Penentuan Tingkat Kekerasan Batuan Menggunakan Metode Seismik Refraksi di Jatikuwung Karanganyar

Abstract

<span>It has been done a research about the determination of rock hardness level by using refraction <span>seismic method in Jatikuwung Karanganyar. The research is done by using <span><em>Seismograph PASI </em><span><em>16S24-P </em><span>with the path length of 48 meters, distance between <span><em>geophone </em><span>2 meters, 5 <span><em>shots </em><span>in <span>each spread and there are four surveys part totally. The processing data is done by using <span>SeisImager software with <span><em>Plotrefa </em><span>and <span><em>Pickwin95 </em><span>program.We use <span><em>intercept time </em><span>method for <span>data processing. The determination of rock hardness use <span><em>Gardner’s relationship </em><span>formula. <span>Based on interpretation, there are three layers lithology structure with P wave propagation <span>velocity of 200-1800 m/s and its density of 1.17<span>–<span>1.93 gr/cc. Based on velocity analysis we <span>determine the velocity of first layer is 200-700 m/s, second layer 700-1500 m/s, and third <span>layer 1500-1800 m/s. The subsurface hardness lithology consists of <span><em>top soil</em><span>, sands and <span>unsaturated pebble (1.17<span>–<span>1.59 gr/cc) with the depth 2<span>–<span>4 meters in the first layer, saturated<br /><span>sands, saturated pebble, and alluvium (1.59<span>–<span>1.93 gr/cc) with the depth 9.5<span>–<span>11.5 meters in the <span>second layer, and clay and sands (1.93<span>–<span>2.02 gr/cc) with the depth of 5.5<span>–<span>6 meters in the third <span>layer. The rock hardness is located at the depth betwen 12 <span>– <span>20 meters.</span></span></span></span></span></span></span></span></span></span></span></span></span><br /></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>