梯形渠道砼衬砌体冻胀破坏断裂力学模型及应用  

Frost heave fracture mechanical model for concrete lining trapezoidal canal and its application

作　　者：孙杲辰[1] 王正中[1,2] 王文杰[1] 李爽[1] 肖旻[1] 安元[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,杨凌712100 [2]中国科学院寒区旱区环境与工程研究所冻土国家重点实验室,兰州730000

出　　处：《农业工程学报》2013年第8期108-114,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(51279168);国家科技支撑计划(2012BAD10B02);陕西水利科技专项(SXSL2011-03);陕西农业科技创新项目(2011NXC01-20);冻土工程国家重点实验室项目(SKLFSE-201105)

摘　　要：在线弹性断裂力学的基础上,运用已有的渠道砼衬砌冻胀结构力学模型,考虑各种冻胀力的作用,通过合理的假设和简化,将砼衬砌板断裂看作是(Ⅰ+Ⅱ)复合型(张拉型+剪切型)裂纹的扩展问题,提出了适用于渠道混凝土衬砌板的冻胀断裂力学破坏准则,建立了渠道阴坡、阳坡和渠底3个不同位置砼衬砌板的冻胀断裂力学模型及砼衬砌板厚度设计方法。运用渠道砼衬砌体冻胀断裂力学模型不仅可以计算出阴坡、阳坡和渠底的砼衬砌板厚度,而且实例应用表明,通过渠道砼衬砌冻胀断裂力学模型指导渠道砼衬砌体设计是一种符合实际工程简单实际有效的方法。As for rigid materials such as concrete there existing some invisible initial cracks which can propagate under the force of frost heave, leading to the decrease of water transportation efficiency and massive loss of precious transport water. That is to say, it is quite meaningful and necessary to analysis the damage of concrete lining canal with initial cracks from the perspective of fracture mechanics in seasonal permafrost zones. Based on the theory of linear elastic fracture mechanics and utilizing existing frost heave mechanical model for concrete lining canal, meanwhile through appropriate assumptions and simplifications and taking the consideration of frost heave force, a frost heave fracture mechanics failure criteria for concrete lining canal was proposed by taking the frost heave damage of lining concrete as a composite fracture problem ofⅠandⅡstyle fracture. In fracture criterion under the force of frost heave, the fracture toughness of concrete is regarded as the criterion on the judgment of whether the concrete is damaged or not. When the fracture strength factor is less than fracture toughness of concrete, the concrete lining plate remained compact. Simultaneously, there is a close relation between fracture toughness and temperature. Therefore, a relationship between frost heave parameters and fracture toughness was formed to solve the shortage of frost heave mechanical model. A frost heave fracture mechanical model for concrete lining channel regarding the reasonable and optimal thickness of lining plate was established for shady slope, sunny slope and channel bottom respectively. For the fracture mechanical model of frost heave concrete lining channel, the reasonable and optimal thickness of lining plate is determined, and the model presents a feasible and simple way for aided design for anti-frost heave of concrete lining channel. Results suggest that the most vulnerable parts with the highest moment and shear force is the middle in channel bottom and 1/3 lining plate length near the bottom in

关 键 词：渠道衬砌 冻胀影响 断裂 破坏准则 

分 类 号：S277[农业科学—农业水土工程]