Bài viết Nghiên cứu mô phỏng sự phân bố nhiệt độ trong dầm cầu bê tông cốt thép có mặt cắt dạng hộp ở giai đoạn khai thác trình bày phương pháp và một số kết quả mô phỏng điển hình về sự phân bố nhiệt độ (gradient nhiệt) trong dầm cầu BTCT có mặt cắt dạng hộp ở nước ta. | Tạp chí Khoa học Giao thông vận tải Tập 73 Số 8 10 2022 752-768 Transport and Communications Science Journal SIMULATION OF TEMPERATURE DISTRIBUTION IN CONCRETE BOX-GIRDER BRIDGES AT THE SERVICE STAGE Ngo Dang Quang1 Nguyen Huy Cuong1 Mai Dinh Loc1 Dinh Huu Tai1 Le Minh Canh2 1Facultyof Construction Engineering University of Transport and Communications No. 3 Cau Giay Street Hanoi Vietnam 2Facultyof Civil Engineering Campus in Ho Chi Minh City University of Transport and Communications No. 450- 451 Le Van Viet Street Thu Duc city Ho Chi Minh City Vietnam ARTICLE INFO TYPE Research Article Received 25 08 2022 Revised 28 09 2022 Accepted 01 10 2022 Published online 15 10 2022 https Corresponding author Email nguyenhuycuong@ Tel 84989832425 Abstract. Thermal actions have frequently been related to the cracking of concrete bridges. The primary source of thermal actions is the environmental effect due to solar radiation. This paper presents simulation results to determine the temperature distribution on reinforced concrete box-girder bridges during the service stage. The simulation was carried out in two steps a validate with observed experimental data to check and modify the numerical model and b predict the performance of structures under extreme weather scenarios with the fundamental input data taken from national regulations. In this simulation solar radiation is particularly calculated considering sunlight s scattering effect following the sun s orbit. The simulation results agree well with the observed experimental data and are consistent with the publications of many authors worldwide. The thermal gradient data for the box girder obtained from the simulation have some differences compared with the thermal gradient model in the design codes for bridges especially in the negative temperature gradients and horizontal temperature gradients on the girder s web. Keywords monitoring simulation temperature variations solar radiation