Retrofitting and strengthening of Existing Building Foundation

摘要

Large numbers of existing buildings are made of concrete. It has been noticed that some of them proved to be inadequate to resist lateral or vertical loads by current code requirements. This may be due to poorly designed or damaged elements of buildings. Also, during the life span of a building, some of its elements may deteriorate damage or simply get older. Adding shear walls and/or wing walls is one method of strengthening buildings to resist lateral loads such as earthquake or wind loads. In the present work, some methods of strengthening existing foundation concrete buildings to resist lateral and vertical loads are presented. A study case of an existing sweet factory in Cairo area is presented. Deterioration of some concrete elements due to old age has been found. The said condition of the foundation was due to washing floors with chemicals to remove sticky sweets. However, no adequate disposal system was found (waste water collection). The analyses of the structural elements of that existing building showed that it is seismically unsafe. Retrofitting of existing damage and deteriorated foundation was done by adding new raft foundation and considering the old foundation as plain concrete. The addition of new shear and wing walls was undoubtedly the best method of strengthening the existing structure to improve seismic performance. The walls were cast-in-site. The shear and wing walls were connected to the foundation.