Laser scanning the Garisenda and Asinelli towers in Bologna (Italy): Detailed deformation patterns of two ancient leaning buildings
Laser scanning the Garisenda and Asinelli towers in Bologna (Italy): Detailed deformation patterns of two ancient leaning buildings
复制标题
DOI：
10.1016/j.culher.2011.01.002
复制
发表时间：
2011-04-01
影响因子：
3.1
通讯作者：
Boschi, Enzo
中科院分区：
文献类型：
--
作者：
Pesci, Arianna;Casula, Giuseppe;Boschi, Enzo
阿西内利塔和加里森达塔是意大利博洛尼亚市的主要标志。这两座斜塔的高度分别约为97米和48米，建于12世纪初，是这座城市约100座高大的中世纪建筑中为数不多的两座。因此，它们是意大利文化遗产的一部分，保护它们是极其重要的。为了详细评估这些塔的变形，特别是偏离其壁的规则倾斜，使用了地面激光扫描（TLS），并开发了一种有效的直接分析方法。这些塔从六个视点进行扫描，提供了19个点的云，完全覆盖了具有大重叠区域的可见表面。对于每个塔，在将部分点云配准到共同参照系后，对获得的表面进行精确的形态学分析。结果表明，有几个区域受到明显的变形和倾斜变化的影响。在Asinelli塔的情况下，其有限元模型是可用的，结果也被解释为基于静载荷和正常模式。地震序列引起的实测变形和理论预期变形之间的对应关系是明确的。这一事实表明，该塔对动荷载具有高度敏感性。虽然不能根据获得的结果对风险进行直接评估，但这些结果表明，必须经常检查这些建筑物的结构健康状况，并应避免或至少减少人为载荷（例如车辆交通引起的振动）。(C) 2011 Elsevier Masson SAS。版权所有。
The Asinelli and Garisenda towers are the main symbols of the city of Bologna (Italy). These leaning towers, whose heights are about 97 and 48m respectively, were built during the early 12(th) century and are two of the few surviving ones from about 100 tall medieval buildings that once characterized the city. Therefore, they are part of the Italian cultural heritage and their safeguard is extremely important. In order to evaluate in detail the deformations of these towers, in particular the deviations from a regular inclination of their walls, the terrestrial laser scanning (TLS) has been used and an efficient direct analysis method has been developed. The towers have been scanned from six viewpoints, providing 19-point clouds with a complete coverage of the visible surfaces with large overlap areas. For each tower, after the registration of the partial point clouds into a common reference frame, an accurate morphological analysis of the acquired surfaces has been carried out. The results show several zones affected by significant deformations and inclination changes. In the case of the Asinelli tower, for which a finite element model is available, the results have also been interpreted on the basis of the static load and normal modes. The correspondence between the measured deformation and the theoretically expected deformation, caused by a seismic sequence, is clear. This fact suggests a high sensibility of the tower to dynamic loads. Although a direct evaluation of the risk cannot be carried out with the obtained results, they lead to the general indication that the structural health of these buildings must be frequently checked and that man-made loads (e.g. vibration due to vehicular traffic) should be avoided or at least reduced. (C) 2011 Elsevier Masson SAS. All rights reserved.