scholarly journals ENHANCING THE SEISMIC RESPONSE OF A MULTIFUNCTIONAL STADIUM EQUIPPED WITH LRB ISOLATORS UNDER NEAR-FIELD EARTHQUAKES

2018 ◽  
pp. 11-23
Author(s):  
Ali Vatanshenas ◽  
◽  
Davood Sharif Bajestany ◽  
Misagh Hajihoseinloo ◽  
Arian Aghelfard
Keyword(s):  
Seismic Response ◽  
Near Field

Are Synthetic Accelerograms Suitable for Local Seismic Response Analyses at Near-Field Sites?

2021 ◽  
Author(s):  
Francesca Mancini ◽  
Sebastiano D’Amico ◽  
Giovanna Vessia
Keyword(s):  
Seismic Response ◽  
Seismic Waves ◽  
Near Field ◽  
Central Italy ◽  
Propagation Path ◽  
Soil Behavior ◽  
Seismic Stations ◽  
Seismic Input ◽  
Local Seismic Response ◽  
Finite Fault

ABSTRACT Local seismic response (LSR) studies are considerably conditioned by the seismic input features due to the nonlinear soil behavior under dynamic loading and the subsurface site conditions (e.g., mechanical properties of soils and rocks and geological setting). The selection of the most suitable seismic input is a key point in LSR. Unfortunately, few recordings data are available at seismic stations in near-field areas. Then, synthetic accelerograms can be helpful in LSR analysis in urbanized near-field territories. Synthetic accelerograms are generated by simulation procedures that consider adequately supported hypotheses about the source mechanism at the seismotectonic region and the wave propagation path toward the surface. Hereafter, mainshocks recorded accelerograms at near-field seismic stations during the 2016–2017 Central Italy seismic sequence have been compared with synthetic accelerograms calculated by an extended finite-fault ground-motion simulation algorithm code. The outcomes show that synthetic seismograms can reproduce the high-frequency content of seismic waves at near-field areas. Then, in urbanized near-field areas, synthetic accelerograms can be fruitfully used in microzonation studies.

scholarly journals Use of Synthetic Accelerograms in Local Seismic Response Analyses at Near Field Sites

2021 ◽  
Author(s):  
Francesca Mancini ◽  
Giovanna Vessia ◽  
Sebastiano D'Amico
Keyword(s):  
Seismic Response ◽  
Near Field ◽  
Local Seismic Response

scholarly journals Numerical Study on the Longitudinal Response Characteristics of Utility Tunnel under Strong Earthquake: A Case Study

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Guoyi Tang ◽  
Yumei Fang ◽  
Yi Zhong ◽  
Jie Yuan ◽  
Bin Ruan ◽  
...  
Keyword(s):  
Seismic Response ◽  
Strong Earthquake ◽  
Numerical Study ◽  
Soft Soil ◽  
Near Field ◽  
Element Model ◽  
Far Field ◽  
Response Characteristics ◽  
Longitudinal Response ◽  
Utility Tunnel

In this paper, the longitudinal seismic response characteristics of utility tunnel subjected to strong earthquake was investigated based on a practical utility tunnel project and numerical method. Firstly, the generalized response displacement method (GRDM) that was used to conduct this study was reviewed briefly. Secondly, the information of the referenced engineering and the finite element model was introduced in detail, where a novel method to model the joints between utility tunnel segments was presented. Thirdly, a series of seismic response of the utility tunnel were provided, including inner force and intersegment opening width. The results showed that (i) the seismic response of the utility tunnel under far-field earthquake may be remarkable and even higher than that under near-field earthquake; (ii) sharp variation of response may occur at the interface between “soft” soil and “hard” soil, and the variation under far-field earthquake could be much more significant. This research provides a reference for the scientific study and design of relevant engineering.

