Transverse temperature gradient model of double-layer steel truss girder bridge

Abstract

The invention discloses a transverse temperature gradient model of a double-layer steel truss girder bridge. The transverse temperature gradient model of the double-layer steel truss girder bridge consists of an upper-layer bridge floor and chord member transverse positive temperature gradient model, an upper-layer bridge floor and chord member transverse negative temperature gradient model, a lower-layer bridge floor and chord member transverse positive temperature gradient model and a lower-layer bridge floor and chord member transverse negative temperature gradient model. According to the method, long-term monitoring data of a temperature field of the double-layer truss girder bridge are utilized, temperature field distribution characteristics are analyzed, statistical analysis and least square fitting are performed on transverse daily extreme temperature differences of upper and lower bridge surfaces and chord member sections of the double-layer truss girder bridge, and transverse temperature gradient models suitable for 100-year, 150-year and 200-year design service lives of the double-layer steel truss girder bridge are constructed. The method can be used for calculating transverse temperature stress of a double-layer steel truss girder bridge system and a local structure.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering, and in particular relates to a transverse temperature gradient model of a double-layer steel truss bridge. Background Art

[0002] Double-deck steel truss bridge is a complex structural system, which consists of upper deck, lower deck and main truss. Solar radiation will form a transverse temperature gradient inside the double-deck steel truss bridge structure. Under the action of transverse temperature gradient, the objective local frame effect and overall frame effect of the double-deck truss bridge will lead to large transverse temperature secondary stress, and the nonlinear part in the transverse temperature gradient will cause transverse temperature self-stress. Studies have shown that the temperature distribution forms of the upper and lower decks and chords of double-deck truss bridges are significantly different, and the generated temperature stress fields are also different. Therefore, it is necessary to carry out long-term monitoring of the transverse temperature field of each structure of the double-deck truss, use the long-term monitoring data of the temperature field to analyze the distribution characteristics of the temperature field of the double-deck steel truss, perform statistical analysis and least squares fitting on the transverse daily extreme temperature difference of the upper and lower decks and chord sections of the double-deck truss bridge, construct a transverse temperature gradient model suitable for the design service life of 100 years, 150 years and 200 years of double-deck steel truss bridge, and calculate the transverse temperature stress of the double-deck steel truss bridge system and local structure. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a transverse temperature gradient model of a double-layer steel truss bridge.

[0004] The above-mentioned transverse temperature gradient model of the double-deck steel truss bridge is composed of a transverse positive temperature gradient model of the upper deck and chord, a transverse negative temperature gradient model of the upper deck and chord, a transverse positive temperature gradient model of the lower deck and chord, and a transverse negative temperature gradient model of the lower deck and chord;

[0005] The positive temperature gradient model T of the upper deck and chord of the double-deck steel truss bridge TP (x1) is as shown in formula (1):

[0006]

[0007] In formula (1), T TP1 is the representative value of the positive temperature gradient at 0.84B1 from the upper bridge deck and the positive side of the chord, T TP2 is the representative value of the positive temperature gradient on the upper deck and the dark side of the chord, is the initial value of the positive temperature gradient at 0.84B1 from the upper bridge deck and the positive side of the chord, is the initial value of the positive temperature gradient on the negative side of the upper deck and chord, x1 is the distance between the upper deck and chord and the positive side, B1 is the width of the upper deck and chord, Ν dIt is the design service life of double-deck steel truss bridge, with a range of 100, 150 and 200, in years. F TP1 (α) is the inverse function of the function, F TP2 (α) The inverse function, F TP1 (α) is the distribution function of the initial value of the positive temperature gradient at 0.84B1 from the upper bridge deck and the positive side of the chord, F TP2 (α) is the distribution function of the initial value of the positive temperature gradient on the upper deck and the negative side of the chord, α, μ TP1 , σ TP1 , μ TP2 , σ TP2 is an intermediate variable;

[0008] The upper deck and chord transverse negative temperature gradient model T of the double-deck steel truss bridge TN (x1) is shown in formula (2):

[0009]

