超高面板堆石坝极限抗震能力与安全性分析

Analysis on ultimate seismic capacity and safety of ultra-high CFRD

大坝的极限抗震能力评价，尤其是高面板堆石坝的极限抗震能力评价，目前尚无统一的标准可参照，开展探索性研究具有重要的现实意义。大渡河猴子岩面板堆石坝具有坝高、河谷狭窄、抗震设计烈度高等特点，大坝抗震设计是工程的关键技术问题之一，以猴子岩面板堆石坝为例，从坝坡稳定、地震永久变形、防渗系统安全等多角度评估大坝的极限抗震能力，并进一步从渗透稳定和坝坡稳定方面评估面板失效后大坝的安全性。研究成果表明，在设计地震下大坝结构满足抗震安全性要求，校核地震下可实现“不溃坝”，大坝的极限抗震能力约为0.5 g；在面板失效的极端条件下大坝安全仍能得到保证。该研究在较好地解决猴子岩大坝抗震设计难题的同时，也为强震区200~300 m级高面板堆石坝的抗震设计研究提供了有益的启示。

Due to lack of consistent evaluation standards for dam ultimate seismic capacity, especially for high CFRD, it is practically important to carry out some related explorative researches. The dam seismic design is a key technological issue for Houziyan CFRD that is characterized as significant height, narrow river valley and high design seismic intensity. Its ultimate seis-mic capacity is comprehensively evaluated from the aspects of dam slope stability, post-earthquake residual deformation, safety of anti-seepage system, and further the dam safety in an extreme case of slab failure is discussed with consideration of seepage stability and dam slope stability. The results show that the dam is in a reliable state subjected to design earthquake and the dam-break can be avoided under check earthquake, the ultimate seismic capacity is approximately of 0. 5g;the dam safety can still be guaranteed under slab failure. The research results not only can solve the seismic design of Houziyan CFRD, but also offer valuable enlightment for seismic design of other high CFRD of 200~300m level.