某水电站坝基缓倾角裂隙抗滑稳定概化模式

General model of anti-sliding stability of the lower angle fissure of dam foundation of a hydropower station

关于坝基抗滑稳定性,对缓倾软弱结构面的研究较多,而关于缓倾硬性结构面的工程实例报道较少。针对某水电站坝基勘察中发现的缓倾角裂隙,利用勘探平洞和钻孔电视录像,分析了缓倾角裂隙的基本特征、分布规律、发育程度和连通率,然后在此基础上建立了坝基抗滑稳定计算概化模式。分析得出:坝基岩体中缓倾角裂隙属硬性结构面,规模不大,呈随机分布,发育程度不均匀,0.50m投影距时连通率为19.5%～27.1%。将走向与坝轴线夹角≤30°的缓倾角裂隙视为坝基抗滑稳定优势结构面,建立双滑面型、单滑面型两种抗滑稳定计算概化模式。分析思路、建模过程丰富了坝基抗滑稳定性的研究,对于类似工程具有借鉴意义。

In terms of the anti-sliding stability of dam foundation,there are many studies on the soft structural plane of lower angle,but there are few reports on the engineering example of rigid structural plane of lower angle.Based on the investigation of the dam foundation of a hydropower station,this paper first analyzes the basic characteristics,distribution law,development degree and connection rate of the lower angle fissure,and then proposes the general calculation model of anti-sliding stability of the dam foundation.It is concluded that the lower angle fissure is a rigid structure,small size,a random distribution,uneven development degree,connection rate is 19.5%~27.1%at 0.5 m projection distance.The lower angle with the dam axis angle of 30°or less slow fissure as advantageous structural plane,basic calculation models of stability against sliding is generalized into double sliding surface type or single sliding surface type.The analysis ideas and modeling process enrich the research on the anti-sliding stability of dam foundation,and has reference significance for similar projects.