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.

Characterization of Thermal and Acoustic Profiles of Potential Underwater Pipeline Leaks

2014 ◽  
Author(s):  
Shane Siebenaler ◽  
Eric Tervo ◽  
Mohan Kulkarni ◽  
Sandeep Patni ◽  
Glenn Gesoff
Keyword(s):  
Near Field ◽  
Thermal Response ◽  
Third Party ◽  
Analytical Models ◽  
Distributed Temperature Sensing ◽  
Offshore Installations ◽  
Underwater Pipeline ◽  
Optic Systems ◽  
Measurement Mechanism ◽  
Gas Leaks

Reliable detection of small potential leaks is a topic of significant interest for remote offshore pipelines. Potential leak cases of interest are pinhole leaks out of the bottom of the pipe due to corrosion, weld or seam cracks, or damage due to third-party contact. There are several emerging technologies that may have the potential to provide a means of detecting such leaks over long segments of underwater pipe. These technologies include distributed acoustic and distributed temperature sensing. A key element of evaluating the applicability of these systems is to characterize the behavior of leaks. It is critically important to understand how leaks behave when employing a technology that has only been previously used for other conditions. A joint-industry program was initiated to evaluate the thermal and acoustic behavior of hypothetical underwater leaks. The environments studied range from shallow, Arctic applications to deep offshore installations. Analytical models were assessed to predict the jetting behavior of simulated leaks and their near-field thermal response. This analysis was performed for both liquid and gas media. These models were validated by means of laboratory experiments. Acoustic characteristics of hypothetical liquid and gas leaks were determined by means of testing with hydrophones. This information can be leveraged by a number of technologies as the data are independent of the measurement mechanism. While the motivation of this work is to evaluate distributed fiber-optic systems, the data on leak characteristics may also provide indications on applicability of other techniques for detecting potential underwater leaks. The data from this project will allow the industry to improve the understanding of potential leaks from underwater pipelines and, hence, lay the foundation for determining appropriate detection systems.

Multifault complex rupture and afterslip associated with the 2018 Mw 6.4 Hualien earthquake in northeastern Taiwan

2020 ◽  
Vol 224 (1) ◽  
pp. 416-434
Author(s):  
Dezheng Zhao ◽  
Chunyan Qu ◽  
Xinjian Shan ◽  
Roland Bürgmann ◽  
Wenyu Gong ◽  
...  
Keyword(s):  
Main Shock ◽  
Near Field ◽  
Active Faults ◽  
Fault Model ◽  
Body Waves ◽  
Coseismic Deformation ◽  
Coseismic Slip ◽  
Coulomb Stress Changes ◽  
Seismic Displacement ◽  
Stress Changes

SUMMARY We investigate the coseismic and post-seismic deformation due to the 6 February 2018 Mw 6.4 Hualien earthquake to gain improved insights into the fault geometries and complex regional tectonics in this structural transition zone. We generate coseismic deformation fields using ascending and descending Sentinel-1A/B InSAR data and GPS data. Analysis of the aftershocks and InSAR measurements reveal complex multifault rupture during this event. We compare two fault model joint inversions of SAR, GPS and teleseismic body waves data to illuminate the involved seismogenic faults, coseismic slip distributions and rupture processes. Our preferred fault model suggests that both well-known active faults, the dominantly left-lateral Milun and Lingding faults, and previously unrecognized oblique-reverse west-dipping and north-dipping detachment faults, ruptured during this event. The maximum slip of ∼1.6 m occurred on the Milun fault at a depth of ∼2–5 km. We compute post-seismic displacement time series using the persistent scatterer method. The post-seismic range-change fields reveal large surface displacements mainly in the near-field of the Milun fault. Kinematic inversions constrained by cumulative InSAR displacements along two tracks indicate that the afterslip occurred on the Milun and Lingding faults and the west-dipping fault just to the east. The maximum cumulative afterslip of 0.4–0.6 m occurred along the Milun fault within ∼7 months of the main shock. The main shock-induced static Coulomb stress changes may have played an important role in driving the afterslip adjacent to coseismic high-slip zones on the Milun, Lingding and west-dipping faults.

scholarly journals Simulation modeling and analysis of job release policies in scheduling an agile job shop with process sequence dependent setting time

2017 ◽  
Vol 7 (1.1) ◽  
pp. 177 ◽  
Author(s):  
K.T. Vinod ◽  
S. Prabagaran ◽  
O.A. Joseph
Keyword(s):  
Simulation Model ◽  
Job Shop ◽  
Statistical Tests ◽  
Setting Time ◽  
Performance Criteria ◽  
Analytical Models ◽  
Due Dates ◽  
Priority Rules ◽  
Work In Process ◽  
Sequence Dependent

This paper analyses the effects of job release policies, priority scheduling rules and setup times on the performance of a dynamic job shop in a sequence dependent setup time environment. Two job release policies namely, immediate job release and job release based on a specified work-in-process are investigated. A simulation model of a realistic manufacturing system is developed for detailed analysis. The dynamic total work content method is adopted to assign the due dates of jobs. Six priority rules are applied for prioritizing jobs for processing on machines. Several performance criteria are considered for analyzing the system performance. The simulation results are used to conduct statistical tests. Analytical models have been formulated to represent the simulation model for post-simulation studies. These models are found to yield a satisfactory estimation of the system outputs.

