Abstract: Spatial and temporal temperature variations are critical for concrete box girders, and non-uniform temperature distributions induced by solar radiation depend on the structural shapes and shadows cast on them. There have been many studies of temperature distributions and temperature gradients of concrete box girders, but few have considered a high altitude plateau climatic environment. In this study, the nonlinear temperature distributions of concrete box girders in the Sichuan-Tibet railway caused by solar radiation were investigated based on experimental analysis, real-time shadow-selection algorithm, and finite element method. Furthermore, a vertical temperature gradient model of the concrete box girders was obtained. The vertical temperature gradient values first rise, then decrease, and finally rise again from Chengdu to Lhasa, with samples forming a normal distribution. The recommended vertical temperature gradient value was 25 °C with a confidence interval of 95%. This provides a reference for the design and maintenance of concrete box girders on the Sichuan-Tibet railway.

川藏铁路太阳辐射致混凝土箱梁温度梯度统计研究

[1]AbidSR, TayşiN, ÖzakçaM, 2016. Experimental analysis of temperature gradients in concrete box-girders. Construction and Building Materials, 106:523-532.

[2]AbidSR, MussaF, TayşiN, et al., 2018. Experimental and finite element investigation of temperature distributions in concrete-encased steel girders. Structural Control and Health Monitoring, 25(1):e2042.

[3]BourgesB, 1985. Improvement in solar declination computation. Solar Energy, 35(4):367-369.

[4]ChenB, SunYZ, WangGJ, et al., 2014. Assessment on time-varying thermal loading of engineering structures based on a new solar radiation model. Mathematical Problems in Engineering, 2014:639867.

[5]DilgerWH, GhaliA, ChanM, et al., 1983. Temperature stresses in composite box girder bridges. Journal of Structural Engineering, 109(6):1460-1478.

[6]DuffieJA, BeckmanWA, 1991. Solar Energy of Thermal Process, 2nd Edition. John Wiley & Sons, New York, USA.

[7]HanuszZ, TarasińskaJ, 2015. Normalization of the Kolmogorov-Smirnov and Shapiro-Wilk tests of normality. Biometrical Letters, 52(2):85-93.

[8]KimSH, ChoKI, WonJH, et al., 2009. A study on thermal behaviour of curved steel box girder bridges considering solar radiation. Archives of Civil and Mechanical Engineering, 9(3):59-76.

[9]LiuJ, LiuYJ, ZhangGJ, et al., 2020a. Prediction formula for temperature gradient of concrete-filled steel tubular member with an arbitrary inclination. Journal of Bridge Engineering, 25(10):04020076.

[10]LiuJ, LiuYJ, BaiYX, et al., 2020b. Regional variation and zoning of temperature gradient pattern of concrete box girder. China Journal of Highway and Transport, 33(3):73-84 (in Chinese).

[11]LouP, ZhuJP, DaiGL, et al., 2018. Experimental study on bridge-track system temperature actions for Chinese high-speed railway. Archives of Civil and Mechanical Engineering, 18(2):451-464.

[12]LuCF, CaiCX, 2019. Challenges and countermeasures for construction safety during the Sichuan-Tibet railway project. Engineering, 5(5):833-838.

[13]MaWQ, MaYM, SuB, 2011. Feasibility of retrieving land surface heat fluxes from ASTER data using SEBS: a case study from the Namco area of the Tibetan plateau. Arctic, Antarctic, and Alpine Research, 43(2):239-245.

[14]MengQL, ZhuJS, 2018. Fine temperature effect analysis-based time-varying dynamic properties evaluation of long-span suspension bridges in natural environments. Journal of Bridge Engineering, 23(10):04018075.

[15]MOT (Ministry of Transport of the People’s Republic of China), 2015. General Specifications for Design of Highway Bridges and Culverts, JTG D60-2015. MOT, Beijing, China(in Chinese).

