支持杭の載荷試験における降伏荷重の力学的意義に関する考察(第2報)

抄録

In this study, the author has tried to obtain an answer to the question what happens on pile under the ground surface when loadind on a bearing pile reaches to "yield bearing capacity". In part 1, the "yield bearing capacity" of bearing piles was defined from the result of the investigation on the characters of load〜settlement〜time curves. And stress〜strain curves of pile materials and load〜settlement curves of plate loading tests on foundation etc., were shown to have yield limits similar to the yield bearing capacity. In part 2, from the consideration on the results of experiments on bearing piles, which the author has performed, it is pointed out that the yield bearing capacity is due to which of the following two causes and not effected by the yield limit of frictional resistance acting on pile surface. (i) yield of point resistance Q_<py> (ii) yield of pile material Q_<my> As the result, it is described that there are three types as shown in equation (19)〜(21), in the relation between Q_<0y> (yield bearing capacity), Q_<0(fu)> (the value of load when the frictional resistance reaches to the ultimate value) and Q_<0(py)> (the value of load when the point resistance reaches to yield limit). (i) Q_<0y>=Q_<my><Q_<0(fu)><Q_<0(py)> (19) (ii) Q_<0(fu)><Q_<0y>=Q_<my><Q_<0(py)>(20) (iii) Q_<0(fu)><Q_<0y>=Q_<0(py)><Q_<my> (21)