抄録
A combined foundation method consists of small size steel piles and compacted gravel on the top of those piles is proposed as foundation works for residential buildings. A series of field tests are conducted to clarify the structural behavior of such foundation system, and the spring constants used in design calculation are studied. Tested parameters are the diameter of steel pile and the thickness of compacted gravel. In general,, the ultimate bearing capacity of the specimen becomes large with the increase of the diameter and the thickness. As a result, well compacted gravel with the thickness more than 50 mm realize a rational structural design, reducing the stress concentration in footing beams, and at the same time, enhancing the bearing capacity of the foundation works.