[0010] In formula (2), T TN1 is the representative value of negative temperature gradient at 0.5B1 from the upper bridge deck and the positive side of the chord, T TN2 is the representative value of negative temperature gradient on the upper deck and the dark side of the chord, is the initial value of the negative temperature gradient at 0.5B1 from the upper bridge deck and the positive side of the chord, is the initial value of negative temperature gradient on the upper deck and the dark side of the chord, F TN1 (α) is the inverse function of the function, F TN2 (α) The inverse function, F TN1 (α) is the distribution function of the negative temperature gradient at 0.5B1 from the upper bridge deck and the positive side of the chord, F TN2 (α) is the distribution function of the negative temperature gradient at the upper bridge deck and the dark side of the chord, μ TN1 , σ TN1 , μ TN2 , σ TN2 is an intermediate variable;

[0011] The positive temperature gradient model T of the lower deck and chord of the double-deck steel truss bridge BP (x2) is shown in formula (3):

[0012]

[0013] In formula (3), T BP1 is the representative value of the positive temperature gradient at 0.5B2 from the lower deck and the positive side of the chord, TBP2 is the representative value of the positive temperature gradient on the lower deck and the dark side of the chord, is the initial value of the positive temperature gradient at 0.5B2 from the lower deck and the positive side of the chord, is the initial value of the positive temperature gradient on the negative side of the lower deck and chord, x2 is the position at any width of the lower deck and chord section, B2 is the width of the lower deck and chord beam, F BP1 (α) is the inverse function of the function, F BP2 (α) The inverse function, F BP1 (α) is the distribution function of the initial value of the positive temperature gradient at 0.5B2 away from the lower deck and the positive side of the chord, F BP2 (α) is the distribution function of the initial value of the positive temperature gradient on the lower deck and the dark side of the chord, μ BP1 , σ BP1 , μ BP2 , σ BP2 is an intermediate variable;

[0014] The negative temperature gradient model T for the lower deck and chord of the double-deck steel truss bridge BN (x2) is shown in formula (4):

[0015]

[0016] In formula (4), T BN1 is the representative value of negative temperature gradient at 0.1B2 from the lower deck and the positive side of the chord, T BN2 is the representative value of negative temperature gradient on the lower deck and the dark side of the chord, is the initial value of the negative temperature gradient at 0.1B2 from the lower deck and the positive side of the chord, is the initial value of negative temperature gradient at the lower deck and the east side of the chord, F BN1 (α) is the inverse function of the function, F BN2 (α) The inverse function, F BN1 (α) is the distribution function of the negative temperature gradient at 0.1B2 away from the lower deck and the positive side of the chord, F BN2 (α) is the distribution function of the negative temperature gradient on the lower deck and the dark side of the chord, μ BN1 , σ BN1 , μ BN2 , σ BN2 is an intermediate variable.

[0017] In formula (1) of the present invention, the μ TP1 The value of is [1.26,1.36], σ TP1 The value of is [5.20,5.28], μTP2 The value of is [2.56,4.46], σ TP2 The value of is [3.45,5.58]. In formula (2), the μ TN1 The value of is [-3.10, 0.02], σ TN1 The value of is [1.0,2.2], μ TN1 The value of is [-1.73,-0.64], σ TN2 The value of is [0.56,2.41]. In formula (3), the μ BP1 The value of is [0.48,2.45], σ BP1 The value of is [1.87,2.92], μ BP2 The value of is [0.52,2.03], σ BP2 The value of is [1.13,3.17]. In formula (4), the μ BN1 The value of is [-2.45,-0.49], σ BN1 The value of is [1.87,2.92], μ BN2 The value of is [-2.30,-0.83], σ BN2 The value of is [1.13,3.17].

[0018] In formula (1) of the present invention, the μ TP1 , σ TP1 , μ TP2 , σ TP2 The best value of is: TP1 The best value is 1.31, σ TP1 The best is 5.24, μ TP2 The best is 3.80, and the best σ TP2 is 4.26.

[0019] In formula (2) of the present invention, the μ TN1 , σ TN1 , μ TN2 , σ TN2 The best value of is: TN1 is -1.95, σ TN1 The best is 1.83, μ TN2 The best value is -1.10, σ TN2 The best is 1.58.