[16]NiuFJ, XuJ, LinZJ, et al., 2008. Permafrost characteristics of the Qinghai-Tibet plateau and methods of roadbed construction of railway. Acta Geologica Sinica, 82(5):949-958.

[17]NMIC (National Meteorological Information Center), 2021. Daily Meteorological Dataset of Basic Meteorological Elements of China National Surface Weather Station (V3.0). NMIC, Beijing, China(in Chinese).

[18]NRA (National Railway Administration of the People‍‍’‍‍‍s Republic of China), 2017. Code for Design of Concrete Structures of Railway Bridge and Culvert, TB 10092-201NRA, Beijing, China(in Chinese).

[19]RazaliNM, WahYB, 2011. Power comparisons of Shapiro-Wilk, Kolmogorov-Smirnov, Lilliefors and Anderson-Darling tests. Journal of Statistical Modeling and Analytics, 2(1):21-33.

[20]RoystonP, 1992. Approximating the Shapiro-Wilk W-test for non-normality. Statistics and Computing, 2(3):117-119.

[21]ShengXW, ZhengWQ, ZhuZH, et al., 2019. Solar radiation time-varying temperature field and temperature effect on small radius curved rigid frame box girder bridge. Journal of Traffic and Transportation Engineering, 19(4):24-34 (in Chinese).

[22]ShengXW, YangY, ZhengWQ, et al., 2020a. Study on the time-varying temperature field of small radius curved concrete box girder bridges. AIP Advances, 10(10):105013.

[23]ShengXW, ZhengYH, ZhengWQ, et al., 2020b. Vertical temperature gradient model of concrete box girders based on real-time shadow technology. Journal of South China University of Technology (Natural Science Edition), 48(10):40-47 (in Chinese).

[24]SongL, LiuHB, CuiCX, et al., 2020. Thermal deformation and interfacial separation of a CRTS II slab ballastless track multilayer structure used in high-speed railways based on meteorological data. Construction and Building Materials, 237:117528.

[25]SongZW, XiaoJZ, ShenLM, 2012. On temperature gradients in high-performance concrete box girder under solar radiation. Advances in Structural Engineering, 15(3):399-415.

[26]TanWD, GanFF, ChangTC, 2004. Using normal quantile plot to select an appropriate transformation to achieve normality. Computational Statistics & Data Analysis, 45(3):609-619.

[27]TayşiN, AbidS, 2015. Temperature distributions and variations in concrete box-girder bridges: experimental and finite element parametric studies. Advances in Structural Engineering, 18(4):469-486.

[28]TongM, ThamLG, AuFTK, 2002. Extreme thermal loading on steel bridges in tropical region. Journal of Bridge Engineering, 7(6):357-366.

[29]WangLM, 2013. Research on Thermal Diffusion Process of Asphlat Paving and Mix Improvement at Low Temperature. PhD Thesis, Harbin Institute of Technology, Harbin, China(in Chinese).

[30]XueYG, KongFM, LiSC, et al., 2021. China starts the world’s hardest “Sky-High Road” project: challenges and countermeasures for Sichuan-Tibet railway. The Innovation, 2(2):‍‍100105.

[31]ZengZP, HuangZB, YinHT, et al., 2018. Influence of track line environment on the temperature field of a double-block ballastless track slab. Advances in Mechanical Engineering, 10(12):‍1-16.

[32]ZhangCY, LiuYJ, LiuJ, et al., 2020. Validation of long-term temperature simulations in a steel-concrete composite girder. Structures, 27:1962-1976.

[33]ZhouGD, YiTH, 2013. Thermal load in large-scale bridges: a state-of-the-art review. International Journal of Distributed Sensor Networks, 9(12):217983.

[34]ZhouGD, YiTH, ChenB, et al., 2015. Analysis of three-dimensional thermal gradients for arch bridge girders using long-term monitoring data. Smart Structures and Systems, 15(2):469-488.