Field Testing of Anchored Diaphragm Quay Wall Supported Using Barrette Piles

Abstract

A diaphragm quay wall anchored using barrette piles was constructed to increase retained soil elevation and reduce quay wall deflection. This article presents the long-term field-test results of the first practical application of the new structure. The performance of the structure is discussed in terms of the settlement, lateral deflection, bending moment, tensile force, and lateral earth pressure. The maximum lateral displacement was found to be approximately .23% of the wall height. The barrette piles exhibited the highest bending moment among the different structures, indicating that they can effectively bear lateral loads. The load-transfer mechanism of the barrette piles can be summarized as a combination of the blocking effect in carrying the horizontal earth pressure and the anchoring effect in carrying the loads from the quay wall through tie-rods. The increase in the spacing between the quay wall and the barrette piles leads to a reduction in the horizontal earth pressure at higher elevations of the structures. Compared to the measurement results, Coulomb’s earth pressure theory significantly overestimates the earth pressure acting on the quay wall. Moreover, the lateral deflection increment as a result of dredging activities is greater than that resulting from superstructure construction.