ubmopa.blogg.se

The construction works started again in 1272, and a total of seven floors were constructed.After five years of construction, work came to a halt due to the scarcity of funds.The walls of the tower are clad with marble and the cavity between the outer and inner wall is filled with a rubble and mortar mix. The tower was constructed as a hollow cylinder.The following points describe the construction of the tower: As a result, the pore pressure distribution is slightly below hydrostatic pressure. However, in the past, water extraction from the lower sand has led to downward seepage from the horizon-A layer. The natural groundwater level is 1-2 m below the ground surface area.This is one of the reasons that led to the tilting of the tower towards the south side. Also, the sand layer is much thinner than on the north side of the tower. The amount of silt and clay is more on the south side of the tower.The thickness of horizon-C extends to a considerable depth. The upper clay layer is very sensitive, whereas the lower clay layer is stiff and less sensitive. Sandy soil is sandwiched between the layers of clayey soil. Horizon-B consists of marine clay and sandy soil.Therefore, the amount of sandy and clayey silts varies under the strata.

This stratum is laid under tidal conditions. Horizon-A consists mainly of estuarine deposits.Soil profile below the tower consists of three horizons.The town of Pisa is located on the alluvial sediments and the mean sea level is only 3-4 m.Moreover, there is a fault passing through the bedrock beneath the town of Pisa. Due to tectonic activities, the city’s strata have undergone severe deformation. The variety of rocks ranges from Paleozoic to tertiary in Pisa city.The following points describe the geology of the site: This article describes the construction of the tower, the ground conditions on which it was constructed, the history behind the tilt, and the temporary and permanent measures taken to stabilize it. However, the future behavior of the tower will depend to a large extent on the effectiveness of the drainage system on the north side. Currently, the tower is stable after the implementation of several stabilization measures. In 1993, the Italian government, concerned about the progressive increase of the rate of inclination and the risk of sudden structural collapse, appointed an international committee to safeguard and stabilize the leaning tower of Pisa.Īfter the formation of the committee, temporary and permanent stabilization measures were taken up to improve the stability of the tower. The continuous increase in the foundation’s inclination originated due to the combined effects of the soil creep and the groundwater fluctuation. The leaning tower of Pisa is constructed on the alluvial sediments over an unstable soil surface, which gradually caused the tower to lean towards one direction.