101 results found
Elghazouli AY, Bompa DV, Xu B, et al., 2018, Performance of Rubberised Reinforced Concrete Members under Cyclic Loading, 16th European Conference on Earthquake Engineering (16ECEE)
Elghazouli AY, Bompa DV, Xu B, et al., 2018, Performance of rubberised reinforced concrete members under cyclic loading, ENGINEERING STRUCTURES, Vol: 166, Pages: 526-545, ISSN: 0141-0296
Lee RL, Bradley BA, Graves RW, et al., 2018, Investigation of Systematic Ground Motion Effects through Ground Motion Simulation of Small-to-Moderate Magnitude Earthquakes, Pages: 494-503, ISSN: 0895-0563
© 2018 American Society of Civil Engineers. This paper presents results of ground motion simulations of small-to-moderate magnitude (3.5≤Mw≤5.0) earthquake events in the Canterbury, New Zealand, region over the past decade, for which centroid moment tensor solutions are available, and an investigation of systematic source and site effects determined via non-ergodic analysis. The simulations are carried out using the Graves and Pitarka methodology with the recently developed 3D Canterbury velocity model. In this study, 144 earthquake ruptures, modelled as point sources, are considered with 1924 quality-assured ground motions recorded at 45 strong motion stations located throughout the Canterbury region. The simulated ground motions, and also empirical prediction equations, are compared with observed ground motions via various intensity measures where the residuals are separated into between-event and within-event components to determine systematic source and site effects. Lastly, the causes of the biases are identified leading to recommendations which could improve the predictive capabilities of the simulation methodology.
Skiada E, Kontoe S, Stafford P, et al., 2018, Ground surface amplification for canyon topographies excited with bi-directional earthquake records, 16th European Conference on Earthquake Engineering
Ulmer KJ, Upadhyaya S, Green RA, et al., 2018, A Critique of b-Values Used for Computing Magnitude Scaling Factors, Pages: 112-121, ISSN: 0895-0563
© 2018 American Society of Civil Engineers. The objective of this paper is to explore the effects of relative density, effective confining stress, and liquefaction initiation criteria on the slope (or b-value) of the cyclic stress ratio versus number of uniform stress cycles to liquefaction curve in log-log space. The b-value is central to the computation of magnitude scaling factors (MSF) used in evaluating liquefaction potential and can be determined from cyclic laboratory tests such as cyclic triaxial (CTRX), cyclic simple shear (CSS), and cyclic torsional (CTS) tests. This paper provides a summary of b-values calculated from published test data representing multiple types of laboratory tests, sands, sample preparation methods, and liquefaction criteria. Trends between b-values and relative density are shown to be more ambiguous than is often assumed. Effective confining stresses and liquefaction criteria are also shown to have an effect on b-values.
Xu B, Bompa DV, Elghazouli AY, et al., 2018, Behaviour of rubberised concrete members in asymmetric shear tests, CONSTRUCTION AND BUILDING MATERIALS, Vol: 159, Pages: 361-375, ISSN: 0950-0618
Bommer JJ, Dost B, Edwards B, et al., 2017, Developing a model for the prediction of ground motions due to earthquakes in the Groningen gas field, NETHERLANDS JOURNAL OF GEOSCIENCES-GEOLOGIE EN MIJNBOUW, Vol: 96, Pages: S203-S213, ISSN: 0016-7746
Bommer JJ, Stafford PJ, Edwards B, et al., 2017, Framework for a Ground-Motion Model for Induced Seismic Hazard and Risk Analysis in the Groningen Gas Field, The Netherlands, EARTHQUAKE SPECTRA, Vol: 33, Pages: 481-498, ISSN: 8755-2930
Bompa DV, Elghazouli AY, Xu B, et al., 2017, Experimental assessment and constitutive modelling of rubberised concrete materials, CONSTRUCTION AND BUILDING MATERIALS, Vol: 137, Pages: 246-260, ISSN: 0950-0618
Elghazouli AY, Bompa DV, Xu B, et al., 2017, Inelastic behaviour of RC members incorporating high deformability concrete, Pages: 2399-2406
©Springer International Publishing AG 2018. This paper examines the inelastic behaviour of dissipative zones in structural members incorporating high deformability concrete materials in which mineral aggregates are partly replaced by rubber particles. An experimental study on three large-scale circular reinforced concrete column specimens, subjected to lateral cyclic displacements and co-existing axial loads, is described. The testing arrangement, specimen details, and main observations, are presented and discussed. The test results enable a direct assessment of the strength and ductility characteristics of the specimens. In particular, the study permits an evaluation of the comparative performance of structural members with and without rubber replacement, as well as the influence of external confinement. The results show that, in comparison with conventional reinforced concrete members, structural elements incorporating a significant proportion of aggregate replacement by rubber particles can offer a good balance between bending capacity and ductility, particularly for modest levels of co-existing axial loads. For column members required to sustain substantial gravity loads, favourable performance can be achieved in rubberised concrete members by means of strength enhancement through external confinement such as fibre reinforced sheets. Based on the experimental findings, the main material and response parameters are discussed and their influence on the overall structural behaviour are highlighted.
