ABSTRACT

The present study takes advantage of a parametric model, which allows one to create automatically complex structural models of ribbed masonry vaults. Two numerical modelling strategies are discussed: a 3D continuum and a 3D contact-based model. The effects of settlements are studied by imposing vertical displacement at the vault supports up to collapse. Predictions of each modelling strategy are compared with actual damage observation. A representative square vault of Milan Cathedral is studied here, aiming to understand the causes of the damage documented through the years. The structure is noted to have suffered structural damage in the vaulting system due to a long history of soil settlements. The geometry is based on a photogrammetric scanning, and the three-dimensional solid models are created through parametric reconstruction procedures, including details such as springing, arch, ribs, web, and rubble-fill. Both modelling strategies allow to highlight the vulnerability of masonry vaults due to settlements. Significant differences in prediction capabilities are noted when large displacements and separation of elements are involved. The simulations show the possibility of predicting and interpreting different complex damage phenomena as arch block damage or sliding, and web–arch detachment, which is frequently observed in historical structures.

摘要

本研究利用了参数模型，该模型允许人们自动创建复杂的带肋砌体拱顶结构模型。讨论了两种数值建模策略：3D 连续体和 3D 基于接触的模型。通过在拱顶支撑处施加垂直位移直至倒塌来研究沉降的影响。将每种建模策略的预测与实际损伤观察结果进行比较。此处研究了具有代表性的米兰大教堂方形拱顶，旨在了解多年来记录的损坏原因。由于土壤沉降的悠久历史，该结构在拱顶系统中遭受了结构性损坏。几何形状基于摄影测量扫描，三维实体模型是通过参数重建程序创建的，包括弹簧、拱形、肋骨、腹板和碎石填充等细节。这两种建模策略都可以突出砌体拱顶由于沉降而造成的脆弱性。当涉及大位移和元素分离时，预测能力的显着差异。模拟显示了预测和解释不同复杂损坏现象的可能性，如拱块损坏或滑动，以及在历史结构中经常观察到的腹板-拱分离。