The construction of underground structures in Lisbon’s downtown, alongside with the fluctuation of the ground water level, generates settlement-induced damages to old heritage Pombalino masonry buildings. Assessing the potential damage caused by soil settlements to masonry structures is essential for adequate evaluation of their seismic performance and the definition of retrofit solutions. The seismic assessment procedures need to take into account the settlement induced damage and the non-linear behaviour of the masonry materials. This paper seizes a rare opportunity to join, in the same analysis, real settlement profiles imposed to well-characterized historical building typology, known as Pombalino, with the evaluation of their seismic performance simulated with advanced numerical models. Lisbon’s downtown settlements were measured for seven years. From these settlement measures, two settlements’ profiles and two settlements’ rate were identified. This paper presents the results of a study developed on a representative Pombalino building where these settlement profiles were applied to assess their impact on the initial damage and on the seismic performance of the building. The expected level of damage for a given ground motion intensity was estimated through the employment of numerical modelling and nonlinear static analysis, which has shown that damages induced by settlements can reduce significantly the global seismic performance of the building. The level of damage of the building at a global level and local level was studied. For the latter, the damage on structural elements is defined by the mean of the drift parameter, while for the former, the damages levels are defined directly in the pushover curve. This study assessed quantitatively the effect of the differential settlement on the seismic performance of Pombalino buildings and their fragility curves. The results showed the seismic action intensity needed to reach the collapse of the structure is roughly half for longitudinal configuration with the curved profile and nearly 1/5 for transversal shape with the linear profile, when compared to the building without differential settlements.

中文翻译：

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受定居点影响的里斯本市区历史民居建筑的抗震性能和脆性曲线

里斯本市区地下建筑的建设以及地下水位的波动，对定居的庞巴利诺旧砌筑物造成了定居点造成的破坏。评估土壤沉降对砖石结构造成的潜在破坏，对于充分评估其抗震性能和确定改造方案至关重要。地震评估程序需要考虑到沉降引起的破坏和砖石材料的非线性行为。本文利用同一个分析方法，抓住了难得的机会，将真实的沉降轮廓加入了具有良好特征的历史建筑类型（称为Pombalino），并通过先进的数值模型对它们的抗震性能进行了评估。里斯本市区的定居点测量了七年。通过这些定居措施，确定了两个定居点的概况和两个定居点的费率。本文介绍了对具有代表性的Pombalino建筑物进行的研究结果，该建筑物使用了这些沉降曲线来评估其对建筑物的初始破坏和抗震性能的影响。通过使用数值模型和非线性静力分析，可以估算出给定地面运动强度下的预期破坏程度，这表明沉降引起的破坏会显着降低建筑物的整体抗震性能。研究了建筑物在全球和地方层面的破坏程度。对于后者，结构元素的损坏由漂移参数的平均值定义，对于前者，损害水平直接在推覆曲线中定义。本研究定量评估了差异沉降对Pombalino建筑抗震性能及其脆性曲线的影响。结果表明，与没有差异沉降的建筑物相比，达到结构坍塌所需的地震作用强度大约为纵向轮廓（弯曲轮廓）的一半，接近横向形状（线性轮廓）的1/5。