Abstract
Based on the compiled data on results of pile driving, loading and boring tests at 131 building sites the author estimated ultimate bearing resistance of each pile, R_s, 1. by drawing each load-settlement curve in semi-logarithm scale, (load: logarithm scale, settlement: arithmetic scale), 2. by analysing each load-settlement curve under the assumption of index law between settlement and applied load, and 3. by calculating the settlement velocity from each time-settlement curve. Then the bearing resistance, R_d, of each pile, the safety factor eliminated, was calculated by the three prevailing formulas in Japan for pile bearing resistance which are the formulas of Japanese building code, old city building code and Engineering News. Statistical study between R_s and R_d was made and the author proposed a method of estimation of a term for energy losses in Hiley's pile formula putting R_s and R_d be equal.