[0020] In formula (3) of the present invention, the μ BP1 , σ BP1 , μ BP2 , σ BP2 The value of is: BP1 The best value is 1.52, σ BP1 The best is 2.23, μ BP2The best value is 1.01, σ BP2 The best is 1.57.

[0021] In formula (4) of the present invention, the μ BN1 , σ BN1 , μ BN2 , σ BN2 The value of is: BN1 The best is -1.33, σ BN1 The best is 2.12, μ BN2 The best is -1.52, σ BN2 The best is 2.23.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The present invention obtains the standard value of the lateral temperature difference between the upper and lower decks and the chord of the double-layer steel truss bridge within different design service lives by analyzing the long-term monitoring data of the temperature field of the double-layer steel truss bridge, and constructs a lateral temperature gradient model of the double-layer steel truss bridge using the least squares method. The model can calculate the additional stress and deformation caused by the lateral temperature gradient of the double-layer steel truss bridge during the operation stage, and can be used for the design of double-layer steel truss bridges with design service lives of 100, 150 and 200 years. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a three-dimensional structural diagram of the double-deck steel truss bridge in the present invention.

[0025] Figure 2 It is a distribution diagram of the temperature representative values ​​of the transverse positive temperature gradient model of the upper deck and chord of the double-deck steel truss bridge in the present invention.

[0026] Figure 3 It is a distribution diagram of the temperature representative values ​​of the transverse negative temperature gradient model of the upper deck and chord of the double-deck steel truss bridge in the present invention.

[0027] Figure 4 It is a distribution diagram of the temperature representative values ​​of the transverse positive temperature gradient model of the lower deck and chord of the double-deck steel truss bridge in the present invention.

[0028] Figure 5 It is a distribution diagram of the temperature representative values ​​of the transverse negative temperature gradient model of the lower deck and chord of the double-deck steel truss bridge in the present invention.

[0029] Figure 6 This is a diagram showing the arrangement of temperature measurement points for the upper deck and chord of the double-deck steel truss bridge in the present invention.

[0030] Figure 7 This is a diagram showing the arrangement of temperature measurement points for the lower deck and chord of the double-deck steel truss bridge in the present invention.

[0031] Figure 8It is the temperature history curve at the measuring points of the upper bridge deck and the chord in the present invention.

[0032] Fig. 9 It is the temperature history curve at the measuring points of the lower bridge deck and the chord in the present invention.

[0033] Fig.10 The upper bridge deck and chord T of the present invention TP1 Probability density histogram of temperature difference at .

[0034] Fig.11 The upper bridge deck and chord T of the present invention TP2 Probability density histogram of temperature difference at .

[0035] Fig.12 The lower deck and chord T of the present invention are TN1 Probability density histogram of temperature difference at .

[0036] Fig.13 The lower bridge deck and chord T of the present invention TN2 Probability density histogram of temperature difference at . DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and examples, but the present invention is not limited to the following embodiments.

[0038] Example 1

[0039] The transverse temperature gradient model of a double-deck steel truss bridge involved in this embodiment is composed of a transverse positive temperature gradient model of an upper bridge deck and a chord, a transverse negative temperature gradient model of an upper bridge deck and a chord, a transverse positive temperature gradient model of a lower bridge deck and a chord, and a transverse negative temperature gradient model of a lower bridge deck and a chord.

[0040] The positive temperature gradient model T of the upper deck and chord of the double-deck steel truss bridge in this embodiment TP (x1) is as shown in formula (1):

[0041]

[0042] In formula (1), T TP1 is the representative value of the positive temperature gradient at 0.84B1 from the upper bridge deck and the positive side of the chord, T TP2 is the representative value of the positive temperature gradient on the upper deck and the dark side of the chord, is the initial value of the positive temperature gradient at 0.84B1 from the upper bridge deck and the positive side of the chord, is the initial value of the positive temperature gradient on the negative side of the upper deck and chord, x1 is the distance between the upper deck and chord and the positive side, B1 is the width of the upper deck and chord, Ν dIt is the design service life of double-deck steel truss bridge, with a range of 100, 150 and 200, in years. F TP1 (α) is the inverse function of the function, F TP2 (α) The inverse function, F TP1 (α) is the distribution function of the initial value of the positive temperature gradient at 0.84B1 from the upper bridge deck and the positive side of the chord, F TP2 (α) is the distribution function of the initial value of the positive temperature gradient on the upper deck and the negative side of the chord, α, μ TP1 , σ TP1 , μ TP2 , σ TP2 is an intermediate variable.

