Non‐structure‐specific intensity measure parameters and characteristic period of near‐fault ground motions

Yang, Dan; Pan, Jian-Wei; Li, Gang

doi:10.1002/eqe.889

Cited by 94 publications

(51 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This sense of linearity, however, should be viewed merely as a mathematical device, for the response of the system is inherently plastic. Equation (21) also suggests that the Plastic Input Acceleration (PIA) coincides with that relative to the ground acceleration of the system. Thereby, the integrals of ü g describe the corresponding relative to ground velocity and displacement.…”

Section: Discussionmentioning

confidence: 99%

“…Alternative proposals have been put forth over the years to determine the initiation and end of these excursions by visual and computational means [15][16][17][18][19][20][21][22]. Owing to a lack of a precise definition for an earthquake pulse 854 E. VOYAGAKI, G. MYLONAKIS AND I. N. PSYCHARIS associated pulse end, and a new surpass of a y is sought in the remainder of the time history.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

A shift approach for the dynamic response of rigid‐plastic systems

Voyagaki

Mylonakis

Psycharis

2010

Earthq Engng Struct Dyn

View full text Add to dashboard Cite

A shift approach is presented for evaluating and interpreting the response of rigid-perfectly plastic singledegree-of-freedom systems to dynamic loading. Scaling laws for such systems are, as the term suggests, multiplicative in nature, relating peak dynamic response to products of key problem parameters such as linear spectral coordinates, force reduction coefficient and peak values of the excitation and its time derivatives. Contrary to classical laws, the proposed approach is additive, imposing a shift in the ordinates and the abscissa of the excitation function by means of a set of parameters uniquely related to the yielding resistance of the system. The dynamic response is then obtained by integrating the modified excitation function in a linear-like manner within a particular yielding branch, for the nonlinearity is incorporated into the forcing term. The mathematical validity of the approach is demonstrated analytically and its importance is highlighted for systems with symmetric yielding resistance subjected to near-fault earthquake motions. The modified excitation function may be discontinuous between different yielding branches and relates uniquely to the development of plastic deformation. It is thereby referred to as Plastic Input Motion (PIM). It is shown that the ordinates and the duration of this function may be significantly (yet not necessarily) smaller than those of the original ground motion depending on yield strength. The relationship of the proposed approach to the existing methods and parameters of earthquake engineering such as Newmark's sliding block and relative ground acceleration, is discussed. A SHIFT APPROACH FOR THE DYNAMIC RESPONSE 853 Figure 4. Definition of integration limits and Plastic Input Acceleration (PIA) according to the proposed approach.and the complexity of the associated time histories, all available methods encompass some degree of ambiguity. By virtue of the physics of a rigid-perfectly plastic system, a simple unambiguous procedure is employed in this study, as depicted in Figure 4: First, acceleration peaks associated with large velocity content are identified. The initiation of the pulse is set at the time wherë u g = |a y |, which coincides with the initiation of yielding and which can be readily established on the acceleration record (point 1, Figure 4(a)). Second, the ordinates and the abscissa of the time history are shifted by a y and t y , respectively, to set the origin of the new axes at the beginning of the pulse (point 1, Figure 4(b)). Third, integration of the modified ground acceleration is carried out considering zero initial conditions, up to the point where the modified ground velocity function becomes zero. This time instant (point 2, Figure 4(b)) corresponds to a possible end of yielding and manifests itself in the form of equal areas of opposite signs in the modified record. Fourth, if the acceleration level in the original record at the zero-velocity time instant (point 2) is smaller than a y (this case does not correspond to the one shown in F...

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

A shift approach for the dynamic response of rigid‐plastic systems

Voyagaki

Mylonakis

Psycharis

2010

Earthq Engng Struct Dyn

View full text Add to dashboard Cite

show abstract

“…Further, sudden tectonic motions due to an earthquake can produce impulsive motions leading to permanent displacements at the site. Such motions have one sided velocity pulses [6,7]. Pulse-type ground motions possess immense damage potential, specifically for intermediate and longperiod structures [8].…”

Section: Introductionmentioning

confidence: 99%

Spectral Characterization of Himalayan Near-Fault Ground Motion

Kumar

Pandey

2016

Period. Polytech. Civil Eng.

