Collaboration of high activity soil and geological structure factors in Pagelaran soil creep occurrence, Indonesia

Abstract

Abstract. Soil creep is a landslide that moves slowly but it does not mean harmless. Soil creep that succeeded in forcing the citizens to migrate occurred in Pagelaran by wiping out 13 houses. This paper aims to know the contribution of geological structures and physical properties of soil toward the creeping occurrence. The methods used in this research consist of geological structure mapping; soil sampling; laboratory works; and analysis of geological structures and soil activity. Geological structures analysis indicates that the main force worked predominantly in NE-SW direction, parallel with creeping. It expresses that the creep was influenced by the orientation of them. Additionally, their distribution can be used as access for rainwater to infiltrate and add to the burden of the slopes. While laboratory results show that, the soil is classified into MH and CH. Calculation of activity numbers of soil indicates that it has a high -very high activity with value between 0.705 -1.4931 (Skempton, 1953). It means that the soil will swell easily if contaminated by water.

Groundwater Fluctuation Simulation in Pagelaran Landslide, Cianjur, Indonesia

“…This land movement destroyed 13 houses and collapsed the road along 200 m. Based on the Landslide Forecasting Map of Cianjur Regency, Pagelaran is one of the hot spots of landslide potential. It means that the location is prone to a landslide if triggered by rainfall, earthquake, landuse change, or other triggering factors (Asriza et al, 2017;Salam et al, 2017;Ramadhika et al, 2018;Anonymous, 2018).…”