Sadowski AJ, Rotter JM, Stafford PJ, et al., 2017, On the gradient of the yield plateau in structural carbon steels, JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH, Vol: 130, Pages: 120-130, ISSN: 0143-974X
Skiada E, Kontoe S, Stafford P, et al., 2017, Ground motion amplification for canyon topographies with different input motions, 3rd International Conference on Performance-based Design in Earthquake Geotechnical Engineering (PBD-III), Publisher: ISSMGE
It is widelyknown that topographic irregularities influence the surfaceground motions, typically with anenhancement of the response close to convex topographic features,such as ridges and slope crests. Several studies have investigatedthe ground motion at the surface of filled valleys and empty canyons, focusingmainly onthe geometry and the soil characteristics rather than the input excitation.Further investigation of the impact of the input excitation to the ground surface response is needed in order to modifyexisting ground motion prediction models to account for topographic effects. The response of canyons has been previously examined; but mainly focusing on simple wavelet input. This paper considers a fully weathered canyon (i.e., without any in-fill material) aiming to investigate the influence of the input excitationon the surface ground motion through a parametric time-domain finite element (FE) study. A two-dimensional plane-strain model of an idealisedcanyon is considered for vertically propagating SV waves, using both wavelets and recorded earthquakes as input excitation. The model consists of two step-like slopes with slope height (H), in a homogeneous linear elastic soil layer overlying rigid bedrock. Topographic aggravation is presented for several points along the canyon ground surface aiming to derive a pattern of its distribution considering input excitation with different characteristics.
Skiada E, Kontoe S, Stafford P, et al., 2017, Canyon topography effects on ground motion, 16th World Conference on Earthquake Engineering, Publisher: WCEE
It is broadly known that topographic irregularities effect ground motions, with a particular enhancement of the ground response close to convex topographic features such as ridges and slope crests. Although there are many studies investigatingthe ground motion in the vicinity of slope crests, the response at the toe has not been studied in great detail, as the toe ground motion is normally considered to be smaller than that of the crest. However, for canyon topographies further investigation of the ground motion at the slope toe, where a more complicated response is expected due to the interaction of the canyon sides, is needed. The response of semi-circular and semi-elliptical canyons has been previously examined; butmainly focusing on valleys filled with soft materials. This paper considers a fully weathered canyon (i.e., without any in-fill material) aiming to investigate the influence of a canyon’s width on the surface ground motion through a parametric time-domain finite element (FE) study. A two-dimensional plane-strain model of an idealised canyon is considered for vertically propagating SV waves, using wavelets as input excitation. The model consists of two step-like slopes with slope height (H), in a homogeneous linear elastic soil layer overlying rigid bedrock. The analyses focus first on the canyon slope areas, where the ground motion is altered depending upon the proximity to the topographic irregularity, identifying the main parameters that effect the response. Results are also presented for several points along the canyon ground surface showing that the distribution of topographic aggravation varies significantly with canyon width.
Stafford PJ, 2017, Interfrequency Correlations among Fourier Spectral Ordinates and Implications for Stochastic Ground-Motion Simulation, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 107, Pages: 2774-2791, ISSN: 0037-1106
Stafford PJ, Rodriguez-Marek A, Edwards B, et al., 2017, Scenario Dependence of Linear Site-Effect Factors for Short-Period Response Spectral Ordinates, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 107, Pages: 2859-2872, ISSN: 0037-1106
Bommer JJ, Dost B, Edwards B, et al., 2016, Developing an Application-Specific Ground-Motion Model for Induced Seismicity, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 106, Pages: 158-173, ISSN: 0037-1106
Bora SS, Scherbaum F, Kuehn N, et al., 2016, On the Relationship between Fourier and Response Spectra: Implications for the Adjustment of Empirical Ground-Motion Prediction Equations (GMPEs), BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 106, Pages: 1235-1253, ISSN: 0037-1106
Fox MJ, Stafford PJ, Sullivan TJ, 2016, Seismic hazard disaggregation in performance-based earthquake engineering: occurrence or exceedance?, EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS, Vol: 45, Pages: 835-842, ISSN: 0098-8847
Skiada E, Kontoe S, Stafford P, et al., 2016, Canyon Depth Effect on Surface Ground Motion, 1st International Conference on Natural Hazards & Infrastructure
Topographic effects are rarely accounted for in seismic design codes, despite their potential to significantly modify surfaceground motions. This paper investigates the influence of a canyon’s slope height on the surface ground motion through aparametric time-domain Finite Element (FE) study. A two-dimensional plane-strain model of an idealised canyon isconsidered for vertically propagating SV waves, using wavelets as input excitation. The model consists of two step-likeslopes with slope height (H), in a homogeneous linear elastic soil layer overlying rigid bedrock. The analysis results showthat the distribution of topographic aggravation at the ground surface varies significantly with normalized canyon depthover the input wavelength (H/λ) and it does not necessarily reach a maximum at a specific H/λ ratio, as has been suggestedin previous studies. The validity of this conclusion is investigated for different depths to bedrock and soil layer properties.
