Effects of Spatial Variable Ground Motions on the Seismic Response of Base-Isolated Building

Aimed to base-isolated building with large plane dimension, the change laws of seismic response for base-isolated building under spatial variable ground motions were researched. Firstly, the artificial spatial variable earthquake time histories were generated using spectral representation method based on code response spectrum. Then the 3-D FEM modal of one based-isolated building with large plane dimension was established and the seismic response of based-isolated building under spatially ground motion was studied by nonlinear time history analysis. The mitigation effects of based-isolated building with large plane dimension were compared each other at the cases of uniform excitation, non-uniform excitation considering only wave passage effect, non-uniform excitation considering both the wave passage effect and incoherence effect, multi-component uniform excitation, multi-component non-uniform excitation considering the wave passage effect and multi-component non-uniform excitation considering both the wave passage effect and incoherence effect. The results show that the seismic response of base-isolated structure with large plane dimension under the uniform excitation is relative safety. When the base-isolated building with large plane dimension is designed by time history analysis, the spatial variability of earthquake ground motion effects can be considered.

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Influence of Wave Passage Effect on Seismic Response of Truss String Structure Co-Working with its Base Frame

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.533.154 ◽

2014 ◽

Vol 533 ◽

pp. 154-158

Author(s):

He Peng Wang ◽

Zhong Gen Xu ◽

Chang Gen Deng

Keyword(s):

Seismic Waves ◽

Time History ◽

Element Model ◽

Seismic Responses ◽

Passage Effect ◽

History Analysis ◽

Insertion Method ◽

String Structure ◽

Wave Passage ◽

Wave Passage Effect

By inputting two groups of seismic waves with phase differences of 0.16s, 0.34s, 0.5 and 0.34s, 0.66s, 1.0s to column elements divided into four parts of lower story of finite element model with insertion method, this paper analyzed the influence of wave passage effect on seismic responses of truss string structure of Guangzhou Convention and Exhibition Centre co-working with its base frame by time history analysis method. The results show that: because of natural vibration characteristics of structure, wave traveling has some effect on seismic responses of truss string structure of Guangzhou Convention and Exhibition Centre.

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Influence of Incoherence and Wave Passage Effects on Seismic Performances of Long Immersed Tunnel

International Journal of Computational Methods ◽

10.1142/s0219876218400121 ◽

2019 ◽

Vol 16 (05) ◽

pp. 1840012 ◽

Cited By ~ 2

Author(s):

Z. Y. Chen ◽

S. B. Liang ◽

C. He

Keyword(s):

Axial Compression ◽

Time History ◽

Earthquake Ground Motion ◽

Seismic Responses ◽

Low Frequencies ◽

Passage Effect ◽

Immersed Tunnel ◽

Support Excitation ◽

Wave Passage ◽

Wave Passage Effect

This paper conducts time history analysis to explore the influence of spatially varying earthquake ground motion (SVEGM) on seismic responses of the long immersed tunnel. Incoherence effect and wave passage effect are mainly focused here. Moreover, three coherency models are adopted to investigate the sensitivity of the computed responses to the models. The calculation results show that SVEGM enlarges seismic responses of the immersed tunnel significantly than uniform excitation. Considering wave passage effect and incoherence effect simultaneously makes the seismic responses increase more sharply than considering the latter only. The deformation of Gina gasket is barely sensitive to coherency model, while the axial compression force is sensitive to coherency model. It indicates suppressing that the fundamental mode and dominating higher-mode response are the hallmark of multi-support excitation. The great differences of three models decay with separation at low frequencies and their coherency in frequency domain are the main reasons that cause the variations of the axial compression forces.

