Proceedings of a Symposium on Downdrag of Piles Held at the Massachusetts Institute of Technology,Cambridge,Massachusetts,on March 8and 9, 1973.

摘要

A symposium on Negative Skin Friction (Downdrag) of Piles was held to acquaint practicing Civil Engineers with the results of a research project conducted by the Geotechnical Division of the Civil Engineering Department at M.I.T. The research was sponsored by the Massachusetts Department of Public Works and the Federal Highway Administration. The bridge chosen for the study had abutments supported on steel piles (14BP 73) driven through 13feet of sand and 50feet of soft clay to bearing in very dense glacial till. A 25-foot high approach fill provided the surcharge. Since the piles were not instrumented prior to driving,an indirect field measurement system was used to determine the downdrag loading on one pile in the west abutment. Predictions of structural and downdrag loads made before the field tests by six engineers were substantially different from the measured loads,but were within reasonable engineering accuracy for the backfigured downdrag loads.