Earth Pressure Against a Hat-shaped Sheet Pile Wall Revealed by Centrifuge Modeling

Abstract:

A pit supported with a wall formed by hatshaped sheet pilings was modeled in centrifuge apparatus to investigate the earth pressure against the wall during excavation. A parallel test using a planar wall with equivalent bending stiffness was also conducted to demonstrate the effect of the extruding surface of the sheet pile wall on the earth pressure distribution. The results show that the distribution of earth pressure on the sheet pile wall is influenced by the crosssectional shape of the wall. The earth pressure against the extruding and denting portions of the wall differs at the same elevation, and the difference is affected by the displacement mode of the wall. The earth pressure against the denting portions is larger than that of the extruding portions when the wall moves away from the soil; it becomes opposite when the wall moves towards the soil. The displacement mode of the wall changes during excavation, and this further complicates the spatial distribution of earth pressure which varies with the elevation.

Key words:earth pressure; centrifuge model; flexible retaining structure; sheet pile wall