USE OF EMBEDDED WALLS FOR MITIGATION OF LIQUEFACTION-INDUCED DISPLACEMENT IN SLOPES AND EMBANKMENTS

YOSHIHIRO KOGAI, IKUO TOWHATA, KEI AMIMOTO and HENDRI GUSTI PUTRA

ABSTRACT: The effects of large displacement and deformation of liquefied subsoil during earthquakes have been seriously discussed in recent years. Although mitigative measures to prevent the onset of liquefaction are desirable, it is important from an economical viewpoint that there is a level of allowable displacement and deformation below which the induced ground movement does not cause serious problems to concerned facilities. That deformation is also acceptable that can be repaired within a reasonably short period of time. The present paper briefly examines the recent experience of a river dike during the 1995 Kobe earthquake and suggests that several measures, inclusive of an embedded sheet pile wall, are able to mitigate the displacement to an acceptable level. Then the study presents the results of small shaking table tests in which displacement of a liquefied slope was mitigated by an embedded wall made of either a sheet pile or compacted sand. The study proceeds to the development of an analytical method by which the mitigative effects of embedded walls are evaluated. The proposed method is so simple that a closed-form solution is available for simplified situations. Example studies were made of several situations.

Key words: compaction, deformation, earth pressure, earthquake resistant, liquefaction, sheet pile wall (IGC: E2/E8)