Dynamic analysis and the Soil Impact on the Piled Raft Foundation of a Tall Office Building (I)

The research starts from an extensive laboratory analysis of foundation soil and concludes by performing a dynamic analysis through a geotechnical computer program. The paper shows the undisguised design stages prior to a foundation project: investigation, design and determining the efficiency through verification. This study aims to highlight the influence of soil type during earthquake upon piled raft foundations (piles with large diameter – columns) of a high civil building. The analysis is performed on two types of earths indigenous to the area of Iaşi city, Romania. Foundation system is designed considering the influence of ground type in terms of sizing and behaviour over time, which means that the piles are computed as friction piles (with lateral friction) which are crossing through a homogeneous layer of earth. The entire structural system is made of reinforced concrete devised at superstructure with frames (columns, beams, plates) and structural walls. The foundation mediums taken into consideration are earths sensitive to moisture and earths with large swellings and shrinkages. The purpose of this research is to obtain a system that supports loads from the normal service of the building and from seismic forces without any major settlements of any kind. This should be possible by adaptation to the environment of foundation soil and by providing safety against quakes.