EVALUATION ON PILE GROUP EFFECT OF UNDER-REAMED DIAPHRAGM-WALL-TYPE PILES SUPPORTING HIGH-RISE TOWER

Abstract

The Tokyo sky tree is supported by the pile group foundation using under-reamed diaphragm-wall-type piles with different sizes. This report describes the outline of the foundation design, the evaluation method in design of the effect of pile group and the analytical results of FEM. The results of this study are shown as follows: (1) The pile group efficiency is 0.58, 0.49 and 0.68 - 0.73 respectively under pushing, pulling and lateral load. (2) In case of the lateral loading, the pile group efficiency changed according to the direction of the load and the position of the piles.