• Title/Summary/Keyword: Seismic resistant

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Serviceability Limit State and Response Modification Factors (기능수행수준과 응답수정계수)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.2
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    • pp.149-154
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    • 2012
  • While the Earthquake Resistant Design Part of Korean Roadway Bridge Design Code provides design procedures for the No Collapse Requirement, requirements for the Serviceability Limit State are not clearly provided. The basic design method to meet the No Collapse Requirement is the spectrum analysis method using response modification factors and the Serviceability Limit State is determined by both the importance factor and the response modification factor applied in the design procedure. The importance factor can be simply applied according to the bridge importance category, however, in moderate/low seismic regions the application of the response modification factor may bring different result according to design conditions. In this study, for a typical bridge in the moderate/low seismic regions, determination procedures for the Serviceability Limit State are reviewed by carrying out earthquake resistant design and supplementary provisions for the Earthquake Resistant Design Part are identified based on the study results.

Seismic Performance of the Framed Apartment Building Structure with Damping System (감쇠시스템을 적용한 라멘조 아파트의 내진성능평가)

  • Chun, Young-Soo;Lee, Bum-Sik;Park, Ji-Young
    • Land and Housing Review
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    • v.8 no.3
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    • pp.181-187
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    • 2017
  • To proactively respond to internal and external changes such as the recent demographic change and rising demand for diversified housing types, this study investigated the framed-structure free plan public house model proposed by the LH to look at the seismic performance of framed-structure apartment according to damper system use through non-linear analysis. The effectiveness thereof was also examined in terms of performance and economy. As a result, the proposed damper system application method to framed-structure free plan public house model was found to meet the performance requirements of the present earthquake-resistant design (KBC2016) and effective to apply to designs. The max response displacement and max response acceleration were compared based on the nonlinear analysis. As a result, the building with damper system showed better earthquake resistance performance than earthquake-resistant structure thanks to the damper system, although the base shear of earthquake-resistant system was reduced by 20% in design. The damper system is expected to help reduce building damage while ensuring excellent earthquake resistance performance. In addition, the framework quantities of earthquake-resistant structure and structure with damping system were compared. As a result, columns were found to reduce concrete amount by about 3.9% and rebar, by about 7.3%. Walls showed about 12.6% reduction in concrete and about 10.7% in rebar. In terms of cost, framework construction cost including formwork and foundation expenses was expected to drop by about 5~6%.

Seismic Retrofit and Seismic Performance Evaluation of Existing School Structures Using diagonal, x-shaped, chevron Braces (가새를 사용한 기존 학교건축물의 내진보강 및 내진성능평가)

  • Kim, Dong-Keon
    • Journal of The Korean Digital Architecture Interior Association
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    • v.11 no.2
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    • pp.115-121
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    • 2011
  • Occurrence of earthquakes have been increased all over the world and also, magnitude of earthquakes have been larger these days. Earthquake can be happened in Korea and is not a safe country any more. Many buildings are exposed at danger without any alternatives against earthquake in Korea. Among various kinds of buildings, school buildings are very important and urgent, because many students stays at school and young students have some difficulty to evacuate. Also, most existing school buildings in Korea were not designed considering earthquake resistant design codes. Thus, in this study, 3 types of braces were applied for seismic retrofits of existing school buildings using commercial structural analysis software and effective seismic retrofits were evaluated and discussed based on results by time history analysis.

Insights from existing earthquake loss assessment research in Croatia

  • Hadzima-Nyarko, Marijana;Sipos, Tanja Kalman
    • Earthquakes and Structures
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    • v.13 no.4
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    • pp.365-375
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    • 2017
  • Seismic risk management has two main technical aspects: to recommend the construction of high-performance buildings and other structures using earthquake-resistant designs or evaluate existing ones, and to prepare emergency plans using realistic seismic scenarios. An overview of seismic risk assessment methodologies in Croatia is provided with details regarding the components of the assessment procedures: hazard, vulnerability and exposure. For Croatia, hazard is presented with two maps and it is expressed in terms of the peak horizontal ground acceleration during an earthquake, with the return period of 95 or 475 years. A standard building typology catalogue for Croatia has not been prepared yet, but a database for the fourth largest city in Croatia is currently in its initial stage. Two methods for earthquake vulnerability assessment are applied and compared. The first is a relatively simple and fast analysis of potential seismic vulnerability proposed by Croatian researchers using damage index (DI) as a numerical value indicating the level of structural damage, while the second is the Macroseismic method.

Earthquake Resistant Verification of a 5-Span Steel Box Girder Bridge (5경간 강박스교의 내진성능검토)

  • 국승규
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.10a
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    • pp.103-112
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    • 1998
  • The earthquake resistant design for roadway bridges introduced in 1992 is conducted according to the "Standard Specification for Roadway Bridges", Division V, Seismic Design and the first revision of the Standard was done in 1996. However, dur to different concepts of the earthquake resistant design from those of the other designs, the provisions given in the Standard are still not applied appropriately. In this paper the verification of the earthquake resistant capacity of a bridge with typical configurations, 5-span steel box girder bridge, is carried out based on the application rules of the present Standard in order to provide clear understandings about the earthquake resistant verification and the earthquake resistant design as well.n as well.

