A group of researchers, including Professor George Mylonakis (George Mylonakis) from the Department of civil engineering Bristol, found out the reasons of stability of the leaning tower that has withstood four major earthquakes in the region with 1280. It turned out that the main role played by a phenomenon called dynamic interaction of the soil structure. About it reported in a press release on Phys.org.
Built in the XIV century tower of Pisa (Italy) before the restoration works between 1990 and 2001 were tilted at an angle of five degrees due to the small Foundation and soft soil. The offset peaks of the 58-foot structure when it was five feet. However, the tower remained stable even during strong aftershocks, although in the opinion of the engineers, it was supposed to collapse in a moderate seismic activity.
The researchers found that a significant height and rigidity of the tower, combined with the softness of the Foundation change the vibration of the ground so that the structure ceases to resonate with the motion of the earth during tremors. According to scientists, the parameters of the dynamic interaction between different factors in the case of the leaning tower of Pisa reach a record high.
Video, photo All from Russia.