甘肃黑方台黄土滑坡地表水入渗机制初步研究

摘要

黑方台黄土底部的地下水对滑坡的发生起了重要作用，地下水的来源主要为台塬大面积灌溉，灌溉水通过孔隙、裂隙进入黄土内部并在底部向台塬四周渗出。通过探地雷达确认了台塬中部与台塬边同样发育大量裂隙延伸至黄土深部。根据灌水和开挖探槽可见裂隙为地表水的主要优势入渗通道，地表水可沿裂隙快速入渗至黄土深部。在台塬四周的陡壁和典型滑坡后壁取样测含水率发现黄土底部只有裂隙渗水点附近含水率较高，其余区域含水率增大不明显，黄土底部含水率大小分布受节理裂隙控制。%The groundwater at the bottom of loess plays an important role on the occurrence of Heifangtai landslides.The main source of groundwater comes from irrigation water .Irrigation water can infiltrate into the loess through cracks, then seep around to the bottom of loess .A large number of cracks are confirmed in deep loess at middle and edge tableland through ground penetrating radar .According to the irrigation and trench excavation , it is found the cracks are the main infiltration channel for surface water .Surface water along the cracks can rapidly infiltrate into the deep loess.At the tableland around the steep and typical landslide , sampling and measuring moisture content are conducted.It is found that high water content only exists at seepage points of cracks .The remaining area of the increase of water content is not obvious .The distribution of water content at the bottom of loess is controlled by joints, fissures and cracks.