Determination of hardwear layer for feasibility building development building using geoelectric method resistivity in Coastal Kahona Beach Central Tapanuly Regency

This study aims to determine the value of soil layer resistivity and then relate to the feasibilityof the construction of high rise buildings in the coastal area of Kahona, Central Tapanuli Regency. Based on resistivity value analysis this research using Geoelectric Method of Schlumberger Configuration. Variations of the type resistivity values will be obtained if the distance of each electrode is changed, then obtained the value of resistivity types that are not real values but in the form of apparent resistivity. The data obtained using the resistivity meter ARES-G4 v4.7 SN: 0609135 of apparentresistivity, then converted to resistivity value. The data obtained is made into two dimensional cross section model image using Res2Dinv software. The results showed that the coastal area of Kahona has a low resistivity value of about 4.84 Ωm to 105 Ωm on the first track and 0.865 Ωm to 165 Ωm on the second track. Based on the resistivity value obtained, the area contains clay at depths of 1.25 - 28.7 meters. Based on the results of this study the coastal areas of Kahona can not be recommended for the construction of high-rise buildings because therehard layers in the structure of subsurface rocks. Measurement of the resistivity value of each path has an error percentage of 23.6 - 24.2%.