Application of Test Results to Quay Wall Design

The problem of reducing the cost of building quay walls and bulkheads is quite old and antedates the science of soil mechanics. Even in “prehistoric” times-when no great distinction was made between clays and sand, when clays were considered ideal foundation materials, before any such thing as pore pressure had been discovered to plague the conscience of economically minded designers, when the subway walls of all the subway systems in New York, N. Y., and Philadelphia, Pa., were designed for a flat K-value of 1/3- even in those distant days the Bureau of Yards and Docks of the United States Navy Department had been grappling with the problem of the excessive cost of quay walls and how to reduce them. The main cost of quay wall construction is invested in two items-(1) the cost of the sheet piling, and (2) the cost of the backfill. To be significant, any saving must be effected in the cost of these two items. The better the backfill material, the shorter will be the length, and the lighter the weight, of sheet piles required for a given dredged depth, and the less will be the cost.