scholarly journals SEISMIC RISK EVALUATION FOR BUILDING PORTFOLIO CONSIDERING AMPLIFICATION CHARACTERISTICS OF EARTHQUAKE GROUND MOTION DUE TO SUBSURFACE STRUCTURE

2008 ◽  
Vol 73 (626) ◽  
pp. 511-518 ◽  
Author(s):  
Yukako SHIMIZU ◽  
Hiroshi ISHIDA
2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Pyi Soe Thein ◽  
Subagyo Pramumijoyo ◽  
Wahyu Wilopo ◽  
Agung Setianto ◽  
Kirbani Sri Brotopuspito ◽  
...  

In this study, we investigated the subsurface structure and strong ground motion parameters for Palu City. One of the major structures in Central Sulawesi is the Palu-Koro Fault system. Several powerful earthquakes have struck along the Palu-Koro Fault during recent years, one of the largest of which was an M 6.3 event that occurred on January 23, 2005 and caused several casualties. Following the event, we conducted a microtremor survey to estimate the shaking intensity distribution during the earthquake. From this survey we produced a map of the peak ground acceleration, velocity and ground shear strain in Palu City. We performed single observations of microtremors at 151 sites in Palu City. The results enabled us to estimate the site-dependent shaking characteristics of earthquake ground motion. We also conducted 8-site microtremor array investigation to gain a representative determination of the soil condition of subsurface structures in Palu. From the dispersion curve of array observations, the central business district of Palu corresponds to relatively soil condition with Vs ≤ 300 m/s, the predominant periods due to horizontal vertical ratios (HVSRs) are in the range of 0.4 to 1.8 s and the resonant frequency are in the range of 0.7 to 3.3 Hz. Three boreholes were throughout the basin especially in Palu area to evaluate the geotechnical properties of subsurface soil layers. The depths are varying from 1 m to 30 m. Strong ground motions of the Palu area were predicted based on the empirical stochastic green’s function method. Peak ground acceleration and peak ground velocity becomes more than 0.04 g and 30 kine in some areas, which causes severe damage for buildings in high probability. Keywords: Palu-Koro fault, microtremor, bore holes, peak ground acceleration and velocity.


2020 ◽  
Vol 15 (2) ◽  
pp. 187-201
Author(s):  
Shinichi Matsushima ◽  

The research program titled “Earthquake and Volcano Hazards Observation and Research Program” was started in fiscal year (FY) 2014 as a new five-year project authorized and funded by the Council for Science and Technology of the Ministry of Education, Culture, Sports, Science and Technology. It included a new format of collaborative research called, “Core-to-Core Collaborative Research between Earthquake Research Institute, The University of Tokyo and Disaster Prevention Research Institute, Kyoto University.” In this format, two types of research, “Participation Type Research” and “Subject Proposal Type Research” were conducted from FY2015. A preliminary study was performed in FY2015 for “Integrated Research” of “Participation Type Research,” which developed a framework for seismic risk evaluation at prefectural offices of Osaka and Kochi for an earthquake occurring along the Nankai Trough, considering the epistemic uncertainty. The secondary study was performed from FY2016 through to FY2018, wherein the methodology for the seismic risk evaluation was improved on three aspects: i.e., revision in ground motion prediction models considering the saturation effect, revision in loss models in terms of the fatalities as well as the direct losses of buildings, and extension of target sites to the whole of Osaka and Kochi prefectures. The results suggest that the epistemic uncertainty in the ground motion prediction models is most sensitive to the overall uncertainty of seismic risk. Along with “Integrated Research,” a total of 14 “Research on Specific Topics” related to time-dependent risk analysis, economical risk evaluation, source characterization, structural damage estimation models, ground motion estimation models, soil amplification models, and disaster prevention planning considering the uncertainty of risk assessment, were studied during this period in order to improve the risk assessment studies for “Integrated Research.” With respect to “Subject Proposal Type Research,” a total of 27 individual research themes focused on research to understand hazards/risks by earthquakes and volcanic eruptions and to mitigate disasters by them.


2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Piotr Adam Bońkowski ◽  
Juliusz Kuś ◽  
Zbigniew Zembaty

AbstractRecent research in engineering seismology demonstrated that in addition to three translational seismic excitations along x, y and z axes, one should also consider rotational components about these axes when calculating design seismic loads for structures. The objective of this paper is to present the results of a seismic response numerical analysis of a mine tower (also called in the literature a headframe or a pit frame). These structures are used in deep mining on the ground surface to hoist output (e.g. copper ore or coal). The mine towers belong to the tall, slender structures, for which rocking excitations may be important. In the numerical example, a typical steel headframe 64 m high is analysed under two records of simultaneous rocking and horizontal seismic action of an induced mine shock and a natural earthquake. As a result, a complicated interaction of rocking seismic effects with horizontal excitations is observed. The contribution of the rocking component may sometimes reduce the overall seismic response, but in most cases, it substantially increases the seismic response of the analysed headframe. It is concluded that in the analysed case of the 64 m mining tower, the seismic response, including the rocking ground motion effects, may increase up to 31% (for natural earthquake ground motion) or even up to 135% (for mining-induced, rockburst seismic effects). This means that not only in the case of the design of very tall buildings or industrial chimneys but also for specific yet very common structures like mine towers, including the rotational seismic effects may play an important role.


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