Establishment and application of mechanics models of frost heaving damage of concrete lining trapezoidal open canal

Thorough analysis of the damage mechanism of frost heaving on the concrete lining of the channel with trapezoidal cross section, this article presents the following conclusions. First, it points out that the calculating diagram of the lining plates of canal bottom and slopes are two-ends-simply-supported beam. Both of them are combined deformation members under the loads of bending and compressing. Second, it gives the mechanics models of frost heaving damage of the concrete lining plates of the canal with trapezoidal cross section. And presents the calculating formula of the control internal forces and maximal tensile stresses of the canal slope lining plates and the canal bottom lining plates. Furthermore, by considering the conditions of crack resistance of the concrete plates, it presents a series of calculating methods of frost heaving forces，position of expansion cracks，proper depth of the lining plates to prevent frost heaving and cracks occurrence, and checking calculation for prevention of frost heaving. Finally, it also elucidates that the intensity and direction of the frost heaving forces, adfreezing forces and interactionally restricting forces, except for the gravity, are all interdependent, and they all can be expressed as the function of the adfreezing forces. Moreover the adfreezing forces is a comprehensive reflection of soil quality, negative temperature and the status of moisture, thereby the mechanics models can be solved provided that adfreezing forces is determined according to the practical experience or experiment. Subjecting the models to the field engineering calculating test, its result shows its safety, rationality, simpleness and practicability.