Analisa Lapisan Keras (Bedrock) dengan Menggunakan Metode Seismik Refraksi

Abstract

Each region generally has a condition of various land surface, usually used as information for making a geological map of the regions, but the information can not provide a real illustration of the depth of the hard layer (bedrock) found in the area. Thus, to determine the depth of the bedrock as the initial information exploited for the region of Banjarbaru more, then done by measuring the depth of the bedrock by seismic refraction. Soil has several compiler layers, the deeper layer from surface is denser and each layer has defferent characteristics. The nature used in this research is the difference of the speed to creep the seismic waves on each layer. By creeping the seismic waves, the information of undercoat surface is obtained depend on the speed in creeping seismic waves. To find out the speed and types of layers under the soil and to know the depth of the bedrock in the region are done by using seismic equipment refraction, by initial assumption that bedrock usually is found in the relatively shallow depth in the region of Banjarbaru. From the results of the data sampling done by measuring the length of the track 72 meters and then processed by using the software winsism 10 bedrock was found on the yard of engeniring faculty Unlam Banjarbaru in depth around 6-15 meters, in the speed of spreading waves in the range of 2800-3200 (m/s) and there is nappe layer (top soil) of the seismic waves creeping velocity 300-400 (m/s) and a much water content-thinner layer spreading speed of seismic wave in the range of 1400-1600 (m/s).

Keywords

• layer of soil, seismic waves, bedrock, speed