堆石混凝土大坝浅层裂缝成因分析

Analysis of the Causes of Shallow Cracks in Rockfill Concrete Dams

以某水库为例,通过对坝体混凝土原材料、生产配合比、抗压强度检测、堆石率、养护条件等因素逐个展开分析,结果认为混凝土薄层长间歇浇筑,加上洪水冷激效应使得新老混凝土之间产生的温度应力超过其变形协调能力,是导致坝体开裂的主要原因;堆石率不足55%、堆石外露不足、养护不到位是导致混凝土出现裂缝的次要原因;混凝土原材料、生产配合比、抗压强度不是导致温度裂缝的原因。

Taking a reservoir as an example, the factors such as raw materials of dam concrete, production mix ratio,compressive strength testing, rockfill rate and curing conditions are analyzed one by one. The results show that the main reason for dam cracking is that the temperature stress between new and old concrete exceeds its deformation coordination capacity due to the long interval pouring of thin concrete layer and the cold shock effect of flood;The secondary causes of concrete cracks are that the rockfill rate is less than 55%, the rockfill is not exposed enough, and the curing is not in place;Concrete raw materials, production mix proportion and compressive strength are not the causes of temperature cracks.