寒区均质土坝混凝土面板冰冻胀破坏的力学分析

Mechanical analysis of frost heaving damage to the concrete face slabs of homogeneous earth dams in cold regions

为了研究寒区均质土坝混凝土面板在冰盖和土体冻胀共同作用下的受力和破坏问题,对北疆奎屯河流域和玛纳斯河流域几个大中型水库进行了野外实地调查。在此基础上,以柳沟水库均质土坝混凝土面板为研究对象,通过合理假设,运用力学基本理论对冰盖作用处混凝土面板的内力分布情况进行了分析。在力学分析的基础上,提出了面板发生冰冻胀破坏的判断准则。研究结果表明:库水面线附近弯矩最大,混凝土面板在该处容易发生断裂,裂缝往往是贯穿性的,并平行于库水面线。在冰盖作用处混凝土面板上部的接缝填充材料容易发生剪切强度破坏。

To study the stress and damage of the concrete face slabs of homogeneous earth dams in cold regions under the dual action of ice sheet and soil frost heaving,field investigations were carried out on several large and medium-sized reservoirs in Kuitun River Basin and Manas River Basin in northern Xinjiang. Taking the concrete face slabs of the earth dam of Liugou Reservoir as the research object,we analyzed the internal stress distribution of the slabs under the action of ice sheet with reasonable hypothesis and basic theory of mechanics,based on which the criteria for judging frost heaving damage of concrete face slabs were put forward. The results show that the bending moment near the water surface line of the reservoir is the largest;it is where the concrete face slabs are prone to fracture and the cracks are often penetrating and parallel to the reservoir water surface line. Furthermore,the joint filling material on the top of the slabs under the ice sheet is prone to shear strength failure.