Geometric Parameter Study Of Slope Siphon Drainage Holes Based On Interception Ratio

Landslide is a common geological disaster,which causes severe losses for people's life and properties as well as economic development.One important factor leading to landslide disasters is the activity of the surface water and groundwater,about 90%of which take place in rainy seasons.Once the underground level rises in slope,the soil will be softened,resulting in the decrease of cohesive force and shear strength and the increase of pore water pressure,which will bring down the sliding resistance of the slope,making it prone to landslide disasters.Intercepting infiltration of surface water and groundwater in a timely and effective manner is important to prevent landslide disasters and to improve the slope stability.Siphon drainage is a kind of dynamic-free real-time drainage measures It drains a inclined holes to the deep side of slope,and raise the drainage pipe to a certain slope level from the bottom of inclined hole of the siphon.Use the height difference at the ends of the siphon drainage to realize drainage in real time as water level rises inside the slope.Siphon drainage can realize efficiently transport of water without impetus.The stability of slope by changing the shape and distribution of underground water level slope can be enhanced by using siphon drainage,which is a new kind of effective slope drainage method.In practice,the siphon drainage holes should be arranged properly in order to lower the underground water level significantly,thus increasing the stability of slope to a great extent.There exists a systematic theory about the vertical well group of hole in Groundwater Dynamics,but it is not well applicable for the tilting of the siphon drainage slope.This paper combines the group of holes precipitation and inclined hole drainage efficiency,introduces the drainage interception ratio X.,gives a relationship formula between the drainage interception ratio and drainage horizontal spacing according to infiltration curve equation of steady flow of groundwater to the diving full well,and gets the influence of different drainage layout spacing on the siphon drainage effect.In practical calculation,the drainage interception ratio can be determined according to the requirement of engineering,which can find out the corresponding holes spacing,providing design basis for actual engineering.This paper constructs physical test model to study the influence of the tilt angle of drainage holes on drainage efficiency.Test results show that there is a linear relationship between the length of underground-water-level drain holes and the drainage intercept.In practical engineering,when the underground water level drawdown is same,the siphon drainage effect can be effectively enhanced by changing the angle of the drain hole to increase the length of underground-water-level drain holes.Experimental results verifies the accuracy of the theory derivation part.