弧形坡脚梯形渠道砼衬砌冻胀破坏断裂力学模型及应用

Development and Application of Frost-heaving Fracture Damage Mechanical Model for Concrete Lining Channel with Curved Slope Toe

为给实际弧形渠道冻胀设计提供一种简单有效的计算方法,应用材料力学方法对渠道砼衬砌冻胀问题进行合理简化,建立了弧形坡脚梯形渠道砼衬砌冻胀力学模型,并在该模型基础上引入断裂力学,将砼衬砌板断裂视为(Ⅰ+Ⅱ)复合型(张拉型+剪切型)裂缝扩展问题,并利用已有的断裂准则,建立弧形坡脚梯形渠坡、渠底两个部位的冻胀断裂力学模型。实例应用结果表明,所建模型计算的砼衬砌板厚度满足抗冻胀要求,且与实际情况相吻合。

To provide a simple and effective calculation method for design of concrete lining channel in trapezoidal section with curved slope toe considering frost heave,this study simplified the frost heave problem by the application of material mechanics,and established the frost heave fracture damage mechanical model of the concrete lining channel in trapezoidal section with curved slope toe.Considering the initial crack defect of concrete material and introducing fracture mechanical to the model：through reasonable simplification and assumption,considering concrete lining plate fracture as（Ⅰ＋Ⅱ）composite（tensioning ＋ shear）crack propagation problems,this study established the frost heave fracture damage mechanical model on the bottom and slope of the channel.The application results of the example show that the calculated thickness of the built model meets the requirement of frost heave and matches the actual situation.