Identification of critical ground motions for seismic performance assessment of structures

Abstract

SummaryA method is established to identify critical earthquake ground motions that are to be used in physical testing or subsequent advanced computational studies to enable seismic performance to be assessed. The ground motion identification procedure consists of: choosing a suitable suite of ground motions and an appropriate intensity measure; selecting a computational tool and modelling the structure accordingly; performing Incremental Dynamic Analysis on a nonlinear model of the structure; interpreting these results into 50 th (median) and 90 th percentile performance bounds; and identifying the critical ground motions that are close to these defining probabilistic curves at ground motion intensities corresponding to the design basis earthquake and the maximum considered earthquake. An illustrative example of the procedure is given for a reinforced concrete highway bridge pier designed to New Zealand specifications. Pseudodynamic tests and finite element based time history analyses are performed on the pier using three earthquake ground motions identified as: (i) a Design Basis Earthquake (10% probability in 50 years) with 90 percent confidence of non-exceedance; (ii) a Maximum Considered Event (2% probability in 50 years) representing a median response; and (iii) a Maximum Considered Event representing 90 percent confidence of non-exceedance.

Computational and rapid expected annual loss estimation methodologies for structures

“…Limit states DS2-3 and DS3-4 were found based on observed damage during physical testing [32]. The selection of these limits was based on the failure mechanisms described in Table 1.…”

High-Force-to-Volume Seismic Dissipators Embedded in a Jointed Precast Concrete Frame

“…Both quasi-static testing using cyclic loading patterns and quasi-earthquake displacement (QED) tests (Dutta et al, 1999) using load patterns from computational simulation of the full 10-storey prototype structure were employed. The QED method is intended to produce realistic displacement demands representative of expected seismic response (Dhakal et al, 2006) Quasi-static displacement profiles Preliminary, low drift level quasi-static tests were used to characterise the specimen for use in a computational model for the QED test (Solberg, 2007). Owing to the damage-free nature of the specimen, it was possible to conduct preliminary tests (both uni-and bidirectional) without damaging the specimen.…”

“…Dhakal et al (2006) proposed a methodology based on Incremental Dynamic Analysis (IDA), where an IDA is conducted using multiple earthquake ground motions and the IDA results are probabilistically processed to select records that give medium and high confidence at desired levels of seismic intensity.…”

Experimental multi‐level seismic performance assessment of 3D RC frame designed for damage avoidance

“…Dhakal et al [13] have proposed a methodology based on incremental dynamic analysis (IDA), in which IDA is conducted using several earthquake records and the IDA results are probabilistically processed to identify records that give medium and high confidence at desired levels of seismic intensity. IDA [16] involves conducting non-linear dynamic analyses of a computational model of a structure subjected to a suite of earthquake ground motion records scaled to different intensity measures (IM).…”

“…A multi-level seismic performance assessment (MSPA) methodology is established and applied to the building by using pre-identified critical ground motion records representative of different levels of seismic hazard [13]. By applying these critical ground motion records to computational models of the prototype building, displacement-time histories of certain elements of the building are extracted.…”