Abstract
The cast-in-place-concrete piles can be slimmed by the construction method of the under-reamed pile. However, the seismic shear stress increases because the area of the pile head decreases. In this paper, first, the specification of such piles and the result of frame analysis which consists of building and foundation are shown as the background data. Secondly, the earthquake-resistant properties of reinforced concrete piles with the normal-strength transverse reinforcement(350MPa) or the high-strength transverse reinforcement(1300MPa) are experimentally considered. Six-teen specimens were tested; two with the diameter of 450mm, twelve with the diameter of 350mm, and two with the diameter of 300mm. The specimens with the diameter of 450mm are models of standard cast-in-place-conerete piles, and the specimens with the diameter of 350mm or 300mm are models of under-reamed piles. Experimental results show that, when properly reinforced with the transverse reinforcement, slim reinforced concrete piles can exhibit stable hysteretic behavior and significant ductility.
