it indicates that both A and D are at the interface. The temperature gradually increases radially inward from point A or from point D (inward from the center of the section). When the temperature increases to a certain level, i.e. Figure 4 When the depth reaches D / x, i.e., point B or C, the temperature does not change with increasing depth. The internal temperature field is determined by the heat of hydration, which is always T2. Therefore, within the depth range from the steel-concrete composite interface to D / x, the temperature field is affected by both the internal heat of hydration and the external temperature. In this region (e.g., Figure 4 The temperature at any point within the short range of AB and the range of CD is calculated using formula (9).

[0074] like Figure 4 As shown: Figure 4 This is a schematic diagram of the radial temperature distribution of a steel-concrete composite section during midday. A represents the sun-facing side of the steel-concrete composite interface, and D represents the shaded side. The temperature gradually decreases radially from A towards D, decreasing from temperature T3 on the sun-facing side to T4. Figure 4 At point B, the depth is D / x. When the depth increases from D / x to D / 2, the temperature gradually increases due to the internal heat of hydration, reaching a maximum of C, which is T5. As the reinforced concrete structure moves from its center towards the shaded side, the temperature gradually decreases from T5 to T6. Figure 4 The temperature at any point within segments AB, BC, and CD is calculated using formula (10); T3 and T6 can be calculated using the circumferential temperature field calculation formula, i.e., the θ value at T3 is 90° and the θ value at T6 is 270°, and are calculated using formula (5). x, T2, T4, and T5 are determined using existing finite element simulation methods, which are existing technologies and will not be elaborated upon here.

[0075] As for the horizontal direction, that is Figure 3The direction perpendicular to the AD line is the horizontal direction, and the formula (8) is used for calculation in this direction.

[0076] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the purpose and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A method for determining the hydration heat temperature field of a steel-concrete composite arch bridge, characterized in that: include: S1. Collect environmental parameters of the target steel-concrete composite arch bridge; S2. Determining the maximum circumferential temperature at the interface of a steel-concrete composite arch bridge based on environmental parameters. and minimum value ; S3. Maximum circumferential temperature based on the interface of the arch bridge and minimum value The circumferential temperature field and radial temperature field of steel-concrete composite tubular ... The circumferential temperature field of concrete-filled steel tubes was determined using the following method: Determine the circumferential temperature distribution curve at the interface between steel-concrete composite pipes: ； The curve establishes a coordinate system with the horizontal direction of the steel-concrete composite section as the horizontal axis, the direction perpendicular to the horizontal direction of the steel-concrete composite section as the vertical axis, and the steel-concrete composite section as the center. This represents the angle between the line connecting a point on the steel-concrete interface to the origin in this coordinate system and the negative half-axis of the horizontal axis of the coordinate system. Coefficient of determination B: ； in, This 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 hour: ； when hour: ； The circumferential temperature field of concrete-filled steel tubular structures is as follows: ； The maximum circumferential temperature at the interface of a steel-concrete composite arch bridge was determined using the following method. and minimum value : ； ;in: The ambient temperature of the steel-concrete composite arch bridge. This represents the peak value of solar radiation intensity. This refers to the amplitude of solar radiation intensity. The air convection heat transfer coefficient of the environment of the steel-concrete composite arch bridge; The radial temperature field of concrete-filled steel tubular structures was determined using the following method: The temperature field along the horizontal diameter direction of the concrete-filled steel tube is: ； During late night and early morning hours, the radial temperature field, excluding the horizontal diameter direction of the steel-concrete composite section, is as follows: ; To set the temperature at the radial depth; During the afternoon hours, the radial temperature field, excluding the horizontal diameter direction of the steel-concrete composite section, is as follows: in, The depth coefficient for the temperature influence of concrete-filled steel tubular structures is given, and , The inner diameter of the steel pipe. The radial temperature of the concrete-filled steel tube section to be evaluated. The distance between the point to be evaluated and the sun-facing interface of the steel-concrete composite tube; This represents the first inflection point value of temperature radially downwards from the steel-concrete composite interface towards the sun during the afternoon hours. This represents the second inflection point value of temperature radially downwards from the steel-concrete composite interface towards the sun during the afternoon hours.

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