高混凝土重力坝关键部位温控防裂研究

Study on temperature control for key components of high concrete dam

混凝土重力坝是当今水利工程中常用的一种坝型,但在已建的混凝土重力坝中,许多都存在不同程度的裂缝,裂缝的存在将大大降低大坝的完整性、抗渗性及耐久性。本文在总结国内数十座混凝土重力坝的基础上,就混凝土重力坝较易开裂的重点部位及防裂措施进行了探讨,主要包括基础约束区、永久暴露面、过流缺口、孔洞周边及初次蓄水上游面等部位。研究表明:这些裂缝的存在均由于施工期及蓄水期温控防裂措施不当造成的,若在施工中采用有效的温控防裂措施,可在一定程度上杜绝裂缝的产生,为今后混凝土重力坝工程的建设提供一定的参考。

Concrete dam is a dam type commonly used in hydraulic projects, but many of the constructed concrete dams suffer from cracks of various degrees that greatly reduce the integrity, anti-permeability and durability of these dams. Based on a survey of several dozens of concrete dams built in China, this paper discusses the key dam components that are prone to cracks, including foundation restraint zone, permanent exposure surface, overflow gap and hole, and upstream face. And crack control measures are also discussed. Results show that all these cracks were caused by improper temperature control in the construction and water storage phases, and that effective temperature control can prevent the cracks. This work lends a useful ~upport to construction and temperature control of concrete dams.