The coupled analysis of phreatic water flow and slope stability at Heifangtai terrace, Gansu Province

The coupled analysis of groundwater flow and slope stability is an important means for studying mechanism of loess landslides induced by irrigation. It is also the basis for the employment of risk mitigation based on water level control. According to the data obtained from investigation, drilling, measuring, and 3D laser scanning, the coupled analysis of phreatic water and slope stability was conducted with Visual Modflow and FLAC3D software. The calculated results with the coupled model fit well with the investigation data. The slope stability was determined by phreatic water table. The deformation area increases with the rise of water table. The maximum value of displacement around Jiaojia cliff in 1990, 2000 and 2010 was 0.85, 1.19 and 1.80 m, respectively.