EFFECT OF BIDIRECTIONAL EXCITATIONS ON SEISMIC RESPONSE OF RC BUILDINGS

2012 ◽  
Vol 06 (03) ◽  
pp. 1250019 ◽  
Author(s):  
AMAN M. MWAFY
Keyword(s):  
Seismic Response ◽  
Near Field ◽  
Active Faults ◽  
Shear Capacity ◽  
Performance Criteria ◽  
Analytical Models ◽  
Rc Buildings ◽  
Response Modification Factor ◽  
Diverse Range ◽  
Axial Forces

This paper investigates the effect of the horizontal and vertical components of ground motions (HGM and VGM, respectively) on the seismic response of Reinforced Concrete (RC) buildings designed to modern capacity design principles and located in the vicinity of active faults. Fiber-based analytical models are used to monitor the global and local response of twelve reference structures, including verifying the response modification factor and tracing the member shear supply-demand response using a ductility- and axial force-sensitive shear strength approach. The simulation models are subjected to near-field earthquake records with increasing severity up to collapse, including and excluding VGM. The results indicate that the lower the contribution of horizontal seismic forces to the seismic response, the higher is the significance of VGM. The fluctuation of axial forces in vertical structural members significantly increases when including VGM. This not only has direct consequences on tension and compression response but also has impact on shear capacity. The diverse range of buildings and performance criteria and large number of incremental dynamic analyses confirm the importance of including VGM in seismic design and assessment of contemporary RC buildings, and hence cast doubts on the reliability of pre-code structures located in the vicinity of active faults.

scholarly journals An Arc-consistent Viscous-spring Artificial Boundary for Numerical Analysis of the Seismic Response of Underground Structures

2021 ◽  
Author(s):  
Dan Ye ◽  
Shangzhi Yin ◽  
Dengzhou Quan
Keyword(s):  
Numerical Analysis ◽  
Seismic Response ◽  
Shaking Table Test ◽  
Near Field ◽  
Shaking Table ◽  
Test Results ◽  
Underground Structures ◽  
Artificial Boundary ◽  
Finite Element Software ◽  
Artificial Boundaries

Abstract A new arc consistent viscous-spring artificial boundary (ACVAB) was proposed by changing a traditional flat artificial boundary based on the theory of viscous-spring artificial boundaries. Through examples, the concept underpinning the establishment, and specific setting of, the boundary in the finite element software were described. Through comparison with other commonly used artificial boundaries in an example for near-field wave analysis using the two-dimensional (2-d) half-space model, the reliability of the ACVAB was verified. Furthermore, the ACVAB was used in the numerical analysis of the effects of an earthquake of underground structures. The results were compared with shaking-table test results on underground structures. On this basis, the applicability of the ACVAB to a numerical model of the seismic response of underground structures was evaluated. The results show that the boundary is superior to common viscous-spring boundaries in terms of accuracy and stability, and therefore it can be used to evaluate radiation damping effects of seismic response of underground structures and is easier to use.

scholarly journals On the Seismic Response of Protected and Unprotected Middle-Rise Steel Frames in Far-Field and Near-Field Areas

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Dora Foti
Keyword(s):  
Seismic Response ◽  
Ground Motions ◽  
Near Field ◽  
Shaking Table ◽  
Far Field ◽  
Base Shear ◽  
Friction Dampers ◽  
Steel Moment Resisting Frames ◽  
Damage Indices ◽  
Moment Resisting

Several steel moment-resisting framed buildings were seriously damaged during Northridge (1994); Kobe (1995); Kocaeli, Turkey (1999), earthquakes. Indeed, for all these cases, the earthquake source was located under the urban area and most victims were in near-field areas. In fact near-field ground motions show velocity and displacement peaks higher than far-field ones. Therefore, the importance of considering near-field ground motion effects in the seismic design of structures is clear. This study analyzes the seismic response of five-story steel moment-resisting frames subjected to Loma Prieta (1989) earthquake—Gilroy (far-field) register and Santa Cruz (near-field) register. The design of the frames verifies all the resistance and stability Eurocodes’ requirements and the first mode has been determined from previous shaking-table tests. In the frames two diagonal braces are installed in different positions. Therefore, ten cases with different periods are considered. Also, friction dampers are installed in substitution of the braces. The behaviour of the braced models under the far-field and the near-field records is analysed. The responses of the aforementioned frames equipped with friction dampers and subjected to the same ground motions are discussed. The maximum response of the examined model structures with and without passive dampers is analysed in terms of damage indices, acceleration amplification, base shear, and interstory drifts.

Sign in / Sign up

Export Citation Format

Share Document