A STUDY ON TIMBER PILES AT THE BEGINNING OF SHOWA ERA

—Review on sharing ratio of point bearing capacity and skin friction of timber piles—

Abstract

The beginning of Showa era was the reconstruction period from the disaster due to Kwanto earthquake occurred on September 1 in 1923, and many geological soil surveys were performed systematically in the eastern part of Tokyo and Yokohama city. Kitazawa^2)-5) studied the relation between the resulted soil condition and driven tests of timber piles, and proposed the design formula of bearing capacity of the piles. This paper reviews Kitazawa's papers from the point of view concerning sharing ratio of point resistance and skin friction of timber piles. As the conclusion obtained from the review, sharing ratio of point resistance is almost less than 30% and timber piles can be estimated to behave as a piled raft foundation.