• Title/Summary/Keyword: High Seismicity

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Linear and nonlinear site response analyses to determine dynamic soil properties of Kirikkale

  • Sonmezer, Yetis Bulent;Bas, Selcuk;Isik, Nihat Sinan;Akbas, Sami Oguzhan
    • Geomechanics and Engineering
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    • v.16 no.4
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    • pp.435-448
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    • 2018
  • In order to make reliable earthquake-resistant design of civil engineering structures, one of the most important considerations in a region with high seismicity is to pay attention to the local soil condition of regions. It is aimed in the current study at specifying dynamic soil characteristics of Kirikkale city center conducting the 1-D equivalent linear and non-linear site response analyses. Due to high vulnerability and seismicity of the city center of Kirikkale surrounded by active many faults, such as the North Anatolian Fault (NAF), the city of Kirikkale is classified as highly earthquake-prone city. The first effort to determine critical site response parameter is to perform the seismic hazard analyses of the region through the earthquake record catalogues. The moment magnitude of the city center is obtained as $M_w=7.0$ according to the recorded probability of exceedance of 10% in the last 50 years. Using the data from site tests, the 1-D equivalent linear (EL) and nonlinear site response analyses (NL) are performed with respect to the shear modulus reduction and damping ratio models proposed in literature. The important engineering parameters of the amplification ratio, predominant site period, peak ground acceleration (PGA) and spectral acceleration values are predicted. Except for the periods between the period of T=0.2-1.0 s, the results from the NL are obtained to be similar to the EL results. Lower spectral acceleration values are estimated in the locations of the city where the higher amplification ratio is attained or vice-versa. Construction of high-rise buildings with modal periods higher than T=1.0 s are obtained to be suitable for the city of Kirikkale. The buildings at the city center are recommended to be assessed with street survey rapid structural evaluation methods so as to mitigate seismic damages. The obtained contour maps in this study are estimated to be effective for visually characterizing the city in terms of the considered parameters.

Seismic Design of Reinforced Concrete Structures of Limited Ductility in New Zealand Standard (뉴질랜드 기준에서의 제한된 연성의 RC 구조물 내진설계)

  • 이한선
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.10a
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    • pp.288-295
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    • 2000
  • As the level of earthquake intensity in Korea is considered to be moderate, some structures or structural elements may be subjected to the reduced ductility demand, in contrast to the structures in high seismicity, due to the large inherent strength induced by gravity loads. New Zealand Standard(NZS) deals with these structures within the category of structures of limited ductility. This paper briefly reviews the concept of structures of limited ductility in NZS, and its applicability to Korean case. A structural wall system which is used as the structural system for typical apartments is taken as an example for the illustration.

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Earthquake Resistance of Masonry Infilled Wall (조적 채움벽의 내진성)

  • 이한선;우성우;유은진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.93-98
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    • 2000
  • The objective of this study is to investigate the results of researches which have been conducted throughout the world and in Korea concerning the behavior modes of masonry infill panels and frames. The influence of masonry infill panels on the seismic behavior of RC frames must be considered in the design and evaluation procedure though current code provisions do not generally require explicitly this consideration. However, since the level of the earthquake intensity in Korea is assumed to be moderate, the masonry infill panels may cause the different effect to the structure from those in high seismicity region and this difference should be studied in depth in the future.

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Evaluating comparisons of geological hazards in landslides using fuzzy logic methods and hierarchical analysis

  • Shasha Yang;Maryam Shokravi;H. Tabatabay
    • Steel and Composite Structures
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    • v.48 no.5
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    • pp.499-505
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    • 2023
  • Geological hazards in landslide is one of the most extensive and destructive phenomena are among natural disasters. According to the topography high mountains, tectonic activity, high seismicity, diverse conditions Geology and climate, basically China to create a wide spectrum of landslides have natural conditions and these landslides are annual. They cause a lot of financial losses to the country. It is very difficult to predict the time of the landslide, hence the identification landslide sensitive areas and zoning of these areas based on the potential risk is very important. Therefore, it should be susceptible areas landslides should be identified in order to reduce damages caused by landslides find. the main purpose of landslide sensitivity analysis is identification high-risk areas and as a result, reducing damages caused by landslides It is the way of appropriate actions.

Analysis of Economic Feasibility and Suitability of Highrise Buildings Using Highstrength Steel (고강도 강재를 활용한 초고층건물의 경제성 및 적합성 분석)

  • Kim, Seonwoong
    • Journal of the Earthquake Engineering Society of Korea
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    • v.21 no.4
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    • pp.197-204
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    • 2017
  • This paper aims to analyze the economic feasibility and investigate the possibility of elastic seismic design of wind-designed highrise concentrically braced frames considering change of mechanical properties of Korean steel under the strong wind and the low seismicity in Korea. To this end, first, highrise concentrically braced frames were designed considering strong wind load. And then, analyses of the economics of them were performed. The seismic performance evaluation of wind-designed highrise buildings was conducted using the response spectrum analysis procedure. Analysis results show that it is possible to save up to approximately 90% of the amount of steel on the 10% increase in steel strength without serviceability. However, with serviceability, the design sectional area of the steel with relatively high strength tends to increment considerably because of the lateral stiffness due to reduction of the inertia moment and so on. This point might apply to limitation of the steel with high tensile yield strength.

