Experimental and Numerical Investigation of Temperature Gradient in "Jenah" Concrete Box-Girder Bridge

Document Type : Original Research

Authors
F. Raeesi 1
H. Veladi 2
A. Abbasnejad 3
1 Department of Civil Engineering, University of Tabriz, Tabriz, Iran.
2 Associate Professor at Tabriz Faculty of Civil Engineering, Tabriz, Iran
3 University of Tabriz
A-10-54191-1
Abstract
Air temperature variations due to daily, seasonal, and annual changes can affect the bridges. The deformation and stress caused under solar radiation should not neglected in bridge design and their effects can be compared with dead and live loads. Thus, the components of bridges such as bearings, dampers and so on, are seriously affected by the combination of external loads and thermal stress. Different countries have provided temperature gradients in their codes. Almost in all of the codes, the vertical temperature gradient is specified, but unfortunately in none of them, the lateral temperature gradient is presented. Furthermore, in the vertical gradient, there are numerous lacks exist in different codes. For an example, most of the codes do not involve either temperature variations due to annual changes, or not considered the longitude or latitude of the location of the designed bridges. These problems lead the engineers to do the precise study beside the codes provided by each country, for temperature effects on the bridge structures. This paper investigates the effect of vertical and lateral thermal gradient loads for concrete box girder designed based on Iranian Standard Loads for Bridge (ISLB) code, using experimental test and three-dimensional finite element analysis. The ISLB code has two main problems in the field of thermal gradients. Firstly, the vertical temperature gradient provided in ISLB code, cannot used for all bridges in Iran, because each bridge has its unique geographical environment, latitude, longitude, and axis of orientation. Secondly, it does not contain any models for the lateral temperature gradient. To handle these problems, the experimental test is done and thermocouples are installed in different parts of the segment to get the thermal gradients and investigate their effects. In the case of predicting vertical gradient, the recorded data show that, the maximum temperature difference occurs in 1430 hrs with the value of 8.8 °C , while by considering the lateral gradient, the maximum temperature difference occurs at 1130 hrs with the value of 2.9 °C . In this paper, comparison between vertical and lateral gradients leads to consider only vertical gradients in further investigations. Moreover, by applying vertical gradient in the finite element model of the Jenah bridge, maximum thermal stress is occurred in the intersection of the web and top flange with the value of 1.96 MPa and maximum deflection of 4.36 mm in the midspan of the bridge. As a solution for mitigating the negative effects of the thermal gradients, using polyurethane insulation is proposed and modeled in the FE model. Results of simulation reveal that utilizing insolation can reduce the top slab temperatures to 30.5 °C , 29.16 °C , 27.5 °C and 26.4 °C from 33.6 °C in the case of using 2, 3, 5 and 6mm polyurethane insulations, respectively, which results in stress reduction from 1.96 MPa to 1.65, 1.35, 0.63 and 0.38 MPa in the case of using 2, 3, 5 and 6 mm polyurethane insulations, respectively. Furthermore, using insulation can reduce the deflection of the bridge, which in this study, the maximum deflection of the 48 m span is reduced from 4.36mm to 3.57, 2.86, 1.63 and 1.07 mm, by utilizing 2, 3, 5 and 6 mm polyurethane insulations, respectively.

