ANALISIS GERAKANTANAH DENGAN GEOLISTRIK METODE SCHLUMBERGER PADA LOKASI PEMBANGUNAN KANTOR PT. ASTRA OTOPART DI KAWASAN INDUSTRI CANDI-KOTA SEMARANG, PROVINSI JAWA TENGAH

Abstract

Geoelectric (resistivity) is a geophysical method used to determine the condition or subsurface geological structures based on the value variation of the resistivity of rock. Research sites located in some industrial area of Semarang Candi-block 17., located at Damar Formation (QTD). The purpose of the study was to determine subsurface lithology types based on the result of measurements of Schlumberger Geoelectic method, type of mass movement, slip surface position and mas movement control method. The method used in this study is the Schlumberger geoelectric method. Geoelectric measurement done as much as 6 point spread among the sites, GL 3, GL 2 and GL 1 stretches from south to north. Meanwhile, GL 4, GL 5 and GL 6 stretches from west to east. Geoelectric data processing to determine the actual value of resistivity and thickness of each layer using IP 2 win Software. Based on the result of data processing geoelectric resistivity values obtained at the study site in the form of rock urugan soil (10-56 Ωm), clay (2.5-10 Ωm), claystone (0-2.5 Ωm). Results of resistivity value created geoelectric section and correlated to analyze the occurence of cracks in the rock sites. From the results of which showed the rising value of geoelectric resistivity in the layer of cla, it can be analyzed that the presence of cracks in the clay layer. Slip plane looks at incision geoelectric A-A’ which consists of GL 3, GL 2 and GL 1 and 2 lies in the clay layer at depth 5-15 meters. Type of mass movement at the study site is a creep along the sites and rotational slide that are likely trending northeast between the measurement points GL 2 and GL 1. Keywords: mass movement, schlumberger geoelectric method, slip surface