Stafford PJ, Sullivan TJ, Pennucci D, 2016, Empirical Correlation between. Inelastic and Elastic Spectral Displacement Demands, EARTHQUAKE SPECTRA, Vol: 32, Pages: 1419-1448, ISSN: 8755-2930
Bommer JJ, Coppersmith KJ, Coppersmith RT, et al., 2015, A SSHAC Level 3 Probabilistic Seismic Hazard Analysis for a New-Build Nuclear Site in South Africa, EARTHQUAKE SPECTRA, Vol: 31, Pages: 661-698, ISSN: 8755-2930
Bora SS, Scherbaum F, Kuehn N, et al., 2015, Development of a Response Spectral Ground-Motion Prediction Equation (GMPE) for Seismic-Hazard Analysis from Empirical Fourier Spectral and Duration Models, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 105, Pages: 2192-2218, ISSN: 0037-1106
Molkenthin C, Scherbaum F, Griewank A, et al., 2015, Sensitivity of Probabilistic Seismic Hazard Obtained by Algorithmic Differentiation: A Feasibility Study, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 105, Pages: 1810-1822, ISSN: 0037-1106
Stafford PJ, 2015, Variability and Uncertainty in Empirical Ground-Motion Prediction for Probabilistic Hazard and Risk Analyses, PERSPECTIVES ON EUROPEAN EARTHQUAKE ENGINEERING AND SEISMOLOGY, VOL 2, Vol: 39, Pages: 97-128
Stafford PJ, 2015, Extension of the Random-Effects Regression Algorithm to Account for the Effects of Nonlinear Site Response, BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, Vol: 105, Pages: 3196-3202, ISSN: 0037-1106
Stewart JP, Douglas J, Javanbarg M, et al., 2015, Selection of Ground Motion Prediction Equations for the Global Earthquake Model, EARTHQUAKE SPECTRA, Vol: 31, Pages: 19-45, ISSN: 8755-2930
Bora SS, Scherbaum F, Kuehn N, et al., 2014, Fourier spectral- and duration models for the generation of response spectra adjustable to different source-, propagation-, and site conditions, BULLETIN OF EARTHQUAKE ENGINEERING, Vol: 12, Pages: 467-493, ISSN: 1570-761X
Camara A, Nguyen K, Ruiz-Teran AM, et al., 2014, Serviceability limit state of vibrations in under-deck cable-stayed bridges accounting for vehicle-structure interaction, ENGINEERING STRUCTURES, Vol: 61, Pages: 61-72, ISSN: 0141-0296
Camara A, Stafford PJ, Nguyen K, et al., 2014, Comfort in slender bridges subjected to traffic loading and hammering effects, Pages: 1512-1519
The verification of the Serviceability Limit State (SLS) of vibrations due to traffic live loads is typically ignored in the design of road bridges with conventional concrete decks. However, the vibrations perceived by pedestrians usually govern the design in slender and light-weight modern structures that take advantage of the improvement in the structural efficiency, material performance and constructive procedures. On the other hand, the comfort of the vehicle users is traditionally ignored in the design of the bridge because pedestrians are usually more sensitive to vibrations. However, in many highway bridges without pathways the only users of the structure are those in the vehicles (drivers and passengers). Considering all the possible bridge users and their specific sensitiveness, this paper addresses the vibration serviceability in a slender under-deck cable-stayed bridge subjected to heavy traffic loading. In this structure the prestressed concrete deck spans a distance of 80 m with a depth-to-span ratio of 1/80. The vehicle-bridge interaction accounts for aspects traditionally ignored like the wheel dimensions and the cross-slope of the bridge. A large number of time-history analyses is conducted to address the influence of road and vehicle properties on the SLS of vibrations. This work is completed with the study of the vehicle impact when it enters and leaves the bridge. The results clearly demonstrate the influence of the wheel dimensions and the road conditions, as well as the importance of high-order modes on the response.
Douglas J, Akkar S, Ameri G, et al., 2014, Comparisons among the five ground-motion models developed using RESORCE for the prediction of response spectral accelerations due to earthquakes in Europe and the Middle East, BULLETIN OF EARTHQUAKE ENGINEERING, Vol: 12, Pages: 341-358, ISSN: 1570-761X
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.