Failure investigation of a drilled shaft stabilised slope

Abstract

In this paper, failure of a drilled shaft stabilised slope during basement excavation of an office building in Taipei city, Taiwan, is investigated. Four and two stages of excavation along the respective east and west sides of the site were planned. A row of drilled shafts was installed along each side before excavation. Severe slope movement occurred and extended outside the project area on both sides during excavation due to a weak clay layer overlying bedrock, unpredicted local trough between the soil/rock interface and improper design of the drilled shafts. Study of the possible reasons for failure includes monitoring results evaluation and numerical studies by means of the computer code Plaxis.