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Chang-Guk Sun Sung-Ho Chun Tae-Gyun Ha Choong-Ki Chung Dong-Soo Kim 《Computers and Geotechnics》2008,35(3):436-449
An integrated GIS-based tool (GTIS) was constructed to estimate site effects related to the earthquake hazards in the Gyeongju area of Korea. To build the GTIS for the study area, intensive site investigations and geotechnical data collections were performed and a walk-over site survey was additionally carried out to acquire surface geo-knowledge data in accordance with the procedure developed to build the GTIS. For practical applications of the GTIS used to estimate the site effects associated with the amplification of ground motion, seismic microzoning maps of the characteristic site period and the mean shear wave velocity to a depth of 30 m were created and presented as a regional synthetic strategy addressing earthquake-induced hazards. Additionally, based on one-dimensional site response analyses, various seismic microzoning maps for short- and mid-period amplification potentials were created for the study area. Case studies of seismic microzonations in the Gyeongju area verified the usefulness of the GTIS for predicting seismic hazards in the region. 相似文献
2.
Chang-Guk Sun 《Environmental Earth Sciences》2012,65(7):1987-2001
A geotechnical information system (GTIS) was constructed within a spatial geographic information system (GIS) framework to
reliably predict geotechnical information and accurately estimate site effects at Gyeongju, an urban area in South Korea.
The system was built based on both collected and performed site investigation data in addition to acquired geo-knowledge data.
Seismic zoning maps were constructed using the site period (T
G) and mean shear wave velocity to a depth of 30 m (V
S30), and these maps were presented as a regional strategy to mitigate earthquake-induced risks in the study area. In particular,
the T
G distribution map indicated the susceptibility to ground motion resonance in periods ranging from 0.2 to 0.5 s and the corresponding
seismic vulnerability of buildings with two to five stories. Seismic zonation of site classification according to V
S30 values was also performed to determine the site amplification coefficients for seismic design and seismic performance evaluation
at any site and administrative subunit in the study area. In addition, we investigated the site effects according to subsurface
and surface ground irregularities at Gyeongju by seismic response analyses in time domains based on both two- and three-dimensional
spatial finite element models, which were generated using spatial interface coordinates between geotechnical subsurface layers
predicted by the GTIS. This practical study verified that spatial GIS-based geotechnical information can be a very useful
resource in determining how to best mitigate seismic hazards, particularly in urban areas. 相似文献
3.
Combined analysis of electrical resistivity and geotechnical SPT blow counts for the safety assessment of fill dam 总被引：1，自引：0，他引：1
Electrical resistivity survey and the geotechnical SPT blow counts (N value) method were simultaneously analyzed to investigate the stability of a center-core type earth-fill dam against the
seepage phenomenon. The coupling of these heterogeneous field methods provided a chance to understand the status of underground
material by comparing the geophysical and geotechnical view. The analysis shows that the zones with low resistivity value
generally have low N value, which means low stiffness. However, some zones with a high resistivity pattern are not accompanied by an increase
of its N value, and are even showing a lower N value. These results imply that one should be careful to directly correlate resistivity value with the real status of the
core material of a fill dam. And a highly resistive zone may be in poor status due to the effect of increase of resistivity
value as a result of the piping condition. Additional laboratory tests show that there is a deficiency of fine soil particles
believed as the clay at the troubled region, which means an increase in resistivity value. Therefore, multiple explorations
should be planned to reduce the uncertainty in application of geophysical methods to dam safety evaluation in order to compensate
the resistivity information of core material. 相似文献
4.
Dong-Soo Kim Choong-Ki Chung Chang-Guk Sun Eun-Seok Bang 《Soil Dynamics and Earthquake Engineering》2002,22(5):358
The earthquake hazard has been evaluated for 10 km×10 km area around Kyeongju. The ground motion potentials were determined based on equivalent linear analysis by using the data obtained from in situ and laboratory tests. In situ tests include 16 boring investigations, 4 crosshole, 12 downhole, 26 spectral analysis of surface waves tests, and in the laboratory, resonant column tests were performed. The peak ground accelerations range between 0.141g and 0.299g on collapse level earthquake and between 0.050g and 0.120g on operation level earthquake, respectively, showing the high potential of amplification in the deep alluvial layer in Kyeongju area. Distribution maps of site amplification for the peak acceleration, amplification factors (Fa and Fv) and dominant site period of Kyeongju are constructed using geographic information system tools. The amplification factor based on the Korean seismic design guide underestimated the motion in short range and overestimated the motion in mid-period range in Kyeongju. The importance of site-specific analysis and the need for the improved site characterization method are introduced. 相似文献
5.
Lee Moon-Gyo Ha Jeong-Gon Cho Hyung-Ik Sun Chang-Guk Kim Dong-Soo 《Acta Geotechnica》2021,16(4):1187-1204
Verifying the seismic performance of port structures when the force balance limit is exceeded is important for the performance-based seismic design of gravity-type quay walls. Over the last three decades, performance verification methods have been developed that consider the effects of the design earthquake motion, geotechnical conditions, and structural details on the deformation of a quay wall to accurately predict earthquake-induced damage. In this study, representative performance verification methods (i.e., simplified dynamic analysis methods extending from the Newmark sliding block method and performance-based seismic coefficients developed in Japan) were quantitatively assessed with actual cases of earthquake-damaged quay walls and the results of dynamic centrifuge tests previously conducted under various conditions (i.e., different wall heights, earthquake motions and the thickness of subsoil). The dynamic centrifuge test results suggested directions for improving the performance-based seismic coefficients of the representative methods, while their field applicability and reliability were confirmed according to the actual earthquake records.