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Development of synthetic ground motion at a specific site in Yogyakarta town, Indonesia utilizing the PSHA Method

E3S Web of Conferences ◽

10.1051/e3sconf/202015602011 ◽

2020 ◽

Vol 156 ◽

pp. 02011

Author(s):

Widodo Pawirodikromo ◽

Lalu Makrup ◽

Mochamad Teguh ◽

Bambang Suryo

Keyword(s):

Pilot Study ◽

Ground Motion ◽

Hazard Analysis ◽

Ground Motions ◽

Time History ◽

Building Structures ◽

Uniform Hazard Spectra ◽

Crustal Earthquakes ◽

History Analysis ◽

Dynamic Time

This paper presents the development of synthetic ground motion at specific sites in Yogyakarta town. In the 2019 Indonesian Seismic Code [1] provides an alternative method in the analysis of building structures by applying the dynamic time history analysis. At least 11-pairs of earthquake recordings must be used in the analysis. Synthetic ground motion utilizing the Method of Probability Seismic Hazard Analysis (PSHA) was used in this study. A selected site in Yogyakarta town was chosen as a pilot study considering that there were many fatalities and building damage caused by the 2006 Yogyakarta earthquake. The Uniform Hazard Spectra (UHS) based on the shallow crustal earthquake source is higher than the Megathrust. The risk targeted spectrum demand MCEr has been considered, which on average 12.3% greater than the UHS. The synthetic ground motions (SGM) are accordingly based on the shallow crustal earthquakes. The dominant magnitude and distance are MD = 6.5 and RD = 14.5 km. They show that the contribution of the Opak River fault to the hazard in Yogyakarta town is very dominant because the distance is very close. Based on the obtained MD and RD, spectral matching, and testing significant duration D595, the 12-synthetic ground motions were successfully developed.

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Seismic Response Analysis of Long Span Cable-Stayed Bridge under Non-Uniform Excitation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.246-247.131 ◽

2012 ◽

Vol 246-247 ◽

pp. 131-135

Author(s):

Bao Fu Wang ◽

Zhong Ren Feng ◽

Xiong Jiang Wang ◽

Bai Ben Chen

Keyword(s):

Dynamic Analysis ◽

Ground Motion ◽

Ground Motions ◽

Time History ◽

Large Mass ◽

Response Analysis ◽

Cable Stayed Bridge ◽

Long Span ◽

History Analysis ◽

Large Mass Method

In this paper, non-uniform dynamic analysis of a cable-stayed bridge is carried out using the large mass method. The Ed Yangtze River highway bridge, constructed in Hubei province, is chosen as a numerical example. In the non-uniform dynamic analysis, various wave velocities are used for the travelling ground motion. Displacements and internal forces solutions obtained for the spatially varying ground motions are compared with those of the uniform excitation. It is observed that the velocity of the ground motion greatly influences the response of the bridge and the variability of the ground motions should be included in the time-history analysis of cable-stayed bridges.

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Modal-Based Ground Motion Selection Method for the Nonlinear Response Time History Analysis of Reinforced Concrete Shear Wall Structures

Applied Sciences ◽

10.3390/app11178230 ◽

2021 ◽

Vol 11 (17) ◽

pp. 8230

Author(s):

Yang Liu

Keyword(s):

Seismic Response ◽

Ground Motion ◽

Nonlinear Response ◽

Time History ◽

Shear Wall ◽

Seismic Demands ◽

Ground Motion Selection ◽

Wall Structures ◽

History Analysis ◽

Rc Shear Wall

This paper presents a modification of the modal-based ground motion selection (MGMS) method for improving the reliability of the nonlinear response time history analysis (NLRHA) of reinforced concrete (RC) shear wall structures. The original MGMS procedure quantified the impact of frequency content combinations in the time domain (FCCTD) of input ground motions (IGMs) on the seismic response of building structures using the level of interaction of the first three modes induced by IGMs. However, previous research found that the first two modes have far larger modal mass coefficients than those of higher modes and dominate the vibration of the RC shear wall structures with a symmetric plan. Therefore, the MGMS procedure should be modified by employing the interaction of the first two modes induced by IGMs to properly account for the effect of the FCCTD of IGMs on the seismic response of structures. In the MGMS procedure for RC shear wall structures, seven IGMs that caused the most significant interactions of the first two modes were selected from a suite of twenty seed IGMs, which were chosen with a conventional spectra-matching-based IGMs selection procedure for the NLRHA of the structure. A comprehensive case study involving three RC shear walls with different heights was conducted to investigate the capability of the MGMS in selecting suitable IGMs for the NLRHA of RC shear wall structures. Sets of seed IGMs were selected, adopting conditional mean spectra and design spectra as the target spectra. It was found that the seismic demands computed using MGMS selected IGMs can ensure a more reliable and reasonable computation of seismic demands compared with conventional spectra-matching-based IGMs selection methods.

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