Vibration Control and Cost-Effectiveness Evaluation of Cable-Stayed Bridges with Semi-Active Control System (준능동 제어시스템을 이용한 사장교의 진동제어 및 비용효율성 평가)

  • Hahm, Dae-Gi;Ok, Seung-Yong;Park, Wonsuk;Koh, Hyun-Moo;Park, Kwan-Soon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.4 s.44
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    • pp.43-54
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    • 2005
  • This paper presents cost-effectiveness evaluation of semi-active control system for cable-stayed bridge under earthquake excitations with various magnitudes and frequency contents. Semi-active control system, which is operated by using Bi-stale control method on the basis of linear quadratic Gaussian (LQG) optimal controller, is designed for the benchmark control problem proposed by Dyke et at. The cost-effectiveness of the proposed control system is defined by the ratio of life-cycle costs between a bridge structure with shock transmission units and a bridge structure with the semi-active control devices. The simulated results show that the damper cost has little influence on the cost-effectiveness of the semi-active control system while the cost-effectiveness is quite sensitive to the damage cost induced by the bridge failure. It is also found that the semi-active control system guarantees relatively high cost-effectiveness for the cable-stayed bridge subject to the ground motions in the regions of moderate seismicity with soft soil condition and strong seismicity with stiff soil condition.

The Engineering Characteristics of Seismicity of Korean Peninsula in 2000 (2000년도 한반도 지진활동의 공학적 특성)

  • 이전희
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.81-90
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    • 2001
  • Several seismic traces of earthquakes observed from the digital new type seismograph instruments of KMA in 2000 were scanned. From these, good quality data which have high signal/noise ratio were selected and they were transformed into ascii data from binary data(min-seed format). The hypo71 program and P-S was applied in order to determine the location of epicenter, origin time and the magnitude. From these data, the 29 earthquakes, 358 seismic records consist of 587 directional components were calculated. Using these, ground acceleration data, acceleration, velocity, and displacemnet response spectrums of the structures were calculated and they could be represented in a picture by the form of tripartite response spectrum. In the result, response spectrums of the 587 directional components of the above seismic data records were obtained respectively.

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Multi-Step Analysis of Seismically Isolated NPP Containment Structures with Lead-Rubber Bearings (납-고무받침에 의해 면진된 원전 격납구조물의 다중단계해석)

  • Lee, Jin Hi;Song, Jong-Keol;Lee, Eun-Haeng
    • Journal of the Earthquake Engineering Society of Korea
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    • v.18 no.6
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    • pp.261-269
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    • 2014
  • In order to increase the seismic safety of nuclear power plant (NPP) structures in high seismicity regions, seismic isolation techniques can be adapted to NPP structures. In this paper, the applicability of multi-step analysis of seismically isolated NPP containment structures with lead-rubber bearings (LRB) is evaluated. The floor response spectrum of NPP containment structures with equivalent linear LRB and nonlinear LRB are compared. In addition, the force-displacement relationships for equivalent linear LRB and nonlinear LRB are compared.

Prediction Equation of Spectral Acceleration Responses in Low-to-Moderate Seismic Regions using Domestic and Overseas Earthquake Records (국내·외 계기지진 정보를 활용한 중·약진 지역의 스펙트럴 가속도 응답 예측식)

  • Shin, Dong Hyeon;Kim, Hyung Joon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.22 no.2
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    • pp.77-86
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    • 2018
  • This study develops an empirical prediction equation of spectral acceleration responses of earthquakes which can induce structural damages. Ground motion records representing hazards of low-to-moderate seismic regions were selected and organized with several influential factors affecting the response spectra. The empirical equation and estimator coefficients for acceleration response spectra were then proposed using a robust nonlinear optimization coupled with a regression analysis. For analytical verification of the prediction equation, response spectra used for low-to-moderate seismic regions were estimated and the predicted results were comparatively evaluated with measured response spectra. As a result, the predicted shapes of response spectra can simulate the graphical shapes of measured data with high accuracy and most of predicted results are distributed inside range of correlation of variation (COV) of 30% from perfectly correlated lines.

Seismic Details of Reinforced Concrete Structures of Limited Ductility in New Zealand Standard (뉴질랜드 기준에서의 제한된 연성의 RC 구조물 내진 상세설계)

  • 이한선;유은진;우성우
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.229-234
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    • 2000
  • As the level of earthquake intensity in Korea is considered to be moderate, some structures or structural elements may be subjected to the reduced ductility demand, in contrast to the structures in high seismicity, due to the large inherent strength induced by gravity loads. New Zealand Standard(NZS) deals with there structures within the category of structures of limited ductility. This paper briefly reviews the applicability of the code, regarding limited ductility, for frame strucures which are commonly used as the office building structural system. The difference of the loading condition is considered. Details of the plastic hinge region are compared between NZS and Korean standard.

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