Surface settlement prediction under non-open cut method with multi-pressed steel pipes in sand

Generally, non-open cut method is applied in urban areas. Since the ground depth above applications of non-open cut method is usually low in urban areas, loads on the upper ground are likely to occur as brittle failure on the surface. In order to minimize the displacement of the upper surface under non-open cut method, steel pipes are press-fitted before excavation for reinforced ground. At this time, surface settlement of the upper ground unavoidably occurs due to friction force between ground and steel pipes, excessive excavation, etc. In this study, settlement data of field tests above the ground water table in sand were analyzed and numerical analyses were performed in order to predict the surface settlement caused by press-fitted steel pipes. A prediction equation of surface settlement, based on Gauss distribution curve, was proposed and verified through field test and numerical analysis.