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Development of a Seismic Test Method for Fire Protecting Components by Equivalent Linear Analysis Theory (등가선형해석이론에 의한 소방설비 구성품의 Lab scale 내진성능평가기법 개발)

  • Kwark, Ji-Hyun;Yoon, Jong-Ku
    • Fire Science and Engineering
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    • v.27 no.1
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    • pp.46-51
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    • 2013
  • In this study a lab scale seismic test method which is able to evaluate seismic resistant performance of the fire protecting components in case of earthquake was developed. This seismic test consists of equivalent accelerating and temporary accelerating. The former is to search for resonance frequency and the latter is to simulate vibrating by earthquake with intensive magnitude. The frequency and displacement accelerated to the components was decided by maximum acceleration of gravity, and whether or not they could maintain function was tried to be confirmed. This test method is expected as an effective one for evaluating seismic resistant performance for the fire protecting components.

Base isolation performance of a cone-type friction pendulum bearing system

  • Jeon, Bub-Gyu;Chang, Sung-Jin;Kim, Sung-Wan;Kim, Nam-Sik
    • Structural Engineering and Mechanics
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    • v.53 no.2
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    • pp.227-248
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    • 2015
  • A CFPBS (Cone-type Friction Pendulum Bearing System) was developed to control the acceleration delivered to a structure to prevent the damage and degradation of critical communication equipment during earthquakes. This study evaluated the isolation performance of the CFPBS by numerical analysis. The CFPBS was manufactured in the shape of a cone differenced with the existing FPS (Friction Pendulum System), and a pattern was engraved on the friction surface. The natural frequencies of the CFPBS were evaluated from a free-vibration test with a seismic isolator system consisting of 4 CFPBS. To confirm the earthquake-resistant performance, a numerical analysis program was prepared using the equation of the CFPBS induced from the equations of motion. The equation reported by Tsai for the rolling-type seismic isolation bearings was proposed to design the equation of the CFPBS. Artificial seismic waves that satisfy the maximum earthquake scale of the Korean Building Code-Structural (KBC-2005) were created and verified to review the earthquake-resistant performance of the CFPBS by numerical analysis. The superstructural mass of the CFPBS and the skew angle of friction surface were considered for numerical analysis with El Centro NS, Kobe NS and artificial seismic waves. The CFPBS isolation performance evaluation was based on the numerical analysis results, and comparative analysis was performed between the results from numerical analysis and simplified theoretical equation under the same conditions. The validity of numerical analysis was verified from the shaking table test.

Investigation of seismic performance of super long-span cable-stayed bridges

  • Zhang, Xin-Jun;Zhao, Chen-Yang;Guo, Jian
    • Earthquakes and Structures
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    • v.14 no.6
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    • pp.493-503
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    • 2018
  • With the further increase of span length, the cable-stayed bridge tends to be more slender, and becomes more susceptible to the seismic action. By taking a super long-span cable-stayed bridge with main span of 1400m as example, structural response of the bridge under the E1 horizontal and vertical seismic excitations is investigated numerically by the multimode seismic response spectrum and time-history analysis respectively, the seismic behavior and also the effect of structural nonlinearity on the seismic response of super long-span cable-stayed bridge are revealed. Furthermore, the effect of structural parameters including the girder depth and width, the tower structural style, the tower height-to-span ratio, the side-tomain span ratio, the auxiliary piers in side spans and the anchorage system of stay cables etc on the seismic performance of super long-span cable-stayed bridge is investigated numerically by the multimode seismic response spectrum analysis, and the favorable earthquake-resistant structural system of super long-span cable-stayed bridge is proposed.

Displacement Ductility Based Seismic Performance Evaluation of Circular RC Bridge Piers (변위연성도 기반 원형철근콘크리트 교각의 내진성능 평가)

  • Park, Chang-Kyu;Lee, Dae-Hyoung;Yun, Sang-Chul;Chung, Young-Soo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.276-283
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    • 2006
  • Korea is considered to be immune from the earthquake hazard because it is located far away from the active fault. However, recent earthquake caused a loss of lives and economical loss worldwide. Hence there has been raised an importance of the earthquake resistant design for various infrastructures. In this research, the seismic design and evaluation criterion for RC bridge pier were proposed from the experimental results of 82 circular RC bridge piers tested in domestic and aboard. New seismic criterion was introduced the limited ductile design provision suitable to Korean peninsula, which would be classified as a low or moderate seismic region. In addition, further important topic for the seismic safety of RC bridge piers in Korea is the seismic performance enhancement of RC bridge piers, which were designed and constructed before the 1992 seismic design provision. Therefore, the proposed seismic performance evaluation criterion could be very useful to judge seismic retrofit need or not according to the residual seismic performance of the RC bridge piers. Also, it could reduce an uncertainty for the safety of the infrastructure under earthquakes.

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