Research On Digital Twin Technique Of Temperature Stress Field During Construction Of Large Aqueduct

The country’s complex terrain and uneven distribution of water resources require the improvement of the water resources infrastructure system and the rational deployment of water resources.The rise of the digital twin theory and its technology has brought new opportunities and directions for the transformation and upgrading of traditional water conservancy construction,promoting the informatization and digitization of water conservancy construction.In this context,the Ministry of Water Resources has proposed to vigorously promote the construction of digital twin water resources and build a digital twin water system.The core idea of digital twin technology is to enable the virtual model to map and predict the behaviour of the physical entity through the interaction and fusion of information between the physical entity and the virtual model.Aqueducts,as one of the most widely used interchanges in hydraulic structures,are prone to cracks during construction due to the hydration heat of concrete.Therefore,the study of digital twinning technology of temperature stress field during the construction of aqueduct concrete has strong engineering application value.Based on the existing research work at home and abroad,this paper takes Dongjiacun aqueduct to be built in the Central Yunnan water diversion project as the research object,and studies the application of digital twin technology in the temperature stress field of the aqueduct during the construction period.The main contents are as follows:(1)Establishment of an overall BIM model of the Dongjiacun aqueduct based on the construction drawings of the Dongjiacun aqueduct;According to the structural characteristics,formulate the temperature control scheme of aqueduct body pouring and design the layout of cooling water pipe,and then select the appropriate electric control valve;According to the relevant specifications,the collection scheme of aqueduct temperature and environmental data is designed,including: the selection of acquisition equipment,the process and requirements of data acquisition,the burial method of temperature sensors and the location of temperature measuring points of concrete aqueduct.(2)The mixture ratio of aqueduct concrete was designed,the thermal and mechanical related parameters of concrete were calculated and their values were taken,and the calculation results of heat flow coupling algorithm and equivalent algorithm were compared by using a three-dimensional concrete cylinder water cooling example to verify the accuracy of the calculation method adopted.(3)The finite element software ANSYS was used to simulate the temperature field and stress field of aqueduct concrete,The variation law of temperature field and stress field of aqueduct concrete with time was analyzed,and the influence of water flow velocity,cooling water temperature and ambient temperature on the temperature stress field of aqueduct concrete was analyzed.(4)The digital twinning technology platform of aqueduct construction period is developed based on the open source framework,and implement basic information management,real-time data monitoring,data storage analysis,and comprehensive evaluation and analysis functions on the platform.(5)The temperature control system of aqueduct construction period based on digital twin technology is constructed,including information acquisition and control module,simulation calculation module,information processing and decision module.The information acquisition and control module realizes the data acquisition of the physical entity of the aqueduct on the construction site and the cooling water regulation;the simulation calculation module realizes the finite element model establishment of the digital space aqueduct and the simulation of the temperature stress field;the information processing and decision module realizes the information storage and processing,the temperature control system realizes the mapping and prediction of the temperature stress field of the digital space aqueduct to the temperature stress field of the aqueduct entity.(6)According to the design entity of Dongjiacun aqueduct,the 1:30 scale model of aqueduct was made,and the model experiment scene was built.The feasibility of the system was verified through the model experiment.