International Journal of Advanced Engineering and Technology

Authors
Maraden Panjaitan

Abstract
Field survey activities are data collection/collection in which nature is the source of data, nature is the source of data, besides requiring personal experience, it is also required to prepare appropriate materials, equipment and work methods and meet standard requirements. The Geoelectrical Study provides an overview of the subsoil structure of SMPN 18 Sepinggan Balikpapan. The research was carried out for 3 months located in the SMPN 18 area in the city of Balikpapan. The research activities carried out included direct observation in the field and examination of soil properties in the field and laboratory which included: consistency, soil type, color, estimated percentage of coarse grains/ smooth according to the USCS Method as well as geoelectric, sondir test, and boring test. From the results of the analysis, it is found that the structure of the soil layer consists of groundwater where the resistivity value is relatively small. The layer containing groundwater is at a depth of 0.00 to 1.25 m with a resistivity of 297-323 m. In addition, there is also a layer of sand mixed with clay, and alluvium and gravel on track three. Sand is a rock material that can pass water, but with the insertion of clay, this layer can store water and drain it in limited quantities. Stratigraphy or lithology of the hills of SMPN 18 Sepinggan Balikpapan is composed of overburden which is clay to a depth of 0-1.25 meters, tuffaceous sand and weathered breccia. The slip plane is the boundary of tuffaceous sand with weathered breccia rock with a depth ranging from 5-7 meters, and shale at a depth of 15-20 meters. The slip plane is included in rocks with a weathering level of 4 meters.