Effects of Stabilisation of the Leaning Tower of Pisa Using the Finite Element Method

• Main Authors: Bang Jhong, 許榜鍾
• Other Authors: Chine Chung Chiang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/56436845822312495684

博士 === 國立雲林科技大學 === 營建工程系碩士班 === 101 === Leaning Tower of Pisa is one of Italy''s world-famous landmarks, while the stabilisation of the tilted tower is worth investigating. This study was mainly based on the literature data, with the analysis of finite element software Geo-studio, to simulate the stabilisation project of lead weights on tower, small-scale and large-scale extraction of soil between the year of 1995 to 2001. The numerical results were compared with field observation data to understand the settlements, vertical stresses and the rotation angle changes of Leaning Tower of Pisa at each stage of the project. According to the linear elastic results of the numerical analysis, small-scale extraction of soil caused the north footing to settle downward about 0.4 cm on average, while the average downward displacement of the footing, about 1 cm was observed in the field. For the south footing, the average downward displacement about 0.1 cm was calculated, while the average upward displacement about 0.3 cm was observed in the field. After the soil extractions were completed and lead weights were removed, the north footing settled downward about 3.4 cm on average, while the average downward displacement of the footing, about 13.5 cm was observed in the field. For the south footing, the average downward displacement about 0.1 cm was obtained, while the average upward displacement about 1.7 cm was observed in the field. As for the rotation of Leaning Tower, small-scale extraction of soil caused the tower to rotate about 0.02 degrees northward, while the rotation angle change of the tower, 0.03 degrees northward was observed in the field. After the soil extractions were completed and lead weights were removed, the tower rotated about 0.16 degrees northward, while the rotation angle change of the tower, 0.4 degrees northward was observed in the field. From the numerical simulation results, lead weights on tower and small-scale extraction of soil both caused the north and south footings to settle downward about 0.4 and 0.1cm respectively on average, while the large-scale extraction of soil caused the north and south footings to settle downward about 3.3 and 0.3cm respectively. As for the rotation angle change of Leaning Tower, lead weights on tower caused the tower to rotate about 0.01 degrees northward; small-scale extraction of soil caused the tower to rotate about 0.02 degrees northward; and the large-scale extraction of soil caused the tower to rotate about 0.14 degrees northward. Therefore, the large-scale extraction of soil is the best stabilization method in this study.