摘要
糯扎渡水电站2号导流洞底板设计高程576 m,大坝下游河床高程594 m,底板高程低于河床高程达18 m。2号导流洞完成过流后,出口泥沙淤积严重,淤积厚度5～8 m。在出口围堰填筑前虽采用抽砂船、负压吸管配合进行了清理,但由于江水回流及抽砂设备自身功能所限,河床底部淤砂仍无法彻底清除,导致出口围堰填筑后形成多个透水通道,渗水问题严重。对围堰心墙区采用高压喷射注浆进行防渗处理,处理效果显著,保证了2号导流洞出口围堰的安全稳定。
The design elevation of the floor of Diversion Tunnel 2, Nuozhadu Hydropower Project, is 576 m. The riverbed elevation at downstream of the dam is 594 m. So, the floor is lower than the riverbed by 18 m. After Diversion Tunnel 2 is put into operation, sedi- ment at the tunnel outlet seriously accumulates with thickness of 5 -8 m. Before the cofferdam at the tunnel outlet is built, the sediment is cleaned by application of sand-pump dredger and negative suction pipe. But the sediment at the riverbed bottom cannot be removed completely because of restriction of the river water return and the dredger itself. Therefore, a couple of seepage passages in the cofferdam at the outlet are available and serious seepage occurs. The cut-off wall area of the cofferdam is treated by high-pressure jet grouting tbr impermeability and outstanding effect is resulted in to assure safety and stability of the cofferdam at the outlet of Diversion Tunnel 2.
出处
《西北水电》
2012年第A02期76-78,共3页
Northwest Hydropower
关键词
高压喷射注浆
糯扎渡水电站
导流洞
围堰
防渗
high-pressure jet grouting
Nuozhadu Hydropower Project
diversion tunnel
cofferdam
impermeability