View full text Add to dashboard Cite

IntroductionThe three moderate-sized shallow-focus earthquakes namely, the 1986 Dharamsala earthquake (M w = 5.5), the 1991 Uttarkashi earthquake (M w = 6.8), and the 1999 Chamoli earthquake (M w = 6.5) occurred in the Himalayan region. The Dharamsala earthquake occurred in the Kangra region of Himachal Lesser Himalaya, at the north-western edge of the rupture zone of great Kangra earthquake of 1905. This earthquake was recorded at nine stations of the Kangra strong motion array, deployed in the epicentral track of the Kangra earthquake in Himachal Pradesh [1]. The two moderate earthquakes, viz., the Uttarkashi earthquake and the Chamoli earthquake, occurred in the Garhwal Himalaya that form part of the Western Himalaya. These earthquakes caused severe damage in and around the Uttarkashi and Chamoli regions. The epicenters of these earthquakes were located in the seismic gap postulated between the rupture zones of the 1905 Kangra earthquake (M w~8 .0) and the 1934 Bihar-Nepal earthquake (M w~8 .4) [2]. The Uttarkashi earthquake was recorded at thirteen stations while the Chamoli earthquake was recorded at eleven stations of the strong motion array, deployed in the Garhwal and Kumaun Himalaya [3]. The purpose of this array was to measure the strong ground motion due to gap-filling earthquakes that were expected in the seismic gap. The strong motion recordings of these three moderate earthquakes have been analyzed for the purpose of identifying near-fault pulses. To allow for pulse detection, standard methodology proposed by [4] has been adopted. Near-fault pulses are attributed to forward directivity, fling, hanging wall and vertical effects [5]. Forward directivity occurs when the fault rupture propagates towards the site with a velocity close to the shear wave velocity. Further, sudden tectonic motions due to an earthquake can produce impulsive motions leading to permanent displacements at the site. Such motions have one sided velocity pulses [6,7]. Pulse-type ground motions possess immense damage potential, specifically for intermediate and longperiod structures [8]. Out of 33 strong ground motion recordings, only three recordings showed pulse-type characteristics. A brief description of the methodology employed for pulse detection, followed by comparison of spectral characteristics of near-

show abstract

“…Considering the frequency property of near-fault ground motions with rich long-period contents, Yang et al (2009) proposed two improved intensity measures, namely, improved effective peak acceleration (IEPA) and improved effective peak velocity (IEPV). They are expressed as: (2) in which Sa TPA+0.2s) represents the mean 5%-damped spectral acceleration in the period range of TPA−0.2s and TPA+0.2s, and the length of interval is 0.4 s as the same as the definition in ATC-3 code; Sv TPA+0.2s) denotes the mean 5%-damped spectral velocity in the period range of TPV.…”

Section: Intensity Measures Of Near-fault Ground Motionsmentioning

confidence: 99%

“…Moreover, note that the existing seismic design codes in many countries are developed based on the earthquake records not enough close to destructive faults, and the associated studies and understandings on damage potentials of near-fault ground motions with long-duration impulses are still insufficient. This paper reviews the recent research developments of authors in the engineering characteristics of near-fault ground motions (Yang et al 2009;Yang and Wang 2012;Yang and Zhang 2013;Yang and Long 2014;Zhou 2015) and seismic performance analysis of building structures (Yang et al 2005;Yang et al 2006;Yang et al 2007;Yang et al 2008;Jiang et al 2010;Yang and Zhao 2010). In particular, two non-structure-specific intensity measures, i.e.…”

Section: Introductionmentioning

confidence: 99%

Recent advances in engineering characteristics of near-fault ground motions and seismic effects of building structures

Yang¹,

Yang²,

Chen³

2015

Proceedings of the Second International Conference on Performance-Based and Life-Cycle Structural Engineering (PLSE 2015)

Self Cite

View full text Add to dashboard Cite

Severe damages of civil infrastructures under near-fault ground motions have impelled the community of earthquake engineering to pay intensive attention and investigation to their engineering characteristics and structural seismic effects. This paper reviews the recent research advances of authors in the engineering characteristics of near-fault ground motions and seismic responses and base-isolated performance analysis of building structures. Firstly, two non-structure-specific intensity measures, such as improved effective peak acceleration and velocity (IEPA, IEPV) were proposed. Two frequency content parameters were also suggested, namely the mean period of Hilbert marginal spectrum Tmh, and coefficient of variance of dominant instantaneous frequency of Hilbert spectrum Hcov which reflects the frequency nonstationary degree of ground motions. Meanwhile, a new stochastic model to synthesize near-fault impulsive ground motions with the feature of the strongest pulse was established. Then, the chaotic and fractal/multifractal characteristics of strong earthquake ground motions were analyzed deeply to explore their complexity from a novel perspective of nonlinear dynamics, and the inherent relation between fractal dimensions and period parameters of near-fault motions was exposed. Moreover, the mechanism of interstory deformation of tall building was illustrated based on engineering properties of pulse-like ground motions and generalized drift spectral analysis. Finally, the influence of ground motion properties on the seismic responses and performance of tall structures and baseisolated buildings was revealed.

show abstract

Non‐structure‐specific intensity measure parameters and characteristic period of near‐fault ground motions

Cited by 94 publications

References 34 publications

A shift approach for the dynamic response of rigid‐plastic systems

A shift approach for the dynamic response of rigid‐plastic systems

Spectral Characterization of Himalayan Near-Fault Ground Motion

Recent advances in engineering characteristics of near-fault ground motions and seismic effects of building structures

Contact Info

Product

Resources

About