Application of discrete wavelet transform in seismic nonlinear analysis of soil–structure interaction problems

2021 ◽  
pp. 875529302098802
Author(s):  
Reza Kamgar ◽  
Reihaneh Tavakoli ◽  
Peyman Rahgozar ◽  
Robert Jankowski
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Nonlinear Analysis ◽  
Soil Structure ◽  
Soil Structure Interaction ◽  
Peak Ground Velocity ◽  
Computational Time ◽  
Discrete Wavelet ◽  
Seismic Responses ◽  
Structure Interaction

Simulation of soil–structure interaction (SSI) effects is a time-consuming and costly process. However, ignoring the influence of SSI on structural response may lead to inaccurate results, especially in the case of seismic nonlinear analysis. In this article, wavelet transform methodology has been utilized for investigation of the seismic response of soil–structure systems. For this purpose, different story outrigger-braced buildings resting on two different types of soil have been considered for SSI analysis. For each SSI system, several seismic records, with different values of peak ground acceleration (PGA) and peak ground velocity (PGV), have been first decomposed into approximate and detailed signals using a discrete wavelet transform. Then, seismic responses of the SSI systems subjected to the approximate signal have been evaluated. The results of the study show that, for earthquakes with low PGA/PGV ratio, the error percentage of all the parameters is smaller than 5% for the first level, and the error index is below 10% for the third level. As the PGA/PGV ratio of an earthquake increases, the concordance of approximate results with the main results decreases. However, even for the earthquakes with the PGA/PGV ratio higher than 1.2 g s/m, the first-level approximation can be used to predict seismic responses with at least 90% accuracy while significantly reducing the computational time.

Effect of Structure-Soil-Structure Interaction (SSSI) between Three Dissimilar Adjacent Bridges

2021 ◽  
Author(s):  
Mohanad Talal Alfach ◽  
Ashraf Ayoub
Keyword(s):  
Seismic Response ◽  
Seismic Behavior ◽  
Soil Structure ◽  
Soil Structure Interaction ◽  
Numerical Analyses ◽  
Seismic Responses ◽  
Structure Interaction ◽  
Internal Forces ◽  
Isolated Bridge ◽  
Effect Of Structure

Abstract The present study assesses the effect of Structure-Soil-Structure-Interaction (SSSI) on the seismic behavior of three dissimilar adjacent bridges by comparing their seismic responses with the seismic response of the isolated bridge including Soil-Structure-Interaction (SSI). To this end, an extensive series of numerical analyses have been carried out to elicit the effects of Structure-Soil-Structure-Interaction (SSSI) on the seismic behavior of three dissimilar bridges with different superstructure masses. The studied bridges are based on groups of piles founded in nonlinear clay. A parametric study has been performed for configurations of three dissimilar bridges with superstructure masses ratios of 200% and 300%, concentrating on the influence of the inter-bridge spacing, and the geometrical position of the bridges towards each other and towards the seismic excitation direction. The numerical analyses have been conducted using a three-dimensional finite difference modeling software FLAC 3D (Fast Lagrangian analysis of continua in 3 dimensions). The results of the numerical simulations clearly show that the seismic responses of the dissimilar grouped bridges were strongly influenced by the neighboring bridges. In particular, the results reveal a salient positive impact on the acceleration of the superstructure by a considerable drop (up to 90.63%) and by (up to 91.27%) for the internal forces induced in the piles. Comparably, the influence of bridge arrangement towards the seismic loading were prominent on both of superstructure acceleration and the internal forces in the piles. The responses were as much as 27 times lesser for the acceleration and 11 times smaller for the internal forces than the response of the isolated bridge. Contrarily, the inter-bridge spacing has a limited effect on the seismic response of the grouped bridges.

scholarly journals On consistent nonlinear analysis of soil–structure interaction problems

2018 ◽  
Vol 40 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Andrzej Truty
Keyword(s):  
Nonlinear Analysis ◽  
Soil Structure ◽  
Limit State ◽  
Design Procedure ◽  
Linear Structure ◽  
Soil Structure Interaction ◽  
Ultimate Limit State ◽  
Structure Interaction ◽  
Finite Element Software ◽  
Computational Strategy

AbstractNonlinear soil–linear structure computational strategy is commonly accepted in the community of geotechnical engineers using advanced finite element software for solving complex soil–structure interaction problems. However, further design procedure of the structural elements is carried out using increased values of the computed elastic stress resultants. It is absolutely not clear whether this method is conservative and, therefore, whether safe or not. To tackle this problem, a fully consistent nonlinear analysis of a deep excavation protected by the diaphragm wall is analysed here. The subsoil is modelled using the Hardening Soil model, while reinforced concrete is modelled using the modified Lee–Fenves model enhanced by the Eurocode 2 (EC2)-compatible creep module, developed by the author. It is shown that the commonly used nonlinear soil–linear structure computational strategy may yield insufficient amount of reinforcement from the ultimate limit state (ULS) and serviceability limit state (SLS) points of view. A consistent and conservative method of combining fully nonlinear analysis and the rules imposed by the EC2 is proposed.

Discrete wavelet assisted correlation optimised warping of chromatograms: optimizing the computational time for correcting the drifts in peak positions

2017 ◽  
Vol 9 (13) ◽  
pp. 2049-2058 ◽  
Author(s):  
Keshav Kumar
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Retention Time ◽  
Computational Time ◽  
Discrete Wavelet ◽  
Efficient Approach

Discrete wavelet transform (DWT) assisted correlation optimised warping (COW) is shown to be a fast and efficient approach for correcting the retention time drifts of the chromatograms.

Sign in / Sign up

Export Citation Format

Share Document