Asymmetric transverse temperature gradient model for steel box-girder bridges without wings

Abstract

A transverse temperature gradient model of unsymmetrical steel box girder bridge without slab is composed of transverse positive temperature gradient model and transverse negative temperature gradient model, both of which are in the form of three-fold line. Temperature measuring points are arranged according to the cross-section characteristics of unsymmetrical steel box girder and the distribution characteristics of temperature field. Long-term monitoring of transverse temperature field of unsymmetrical steel box girder bridge without slab is carried out. Through statistical analysis and least square fitting of transverse daily extreme temperature difference, transverse temperature gradient models applicable to 100-year, 150-year and 200-year design service life of unsymmetrical steel box girder bridge without slab are established. The models take into account the influence of design service life and cross-section height, and can be used for solving transverse temperature stress of unsymmetrical steel box girder bridge without slab.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bridge engineering, and particularly relates to a transverse temperature gradient model of an asymmetric non-wing-plate steel box girder bridge. BACKGROUND

[0002] The steel box girder section is a typical closed section, and a transverse temperature field will be generated in the structure under the action of solar radiation. Due to the frame effect of the closed section, a large transverse temperature additional stress will be generated in the structure. The asymmetric non-wing-plate steel box girder section has a great influence on the area of solar radiation and the flow field around the section, and the distribution characteristics of the transverse temperature field are quite different from those of the steel box girder bridge with a wing plate. However, there is no temperature gradient model for the asymmetric non-wing-plate steel box girder bridge in the bridge design specification. Therefore, it is necessary to arrange measuring points according to the distribution characteristics of the transverse temperature field of the asymmetric non-wing-plate steel box girder bridge, carry out long-term temperature field monitoring, construct a transverse temperature gradient model suitable for the asymmetric non-wing-plate steel box girder bridge with a design service life of 100 to 200 years, and support the calculation and analysis of the transverse temperature stress of the non-wing-plate steel box girder bridge. SUMMARY

[0003] The technical problem to be solved by the application is to provide a transverse temperature gradient model of an asymmetric non-wing-plate steel box girder bridge, which can be used for calculation.

[0004] The transverse temperature gradient model of the asymmetric non-wing-plate steel box girder bridge comprises a transverse positive temperature gradient model and a transverse negative temperature gradient model .

[0005] The transverse positive temperature gradient model is shown in formula (1):

[0006]

[0007] In formula (1), is a representative value of the positive temperature gradient at the sunny side, with the unit of ℃, is a representative value of the positive temperature gradient at the shady side, with the unit of ℃, x is the distance between the transverse position of the asymmetric non-wing-plate steel box girder bridge section and the sunny side, and L is the width of the asymmetric non-wing-plate steel box girder bridge, is the design service life of the asymmetric non-wing-plate steel box girder bridge, with the unit of year, and the value is 100 or 150 or 200, is a function, is an inverse function of the function, is a function, is an inverse function of the function, is a distribution function of the representative value of the positive temperature gradient at the sunny side, is a distribution function of the representative value of the positive temperature gradient at the shady side, 、 、 、 、 is an intermediate variable.

[0008] The transverse negative temperature gradient model As shown in formula (2):

[0009]

[0010] In formula (2), is the representative value of negative temperature gradient at the position away from the sun surface , unit: ℃, is the representative value of negative temperature gradient at the position away from the sun surface , unit: ℃, x is an arbitrary transverse position of the asymmetric non-wing plate steel box girder bridge section, and L is the width of the asymmetric non-wing plate steel box girder bridge, is the inverse function of function, is the inverse function of function, is the distribution function of the representative value of negative temperature gradient at the position of the sun surface, is the distribution function of the representative value of negative temperature gradient at the position of the sun surface, 、 、 、 is an intermediate variable.

[0011] In formula (1) of the application, the value of is [14.34, 18.85], is [2.04, 3.52], is [9.60, 12.00], is [2.52, 4.28], in formula (2), the value of is [5.66, 6.26], is [5.52, 9.29], is [6.36, 6.95], is [6.42, 10.63].

[0012] In formula (1) of the application, the value of 、 、 、 、 is: is 100 years, is 16.44, and the best is 2.68, The optimal value is 10.74. The optimal value is 3.28.

[0013] In formula (2) of the present invention, the said , , , , The value can be: For 100 years, The optimal value is 5.95. The optimal value is 7.16. The optimal value is 6.65. The optimal value is 8.26.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. This invention utilizes long-term monitoring data of the transverse temperature field of an asymmetric wingless steel box girder bridge to construct a transverse temperature gradient model for the asymmetric wingless steel box girder bridge. The constructed transverse temperature gradient model considers the influence of the width of the top plate of the asymmetric wingless steel box girder, the design service life, and the temperature probability distribution characteristics.

