Identification of soil degradation during earthquake excitations by Bayesian inference

Ching, Jianye; Glaser, Steven D.

doi:10.1002/eqe.251

Cited by 14 publications

(6 citation statements)

References 24 publications

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“…2(a)-(b)), corresponding to a decrease in shear-wave velocity as large as 2 orders of magnitude. Such softening is consistent with previous findings from shear tests in the laboratory (Vucetic, 1994) and in the field (Holzer et al, 1989;Ching and Glaser, 2003;Wang et al, 2006). Our measurements also showed a large increase in internal friction (Eq.…”

Section: Comparison With Previous Rheology Measurementssupporting

confidence: 93%

Suspension rheology under oscillatory shear and its geophysical implications

Sumita

Manga

2008

Earth and Planetary Science Letters

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Editor: C.P. JaupartKeywords: suspension rheology coseismic response liquefaction dilatancy triggering Dynamic strain generated by seismic waves is often invoked to explain coseismic responses to earthquakes, such as liquefaction, dilatancy and the remote triggering of earthquakes and eruptions. In order to expand our understanding of the conditions under which such responses occur, we measure the rheology of non-Brownian particle suspensions under oscillatory shear at frequencies corresponding to the seismic band (0.1-10 Hz). We characterize the changes in rheology as a function of volumetric particle packing fraction (0.2-0.6), particle diameter (9, 39 μm), and the viscosity of the suspending fluid (0.97, 12.14 Pas). By varying the stress (corresponding to a strain range 10 − 5 b γ b 10 1 ) we identify three rheological regimes. In order of increasing strain amplitude these are (I) linear viscoelastic, (II) shear-thinning and (III) shear-thickening. Transitions between regimes are better defined by a critical strain, rather than stress, particularly for large packing fractions. We find that critical strains are independent of the shearing frequency and fluid viscosity, whereas they decrease with particle packing fraction. We also monitor how the rheology recovers after imposing a large amplitude shear and find that the time scale for recovery is shorter for larger particles, suggesting that structural recovery is controlled by permeable fluid flow. Our results are consistent with the different regimes identified in previous shear tests of water-saturated sands which have a smaller fluid viscosity, suggesting that the same strain criteria can be applied to a wide variety of geological situations.

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Section: Comparison With Previous Rheology Measurementssupporting

confidence: 93%

Suspension rheology under oscillatory shear and its geophysical implications

Sumita

Manga

2008

Earth and Planetary Science Letters

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“…The degree of degradation and non-recoverable damage is more pronounced in the sandy clay case (experiment #6) than in the soft clay case (experiment #3). This observation is consistent with the conclusion of Ching and Glaser [33].…”

Section: Model Slope Experiments Data Analysissupporting

confidence: 94%

“…These results are compatible to our common understanding of soil degradation behavior. Also, this result is consistent with the results of Chang et al [7], Elgamal et al [8], Glaser and Baise [32], and Ching and Glaser [33]. All of these researchers adapted linear methods and obtained similar results about the degradation of the soil.…”

Section: Vertical Seismic Array Data Analysissupporting

confidence: 93%

Tracking rapidly changing dynamical systems using a non‐parametric statistical method based on wavelets

Ching¹,

Glaser²

2003

Earthq Engng Struct Dyn

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SUMMARYA non-parametric statistical method of tracking rapidly changing dynamical systems is introduced. The method implements the non-linear wavelet thresholding estimator to estimate the evolutionary transfer function of the system. The consistency and optimality of the resulting estimate of our method on rapidly changing systems are stated, while no linear estimator can achieve the same optimality. Two examples of real data are studied using this non-parametric method, including two vertical seismic array case studies and a series of seismic slope experiments. The analysis results are consistent with previous research for the vertical seismic array data. Moreover, our estimate is superior to those from previous research in the sense that our estimate is neither over-smoothed nor under-smoothed. The analysis results are also consistent with the experimental observations for the seismic slope experimental data.

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“…Shumway and Stauffer, 1982;Ching and Glaser, 2003). The Bayesian probabilistic approach has the following advantages: (1) probabilistic methods have the ability to model system disturbances, (2) system identification problems are usually ill-conditioned.…”

Section: Approach To Structural Data Interpretationmentioning

confidence: 99%

Some real-world applications of wireless sensor nodes

Glaser

2004

Smart Structures and Materials 2004: Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems

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This paper presents two case histories of the use of wireless sensor Mote technologies. These are devices that incorporate communications, processing, sensors, sensor fusion, and power source into a package currently about two cubic inches in size -networked autonomous sensor nodes. The first case discussed is the November, 2001, instrumentation of a blastinduced liquefaction test in Tokachi Port, Japan. The second case discussed is the dense-pak™ instrumentation of the seismic shaking test of a full-scale wood-frame building on the UCB Richmond shake table. The utility of dense instumentation is shown, and how it allows location of damage globally unseen. A methodology of interpreting structural seismic respose by Bayesian updating and extended Kalman filtering is presented. It is shown that dense, inexpensive instrumentation is needed to identify structural damage and prognosticate future behavior. The case studies show that the current families of Motes are very useful, but the hardware still has difficulties in terms of reliability and consistancy. It is apparent that the TinyOS is a wonderful tool for computer science education but is not an industrual quality instrumentation system. These are, of course, growing pains of the first incarnations of the Berkeley Smart Dust ideal. We expect the dream of easy to use, inexpensive, smart, wireless, sensor networks to become a reality in the next couple of years.

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Identification of soil degradation during earthquake excitations by Bayesian inference

Cited by 14 publications

References 24 publications

Suspension rheology under oscillatory shear and its geophysical implications

Suspension rheology under oscillatory shear and its geophysical implications

Tracking rapidly changing dynamical systems using a non‐parametric statistical method based on wavelets

Some real-world applications of wireless sensor nodes

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