Kinematics of Slope Mass
Failure at the Zone of Initiation, Guinsaugon Slide, St. Bernard,
of kinematic admissibility analysis and engineering geological
zoning using Laubscher’s Rock Mass Rating Scheme and Hack’s Slope
Stability Probability Classification Scheme indicate that the slope
mass at the zone of initiation of the Guinsaugon landslide at St.
Bernard, Southern Leyte failed by a combination of toppling, wedging
and plane sliding. Among the various factors that contributed to
slope failure are topography, lithology, structures, hydrogeology,
and geomorphology. Field evidences also strongly suggest that
various natural processes like weathering, gully erosion, previous
slope failures and past earthquakes had significantly contributed to
the geotechnical weakening of the slope mass prior to its failure.
Among the identified triggering mechanisms are intense rains of long
duration (i.e. 478 to 571.2 mm which is four times more than the
average rainfall reading at Southern Leyte) coupled with the
occurrence of low magnitude earthquake.