Abstract

Landslides are major problems in hilly areas. There have been many damaging landslides in recent times that
have taken huge toll of life. Cloud burst, heavy rains and earthquake are among many triggering mechanisms
causing landslides. Recent earthquakes in Sikkim (2013), Nepal (2015), and Kumamoto (2016) have all caused
seismic induced landslides leading to heavy damage. Hence, it is extremely important to assess the performance
of slopes during earthquakes. Earthquakes are unpredictable and uncertain. The behavior of soil slopes are
complex and it is hard to collect relevant input data. These result in difficulty in assessing the seismic performance
of slopes. It may, therefore, be necessary to simplify the analysis of slopes subjected to earthquake. One simplified
approach is to idealize the dynamic earthquake force by equivalent static inertial force. This idealization is
acceptable considering the massive volume and weight of geotechnical structures. The majority of failures happen
in first mode of vibration and failures are mainly due to weakening of the strength and stiffness characteristics
of soil. This paper focuses on the use of GEOSTUDIO, a finite element software for problems associated with
geotechnical engineering, to solve seismic slope stability problems from pseudostatic approach. The effects of
horizontal and vertical components of acceleration on the factor of safety against slope failure are assessed and
represented in graphical form. The influence of slope geometry on seismic slope instability is presented.