寒冷地区面板堆石坝施工期面板开裂原因

Cause analysis of face cracking of a CFRD during construction period in cold regions

针对寒区面板堆石坝施工期面板开裂问题,结合某实际工程,在原型监测基础上,通过结构变形、气温变化、水化温升、自身收缩等方面的计算分析,发现水化温升与环境温差是影响累积降温温差的主要因素,当累积降温温差较大时,混凝土内的温度应力可能超出面板混凝土的抗拉强度,导致面板开裂。因此,针对年度温差较大、混凝土浇筑期水化升温较高的工程,提出了避免此类温度裂缝的处理建议,如优化混凝土配合比,优化施工工序,提高混凝土抗裂能力。

In view of the face cracking of a CFRD during construction in cold regions, the structural deformation, temperature variation, hydration temperature rise and its own shrinkage were analyzed with an actual project based on prototype monitoring. It is found that the highest value of the hydration temperature rise and the maximum temperature difference in the later cooling is the main factor affecting the temperature difference of cumulative cooling. When the temperature difference of the cumulative cooling is larger, the temperature stress may exceed the tensile strength of the panel concrete, causing panel cracking. Suggestions for avoiding temperature cracks were put forward for construction projects with larger annual temperature difference and higher hydration temperature during the concrete pouring period, such as optimizing the concrete mix ratio, optimizing the construction process and improving concrete crack resistance.