Analytical fragility curves of reinforced concrete buildings subject to tsunami waves

Author(s):  
Fritz Sihombing ◽  
Marco Torbol
2021 ◽  
Vol 1203 (3) ◽  
pp. 032124
Author(s):  
Carlos Julio Calle Castro ◽  
Juan Sebastián Maldonado Noboa ◽  
Luis Mario Almache Sánchez

Abstract Ecuador is located in the Pacific Ring of Fire, a country with high risk and seismic sensitivity, evidenced by the 6.8-degree earthquake in Ambato in 1949, which left approximately 6000 dead, the 7.8-degree earthquake in Manabí and Esmeraldas in the year 2016 with 663 victims and 29672 buildings without the possibility of use. Currently there is a problem about seismic performance in reinforced concrete buildings, since many were built with old regulations; so, it is necessary to assess their vulnerability. Quito, Guayaquil and Cuenca, large cities in Ecuador, have formal studies of seismic vulnerability, mostly carried out by university students and teachers. In contrast, most small cities do not have these studies; or, they need to be updated to validate their results. This is the case of the city of Azogues. The objective of this research is to evaluate the vulnerability of structures using the Hazus methodology, adapted to Ecuador, in the downtown area of the city of Azogues, in structures located around the Central Park, to establish the seismic performance in reinforced concrete buildings. The Hazus methodology, which determines the vulnerability of buildings from fragility curves, which are entered with inputs as the capacity, performance level and drift curves calculated through Ecuadorian models. The capacity curves, depending on various aspects such as: the material, number of floors, spans between columns, among others; they vary from building to building. In this sense, capacity curves were defined for sets of buildings with similar characteristics, coinciding with the Hazus methodology. The performance levels and the displacements were calculated with the ETABS computer package. For fragility curves, the model that most real simulates the response of a structure is the non-linear analysis, because it considers the decrease in stiffness in columns and beams, as well as the deterioration of the properties of the materials. In this sense, there are fragility curves of Ecuadorian buildings for four levels. The earthquake readings enable the construction of a demand spectrum, which, when contrasted with the capacity spectrum, leads to the performance point. Its position sometimes varies per the elastic demand spectrum, which is diminished by its inelastic behavior. As the demand spectrum decreases, the damage will increase. Once the coordinates of the performance point are known, the fragility curves are used; and, the possible damages are defined, quantifying them in percentage.


2010 ◽  
Vol 10 (10) ◽  
pp. 2055-2066 ◽  
Author(s):  
O. Mavrouli ◽  
J. Corominas

Abstract. The vulnerability of buildings to the impact of rockfalls is a topic that has recently attracted increasing attention in the scientific literature. The quantification of the vulnerability, when based on empirical or heuristic approaches requires data recorded from historical rockfalls, which are not always available. This is the reason why appropriate alternatives are required. The use of analytical and numerical models can be one of them. In this paper, a methodology is proposed for the analytical evaluation of the vulnerability of reinforced concrete buildings. The vulnerability is included in the risk equation by incorporating the uncertainty of the impact location of the rock block and the subsequent damage level. The output is a weighted vulnerability that ranges from 0 to 1 and expresses the potential damage that a rock block causes to a building in function of its velocity and size. The vulnerability is calculated by the sum of the products of the probability of block impact on each element of the building and its associated damage state, the latter expressed in relative recovery cost terms. The probability of exceeding a specific damage state such as non-structural, local, partial, extensive or total collapse is also important for the quantification of risk and to this purpose, several sets of fragility curves for various rock diameters and increasing velocities have been prepared. An example is shown for the case of a simple reinforced concrete building and impact energies from 0 to 4075 kJ.


Sign in / Sign up

Export Citation Format

Share Document