Ground penetration radar obseravtions at Kahagolla Landslide and evaluation of potential failure mechanism

Abstract

The term landslide is used to describe a wide variety of processes that result in the perceptible downward and outward movement of soil, rock and vegetation under gravitational influence. The material may move by falling, sliding, spreading, or flowing. Landslide disaster is caused to produce a significant impact to the economy of the country and caused to create number of social and enviromentalimpacts. This research was forced on studying the methods that can be used for evaluating the potential mechanism of Kahagolla landslide by applying geotechnical and geophysical techniques. The study was based on slow moving landslide located near the Kahagolla Estate. It belongs to Haputhale District Secretariate divisionin Badulla district.This study involves the use of Ground Penetrating Radar (GPR) and existing borehole information.GPR, technique used for defining underground structure, providing a time effective survey that yield high resolution data making it suitable for shallow and deep subsurface analyzing. The results were validated using the available borehole information. The GPR survey information revealed a close relationship with the borehole data. Hence, an optimum combination of GPR survey and borehole drilling can be proposed for cost controlling in landslide monitoring and instrumentation programme. After interpretation of GPR observations, could identify some of active slip surfaces and their depths from the ground surface.