Vol16 No.3: 701-713
【Title】An improved siphon drainage method for slope stabilization
【Author】SUN Hong-yue1; WANG Dong-fei1; SHANG Yue-quan2*; CAI Yue-liang2; WEI Zhen-lei2
【Addresses】1 Ocean College, Zhejiang University, Zhoushan 316021, China; 2 College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China
【Corresponding author】SHANG Yue-quan
【Citation】Sun HY, Wang DF, Shang YQ, et al. (2019) An improved siphon drainage method for slope stabilization. Journal of Mountain Science 16(3). https://doi.org/10.1007/s11629-018-5171-3
【Abstract】The siphon drainage is an effective measure for the slope groundwater control. However, for the traditional siphon drainage, limitations such as siphon lift restriction and poor reliability in long-term service prevent it from being widely used. In this study, an improved siphon drainage method with inclined borehole penetrating the deep part of the slope is proposed to overcome the limitations suffered by the traditional method. Through experimental research, theoretical analysis and engineering practice, the reliability and capability of the proposed method are investigated. The results demonstrate that with the inclined pipe the height difference between the control point of the groundwater level and the orifice can be controlled to be less than the height of the water column corresponding to the local atmospheric pressure. As a result, deep drainage can be achieved. In addition, by controlling the diameter of siphon drainage pipe not larger than 4 mm, a plug flow can be formed in the siphon pipe, which can prevent air accumulation in the siphon process and a continuous and effective siphon drainage is achieved. Through a practical project running smoothly since September 2013, it is found that the proposed method can effectively drain the groundwater deep in the slope and the maximum drawdown of groundwater level in boreholes can reach 8.5 m with an average drainage flow of 5.5 m3/d. The practical results also illustrate that 4 mm siphon pipe can be used to realize deep slope drainage and restart siphon automatically.
【Keywords】Landslide; Drainage; Siphon; Inclined borehole; 4 mm diameter siphon pipe