ABSTRACT

The repair of historical masonry columns damaged by earthquakes is a complex engineering procedure. In most cases, these elements support important vertical loads, and, for this reason, the repairing interventions (such as block replacement) could generate critical modifications of the stress pattern and eventually lead to local failures of the masonry material. In order to prevent critical situations, the repair work should account a complete unloading-reloading process of the column. However, at this time, no specific indications are provided by technical codes and guidelines. In the present paper, the unloading-reloading process developed for the stone masonry columns of the Basilica di Collemaggio in L’Aquila (Italy) is presented. Particularly, two specific unloading systems were designed and verified with advanced finite element analyses. A three-dimensional finite element model of the colonnade and supported nave wall was implemented to check if the unloading-reloading process would significantly change the state of stress in the masonry, causing local failures. The geometry of the structure was reconstructed from a complete laser scanner survey of the church, by considering all the intrinsic irregularities of heritage constructions. Finally, a comparison between the numerical results and the corresponding values measured during the worksite intervention was carried out.

摘要

修复因地震损坏的历史砌体柱是一项复杂的工程过程。在大多数情况下，这些元件支持重要的垂直载荷，因此，修复干预（例如块更换）可能会对应力模式产生重大修改，并最终导致砌体材料的局部失效。为防止出现危急情况，维修工作应考虑到柱子的完整卸载-重装过程。但是，目前，技术规范和指南没有提供具体的指示。本文介绍了为意大利拉奎拉大教堂的石砌柱开发的卸载-重装过程。特别是，设计了两个特定的卸载系统，并通过先进的有限元分析进行了验证。实施了柱廊和支撑中殿墙的三维有限元模型，以检查卸载-重载过程是否会显着改变砌体中的应力状态，导致局部失效。该结构的几何形状是通过对教堂的完整激光扫描仪调查重建的，并考虑了遗产建筑的所有内在不规则性。最后，将数值结果与工地干预期间测量的相应值进行了比较。该结构的几何形状是通过对教堂的完整激光扫描仪调查重建的，并考虑了遗产建筑的所有内在不规则性。最后，将数值结果与工地干预期间测量的相应值进行了比较。该结构的几何形状是通过对教堂的完整激光扫描仪调查重建的，并考虑了遗产建筑的所有内在不规则性。最后，将数值结果与工地干预期间测量的相应值进行了比较。