Pencirian dan pengekelasan pasir dalam tanah menggunakan gelombang ultrasonik

Abstract

Study of classification and characterization of sand in soils profile using ultrasonic wave is developed because of nowadays demand in classification method that is quick and precise. The focus of this study is to create a method in classification of sands in soil profile without using chemical reagent and study of ultrasonic application in characterization of sands in soils. 36 soil samples with different depth were collected from 3 regions with different environment. The first is agricultural area in Kg. Manir, Kuala Terengganu, the second soil sampling is done at Pantai Tok Jembal, Kuala Terengganu and the third set of soil is collected from mangrove area at Sungai Terengganu, Kg Bunut. The ultrasonic wave with 5 W and frequency of 40000 Hz is radiated trough soil samples in critical angle of 90°· Attenuation Coefficient, a is then determines and the data is compared to percentage of sands in soil using variety size of sieves which are 2.00 mm, 1.00 mm, 500 μm, 250 μm, and 125 μm in size. The comparison between attenuation coefficient and sand percentage show that maximum attenuation coefficient having higher percentage in very coarse sand (<2 mm and 2.00 mm) than minimum attenuation coefficient. However, percentage of very fine sand (125 μm) or fine sand (250 μm) in maximum attenuation coefficient is higher than soil sample which having minimum attenuation coefficient. In conclusion, the smaller particle filled empty spaces between the coarse sand and because of that, resistivity of ultrasonic increase. Hence, attenuation coefficient increased.