Abstract
A rational method of evaluating the skin friction of cast-in place piles in sandy soils is presented on the basis of geomechanical considerations. A critical state friction angle is shown to be effective as a design parameter to evaluate the skin friction. An empirical equation for coefficient of horizontal stress was also proposed on the basis of a few considerations of the soil-pile interaction mechanism. In addition, utilizing this proposed equation, the mean horizontal stress acting on piles was derived, to calculate rationally the total skin friction in piles. The applicability of the model is verified through the use of a newly developed in-situ friction test, a lull scale pile load test in volcanic ash ‘Shirasu’ ground and comparison with the data-base of pile load tests.
