Early Identification for Prospective Housing Area in the Landslide Potential Zone

Abstract

Identification of area for prospective housing before construction is much needed, especially area with a steep slope and young volcanic that have landslide risk. The risk of landslides is not only caused by high rainfall or steep slope but can be caused by shocks due to earthquakes. It is necessary to identify the rock types in the prospective housing near Mount Salak in Cijeruk area, Bogor Regency. The purpose of this research is early identification types of rocks, soils, and potential of a landslide in prospective housing by geological and soil survey methods. The geological survey method used is to identify morphometry and lithology specially landslide, whereas soil survey identifies soil characteristics. According to results of research, morphometry at prospective housing is included moderately until steep slope category. Steep slopes potentially cause landslides with debris avalanche type. Characteristics of soil at Cijeruk support it has an of high coefficient of linear extensibility; this condition affects the shallow foundation movement. Therefore needs additional material so that the coefficient of linear extensibility value becomes low. The soil in this location comes from volcanic activity with tuff and lapilli types, sometimes found pebbles until boulder, and they are not lithification. If the location of the housing is exposed to an earthquake with a scale of 5 SR, it would be high shocks and areas with steep slopes would cause landslides. For maintenance from landslides, retaining walls need to be made with the type of gravity wall and cantilever wall. The distance between the retaining wall and housing is 15 meters. The type of foundation to be used is the foundation of the spread footing.