Nima Tafazzoli - MSc. of Geotechnical Engineering, College of Civil Engineering,
Mohammad Hassan Baziar - Professor of Geotechnical Engineering, College of Civil Engineering,

Retrofitting of the foundations are needed due to the changes in the loads applied on them and implies any changes in the structure or dimensions of existing foundations for the purpose of adapting them for service under new conditions.Retrofitting is associated with restoration or replacement of their damaged or physically broken-down construction elements due to the increasing in loads on foundations. Existence of some errors in calculating the loads, especially lateral forces such as earthquake, during the designation procedure is another important parameter that makes the retrofitting necessary. Sometimes seismic strengthening of foundations is required due to earthquake loads which may directly cause some problems for foundation or in addition to the other loads uplifts may be founded. Problems of retrofitting of the foundations are practically untouched in the standard specifications and corresponding reference materials which are in present-day use. In this research some of the general methods of retrofitting of the foundations are described which are used widely. Obviously, selecting the appropriate method of retrofitting will be done by consideration the reasons necessitating such reinforcement, constructional features of existing foundations and engineering geological conditions of the area on which the foundation is located.

Retrofitting, Foundation, Concrete Jacket, Pile, Micropile