The responsibility of high activity clay mineral toward landslide occurrence in volcanic sediment area, Cianjur

Slope that formed by soil which contained high activity clay mineral can be prone of creeping. One of soil creep, that affects several houses destroyed and forces the citizens to be relocated, happened in Pagelaran, Southern Cianjur, Indonesia. This research has a purpose to know the ante of the high activity clay mineral toward the soil creep occurrence. The methods that used in this research consisted of three parts, they are: (i) field activity to get undisturbed soil sample; (ii) laboratory analysis to get the physical properties of the soil and its mineral contents by using XRD analysis; and (iii) studio analysis to know the ante of mineral contents and its effect toward the soil creeping. The results show that the types of soil in this research are consisted of fine grained soil with high plasticity (MH and CH). Activity number analysis shows that the soil in the research area has a high activity number, i.e.: 0.62 - 1.33. It is confirmed by XRD analysis which shows that the soil in the research area is contained by Kaolinite and Montmorillonite clay mineral which have a high activity potential. It can be concluded that the presence of Kaolinite and Montmorillonite, as high activity clay mineral, was responsible toward soil creeping occurrence in the research area.