FUNDAMENTAL STUDY ON SUPERIORITY OF FOUNDATION COMPOSED OF SOILBAGS AND PILES AGAINST VERTICAL FAULT DISPLACEMENT

Abstract

 The authors have proposed a new type “spread foundation” composed of micropiles and soilbags as a method of constructing a spread foundation on soft ground. By separating the piles and the footing, the response acceleration can be reduced, the pile-head joints can be omitted, and the diameter of the piles can be reduced. Moreover, the separation of the piles and the footing may reduce the damage of the footing and the piles and improve the recoverability against the vertical surface fault displacement. In this study, therefore, the displacement and cross-sectional forces of the proposed structure and the pile foundation under the vertical surface fault displacement were compared analytically. The analysis results showed that the bending moment of the footing and the response curvature of the piles can be suppressed significantly compared to the pile foundation, although the displacement at the track may be slightly larger in the proposed structure than in the pile foundation.