Reasons why the Leaning Tower of Pisa survives the 4th big earthquake and is not falling down yet is known from the latest survey

ByLarry Koester

It is one of the sights of Italy and it is also registered as a World Heritage SiteLeaning tower of PisaIs a building rarely seen in the world where the entire building stands leaning at an angle of about 4 degrees. Although gradually started to slope from the middle of the construction, despite having experienced at least four big earthquakes from the completion of 1372 until the present, the strength of the Leaning Tower of Pisa which has been standing without failing over 600 years The secret is revealed from the study by the latest civil engineering.

May: Leaning Tower of Pisa | News | University of Bristol
http://www.bristol.ac.uk/news/2018/may/tower-of-pisa.html

This research was led by Professor Camilo Nutti of the Third University of Rome, the research team of 16 scientists was advancing. Members of the Bristol University Department of Civil EngineeringGeorge MironakisProfessors are invited.

The leaning tower of Pisa is a building that took a long time of about 200 years from the start of construction to completion, its construction phase is largely divided into three construction periods. Immediately after the start of construction, the tower was built straight vertically, but gradually it began to be seen from the time the first construction term was over. After that, construction was attempted while attempting to correct the tilt, but finally the trend came to completion in 1372 without returning. At this time, the height of the tower reached about 58 meters.

Although the inclination correction of several degrees was tried even after completion, there was also a circumstance that the inclination got worse further due to problems in the construction method, and the inclination of the tower reached about 5.5 degrees at the maximum. After that, the inclination was corrected by the construction carried out from the 1990s to 2001, and it continues to stand still with the inclination returned to about 3.99 degrees.

The leaning tower of Pisa is inclined to believe that the soil quality of the ground on which the tower is standing is heterogeneous. Although the diameter of the tower is as small as about 15 m at the base part, the soil is not homogeneous in this range but there is a soft part, so the ground subsides due to the weight of the tower and the building is inclined That's why.

BySteve

In spite of standing on such a soft ground, the leaning tower of Pisa does not look like increasing the inclination from a certain angle, but also it can not fall over the past 4 great earthquakes that hit this area I have survived. In order to clarify the reasons, the research team conducted a survey based on elements such as seismology, geotechnical engineering, building structure information, etc. The secret was that the combination of the ground characteristics and the structural features of the building was an exquisite balance We have reached the conclusion that it is in the fact that it is made of.

This is called "Dynamic Soil - Structure Interaction (DSSI: Dynamic Interaction of Soil and Structure)", the softness of the soil where the building is built, the height and robustness of the building on it The vibration characteristics of the building are affected by the fastness). When the building breaks due to the earthquake, the building will resonate against the earthquake causing energy to increase, destroying the structure that can not be tolerated, but a certain height above the unstable and soft ground When resonance and robustness structures are on, this resonance is canceled out. The leaning tower of Pisa is that this balance is established exquisitely by chance, so even if a big earthquake hits it, the building has not collapsed or collapsed.

Thus, we know that the Leaning Tower of Pisa is more exquisite than the ordinary building. Ironically, Mr. Milonakis said, "Ironically, it is also helping to prevent the tower from falling down its ground that tilted the tower to the brink of collapse.

Byravindra gandhi