Abstract

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Title:: Inverse Analysis of Mass Concrete Thermal Parameter Based on Genetic Algorithm

Author(s):: YU Zheng-fu; ZHANG Xiao-yu; LIU Lai-jun; CHEN Yong-rui; Headquarter of Puxuan Expressway

Keywords:: bridge engineering; mass concrete; temperature control and crack prevention; thermal parameter; inverse analysis; genetic algorithm

Abstract:: In order to accurately and efficiently determine concrete thermal parameters, such as adiabatic temperature rise, the thermal conductivity, the surface heat transfer coefficient and reaction speed, which were difficult to be obtained, the genetic algorithms were applied in inverse analysis of concrete thermal parameters according to the measured temperature during the mass concrete construction in Puli bridge vice cable saddle pier foundation, Yunnan Province. Meanwhile, three-dimensional finite element model was established to predict temperature field in followup concrete construction and verified by the measured temperature and stress. Finally, according to the predicted results, surface cooling and cooling water pipes inside can effectively reduce the temperature difference between inside and outside, and prevent cracks in early stage after concrete pouring. The results show that the surface maximum tensile stress is 1.5 MPa when internal temperature of concrete reaches peak value, that means none possibility of cracks. After concrete pouring 3 d, crack resistance index is greater than 1.5, that indicates few possibility of cracks. The calculation value of temperature field coincides well with the measured value based on the inverse parameters.