[0016] 2. The transverse temperature gradient model for asymmetric wingless steel box girder bridges constructed in this invention is simple in form and can be used for long-life design of asymmetric wingless steel box girder bridges with service life of 100 years, 150 years and 200 years. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of an asymmetric, wingless steel box girder bridge.

[0018] Figure 2 This is a distribution diagram of representative temperature values ​​in the transverse positive temperature model of an asymmetric wingless steel box girder bridge.

[0019] Figure 3 This is a distribution diagram of representative temperature values ​​in the transverse negative temperature model of an asymmetric wingless steel box girder bridge.

[0020] Figure 4 This is a diagram showing the layout of transverse temperature measuring points in the measured temperature field of an asymmetric, wingless steel box girder bridge.

[0021] Figure 5 This is the temperature history curve at the measuring point of an asymmetric wingless steel box girder bridge.

[0022] Figure 6 It is the actual measured T HP1 Histogram of positive temperature difference at location.

[0023] Figure 7 It is the actual measured T HP2 Histogram of positive temperature difference at location.

[0024] Figure 8 is the measured T HN1 negative temperature difference statistical histogram at the position.

[0025] Figure 9 is the measured T HN2 negative temperature difference statistical histogram at the position. DETAILED DESCRIPTION

[0026] The application will be further described in detail below in conjunction with the accompanying drawings and examples, but the application is not limited to the following embodiments.

[0027] Example 1

[0028] The transverse temperature gradient model of the asymmetric wingless plate steel box girder bridge of the present embodiment is composed of a transverse positive temperature gradient model and a transverse negative temperature gradient model In the present embodiment, the left side of the beam section is defined as the sun side, and the right side of the beam section is defined as the shade side. In actual use, the side with high light intensity within a day is the sun side.

[0029] The transverse positive temperature gradient model As shown in formula (1):

[0030]

[0031] In formula (1), is the representative value of the positive temperature gradient at the sun side position, with the unit of ℃, is the representative value of the positive temperature gradient at the shade side position, with the unit of ℃, x is the distance between the transverse position of the cross section of the asymmetric wingless plate steel box girder bridge and the sun side, and L is the beam width of the asymmetric wingless plate steel box girder bridge, is the design service life of the asymmetric wingless plate steel box girder bridge, with the unit of year, and the value is 100 or 150 or 200, is the inverse function of the function is the inverse function of the function is the representative value of the positive temperature gradient at the sun side position, is the representative value of the positive temperature gradient at the shade side position, is the distribution function of the representative value of the positive temperature gradient at the sun side position, is the distribution function of the representative value of the positive temperature gradient at the shade side position, , , , , is an intermediate variable.

[0032] The transverse negative temperature gradient model As shown in formula (2):

[0033]

[0034] In equation (2), Distance from the sun The negative temperature gradient at the location is represented by the value in °C. Distance from the shady side The negative temperature gradient at the location is represented by the value in °C, x represents any transverse position of the cross-section of the asymmetric wingless steel box girder bridge, and L represents the width of the asymmetric wingless steel box girder bridge. for The inverse function of a function for The inverse function of a function Let be the distribution function representing the negative temperature gradient at the sunny side. Let be the distribution function representing the negative temperature gradient at the shaded side. , , , It is an intermediate variable.

[0035] This embodiment takes an asymmetric, wingless steel box girder bridge in Guangdong as an example, and its three-dimensional cross-section is as follows: Figure 1 As shown, in equation (1), It is 16.44. It is 2.68. It is 10.74. The value is 3.28. Based on this parameter, a transverse temperature gradient model for an asymmetric, wingless steel box girder bridge was constructed. The representative temperature values ​​in the transverse positive temperature gradient models corresponding to the 100-year, 150-year, and 200-year design service life are shown in Table 1. The distribution of representative temperature values ​​in the transverse positive temperature model constructed according to this parameter is as follows: Figure 2 As shown.

[0036] Table 1. Representative temperature values ​​in the transverse positive temperature gradient model

[0037] In equation (2), It is 5.95. It is 7.16. It is 6.65. The value is 8.26. Based on this parameter, a transverse temperature gradient model for an asymmetric, wingless steel box girder bridge was constructed. The representative temperature values ​​in the transverse negative temperature gradient models corresponding to the 100-year, 150-year, and 200-year design service life are shown in Table 2. The distribution of representative temperature values ​​in the transverse negative temperature model constructed according to this parameter is as follows: Figure 3 As shown.

[0038] Table 2. Representative temperature values ​​in the transverse negative temperature gradient model.

