Seismic performance and fragility curves of historical residential buildings in Lisbon downtown affected by settlements

Defining the soil stratigraphy from seismic piezocone data: A clustering approach

“…This soil is resting over glacial Miocene deposits of stiff clays (Miranda et al, 2020). Shallow layers are composed by fine clean sands and sandy silts with intercalations of plastic soils (Couto et al, 2020). The presence of such intercalations seems to indicate that the valley was infilled in a heterogeneous process, corresponding to tidal variations in the Tagus River.…”

“…There is historical evidence about the occurrence of medium to large magnitude seismic events (M > 6) that have induced soil liquefaction in this region (Ferreira et al, 2020). An example of earthquake-induced liquefaction is the 1755 earthquake (M = 8.5), which almost destroyed the centre of Lisbon (Couto et al, 2020). Table 1 summarises the parameters to compute the peak ground acceleration (a max ) of the Lisbon area according to EC8-NA (CEN, 2010) for a return period of 475 years.…”

“…This paper presents the results of a comprehensive experimental study aimed at assessing the mechanical behaviour of the fine sand composing the liquefiable layer at the 'Prac ¸a do Come ´rcio' site (Lisbon), which is locally denominated as Terreiro do Pac ¸o since this site was the King's palace courtyard before 1755. Terreiro do Pac ¸o sand (hereafter referred as TP-Lisbon sand) is a historically liquefiable soil that has experienced liquefaction during the 1755 earthquake (Couto et al, 2020;Jorge & Vieira, 1997). Such a seismic event is a well-known major earthquake (M = 8.5) occurred in the Portuguese onshore mainland, which induced the collapse of several buildings in Lisbon, emphasising the King's palace.…”

Soil Injection Technology Using an Expandable Polyurethane Resin: A Review

“…As a result, it leads to the appearance of the foundation's imperfections threatening the whole overlaying constructions status, varying from minor defects to the collapse of the construction due to the foundation's failure. According to the following authors [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]28,39,[47][48][49][50][51], these factors could be sorted as Collapsible/Metastable soil, Liquefiable Soil, Expansive soil, Slope instability, seismic impact, seasonal variation of ground water level, and other natural geological and environmental reasons [52][53][54][55][56][57][58][59][60] • Industrial (technical) reasons: summarized as complex factors caused by engineering errors, such as inadequate preliminary design, insufficient or incorrect geotechnical investigations, poor quality of construction work, violation of building codes, and poor soil compaction during the construction process. In addition, there are aspects related to changes in the capacity concerning a particular project, the poor quality of the construction materials, reconstruction processes, cities planning and developments, the insufficient distance between the adjacent foundations, vibration effect of the neighborhood construction equipment, the changes in the groundwater level due to inappropriate seepage network, and other factors.…”