坝基破碎岩体高压渗透变形原位试验

IN-SITU TEST OF FRACTURED ROCK MASS WITH HIGH PRESSURE SEEPAGE IN DAM FOUNDATION

为获取向家坝水电站坝基挤压破碎带岩体的渗透变形特性,针对坝基破碎岩体空间分布特点,研究适合于渗透变形试验的现场压水试验系统和压水试验方法,提出坝基岩体渗透变形的原位高压试验方法。本研究最大特点是采用对观测孔内的水质取样分析和钻孔电视录像进行对比分析方法来研究原位渗透变形特征,并提出确定临界水力坡降的基本判据。研究结果表明,所提出的原位渗透变形高压压水试验方法可以较好地反映破碎岩体实际环境状态,原位渗透变形试验获得的临界水力坡降较室内试验成果更真实合理。

To acquire the seepage characteristics of fractured rock mass under the dam foundation of Xiangjiaba hydropower station, high pressure seepage test system and experimental method are researched based on spatial distribution of fractured rock mass. An in-situ high pressure seepage test method for the seepage of dam foundation fractured rock mass is proposed. The focus of this study is that the in-situ seepage deformation is researched by method of comparative analysis of water quality and video in measured borehole. Basic criterion is put forward to determine critical hydraulic gradient. Study results indicate that the critical hydraulic gradient obtained from in-situ seepage test is more reasonable than that of indoor test because in-situ high pressure seepage test method can reflect the actual environment state of fractured rock mass better.