An Integrated Computational Approach for Seismic Risk Assessment of Individual Buildings

Abstract

The simultaneous assessment of a great number of buildings subjected to different ground motions is a very challenging task. For this reason, a new computational integrated approach for seismic assessment of individual buildings is presented, which consists of several independent computer objects, each having its own user interface, yet being totally interconnectable like in a puzzle. The hazard module allows considering a code-based response spectrum or a predicted response spectrum for a given earthquake scenario, which is computed throughout the resolution of an optimization problem. The vulnerability of each building is assessed based on structural capacity curves. Damage is evaluated using an innovative proposal, which is to use what was called a performance curve associated with a capacity curve. This curve reproduces the percentage of a given response spectrum corresponding to a performance point for each displacement value of a capacity curve. Therefore, it becomes possible to do a very fast association of any limit state to a percentage of a seismic action. This approach was implemented in the PERSISTAH software, and the result outputs can be exported, instantaneously, to the Google Earth software throughout the creation of a kml file, or to MS Excel.

Specific seismic retrofitting of a compact reinforced concrete building with X-bracings and steel jackets. Application to a primary school in Huelva

“…All of the information related to the building (capacity curves, building's location, structural characteristics, etc.) are imported in the specific software, which has been developed in the PERSISTAH project to evaluate the seismic vulnerability of building´s schools [49]. The aim is to obtain the different points of damage limit states (S d1 (OP), S d2 (DL), S d3 (SD), S d4 (NC)) (Fig 2), the PP displacement (d t ), fragility curves and the probability percentage of the damage limit state.…”

Nonlinear Seismic Analysis of Existing RC School Buildings: The “P3” School Typology

“…An alternative to NTHA is to adopt nonlinear static analysis (NSA), which is a less computer demanding alternative, often used for seismic assessment of school buildings [9,[18][19][20]. Moreover, the validation tests that were carried out upon the development of a dedicated seismic assessment software show a good agreement between NTHA and NSA [16].…”

“…Because the capacity curves are also used for civil protection purposes, namely for assessing the degree of damage associated with any given earthquake scenario [16], and not only for assessing the seismic safety level that is established in the EC3-3, a different approach was adopted in the context of the PERSISTAH project, which was already used in past seismic assessment studies [26], namely: if the NC shear capacity limit was reached during the iterative process, which corresponds to the shear capacity that is given by Equation (A.12) of EC8-3, then the shear strength was reduced to a value corresponding to 20% of the initial shear strength without stopping the pushover analysis. This value is the SeismoStruct default option, which agrees with results obtained from some laboratorial tests results [27].…”

“…In this context, one of the main goals of the PERSISTAH project was to evaluate the seismic safety of the primary school buildings (Figure 1) that exist in the neighbouring regions of Algarve (Portugal) and Huelva (Spain). To accomplish such a demanding goal, software for the evaluation of the seismic safety of several individual school buildings was developed [16], not only for ranking their seismic vulnerability for retrofitting purposes, using the new concept of performance curve, but also for the evaluation of the damage level resulting from a given earthquake scenario, mainly for civil protection purposes, because schools are often used as emergency centres and for sheltering the populations after the occurrence of a destructive earthquake. This work is about the use of this new ranking approach for studying the seismic safety of the so-called "P3" school, which is an RC school typology that began construction in the Algarve before the existence of more demanding seismic codes.…”

Seismic Performance Assessment of an Existing RC Wall Building with Irregular Geometry: A Case-Study of a Hospital in Croatia

“…A further interesting approach to perform the seismic assessment of individual buildings, that may also be used for health care facilities, using several independent computer objects, has been presented in [10]. Ferraioli [11] evaluated the seismic vulnerability of the irregular RC hospital building of Avezzano in Italy using the pushover method, and studied the sensitivity of torsional inelastic responses to lateral force distributions, higher mode contributions, accidental eccentricity and controlled points for monitoring the target displacement.…”