EXAMINATION OF BEARING CAPACITY OF JAPANESE CEDAR PILES USED IN FOUNDATION OF CHECK DAMS

Abstract

 When installing concrete or steel check dams, the ground support at the bottom of the check dam may be inadequate. One of the countermeasures for such situations is to reinforce the ground by driving wooden piles into the foundation of the check dam. The formula for calculating the bearing capacity of wood piles is based on that for pine trees. The applicability of the formula in its unmodified form to cedar piles, which have been considered in recent years, is yet to be confirmed. Therefore, to determine the bearing capacity when cedar piles are used in the foundation of the check dam instead of conventional pine piles, we perform vertical loading tests of cedar and larch piles. After the test is completed, the test piles are accumulated and subjected to a longitudinal compression test to evaluate their compressive strength.

 The results show that the bearing capacity and compressive strength of cedar are lower than those of larch. To calculate the bearing capacity when cedar is used as piles, a correction formula obtained by multiplying the conventional bearing capacity formula by 0.7 to 0.6 should be used.