A Treatise On The Principles And Practice Of Harbour Engineering

78 HARBOUR ENGINEERING. sinking fredy, say 1 inch per blow, at the end of driying operations should not be loaded with more than a tenth of a ton per square inch, and even then some slight settlement may be anticipated.1 Illustrative of the first class, the following instances may be cited of piles driven to refusal in various situations at the port of Liverpool :____ Nature of Super- structure. Sectional Dimensions of Pile. Sectional Area of Pile. Length of Pile. Total Load on Pile. Load per sq. inch of Pile Area. Riverside Warehouse . Quay Cargo Shed Riverside Warehouse . 12" dia. 15" x 15" 12" x 12" 14"x l4" sq. ins. 113 225 144 196 40' to 50' 40' to 45' 40' to 45' 40' to 45' cwts. 1568 2296 1170 2177 13-88 10-20 812 11 11 — — At the port of New York, the conditions in many instances are sucli as to be typical of the second class. Along the North River, for example, where Fic. 71. —Piled Foundation to New York Quay. most of the transatlantic liners are berthed, a firm stratum cannot be reached by piles 80 feet long. Such piles, therefore, are dependent on the friction of 1 This figure relates to piles of ordinary size, say 12 inehes square in cross section. As a matter of faet, the supporting power depends upon the surface exposed to friction and there- fore is governed by the sectional perimeter of the pile.