A rainfall threshold for the occurrence of landslides in manmade slopes in residual soils in the northwest of Colombia

Abstract

The purpose of this paper was to determine a rainfall threshold to estimate the probability of occurrence of landslides in roadway slopes. The analysis was performed for a roadway slopes excavated in residual soils derived from igneous intrusive rocks from the stock of Altavista, Medellin, Colombia. The threshold were raised in terms of total rainfall accumulated for short term of 1, 3 and 5 days and precedent moisture in soil due to long term rainfall of 15, 30 and 60 days. Rainfall data and landslides recorded for a period of four years were used to determine the thresholds. The thresholds found show that for slopes excavated in these soils the amount of rainfall that triggers the landslide is about 50% of the rainfall that causes landslides in natural slopes in the same area. © 2013 Taylor & Francis Group, London.