A Study on the Utilization of Organic Mixed Soil as Earthwork Materials

유기질 혼합토의 토공재로서의 활용에 관한 연구

In order to establish the applicability of organic soil as Earthwork Materials, this research conducts a battery of laboratory tests using two kinds of test materials. The test material A, a mixture of sand and organic soil, and the test material B, a mixture of granite soil and organic soil varying the proportion of organic soil through 5%, 10%, 20%, 30%, 40%, and 50% are used. Continuous column leaching tests of the test materials A and B indicate that their COD value is substantially smaller than that of pure organic soil, the COD value of the early leached water slightly exceeds the standard level for leached water. The COD value after 4 hours of leaching becomes very small. The mixed soil of sand and organic soil is considered usable as embankment materials when the proportion of organic soil is up to 40% with the corresponding concentration ratio of organic contents is less than 11.3%. Similarly, the mixed soil of granite soil and organic soil is considered usable as earthwork materials when the proportion of organic soil is less than 30% with the corresponding concentration ratio of organic contents is less than 16.4%.

본 연구는 유기질토를 토공재로서 활용할 목적으로 시료A(모래+유기질토)와 시료B(풍화토+유기질토)의 두 가지 시료를 유기질토 혼합비를 5%, 10%, 20%, 30%, 40%, 50%로 혼합하여 각종 실내시험을 실시하였다. 시료A, B의 용출시험에 의한 COD값은 순수 유기질토에 비해 상당히 낮은 값을 보였으며, 초기 침출수의 COD 값은 침출수 수질기준을 약간 상회하였지만 용출시작 4시간후의 COD 값은 매우 적게 나타났다. 모래와 유기질토의 혼합토는 유기질토 혼합비 40%(유기물함유량 11.3%)내에서는 성토재로서의 활용이 가능한 것으로 나타났으며, 풍화토와 유기질토의 혼합토는 유기질토 혼합비 30%(유기물함유량 16.4%)이내에서 토공재로서 활용이 가능하다고 판단되어진다.