Abstract
Determining the dynamic characteristics in advance and increasing durability of ground and structures beyond the presumed seismic force is a fundamental for preserving the historical structures. Main purpose of this study is to investigate the dynamic and other characteristic features of Pisa tower and answer the questions such as in which frequency the tower vibrates and where is the center and direction of this movement? Microtremor method is applied for this purpose. Rocking vibration frequency for entire structure is found as 0.98Hz in NS and 1.06Hz for EW direction. Center of this movement in NS direction is located in rather southern site of the central axis, almost under the bottom of foundation. In EW side this depth is about 1.5m under the foundation. Amplification is bigger in EW direction which shows tendency to move to thisdirection also. Ground bearing capacity is also calculated and it has been found that it changesbetween lkg/cm3 to 2.5 kg/cm3 for the vertical frequency changing between 2.2-2.5 Hz. From theresults, microtremor method is proved to be a useful tool for this kind of investigations, since iteasily gives needed information in a short period of time.
