Centrifuge modeling for a new type sheet pile bulkhead with barrier piles

Abstract

A centrifuge modeling for a new-type sheet pile bulkhead is presented in the paper. As one of the most typical waterfront constructions of the bottom-fixed port marine pier structure, sheet pile bulkhead is widely used in small size piers or medium size piers. It is usually composed of two rows of sheet pile walls connected by tie-rods, namely, the front wall for retaining soil and the anchor wall. A new type of sheet pile pier structure, with retaining structure up to 18 m, is being devised in the construction of new ports in China, especially where the muddy or sandy seashore is prevailing without rock foundation or very stiff soil foundation. The distinct feature of this new sheet pile pier structure is to add a row of barrier piles in between two rows of sheet pile walls. With the presence of barrier piles, lateral earth pressure acting against the front wall will expectantly be reduced that it can withstand much higher height of soil than the usual sheet-pile wall. But the lateral earth pressure acting on both sides of barrier piles is unknown, which leaves much uncertainty in the structural design. In order to better understand the contribution of barrier piles in the reduction of lateral thrust to the front sheet-pile wall and to provide experimental data to optimize the current design of this new structure, a sheet pile pier of this innovative structure has intensively been studied by centrifuge modeling with respect to a prospect pier structure design. One model test and its result is reported in the paper in which lateral earth pressure acting on barrier pile and its response of bending moment are measured by means of custom-made miniature earth pressure cells and strain gauges. An insight of the inherent working mechanism of barrier pile in this new structure is gained from the analysis of the test results.