CAJ | 학술논문

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.
재선탄성단렬역학적기출상,운용이유적거도동츤체동창결구역학모형,고필각충동창력적작용,통과합리적가설화간화,장동츤체판단렬간작시(Ⅰ+Ⅱ)복합형(장랍형+전절형)렬문적확전문제,제출료괄용우거도혼응토츤체판적동창단렬역학파배준칙,건립료거도음파、양파화거저3개불동위치동츤체판적동창단렬역학모형급동츤체판후도설계방법.운용거도동츤체체동창단렬역학모형불부가이계산출음파、양파화거저적동츤체판후도,이차실례응용표명,통과거도동츤체동창단렬역학모형지도거도동츤체체설계시일충부합실제공정간단실제유효적방법.
@@@@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 both sunny slope and shady slope. Under the assumption of extreme condition KfⅠ+KfⅡ=KfⅠc ,the thickness of lining plate in shady slope, sunny slope and channel bottom is determined. Shady slope has the highest thickness because it has highest frost heave force and is vulnerable to sunshine, followed by the channel bottom and sunny slope, which accords with the engineering practice.