[0043] The upper deck and chord transverse negative temperature gradient model T of the double-deck steel truss bridge in this embodiment TN (x1) is shown in formula (2):

[0044]

[0045] In formula (2), T TN1 is the representative value of negative temperature gradient at 0.5B1 from the upper bridge deck and the positive side of the chord, T TN2 is the representative value of negative temperature gradient on the upper deck and the dark side of the chord, is the initial value of the negative temperature gradient at 0.5B1 from the upper bridge deck and the positive side of the chord, is the initial value of negative temperature gradient on the upper deck and the dark side of the chord, F TN1 (α) is the inverse function of the function, F TN2 (α) The inverse function, F TN1 (α) is the distribution function of the negative temperature gradient at 0.5B1 from the upper bridge deck and the positive side of the chord, F TN2 (α) is the distribution function of the negative temperature gradient at the upper bridge deck and the dark side of the chord, μ TN1 , σ TN1 , μ TN2 , σ TN2 is an intermediate variable.

[0046] The positive temperature gradient model T of the lower deck and chord of the double-deck steel truss bridge in this embodiment BP (x2) is shown in formula (3):

[0047]

[0048] In formula (3), T BP1 is the representative value of the positive temperature gradient at 0.5B2 from the lower deck and the positive side of the chord, TBP2 is the representative value of the positive temperature gradient on the lower deck and the dark side of the chord, is the initial value of the positive temperature gradient at 0.5B2 from the lower deck and the positive side of the chord, is the initial value of the positive temperature gradient on the negative side of the lower deck and chord, x2 is the position at any width of the lower deck and chord section, B2 is the width of the lower deck and chord beam, F BP1 (α) is the inverse function of the function, F BP2 (α) The inverse function, F BP1 (α) is the distribution function of the initial value of the positive temperature gradient at 0.5B2 away from the lower deck and the positive side of the chord, F BP2 (α) is the distribution function of the initial value of the positive temperature gradient on the lower deck and the dark side of the chord, μ BP1 , σ BP1 , μ BP2 , σ BP2 is an intermediate variable.

[0049] The negative temperature gradient model T of the lower deck and chord of the double-deck steel truss bridge in this embodiment BN (x2) is shown in formula (4):

[0050]

[0051] In formula (4), T BN1 is the representative value of negative temperature gradient at 0.1B2 from the lower deck and the positive side of the chord, T BN2 is the representative value of negative temperature gradient on the lower deck and the dark side of the chord, is the initial value of the negative temperature gradient at 0.1B2 from the lower deck and the positive side of the chord, is the initial value of negative temperature gradient at the lower deck and the east side of the chord, F BN1 (α) is the inverse function of the function, F BN2 (α) The inverse function, F BN1 (α) is the distribution function of the negative temperature gradient at 0.1B2 away from the lower deck and the positive side of the chord, F BN2 (α) is the distribution function of the negative temperature gradient on the lower deck and the dark side of the chord, μ BN1 , σ BN1 , μ BN2 , σ BN2 is an intermediate variable.

[0052] In this embodiment, a double-deck steel truss bridge in Northwest China is taken as an example. Its three-dimensional structure is as follows: Figure 1 As shown in formula (1), μ TP1 is 1.31, σTP1 is 5.24, μ TP2 is 3.80, σ TP2 =4.26, and the corresponding transverse positive temperature gradient model of the upper deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​in the transverse positive temperature gradient model corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 1. The temperature representative values ​​of the transverse positive temperature gradient model of the upper deck and chord are shown in Figure 2 shown.

