拉西瓦拱坝坝基混凝土浇筑初期裂缝分析

Crack Analysis on Dam Base Concrete in the Initial Pouring Stage of Laxiwa Arch Dam

拉西瓦拱坝混凝土浇筑初期,先后在11～13号坝段基础混凝土部位发现11条裂缝。为此,从坝基开挖卸荷回弹、开挖坑槽及起伏差、固结灌浆、基础约束、施工温度等方面对裂缝的产生进行了分析,并对混凝土应力进行了初步估算。分析认为,温控措施不力及混凝土浇筑薄层长间歇是裂缝产生的主要原因。

In the initial pouring stage, 11 cracks occurred in the base concrete of Laxiwa Arch Dana from No. 11 to 13 dam section. For this reason, we analyze the factors which could cause the occurrence of crack, such as the unloaded elasticity of dam foundation excavation, the excavated pit and trench, consolidation grouting, base restrictions, construction temperature, and so on. Then we preliminarily estimate the concrete stresses. The analysis results concluded that poor temperature control measures and long interval between thin concrete pouring layers are the main causes of crack occurrence.