EFFECTS OF THE SHAPE ON VERTICAL BEARING CAPACITY OF THE TIMBER PILE INSTALLED IN SOFT CLAY GROUND

Abstract

 The ultimate bearing capacity of a timber pile in clay is evaluated by the circumferential resistance of a cylindrical body whose diameter is the end diameter. Since timber piles are originally tapered, the taper angle and the shape of the joint may affect the bearing capacity. In this study, four types of single piles and two types of jointed timber piles with the same end diameter and different taper angles were used for vertical loading tests of timber piles in clay ground to investigate the effects of timber pile shape on the vertical bearing capacity and changes in the surrounding ground conditions. It was found that the vertical bearing capacity of the timber pile in clay increased with taper, and that the vertical bearing capacity of a jointed pile decreased as the area of non-contact between the pile and the surrounding clay increased at the joint. Furthermore, it was confirmed that the timber pile had the effect of reducing the water content of the clay around the pile.