Application of a New Concept of Cracked Soils in Slope Stability Analysis with Heavy Rain and the Pattern of Cracks as the Governing Factors

Abstract

The results of slope stability analyses in a new construction area at the State Polytechnic of Balikpapan, Indonesia revealed that the slopes are all in a stable condition with a safety factor (SF) greater than 1, even when the slopes were assumed to be fully saturated. However, in reality the slopes had been sliding and creeping downward, especially when heavy to very heavy rain occurred. The slope movements had caused severe damage and destruction to parts of the surrounding structures. This phenomenon of contradiction between geotechnical analysis and field conditions would not have occurred if the new concept of cracked soil was used. In the concept of cracked soils, heavy to very heavy rains and the crack patterns are the governing factors for slope stability. The results of the re-analysis, conducted with the new concept of cracked soils, reveal that the slopes are indeed sliding and unsafe (SF < 1). Therefore, the new concept of cracked soils is a more appropriate method for slope stability analysis.