[0053] Table 1 Representative values ​​of the temperature of the upper deck and chord transverse positive temperature gradient model

[0054]

[0055] In formula (2), μ TN1 is -1.95, σ TN1 is 1.83, μ TN2 is -1.10, σ TN2 =1.58, and the corresponding transverse negative temperature gradient model of the upper deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​in the transverse negative temperature gradient model corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 2. The temperature representative values ​​of the transverse negative temperature gradient model of the upper deck and chord are shown in Figure 3 shown.

[0056] Table 2 Representative values ​​of the temperature of the upper deck and chord transverse negative temperature gradient model

[0057]

[0058] In formula (3), μ BP1 is 1.52, σ BP1 is 2.23, μ BP2 is 1.01, σ BP2 =1.57, and the corresponding transverse positive temperature gradient model of the lower deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​of the transverse positive temperature gradient model of the lower deck and chord corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 3. The temperature representative values ​​of the transverse positive temperature gradient model of the lower deck and chord are shown in Table 3. Figure 4 shown.

[0059] Table 3 Representative values ​​of the temperature of the lower deck and chord transverse positive temperature gradient model

[0060]

[0061] In formula (4), μ BN1 is -1.33, σ BN1 is 2.12, μ BN2is -1.52, σ BN2 =2.23, and the corresponding negative temperature gradient model of the lower deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The representative values ​​of the temperature in the negative temperature gradient model of the lower deck and chord corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 4. The representative values ​​of the temperature in the positive temperature gradient model of the lower deck and chord are shown in Table 4. Figure 5 shown.

[0062] Table 4 Representative values ​​of the temperature of the lower deck and chord transverse negative temperature gradient model

[0063]

[0064] Example 2

[0065] The expression of the transverse temperature gradient model of the double-deck steel truss bridge involved in this embodiment is the same as that in Embodiment 1, but the temperature representative value is different.

[0066] In this embodiment, a double-deck steel truss bridge is taken as an example, and its three-dimensional structure is as follows: Figure 1 As shown in formula (1), μ TP1 is 1.26, σ TP1 is 5.20, μ TP2 is 2.56, σ TP2 =3.45, and the corresponding transverse positive temperature gradient model of the upper deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​in the transverse positive temperature gradient model corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 5. The distribution of the temperature representative values ​​of the transverse positive temperature gradient model of the upper deck and chord is shown in Figure 2 shown.

[0067] Table 5 Representative values ​​of the upper deck and chord transverse positive temperature gradient model temperature

[0068]

[0069] In formula (2), μ TN1 is -3.10, σ TN1 =1.0, μ TN2 is -1.73, σ TN2 =0.56, and the corresponding transverse negative temperature gradient model of the upper deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​in the transverse negative temperature gradient model corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 6. The distribution of the temperature representative values ​​of the transverse negative temperature gradient model of the upper deck and chord is shown in Figure 3 shown.

[0070] Table 6 Representative values ​​of the temperature of the upper deck and chord transverse negative temperature gradient model

[0071]

[0072] In formula (3), μ BP1 is 0.48, σ BP1 is 1.87, μ BP2 is 0.52, σ BP2 =1.13, and the corresponding transverse positive temperature gradient model of the lower deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​of the transverse positive temperature gradient model of the lower deck and chord corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 7. The distribution of the temperature representative values ​​of the transverse positive temperature gradient model of the lower deck and chord is shown in Figure 4 shown.

[0073] Table 7 Representative values ​​of the temperature of the lower deck and chord transverse positive temperature gradient model

[0074]

[0075] In formula (4), μ BN1 is -2.45, σ BN1 is 1.87, μ BN2 is -2.30, σ BN2 =1.13, and the corresponding negative temperature gradient model of the lower deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The representative values ​​of the temperature in the negative temperature gradient model of the lower deck and chord corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 8. The representative values ​​of the temperature in the positive temperature gradient model of the lower deck and chord are shown in Table 8. Figure 5 shown.

[0076] Table 8 Representative values ​​of the temperature of the lower deck and chord transverse negative temperature gradient model

[0077]

[0078] Example 3

[0079] The transverse temperature gradient model of the double-deck steel truss bridge of this embodiment is the same as that of Embodiment 1, but the temperature representative values ​​are different.

