Geology topics

A.B. Liel

Publications and source records attributed to A.B. Liel.

3 recordsLinked to original sources

USGS2018

Damage accumulation for a two-story wood-frame building in sequences of induced earthquakes

In this study, a nonlinear model of a two-story multifamily wood-frame residential structure is subjected to recordings of sequences of induced earthquakes in order to quantify changes in fragility and accumulation of damage throughout multiple earthquake loadings. Initial efforts consisting of ground motion selection, building design, numerical modeling, and preliminary results are presented. Damage is quantified through a seismic loss estimation procedure that accounts for damage to nonstructural and structural components of the building. Examining damage accumulation from sequential earthquake shaking enables us to explore how the occurrence of damage in an earthquake, even to relatively small levels, may increase a structure’s susceptibility to collapse or damage in subsequent ground shaking. Ultimately, the goal is to compare damage fragilities and seismic losses as a function of the building’s initial damage state.

Kansas, Oklahoma↗

USGS2011

A methodology for post-mainshock probabilistic assessment of building collapse risk

This paper presents a methodology for post-earthquake probabilistic risk (of damage) assessment that we propose in order to develop a computational tool for automatic or semi-automatic assessment. The methodology utilizes the same so-called risk integral which can be used for pre-earthquake probabilistic assessment. The risk integral couples (i) ground motion hazard information for the location of a structure of interest with (ii) knowledge of the fragility of the structure with respect to potential ground motion intensities. In the proposed post-mainshock methodology, the ground motion hazard component of the risk integral is adapted to account for aftershocks which are deliberately excluded from typical pre-earthquake hazard assessments and which decrease in frequency with the time elapsed since the mainshock. Correspondingly, the structural fragility component is adapted to account for any damage caused by the mainshock, as well as any uncertainty in the extent of this damage. The result of the adapted risk integral is a fully-probabilistic quantification of post-mainshock seismic risk that can inform emergency response mobilization, inspection prioritization, and re-occupancy decisions.

Conference Paper↗

USGS2011

Comparison of main-shock and aftershock fragility curves developed for New Zealand and US buildings

Seismic risk assessment involves the development of fragility functions to express the relationship between ground motion intensity and damage potential. In evaluating the risk associated with the building inventory in a region, it is essential to capture 'actual' characteristics of the buildings and group them so that 'generic building types' can be generated for further analysis of their damage potential. Variations in building characteristics across regions/countries largely influence the resulting fragility functions, such that building models are unsuitable to be adopted for risk assessment in any other region where a different set of building is present. In this paper, for a given building type (represented in terms of height and structural system), typical New Zealand and US building models are considered to illustrate the differences in structural model parameters and their effects on resulting fragility functions for a set of main-shocks and aftershocks. From this study, the general conclusion is that the methodology and assumptions used to derive basic capacity curve parameters have a considerable influence on fragility curves.

Conference Paper↗