scholarly journals Empirical Relationship for Assessing the Near-Field Horizontal Coseismic Displacement Using GPS Seismology Data

2021 ◽  
Vol 60 (1) ◽  
pp. 31-50
Author(s):  
Ryad Darawcheh ◽  
Riad Al Ghazzi ◽  
Mohamad Khir Abdul-wahed
Keyword(s):  
Near Field ◽  
Empirical Relationship ◽  
Active Faults ◽  
Historical Earthquakes ◽  
Dead Sea ◽  
Fault System ◽  
Coseismic Displacement ◽  
Data Set ◽  
Earthquake Parameters ◽  
Gps Station

In this research, a data set of horizontal GPS coseismic displacement in the near-field has been assembled around the world in order to investigate a potential relationship between the displacement and the earthquake parameters. Regression analyses have been applied to the data of 120 interplate earthquakes having the magnitude (Mw 4.8-9.2). An empirical relationship for prediction near-field horizontal GPS coseismic displacement as a function of moment magnitude and the distance between hypocenter and near field GPS station has been established using the multi regression analysis. The obtained relationship allows assessing the coseismic displacements associated with some large historical earthquakes occurred along the Dead Sea fault system. Such a fair relationship could be useful for assessing the coseismic displacement at any point around the active faults.

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.

Reexamination of Tsunami Source Models For the 20th Century Earthquakes Off Hokkaido and Tohoku Along the Eastern Margin of the Sea of Japan

2021 ◽  
Author(s):  
Satoko Murotani ◽  
Kenji Satake ◽  
Takeo Ishibe ◽  
Tomoya Harada
Keyword(s):  
20Th Century ◽  
Sea Of Japan ◽  
Near Field ◽  
Active Faults ◽  
Source Area ◽  
Tsunami Source ◽  
The Sea Of Japan ◽  
Scaling Relation ◽  
Multiple Faults ◽  
Tsunami Waveforms

Abstract Large earthquakes around Japan occur not only in the Pacific Ocean but also in the Sea of Japan, and cause both damage from the earthquake itself and from the ensuing tsunami to the coastal areas. Recently, offshore active fault surveys were conducted in the Sea of Japan by the Integrated Research Project on Seismic and Tsunami Hazards around the Sea of Japan (JSPJ), and their fault models (length, width, strike, dip, and slip angles) have been obtained. We examined the causative faults of M7 or larger earthquakes in the Sea of Japan during the 20th century using seismic and tsunami data. The 1940 off Shakotan Peninsula earthquake (MJMA 7.5) appears to have been caused by the offshore active faults MS01, MS02, ST01, and ST02 as modelled by the JSPJ. The 1993 off the southwest coast of Hokkaido earthquake (MJMA 7.8) likely occurred on the offshore active faults OK03a, OK03b, and OK05, while the 1983 Central Sea of Japan earthquake (MJMA 7.7) probably related to MMS01, MMS04, and MGM01. For these earthquakes, the observed tsunami waveforms were basically reproduced by tsunami numerical simulation from the offshore active faults with the slip amounts obtained by the scaling relation with three stages between seismic moment and source area for inland earthquakes. However, the observed tsunami runup heights along the coast were not reproduced at certain locations, possibly because of the coarse bathymetry data used for the simulation. The 1983 west off Aomori (MJMA 7.1) and the 1964 off Oga Peninsula (MJMA 6.9) earthquakes showed multiple faults near the source area that could be used to reproduce the observed tsunami waveforms; therefore, we could not identify the causative faults. Further analysis using near-field seismic waveforms is required for their identification of their causative faults and their parameters. The scaling relation for inland earthquakes can be used to obtain the slip amounts for offshore active faults in the Sea of Japan and to estimate the coastal tsunami heights and inundation area which can be useful for disaster prevention and mitigation of future earthquakes and tsunamis in the Sea of Japan.

TREND OF SEISMIC RESPONSES OF EXISTING HIGH-RISE RC BUILDINGS

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yusuke Maida ◽  
Tomofusa Akita ◽  
Nobuyuki Izumi
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Seismic Isolation ◽  
Rc Buildings ◽  
Response Control ◽  
Control Structures ◽  
Seismic Ground Motion ◽  
Seismic Response Control ◽  
High Rise ◽  
Seismic Resistant

This report presents studies on the seismic response of high-rise RC buildings in Japan. Data concerning the seismic response of approximately 600 high-rise RC buildings constructed from 1972 to 2015 were collected. Seismic response characteristics were analyzed by focusing on differences in seismic resistant structures, seismic response control structures, and seismic isolation structures. The results indicated that the maximum story drift ratio response under the level 1 study seismic ground motion (R) and the level 2 study seismic ground motion (R) criteria is smaller for seismic isolation structures than that of the seismic resistant structure and seismic response control structures. In addition, focusing on the R-R relationship, the correlation is low in the seismic resistant and seismic response control structures, but is almost linear in the seismic isolation structure. This is because the seismic isolation structure is designed such that the superstructure does not become plastic even with level 2 seismic ground motion.

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