摘要
概要:拉西瓦水电站坝基地应力达30~70MPa,坝基的开挖将会引起坝基回弹进而发生卸荷破坏,岩体质量下降。用平面非线性有限元,三维非线性有限元等不同的方法对拉西挖拱坝坝基平底开挖形式和反弧开挖形式等进行了分析研究。成果表明,采用光滑反弧形开挖,河谷应力集中区随坝基开挖向建基面下部转移,坝基开挖过程中未出现明显岩爆、剥离等高地应力现象;反弧形开挖较传统的平底开挖,坝基两侧应力集中现象、应力屈服范围等情况得到改善,坝基卸荷破坏有所减弱。这为高地应力区的拱坝坝基开挖设计提供了可以借鉴的经验。
The terrestrial stress in dam foundation of Laxiwa Hydropower Station is up to 30-70 MPa. The excavation of dam foundation would result in dam foundation rebound and then unloaded failure so that it makes the quality of foundation rock mass poor. The plane nonlinear finite element method and 3D nonlinear finite element method were used to analyze and study the different types of flat-bottom excavation and inverted-arc excavation of the Laxiwa arch dam foundation. The results showed that stress concentration zone in valley will be shifted with the dam foundation excavation to the construction surface of dam foundation by the use of the smooth inverted-arc excavation method and no high terrestrial stress occurred in the dam foundation excavation. The smooth inverted-arc excavation has much improvement compared to the traditional flat-bottom excavation, and the stress concentration at both sides of dam foundation, stress yield extent and the dam foundation unload failure have somewhat been mitigated, which provides some reference experience for the excavation and design of arch dam foundation in high terrestrial stress area.
出处
《水力发电》
北大核心
2007年第11期45-47,62,共4页
Water Power
关键词
坝基开挖
反弧形坝基
拉西瓦水电站
excavation of dam foundation
inverted-arc dam foundation
Laxiwa Hydropower Station