摘要
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。
Maintaining the safe operation of thousands of aging dams in North America is a daunting task for dam owners. Whether it is the need to increase spillway capacity, solve erosion problems at outlet structures, or improve stability for seismic, sliding, and/or overturning, finding a solution that protects the public and is economical can be difficult. Of the more than 76,000 dams on the national inventory in the United States, many have either exceeded their design life or will over the next decade. In addition, many dams once classified as low hazard are now being reclassified as high hazard due to de- velopment downstream of the dams necessitating a reevaluation of the dam＇s overall safety. Roller compacted concrete （RCC） has now been in use in rehabilitating dams for over 22 years with over 200 projects com- pleted in North America. The economics of using RCC for rehabilitating dams is well documented and its performance prov- en under some of the most severe climatic and hydraulic loading conditions. Seventy four embankment dams have had over- topping protection provided with RCC to provide the safe passage of extreme flood events, aging concrete and masonry dams have used RCC as a buttress material to provide additional stability particularity during the design seismic event, and RCC has been used to extend or reinforce stilling basins subjected to high velocity and turbulent flows.
出处
《大坝与安全》
2011年第4期69-74,共6页
Dam & Safety
关键词
老坝
修复
碾压混凝土
aging dam
rehabilitation
roller compacted concrete