[0039]

[0040] Example 2

[0041] The expression of the transverse temperature gradient model of the asymmetric non-wing plate steel box girder bridge involved in this embodiment is the same as that of Example 1, but the representative value of temperature is different.

[0042] In this embodiment, taking a certain asymmetric non-wing plate steel box girder bridge as an example, in formula (1), is 14.34, is 2.04, is 9.60, is 2.52, and the corresponding transverse temperature gradient model of the asymmetric non-wing plate steel box girder bridge is constructed according to the parameters. The representative value of temperature in the transverse positive temperature gradient model corresponding to the design service life of 100 years, 150 years and 200 years is shown in Table 3. The distribution of the representative value of temperature in the transverse positive temperature model constructed according to the parameters is shown in Figure 2 .

[0043] Table 3 Representative value of temperature in transverse positive temperature gradient model

[0044]

[0045] In formula (2), is 5.66, is 5.52, is 6.36, is 6.42, and the corresponding transverse temperature gradient model of the asymmetric non-wing plate steel box girder bridge is constructed according to the parameters. The representative value of temperature in the transverse negative temperature gradient model corresponding to the design service life of 100 years, 150 years and 200 years is shown in Table 4. The distribution of the representative value of temperature in the transverse negative temperature model constructed according to the parameters is shown in Figure 3 .

[0046] Table 4 Representative value of temperature in transverse negative temperature gradient model

[0047] Example 3

[0048] The expression of the transverse temperature gradient model of the asymmetric non-wing plate steel box girder bridge involved in this embodiment is the same as that of Example 1, but the representative value of temperature is different.

[0049] In this embodiment, taking a certain asymmetric non-wing plate steel box girder bridge as an example, in formula (1), is 18.85, is 3.52, is 12.00, 4.28, the corresponding asymmetric non-wing plate steel box girder bridge transverse temperature gradient model is constructed according to the parameter. The temperature representative value in the transverse positive temperature gradient model corresponding to the design service life of 100 years, 150 years, 200 years is shown in Table 5. The temperature representative value distribution of the transverse positive temperature model constructed according to the parameter is shown in Figure 2 .

[0050] Table 5 Temperature representative value in transverse positive temperature gradient model

[0051] In formula (2), 6.26, 9.29, 6.95, 10.63, the corresponding asymmetric non-wing plate steel box girder bridge transverse temperature gradient model is constructed according to the parameter. The temperature representative value in the transverse negative temperature gradient model corresponding to the design service life of 100 years, 150 years, 200 years is shown in Table 6. The temperature representative value distribution of the transverse negative temperature model constructed according to the parameter is shown in Figure 3 .

[0052] Table 6 Temperature representative value in transverse negative temperature gradient model

[0053] Test 1

[0054] In order to verify the effect of the transverse temperature gradient model of the asymmetric non-wing plate steel box girder bridge, the inventors arranged the transverse temperature sensor on the Taiping Waterway Bridge in Humen Town, Dongguan City, Guangdong Province and carried out long-term temperature field monitoring, and the specific construction process is as follows:

[0055] I. Long-term monitoring equipment

[0056] The monitoring equipment is a remote temperature collection instrument DH2002 produced by Donghua in Taizhou, Jiangsu, and the temperature measuring point selects a three-wire Pt100 sensor.

[0057] II. Temperature measuring point arrangement

[0058] The temperature measuring points are arranged on the top plate of the asymmetric non-wing plate steel box girder bridge, and a coordinate system is established with the edge of the top plate of the asymmetric non-wing plate steel box girder bridge on the sunny side as the coordinate origin. The temperature measuring point arrangement principle on the top plate of the asymmetric non-wing plate steel box girder bridge is: taking the edge of the sunny side of the top plate as the coordinate origin, arranging the temperature measuring points in the width direction of the top plate, and the measuring point positions are represented as 0.000 m, 5.375 m, 10.375 m, 15.750 m from the coordinate origin, which are denoted as LT1~LT4, as shown in Figure 4 , and the collection interval is 1 minute.

[0059] III. Effect analysis of the transverse positive temperature gradient load model

[0060] Taking the positions of T HP1 and T HP2 in the transverse positive temperature gradient model of the asymmetric non-wing-plate steel box girder bridge as examples, the temperature history curves are plotted using the measured temperature field data, as shown in Figure 5 . The temperature difference between the positions of T HP1 and T HP2 and the position with the lowest average temperature of the box girder section measuring point is calculated, the probability density histogram is plotted based on the data, and the probability density function is fitted, as shown in Figure 6 and Figure 7 . The temperature difference corresponding to the 99% guarantee rate in the probability density function is taken to obtain the representative values of the temperature gradient at the positions of T HP1 and T HP2 , which are 20.9℃ and 14.2℃, respectively.

