Analysis on Temperature Sensitivity and Cracking Causes of Suspension Bridge Anchorage Based on Numerical Simulation
姬伟1, 左新黛2
1. Beijing Rail Transit Construction Management Co., LTD, Beijing 100068, China; 2. Research Institute of Highway, Ministry of Transport, Beijing 100088, China
Analysis on Temperature Sensitivity and Cracking Causes of Suspension Bridge Anchorage Based on Numerical Simulation
JI Wei1, ZUO Xin-dai2
1. Beijing Rail Transit Construction Management Co., LTD, Beijing 100068, China; 2. Research Institute of Highway, Ministry of Transport, Beijing 100088, China
摘要Mass concrete, a common structure in bridge engineering, is frequently threatened by cracking. Based on the gravity anchorage of a long-span suspension bridge that has been in operation for more than ten years, the causes of the cracks growing year by year in the anchorage were analyzed in this paper. The refined numerical model of the anchorage was established via the space finite element software. Taking full account of the environmental characteristics of the bridge site, the temperature sensitivity of the anchorage was simulated and analyzed, and the stress distributions on the surface of each side of the anchorage at different temperatures were analyzed. The calculation results showed that there is little correlation between anchorage cracking and anchorage bolt force. Under condition 2 temperature increased 20 ℃, the principal tensile stress of anchorage reached to 1.5 times of the allowable stress, Under condition 6 anchorage surface from 40 ℃ suddenly dropped to 20 ℃, the principal tensile stress reached to 2.4 times of the allowable stress. Thus, under the dual effects of internal and external constraints, the cold hit effect of the mass concrete anchorage resulted in the sudden drop of the surface temperature of the anchorage concrete to produce "internal constraint cracks", and the overall temperature rise caused the expansion of the anchorage concrete to produce "external constraint cracks". The two types of cracks led to the vertical cracks of the anchorage. Besides, the environmental and construction factors were the main causes of cracking of transverse construction joints. At last, the anchorage was reinforced with high-performance concrete with an anti-crack reinforcement mesh, which presented good results in the follow-up observation, providing a certain reference value for similar projects.
Abstract：Mass concrete, a common structure in bridge engineering, is frequently threatened by cracking. Based on the gravity anchorage of a long-span suspension bridge that has been in operation for more than ten years, the causes of the cracks growing year by year in the anchorage were analyzed in this paper. The refined numerical model of the anchorage was established via the space finite element software. Taking full account of the environmental characteristics of the bridge site, the temperature sensitivity of the anchorage was simulated and analyzed, and the stress distributions on the surface of each side of the anchorage at different temperatures were analyzed. The calculation results showed that there is little correlation between anchorage cracking and anchorage bolt force. Under condition 2 temperature increased 20 ℃, the principal tensile stress of anchorage reached to 1.5 times of the allowable stress, Under condition 6 anchorage surface from 40 ℃ suddenly dropped to 20 ℃, the principal tensile stress reached to 2.4 times of the allowable stress. Thus, under the dual effects of internal and external constraints, the cold hit effect of the mass concrete anchorage resulted in the sudden drop of the surface temperature of the anchorage concrete to produce "internal constraint cracks", and the overall temperature rise caused the expansion of the anchorage concrete to produce "external constraint cracks". The two types of cracks led to the vertical cracks of the anchorage. Besides, the environmental and construction factors were the main causes of cracking of transverse construction joints. At last, the anchorage was reinforced with high-performance concrete with an anti-crack reinforcement mesh, which presented good results in the follow-up observation, providing a certain reference value for similar projects.
姬伟, 左新黛. Analysis on Temperature Sensitivity and Cracking Causes of Suspension Bridge Anchorage Based on Numerical Simulation[J]. Journal of Highway and Transportation Research and Development, 2022, 16(4): 33-42.
JI Wei, ZUO Xin-dai. Analysis on Temperature Sensitivity and Cracking Causes of Suspension Bridge Anchorage Based on Numerical Simulation. Journal of Highway and Transportation Research and Development, 2022, 16(4): 33-42.
[1] Architectural Institute of Japan. Building Engineering Construction Standard and Explanation. 2. Specification:JASS5 Reinforced Concrete Engineering[M]. Tokyo:Architectural Institute of Japan, 1980. (in Japanese) [2] ACI 207.1R-05, Mass Concrete Guidelines[S]. [3] GB50496-2018, Mass Concrete Construction Specification[S]. [4] ZHU Bo-fang. Temperature Stress and Temperature Control of Mass Concrete[M]. Beijing:China Electric Power Preress, 1999. (in Chinese) [5] LIU Xing-fa. Temperature Stress Analysis of Concrete Structure[M]. Beijing:China Communications Press, 1991. (in Chinese) [6] WANG Feng. Temperature Monitoring and Crack Control of Mass Concrete for Anchorage of Guangzhou Huangpu Bridge[D]. Wuhan:Wuhan University of Technology, 2007. (in Chinese) [7] SI Zheng, YANG Dan, HUANG Ling-zhi, et al. Effects of Small Temperature Difference Cooling on Temperature Stress of Mass Concrete[J]. Chinese Journal of Applied Mechanics, 2018, 35(5):1146-1151. (in Chinese) [8] WU Guo-guang, ZHANG Yong-jian, CHEN Guo-ping, et al. Stress Analysis of Gravity Anchorage of Aizhai Bridge[J]. Bridge Construction, 2013, 43(6):40-44. (in Chinese) [9] SHI Tie-hua, ZHAO Xiao-ming, YE Yong-guo. Effect of Temperature Load on Reinforced Concrete Structure Crack[J]. Earthquake Resistant Engineering and Retrofitting, 2007, 29(5):114-116. DOI:10.3969/j.issn.1002-8412.2007.05.022(in Chinese) [10] MENG Yun, CHEN Guo-xiang, SONG Jun-wei. Causes for Late Forming Cracking in Bulk Concrete of the Suspension Bridge[J]. Transportation Science and Technology, 2016, 274(1):45-48. (in Chinese) [11] DU Feng, CHANG Pan. Temperature Control and Crack Prevention of Mass Concrete Anchorage[J]. Highway, 2019, 64(8):89-94. (in Chinese) [12] CHEN Guo-xiang. Analysis of Causes of Late Cracks in Massive Concrete[J]. World Bridgse, 2015, 176(4):64-68. (in Chinese) [13] CHEN Wei-guo, TU Liu-qing, LIU Ke-xin, et al. Temperature Control Technology of Mass Concrete for South Anchorage of Zhoushan Xihoumen Bridge[J]. Highway, 2006(6):112-116. (in Chinese) [14] LI Chun-qi. Analysis on Cause of Non-load Cracks in Mass Concrete Members of Bridges[D]. Wuhan:Wuhan University of Technology, 2009. (in Chinese) [15] JTG/TJ21-2011, Specification for Inspection and Evaluation of Load-bearing Capacity of Highway Bridge[S]. (in Chinese) [16] LI Dong-qing. Analysis and Countermeasures to Temperature Cracks of RC Structure[J]. Journal of Guangzhou University (Natural Science Edition), 2003, 2(1):78-80. (in Chinese) [17] WU Qing-xiang. Study on Sunshine Temperature Field and Influence of Box Beams in Beijing[D]. Beijing:Beijing University of Civil Engineering and Architecture, 2016. (in Chinese) [18] JTG D60-2015, General Specifications for Design of Highway Bridges and Culverts[S]. (in Chinese)
2022, Vol. 16 