[0080] In this embodiment, a double-deck steel truss bridge is taken as an example, and its three-dimensional structure is as follows: Figure 1 As shown in formula (1), μ TP1 is 1.36, σ TP1 is 5.28, μ TP2 is 4.46, σ TP2=5.58, and the corresponding transverse positive temperature gradient model of the upper deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​in the transverse positive temperature gradient model corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 9. The temperature representative values ​​of the transverse positive temperature gradient model of the upper deck and chord are shown in Table 9. Figure 2 shown.

[0081] Table 9 Representative values ​​of the upper deck and chord transverse positive temperature gradient model temperature

[0082]

[0083] In formula (2), μ TN1 is 0.02, σ TN1 is 2.20, μ TN2 is -0.64, σ TN2 =2.41, and the corresponding transverse negative temperature gradient model of the upper deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​in the transverse negative temperature gradient model corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 10. The temperature representative values ​​of the transverse negative temperature gradient model of the upper deck and chord are shown in Figure 3 shown.

[0084] Table 10 Representative values ​​of the upper deck and chord transverse negative temperature gradient model temperature

[0085]

[0086] In formula (3), μ BP1 is 2.45, σ BP1 is 2.92, μ BP2 is 2.03, σ BP2 =3.17, and the corresponding transverse positive temperature gradient model of the lower deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​of the transverse positive temperature gradient model of the lower deck and chord corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 11. The temperature representative values ​​of the transverse positive temperature gradient model of the lower deck and chord are shown in Figure 4 shown.

[0087] Table 11 Representative values ​​of the temperature of the lower deck and chord transverse positive temperature gradient model

[0088]

[0089] In formula (4), μ BN1 is -0.49, σ BN1 is 2.92, μ BN2 is -0.83, σ BN2=3.17, and the corresponding transverse negative temperature gradient model of the lower deck and chord of the double-deck steel truss bridge is constructed according to this parameter. The temperature representative values ​​of the transverse negative temperature gradient model of the lower deck and chord corresponding to the design service life of 100 years, 150 years, and 200 years are shown in Table 12. The temperature representative values ​​of the transverse negative temperature gradient model of the lower deck and chord are distributed as shown in Figure 5 shown.

[0090] Table 12 Representative values ​​of the model temperature of the negative temperature gradient in the lower deck and chord

[0091]

[0092] Test 1

[0093] In order to verify the effect of the transverse positive temperature gradient model of the upper and lower decks and chords of a double-deck steel truss bridge, the inventors arranged temperature sensors on the upper and lower decks and chords of the Weihe Bridge in Baqiao District, Xi'an, and conducted long-term temperature field monitoring. The specific construction process is as follows:

[0094] 1. Long-term monitoring equipment

[0095] The monitoring equipment is the Jingming JM3813 temperature acquisition instrument (60 channels) produced in Yangzhou, Jiangsu, and the temperature measurement points use three-wire Pt100 sensors.

[0096] 2. Temperature measurement point arrangement

[0097] The upper and lower decks and chords of the double-deck steel truss bridge are selected to arrange temperature measuring points, and the coordinate system is established with the upper and lower sunny sides of the double-deck truss bridge as the coordinate origin. The temperature measuring points are arranged on the upper deck and chord of the double-deck steel truss bridge. The distances from each measuring point on the upper deck and the chord to the sunny side are 0.00m, 1.20m, 5.05m, 15.85m, 26.65m, 30.50m, and 31.70m, respectively, recorded as TH1~TH7, and the distances from each measuring point on the lower deck and the chord to the sunny side are 0.00m, 1.20m, 5.20m, 15.85m, 30.50m, and 31.70m, respectively, recorded as BH1~BH6. The measuring point arrangement scheme is as follows Figure 6 and Figure 7 As shown, the acquisition interval is 5 minutes.