[0061] The temperature gradient model corresponding to the 100-year design service life is constructed using the transverse temperature gradient model of the asymmetric non-wing-plate steel box girder bridge, is 16.44, is 2.68, is 10.74, is 3.28, the calculated T HP1 and T HP2 are 21.9℃ and 14.4℃, respectively, which has a small difference from the measured results, and the test shows that the transverse positive temperature gradient model has good applicability.

[0062] Test 2

[0063] In order to verify the effect of the transverse temperature gradient model of the asymmetric non-wing-plate steel box girder bridge, the inventors arranged the transverse temperature sensors on the Taiping Waterway Bridge in Humen Town, Dongguan City, Guangdong Province and conducted long-term temperature field monitoring, and the specific construction process is as follows:

[0064] I. Long-term monitoring equipment

[0065] The same as Test 1.

[0066] II. Temperature measuring point arrangement

[0067] The same as Test 1.

[0068] III. Effect analysis of the transverse negative temperature gradient load model

[0069] Taking the positions of T HN1 and T HN1 in the transverse negative temperature gradient model of the asymmetric non-wing-plate steel box girder bridge as examples, the measuring point temperature history curves are plotted based on the measured temperature monitoring data. The temperature difference between the positions of T HN1 and T HN1The temperature difference at the position with the highest average value of the temperature at the measuring points of the cross section of the box girder was calculated, and a probability density histogram was plotted based on the data and a probability density function was fitted, as shown in FIGS. Figure 8 and Figure 9 respectively. The values of 1% guarantee rate in the probability density function were obtained, and the T HN1 and T HN2 values were-14.1℃ and-9.2℃, respectively.

[0070] The transverse temperature gradient model of the asymmetric wingless plate steel box girder bridge was used to construct the temperature gradient model corresponding to the 100-year design service life, 5.95, 7.16, 6.65, 8.26, and the T HN1 and T HN2 values were-14.4℃ and-9.8℃, respectively. The test showed that the transverse negative temperature gradient model has good applicability.

Claims

1. A transverse temperature gradient model for an asymmetric, wingless steel box girder bridge, characterized in that: The temperature gradient model is derived from the transverse positive temperature gradient model. With the transverse negative temperature gradient model constitute; The aforementioned transverse positive temperature gradient model As shown in equation (1): In equation (1), This represents the positive temperature gradient at the sunny side, in °C. denoted as the representative value of the positive temperature gradient on the shaded side, in °C; x represents the distance between the transverse position of the asymmetric wingless steel box girder bridge section and the sunny side; and L represents the width of the asymmetric wingless steel box girder bridge. The design service life of an asymmetric, wingless steel box girder bridge is given in years, and the value can be 100, 150, or 200. for The inverse function of a function for The inverse function of a function Let be the distribution function of the representative value of the positive temperature gradient at the sunny side. Let be the distribution function of the representative value of the positive temperature gradient at the shaded side. , , , , As an intermediate variable; The aforementioned transverse negative temperature gradient model As shown in equation (2): In equation (2), Distance from the sun The negative temperature gradient at the location is represented by the value in °C. Distance from the shady side The negative temperature gradient at the location is represented by the value in °C, x represents any transverse position of the cross-section of the asymmetric wingless steel box girder bridge, and L represents the width of the asymmetric wingless steel box girder bridge. for The inverse function of a function for The inverse function of a function Let be the distribution function representing the negative temperature gradient at the sunny side. Let be the distribution function representing the negative temperature gradient at the shaded side. , , , It is an intermediate variable.

2. The transverse temperature gradient model for an asymmetric, wingless steel box girder bridge according to claim 1, characterized in that: In equation (1), the stated The value is [14.34, 18.85]. The value range is [2.04, 3.52]. The value range is [9.60, 12.00]. The value of is [2.52, 4.28]. In equation (2), the value of is... The value range is [5.66, 6.26]. The value of is [5.52, 9.29]. The value range is [6.36, 6.95]. The value is [6.42, 10.63].

3. The transverse temperature gradient model for an asymmetric, wingless steel box girder bridge according to claim 1, characterized in that: In equation (1), the stated , , , , The value can be: For 100 years, It is 16.

44. It is 2.

68. It is 10.

74. It is 3.

28.

4. The transverse temperature gradient model for an asymmetric, wingless steel box girder bridge according to claim 1, characterized in that: In equation (2), the stated , , , , The value can be: For 100 years, It is 5.

95. It is 7.

16. It is 6.

65. It is 8.26.

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