Simulation Study On Temperature Control Of Concrete Lining Of Diversion Tunnel In Dongzhuang Reservoir

Limited by the construction conditions,the pumped concrete is usually adopted in the diversion tunnel of the water conservancy project.Moreover,in the flow surface of the orifice,the against abrasion of concrete with high-grade strength rank is used to release flood during the construction period.Therefore,under the constraint of high hydration heat of cement,en-vironment temperature change and surrounding rock,the temperature stress has a significant impact on the safety of lining concrete,causing the cracking in the lining concrete.Especially for the surrounding rock with better integrity,the risk of the cracking in the lining concrete increase as the constraint function of the surrounding rock.The concrete,which is in the diver-sion tunnel with relatively complete surrounding rock,large tunnel section,thick lining,large flow and long service time,is easier to occur the temperature cracks during the construction period.Considering to the characteristics of the diversion tunnel of Dongzhuang reservoir,in this paper,the commercial software ANSYS is applied to simulate the temperature and creep stress field of the diversion tunnel during the construction period,combined w ith the technology and the practical experience of temperature control and crack prevention in the world.In this thesis,a set of temperature control standards for the lining concrete is proposed to ensure the safety of crack resistance.The specific research contents are as follows:(1)The background and significance of temperature control simulation research on the concrete lining of the diversion tunnel in water conservancy project,as well as the research progress in the world at present,are described,laying a foundation for the temperature control simulation research of concrete lining in this paper;(2)The layout of the diversion tunnel of the Dongzhuang reservoir is introduced,and the hydrological,meteorological,geological conditions and the thermodynamic parameters of bed-rock and concrete are described in detail,providing the basis for the temperature control sim-ulation study of lining concrete;(3)The A-section of diversion tunnel with large lining thickness is selected as the re-search object.under the temperature control measures such as pipe cooling,the temperature and stress field with the pouring temperature in high-and low-temperature seasons are calcu-lated,respectively.On this basis,the feasible temperature control measures are put forward for the construction period;(4)Furthermore,according to the cracks on the surface of the lining concrete on-site,the reseasons of the cracks of the diversion tunnel are analyzed combined with the temperature monitoring data of the warehouse surface.Then,the corresponding treatment measures are proposedThe research results provide guidance for concrete construction of diversion tunnel in dongzhuang reservoir and theoretical basis for temperature control and crack prevention of concrete in diversion tunnel.