[0098] 3. Analysis of the effect of the transverse positive temperature gradient load model

[0099] The T TP1 、T TP2 The position and the transverse positive temperature gradient model of the lower deck and chord are T BP1 、T BP2 Taking the location as an example, the temperature history curve of the measuring point is drawn based on the actual temperature monitoring data, such as Figure 8and Fig. 9 As shown. Calculate T TP1 、T TP2 、T BP1 、T BP2 The temperature difference between the position and the position with the lowest average temperature of the corresponding cross-sectional measuring point is plotted based on the data and the probability density function is fitted, as shown in Fig.10 , Fig.11 , Fig.12 and Fig.13 As shown. The 99% guarantee rate in the probability density function is taken as the value, and the obtained T TP1 、T TP2 、T BP1 、T BP2 The representative values ​​of temperature gradients at the locations are 19.7℃, 10.2℃, 11.0℃, and 11.2℃, respectively.

[0100] The temperature gradient model corresponding to the 100-year design service life is constructed by using the transverse positive temperature gradient model of the upper deck and chord of the double-deck steel truss bridge and the transverse positive temperature gradient model of the lower deck and chord. TP1 is 1.31, σ TP1 is 5.24, μ TP2 is 3.80, σ TP2 is 4.26, μ BP1 is 1.52, σ BP1 is 2.23, μ BP2 is 1.01, σ BP2 is 1.57, and T TP1 、T TP2 、T BP1 、T BP2 The results are 19.9℃, 10.7℃, 11.2℃ and 12.0℃, which are slightly different from the measured results. This experiment shows that the transverse positive temperature gradient model of double-deck steel truss bridge has good applicability.

Claims

1. A transverse temperature gradient model for a double-deck steel truss bridge, characterized by: The transverse temperature gradient model of the double-deck steel truss bridge consists of a transverse positive temperature gradient model of the upper deck and chord, a transverse negative temperature gradient model of the upper deck and chord, a transverse positive temperature gradient model of the lower deck and chord, and a transverse negative temperature gradient model of the lower deck and chord. The positive temperature gradient model T of the upper deck and chord of the double-deck steel truss bridge TP (x1) is shown in formula (1): In formula (1), T TP1 is the representative value of the positive temperature gradient at 0.84B1 from the upper bridge deck and the positive side of the chord, T TP2 is the representative value of the positive temperature gradient on the upper deck and the dark side of the chord, is the initial value of the positive temperature gradient at 0.84B1 from the upper bridge deck and the positive side of the chord, is the initial value of the positive temperature gradient on the negative side of the upper deck and chord, x1 is the distance between the upper deck and chord and the positive side, B1 is the width of the upper deck and chord, Ν d It is the design service life of double-deck steel truss bridge, with a range of 100, 150 and 200, in years. F TP1 (α) is the inverse function of the function, F TP2 (α) The inverse function, F TP1 (α) is the distribution function of the initial value of the positive temperature gradient at 0.84B1 from the upper bridge deck and the positive side of the chord, F TP2 (α) is the distribution function of the initial value of the positive temperature gradient on the upper deck and the negative side of the chord, α, μ TP1 , σ TP1 , μ TP2 , σ TP2 is an intermediate variable; The upper deck and chord transverse negative temperature gradient model T of the double-deck steel truss bridge TN (x1) is shown in formula (2): In formula (2), T TN1 is the representative value of negative temperature gradient at 0.5B1 from the upper bridge deck and the positive side of the chord, T TN2 is the representative value of negative temperature gradient on the upper deck and the dark side of the chord, is the initial value of the negative temperature gradient at 0.5B1 from the upper bridge deck and the positive side of the chord, is the initial value of negative temperature gradient on the upper deck and the dark side of the chord, F TN1 (α) is the inverse function of the function, F TN2 (α) The inverse function, F TN1 (α) is the distribution function of the negative temperature gradient at 0.5B1 from the upper bridge deck and the positive side of the chord, F TN2 (α) is the distribution function of the negative temperature gradient at the upper bridge deck and the dark side of the chord, μ TN1 , σ TN1 , μ TN2 , σ TN2 is an intermediate variable; The positive temperature gradient model T of the lower deck and chord of the double-deck steel truss bridge BP (x2) is shown in formula (3): In formula (3), T BP1 is the representative value of the positive temperature gradient at 0.5B2 from the lower deck and the positive side of the chord, T BP2 is the representative value of the positive temperature gradient on the lower deck and the dark side of the chord, is the initial value of the positive temperature gradient at 0.5B2 from the lower deck and the positive side of the chord, is the initial value of the positive temperature gradient on the negative side of the lower deck and chord, x2 is the position of any width of the lower deck and chord section, B2 is the width of the lower deck and chord beam, F BP1 (α) is the inverse function of the function, F BP2 (α) The inverse function, F BP1 (α) is the distribution function of the initial value of the positive temperature gradient at 0.5B2 away from the lower deck and the positive side of the chord, F BP2 (α) is the distribution function of the initial value of the positive temperature gradient on the lower deck and the dark side of the chord, μ BP1 , σ BP1 , μ BP2 , σ BP2 is an intermediate variable; The transverse negative temperature gradient model T of the lower deck and chord of the double-deck steel truss bridge BN (x2) is shown in formula (4): In formula (4), T BN1 is the representative value of negative temperature gradient at 0.1B2 from the lower deck and the positive side of the chord, T BN2 is the representative value of negative temperature gradient on the lower deck and the dark side of the chord, is the initial value of the negative temperature gradient at 0.1B2 from the lower deck and the positive side of the chord, is the initial value of negative temperature gradient at the lower deck and the east side of the chord, F BN1 (α) is the inverse function of the function, F BN2 (α) The inverse function, F BN1 (α) is the distribution function of the negative temperature gradient at 0.1B2 away from the lower deck and the positive side of the chord, F BN2 (α) is the distribution function of the negative temperature gradient on the lower deck and the dark side of the chord, μ BN1 , σ BN1 , μ BN2 , σ BN2 is an intermediate variable.

