Iichiro Kohno

Finite Element Analysis of Interface Problem in Nonsteady Seepage

The saltwater intrusion into coastal aquifers and the lealcage of oil from the oil tank or pipe line into groundwater belong to the interface problem of seepage of two fluids with different densities and different viscosities. The free surface and the seepage surface of unconfined groundwater can be dealt with similarly because in that flow one liquid is groundwater and the other is air, namely it being the special case of the interface problem. Actually, freshwater and saltwater are two miscible fluids with a trasition zone between them. Across this zone dispensive mixing will occur between freshwater and saltwater. However, the width of this transition zone is usually thin enough to compare with the thickness of the aquifers (Bear, 1979). So it can be assumed that an immiscible interface is introduced between freshwater and seawater. In this paper are described on the finite element analysis of the nonsteady behavior of interface between salt- and freshwater in coastal groundwater and some experimental studies.

A COMPARISON OF STABILIZATION EFFECTS OF LIME-FLYASH MIXTURES FOR CLAY AND SANDY SOILS

フライアッシュはポゾラン物質として石灰とともに土質安定材として用いられている. 近年では質の多様化した海外炭が使用されてきており, フライアッシュも様々なものが産出されている. 本論文では海外炭を燃焼した質の異なる2種のフライアッシュを, 砂質土と粘性土に適用した時の安定処理効果について検討したものである. その結果, フライアッシュの質と対象土質によって安定処理効果が異なることを明らかにした. そして, 安定処理効果の判定を110℃から200℃の加熱減量値により評価できることを提案している.