Numerical Simulation Research Of Frost Heave Resistance On Concrete Lined Structure With Small U-shaped Canal Based On ABAQUS

In north of China,especially in the high-cold areas,due to the negative temperature effect,frost heave in the foundation soil of the canals,and the frost heaving damage of concrete lining engineering often occur,which directly affects the normal application of the farmland irrigation canals.Therefore,the anti-frost heaving damage of the concrete lining canals has become an urgent problem to be solved.This thesis combines the knowledge of elasticity mechanics,frozen soil physics and other related knowledge,Simulation analysis of anti-frost heaving of concrete lining structure with small U-shaped canal in Ningxia Yellow River irrigation area.The research work and research results are as follows:(1)The frost heaving damage characteristics of monolithic,two arc-plate and three arc-plate small U-shaped concrete lining canals are analyzed.In terms of anti-frost heave performance,monolithic U-shaped is the best,two arc-plate U-shaped is the second,and three arc-plate U-shaped is the worst;in terms of overall performance,monolithic U-shaped is the best,two arc-plate U-shaped is the middle,and three arc-plate U-shaped is the worst;according to the prototype observation test,The rigid joints of three arc-plate small U-shaped canals were weakly stressed.(2)The small U-shaped concrete lining canal as research object,Applying the software ABAQUS,a numerical model for frost heaving of a monolithic small U-shaped canal concrete lining structure was established.The validity of the numerical model was verified by an example.(3)Taking into account the interaction between the permafrost and monolithic the U-shaped concrete lining plates,a more realistic normal contact model and tangential contact model were established.The calculation results show that compared with simulation results without considering contact,the frost heaving displacement of the lining plate is reduced by 5%to 15%,the normal frost heaving force of the lining plate is reduced by 30%to 50%,the tangential freezing force of the lining plate is reduced by 40%to 60%,the frost heave displacement are distributed uniformly along the cross section of the canal lining plate;the normal frost heave force distributed uniformly along the cross section of the canal lining plate;and the tangential freezing force is distributed more evenly along the cross section of the canal lining plate.The simulation results are basically consistent with the measured results.(4)The effect of anti-frost heave on the concrete lining structure of small U-shaped canal with different inclination angles was discussed,After analysis,the anti-frost heave effect of lining plates at 20° is better than that of 15° angle lining plates;Among them,the maximum frost heave displacement of the 15° inclination angle lining plate is 1.5 times that of the 20° inclination angle lining plate,and the frost heave displacement at the 20° inclination is distributed more evenly along the cross section of the canal lining plate;the maximum normal frost heave force of the 15°inclination lining plate is 1.3 times that of the 20° inclination lining plate,and the normal frost heave force of the 20° inclining angle is more evenly distributed along the cross section of the canal lining plate;the maximum tangential freezing force of the 15° inclination lining plate is 1.1 times that of the 20°inclination lining plate,and the tangential freezing force of the 20°inclination is more evenly distributed along the cross section of the canal lining plate.