高心墙堆石坝坝基廊道结构型式深化研究

Deepening Research on Structural Types of Foundation Gallery of High Core Rockfill Dam

刚性坝基上高心墙堆石坝的研究重点常在筑坝材料特性及坝体变形控制等方面,对坝基廊道的研究相对较少。对此,通过有限元数值计算,对某310 m高心墙堆石坝坝基廊道嵌入地基和凸出心墙内两种布置型式进行深化研究,计算结果表明,廊道嵌入地基的隔水作用较好,导致帷幕顶部渗透坡降大于廊道凸出心墙方案;廊道凸出心墙使心墙底部中心位置渗透坡降大于心墙下游侧出逸位置;廊道朝向对坝体的变形影响不显著,但对心墙底部和廊道应力影响较大。廊道嵌入地基方案对心墙应力有利,廊道凸出心墙内方案对廊道应力有利;施加渗透力荷载与心墙上游面施加水荷载的方式相比,在蓄水期施加渗透力使得坝体位移和廊道拉应力明显增大;廊道嵌入地基方案中,顶拱厚度对廊道应力影响不明显。

The research priorities of high core rockfill dam are dam material characteristics and deformation control,and the research on dam foundation gallery is relatively less.Through the finite element numerical calculation,this paper studied on the two structural types of gallery which are the gallery embedded in foundation and protruded into core wall on the 310 m high core rockfill dam.The results show that the seepage slope at top of curtain is larger when the gallery is embedded in the foundation because of good waterproof effect.The seepage slope at the bottom of core wall is larger than the overflow position because of the gallery protruded into core wall.The gallery orientation has no significant impact on the dam deformation,but has a great impact on the stress of the bottom of the core wall and the gallery.Gallery embedded in the foundation is beneficial to the stress of the core wall,and gallery protruded into core wall is beneficial to the stress of the gallery.Compared with water load on the upstream face of the core wall,the dam displacement and the tensile stress of the gallery increase significantly when the seepage force is applied.The thickness of gallery crown has no obvious impact on the stress of the gallery in the scheme of gallery embedded in the foundation.