Keywords

Subjects

[1] Hossain T., Segura S., & Okeil A. M. 2020 Structural effects of temperature gradient on a continuous prestressed concrete girder bridge: analysis and field measurements. Structure and Infrastructure Engineering, 16(11), 1539-1550.
[2] Abid S. R., Abbass A. A., & Alhatmey I. A. 2019 Seasonal temperature gradient distributions in concrete bridge girders: A finite element study. In 2019 12th International Conference on Developments in eSystems Engineering (DeSE) (pp. 374-379). IEEE.
[3] Guo T., Liu J., Zhang Y., & Pan S. 2015 Displacement monitoring and analysis of expansion joints of long-span steel bridges with viscous dampers. Journal of Bridge Engineering, 20(9), 04014099.
[4] Saetta A., Scotta, R., & Vitaliani R. 1995 Stress analysis of concrete structures subjected to variable thermal loads. Journal of Structural Engineering, 121(3), 446-457.
[5] Roberts-Wollman C. L., Breen J. E., & Cawrse J. 2002 Measurements of thermal gradients and their effects on segmental concrete bridge. Journal of Bridge Engineering, 7(3), 166-174.
[6] Xia Y., Xu Y. L., Wei Z. L., Zhu H. P., & Zhou X. Q. 2011 Variation of structural vibration characteristics versus non-uniform temperature distribution. Engineering Structures, 33(1), 146-153.
[7] Standard Loads for Bridges (Number 139), Islamic Republic of Iran, Management and Planning Organization (In Persian).
[8] Cao Y., Yim J., Zhao Y., & Wang M. L. 2011 Temperature effects on cable stayed bridge using health monitoring system: a case study. Structural Health Monitoring, 10(5), 523-537.
[9] Westgate R., Koo K. Y., & Brownjohn J. 2015 Effect of solar radiation on suspension bridge performance. Journal of Bridge Engineering, 20(5), 04014077.
[10] Chen B., Ding R., Zheng J., & Zhang S. 2009 Field test on temperature field and thermal stress for prestressed concrete box-girder bridge. Frontiers of Architecture and Civil Engineering in China, 3(2), 158-164.
[11] Song X., Melhem H., Li J., Xu Q., & Cheng L. 2016 Effects of solar temperature gradient on long-span concrete box girder during cantilever construction. Journal of Bridge Engineering, 21(3), 04015061.
[12] Lei X., Jiang H., & Wang J. 2019 Temperature effects on horizontally curved concrete box-girder bridges with single-column piers. Journal of Aerospace Engineering, 32(3), 04019008.
[13] Laosiriphong K., GangaRao H. V., Prachasaree W., & Shekar V. 2006 Theoretical and experimental analysis of GFRP bridge deck under temperature gradient. Journal of Bridge Engineering, 11(4), 507-512.
[14] Peng Y. S. 2007 Studies on theory of solar radiation thermal effects on concrete bridges with application. Southwest Jiaotong Univ., Sichuan, China.
[15] Tayşi N., & Abid S. 2015 Temperature distributions and variations in concrete box-girder bridges: experimental and finite element parametric studies. Advances in structural engineering, 18(4), 469-486.
[16] He J., Xin, H., Wang Y., & Correia J. A. 2021 Effect of temperature loading on the performance of a prestressed concrete bridge in Oklahoma: Probabilistic modelling. Structures 34, 1429-1442.
[17] Xia Y., Chen B., Zhou X. Q., & Xu Y. L. 2013 Field monitoring and numerical analysis of Tsing Ma Suspension Bridge temperature behavior. Structural Control and Health Monitoring, 20(4), 560-575.
[18] Zhou L., Xia Y., Brownjohn J. M., & Koo K. Y. 2016 Temperature analysis of a long-span suspension bridge based on field monitoring and numerical simulation. Journal of Bridge Engineering, 21(1), 04015027.
[19] Lee J. H., & Kalkan I. 2012 Analysis of thermal environmental effects on precast, prestressed concrete bridge girders: temperature differentials and thermal deformations. Advances in Structural Engineering, 15(3), 447-459.
[20] Zhou G. D., & Yi T. H. 2013 Thermal load in large-scale bridges: a state-of-the-art review. International Journal of Distributed Sensor Networks, 9(12), 217983.
[21] SIMULIA, Abaqus Analysis User's Manual, version 6.11. SIMULIA, The Dassault Systemes, Realistic Simulation, USA, 2011.
Modares Civil Engineering journal
Volume 24, Issue 2
May and June 2024
Pages 7-18