碾压混凝土重力坝度汛缺口温控分析

摘要

Preset dam body gaps are commonly used for the flood discharging of concrete dams during the construction period.However, the cold flood water flow will produce excessive thermal stresses in the gap part of the dam body .For the roller compacted concrete ( RCC) dams, the stress situation could be even worse due to the special characteristics in materials and construction method , thus a higher risk of thermal cracks .Taking a RCC gravity dam on the Lancang Riv-er as an example , a thermal analysis of the preset flood discharging gap is presented .Excessive thermal stresses are ob-served in the gap part which is obviously unfavorable for the safety of the dam .The results also show that the stress situa-tion in the gap part could be significantly improved with some effective temperature control measures , which ensures the cracking prevention safety of the gap part in flood season .%鉴于混凝土坝通常采用预留缺口方式进行施工期度汛，缺口部位在水流冷击作用下会产生较大的温度应力，而碾压混凝土坝，由于材料以及施工工艺的独特性，缺口部位应力状况更加不利，有很大开裂风险，为此以澜沧江某碾压混凝土重力坝为例，进行度汛缺口部位仿真分析，结果表明：度汛缺口附近温度应力较大，汛期过水十分不利；增加有效温控措施后，缺口应力状况获得明显改善，可保证度汛期间缺口部位的防裂安全。