枠基礎の模型実験結果ならびに枠内土の挙動に関する考察

抄録

To study on load-settlement mechanism and on behavior of inside soil of Framed Foundation, vertical loading tests of model Framed Foundation (internal diameter of frame D = 150mm) were performed on three different loading types (separate type, combined type and frame loading type) and four different depth ratios (L/D = 1 to 4) respectively. In this paper the result of model tests and of investigation on behavior of inside soil are reported. The conclusions are summarized as follows. (1) The bearing capacity increases according as L/D increases in all loading types. There is no significant difference between separate type and combined type at the same L/D. But the bearing capacity of frame loading type decreases after inside soil slips. (2) On separate type and combined type, frictional resistance of outside of frame and point resistance of frame is very small, and point resistance of inside soil is dominant. (3) Inside soil of separate type is compressed from both the top and the bottom under the condition that soil is fixed to frame at the central depth. Inside soil of combined type is thrust up from the bottom under the condition that soil is fixed to frame at the top. Compressibility of inside soil of frame loading type is equal to that of combined type at L/D when inside soil is blockaded. (4) The behavior of inside soil of Framed Foundation can be explicable by model analysis using authors' theory.