2. The transverse temperature gradient model of a double-deck steel truss bridge according to claim 1 is characterized in that: In formula (1), the μ TP1 The value of is [1.26,1.36], σ TP1 The value of is [5.20,5.28], μ TP2 The value of is [2.56,4.46], σ TP2 The value of is [3.45,5.58]; in formula (2), the μ TN1 The value of is [-3.10, 0.02], σ TN1 The value of is [1.0,2.2], μ TN1 The value of is [-1.73,-0.64], σ TN2 The value of is [0.56,2.41]; in formula (3), the μ BP1 The value of is [0.48,2.45], σ BP1 The value of is [1.87,2.92], μ BP2 The value of is [0.52,2.03], σ BP2 The value of is [1.13,3.17]; in formula (4), the μ BN1 The value of is [-2.45,-0.49], σ BN1 The value of is [1.87,2.92], μ BN2 The value of is [-2.30,-0.83], σ BN2 The value of is [1.13,3.17].

3. The transverse temperature gradient model of a double-deck steel truss bridge according to claim 1 is characterized in that: In formula (1), the μ TP1 , σ TP1 , μ TP2 , σ TP2 The value of is: TP1 is 1.31, σ TP1 is 5.24, μ TP2 is 3.80, σ TP2 is 4.

26.

4. The transverse temperature gradient model of a double-deck steel truss bridge according to claim 1 is characterized in that: In formula (2), the μ TN1 , σ TN1 , μ TN2 , σ TN2 The value of is: TN1 is -1.95, σ TN1 is 1.83, μ TN2 is -1.10, σ TN2 It is 1.

58.

5. The transverse temperature gradient model of a double-deck steel truss bridge according to claim 1 is characterized in that: In formula (3), the μ BP1 , σ BP1 , μ BP2 , σ BP2 The value of is: BP1 is 1.52, σ BP1 is 2.23, μ BP2 is 1.01, σ BP2 is 1.

57.

6. The transverse temperature gradient model of a double-deck steel truss bridge according to claim 1 is characterized in that: In formula (4), the μ BN1 , σ BN1 , μ BN2 , σ BN2 The value of is: BN1 is -1.33, σ BN1 is 2.12, μ BN2 is -1.52, σ BN2 is 2.23.

Images