Multipoint Traveling Wave Decomposition Method and Its Application in Extended Pile Shaft Integrity Test

2021 ◽  
Vol 147 (11) ◽  
pp. 04021128
Author(s):  
Juntao Wu ◽  
M. Hesham El Naggar ◽  
Jian Ge ◽  
Kuihua Wang ◽  
Shuang Zhao
Keyword(s):  
Traveling Wave ◽  
Decomposition Method ◽  
Integrity Test ◽  
Pile Shaft ◽  
Extended Pile Shaft ◽  
Wave Decomposition

Estimating Inelastic Displacements for Design: Extended Pile-Shaft-Supported Bridge Structures

2004 ◽  
Vol 20 (4) ◽  
pp. 1081-1094 ◽  
Author(s):  
T. C. Hutchinson ◽  
Y. H. Chai ◽  
R. W. Boulanger ◽  
I. M. Idriss
Keyword(s):  
Numerical Study ◽  
Accurate Estimation ◽  
Displacement Estimation ◽  
Displacement Ductility ◽  
Inelastic Displacement ◽  
Pile Shaft ◽  
Alternative Approach ◽  
Bridge Structures ◽  
The Mean ◽  
Extended Pile Shaft

Accurate estimation of inelastic displacements is important for the evaluation of the seismic performance of structures with desired ductile response. In this paper, nonlinear dynamic analyses results from a companion numerical study investigating the response of ductile-designed bridge structures, were compared with a commonly applied inelastic displacement estimation approach and an alternative approach. The extended pile-shaft-supported bridge structures considered are susceptible to amplified response under long-period velocity pulses, and hence an evaluation of design methods for estimating inelastic displacement demands is warranted. In this case, force-reduction–displacement-ductility–period (R−μΔ−T) relations and a mean spectral displacement approach are investigated. The alternative approach estimates inelastic displacement demand using the mean elastic spectral displacement between two spectral periods that are important for the structure's response. Results support the conceptual merits of using the mean spectral displacement method, indicating that the approach is capable of reducing the uncertainty in predicting inelastic displacement demands for the types of structures considered when subjected to near-fault ground motions.

scholarly journals Superposition of gravity waves with different propagation characteristics observed by airborne and space-borne infrared sounders

2020 ◽  
Author(s):  
Isabell Krisch ◽  
Manfred Ern ◽  
Lars Hoffmann ◽  
Peter Preusse ◽  
Cornelia Strube ◽  
...  
Keyword(s):  
Ray Tracing ◽  
Gravity Wave ◽  
Gravity Waves ◽  
Decomposition Method ◽  
Wave Packets ◽  
Wave Structure ◽  
Multiple Wave ◽  
Wave Decomposition ◽  
D Wave ◽  
Middle Stratosphere

Abstract. A complex gravity wave structure consisting of a superposition of multiple wave packets was observed above southern Scandinavia on 28 January 2016 with the Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA). The tomographic measurement capability of GLORIA enabled a detailed 3-D reconstruction of the gravity wave field and the identification of multiple wave packets with different horizontal and vertical scales. The larger-scale gravity waves with horizontal wavelengths 5 around 400 km could be characterised using a 3-D wave-decomposition method. For the characterization of the smaller-scale wave components with horizontal wavelengths below 200 km, the 3-D wave-decomposition method needs to be further improved in the future. For the larger-scale gravity wave components, a combination of gravity-wave ray-tracing calculations and ERA5 reanalysis fields identified orography as well as a jet-exit region and a low pressure system as possible sources. All gravity waves propagate 10 upward into the middle stratosphere, but only the orographic waves stay directly above their source. The comparison with ERA5 also shows that ray-tracing provides reasonable results even for such complex cases with multiple overlapping wave packets. AIRS measurements in the middle stratosphere support these findings, even though their coarse vertical resolution barely resolves the observed wave structure in this case study. The high-resolution GLORIA observations are therefore an important source of information on gravity wave characteristics in the upper troposphere and lower stratosphere region.

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