相似文献6.
Cho Hyung-Ik Lee Moon-Gyo Ahn Jae-Kwang Sun Chang-Guk Kim Han-Saem 《Bulletin of Earthquake Engineering》2022,20(11):5775-5795
Bulletin of Earthquake Engineering - This study constructed a flatfile with the information useful to satisfy the site characterization requirements of Korea Meteorological Administration’s... 相似文献
7.
Chang-Guk Sun Chang-Soo Cho Minkyung Son Jin Soo Shin 《Pure and Applied Geophysics》2013,170(3):271-281
Shear wave velocity (V S) can be obtained using seismic tests, and is viewed as a fundamental geotechnical characteristic for seismic design and seismic performance evaluation in the field of earthquake engineering. To apply conventional geotechnical site investigation techniques to geotechnical earthquake engineering, standard penetration tests (SPT) and piezocone penetration tests (CPTu) were undertaken together with a variety of borehole seismic tests for a range of sites in Korea. Statistical modeling of the in-situ testing data identified correlations between V S and geotechnical in-situ penetration data, such as blow counts (N value) from SPT and CPTu data including tip resistance (q t), sleeve friction (f s), and pore pressure ratio (B q). Despite the difference in strain levels between conventional geotechnical penetration tests and borehole seismic tests, it is shown that the suggested correlations in this study is applicable to the preliminary determination of V S for soil deposits. 相似文献
8.
Geologic site conditions and site coefficients for estimating earthquake ground motions in the inland areas of Korea 总被引：3，自引：0，他引：3
Site characterization and site-specific ground response analyses were conducted at two representative inland areas in Korea. In situ tests included 25 boring investigations, 7 crosshole tests, 18 downhole tests and 41 SASW tests, and in the laboratory, resonant column tests were performed. The soil deposits in Korea, which were shallower and stiffer than those in the western US, were examined. The fundamental site periods were distributed in the narrow band ranging from 0.1 to 0.4 s. Most sites were designated as site classes C and D based on the mean shear wave velocity of the upper 30 m from the current Korean seismic design guide. Based on the ratio of the acceleration response spectra of ground surface to rock-outcrop, short-period (0.1–0.5 s) site coefficient, Fa ranged from 1.0 to 2.7, and mid-period (0.4–2.0 s) site coefficient, Fv ranged from 1.0 to 1.6, regardless of the input rock outcrop acceleration levels of 0.05 and 0.14 g. The site coefficients specified in the Korean seismic design guide, which is similar to NEHRP provisions and UBC, underestimate the ground motion in the short-period band and overestimate the ground motion in the mid-period band. These differences can be explained by the differences in the depth to bedrock and the soil stiffness profile between Korea and western US. Also, the site coefficients should be re-evaluated accounting for the local geologic conditions on the Korean peninsula. 相似文献
9.
Earthquake-induced hazards are profoundly affected by site effects related to the amplification of ground motions, which are strongly influenced by local geologic conditions such as soil thickness, bedrock depth, and soil stiffness. Seismic disasters are often more severe over soft soils than over stiff soils or rocks due to differences in local site effects. In this study, on the basis of a geotechnical information system (GTIS) framework, we developed an advanced geostatistical assessment for the regional zonation of seismic site effects. In particular, to reliably predict spatial geotechnical information, we developed a procedural methodology for building an advanced GTIS within a geographic information system framework and applied it to the Busan area in Korea. The systemized GTIS comprised four functional components: database, geostatistical analysis, geotechnical analysis, and visualization. First, to build the GTIS, we collected pre-existing geotechnical data in and around the study area, and then conducted a walk-over site survey to acquire surface geo-knowledge data. Second, we determined the optimum geostatistical estimation method using a cross-validation-based verification test, considering site conditions. The advanced GTIS was used in a practical application to estimate the site effects in the study area. We created seismic zoning maps of geotechnical earthquake parameters, such as the depth to bedrock and the site period, and present them as part of a regional synthetic strategy for earthquake risk assessment. 相似文献
10.
To establish viable earthquake counterplans for ports in Korea, data regarding earthquake motion on the ground and in buildings must be collected using acceleration monitoring systems. Acceleration monitoring-based strategies for port facilities are useful not only for ensuring rapid responses during and after earthquakes but also for regional data collection to assist reliable seismic design. Acceleration monitoring systems were installed at coastal facility sites in target ports, including a soil site to represent the facility and a rock site as a reference. The systematic earthquake alert software was designed to help them in decision-making about a possible seismic hazard and its reporting. The earthquake alert system was composed of two sequential functional software systems sharing an acceleration monitoring database applied to the target ports. The earthquake response software system triggers an alarm based on the peak ground acceleration per second computed from the monitored data. Then, the earthquake hazard estimation software system evaluates possible earthquake-induced site-specific geotechnical hazards linked to the peak ground acceleration. The integrated system was successfully operated and was able to rapidly provide an emergency report containing event records and geotechnical earthquake hazards during the September 2016 Gyeongju earthquake, the largest recorded earthquake in Korea. 相似文献
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