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对于北美的大坝业主来说,保证大量老坝的安全运行是充满挑战的工作。不管是增加泄洪能力、解决泄洪设施的冲刷问题或是提高抗震、抗滑、抗倾稳定性,找到一个既能有效保护公众又经济的方案是很困难的。美国有超过76000座水坝,其中很多已经超过设计寿命或已进入最后20a。另外,由于下游工农业发展,许多最初被归为低风险的大坝现在被重新归于高风险行列,这些都需要对大坝的整体安全进行重新评估。碾压混凝土(RCC)技术已被广泛应用于大坝的修复加固,在北美完工的这样的项目有200多个。其经济性被交口称赞,而且也在一些极端气候和水力条件下得到了验证。74个堤坝工程使用了RCC进行漫顶保护,为超标准洪水提供安全的宣泄通道;老化的混凝土坝和砌石坝使用碾压混凝土做加固材料以提高稳定性,特别是在设计地震工况。碾压混凝土也被用来延长、加固消力池,抵御高速水流和紊流的破坏。
For North American dam owners, ensuring the safe operation of large numbers of dams is a challenging task. Whether it is to increase flood discharge capacity, solve the scouring problem of flood discharge facilities, or improve the stability against vibration, slip and stability, it is very difficult to find a solution that can effectively protect both the public and the economy. There are over 76,000 dams in the United States, many of which have already exceeded their design life or have entered the last 20a. In addition, many dams initially classified as low-risk are now being relegated to high-risk positions due to downstream industrial and agricultural developments, all of which require a re-evaluation of the dam’s overall safety. RCC technology has been widely used in the repair and reinforcement of dams. More than 200 such projects have been completed in North America. Its economy is bolstered and also validated in extreme weather and hydraulics. The 74 dykes use RCC for overprotective protection, providing safe venting for over-standard floods; and aging concrete and masonry dams using RCC for reinforcement to improve stability, especially in the design of seismic conditions. Roller compacted concrete is also used to extend and reinforce the trough to protect against the destruction of high-speed currents and turbulence.