棉花滩大坝渗流监测资料分析

棉花滩大坝已蓄水运行10多年，布置有坝基扬压力、渗流量和绕坝渗流监测项目。监测资料分析表明，大坝坝基扬压力、渗漏量和绕坝渗流测孔水位主要受水位因素影响，时效分量已基本稳定，大坝渗流性态基本正常。但高水位时段5′和3″坝段的扬压力系数超过设计值，5^#横断面上测压孔水位呈上下游较高，中间测孔水位相对较低分布，与坝段基础有F18等断层穿过，地质情况复杂有关，建议加强监测和分析。

Seepage Monitoring Data Analysis of Mianhuatan Dam

Mianhuatan dam has impounded and operated for over 10 years, with monitoring on uplift pressure at dam foun- dation, seepage discharge and bypass seepage. The monitoring data shows that uplift pressure at dam foundation, seepage discharge and water level of bypass seepage measuring holes are mainly influenced by water level; ageing component has been basically stable; Seepage behavior in the dam is basically normal. While the uplift pressure on the 5^th and the 3rd dam section exceeds design value during high level period ; both water level of uplift pressure hole close to upstream and downstream on the cross section of the 5^th dam section is higher whereas it is correspondingly lower in the middle. This is related to the 18^th and other faults through foundation of the dam section as well as complicated geological conditions, which needs strengthening monitoring and analysis.