• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.29-34
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• 2006

In general, the vertical vibration problems for .strength of members and serviceability of building structures are not considered in structural design process, but the prediction of the vertical vibration is very important and essential to structural design process. This study aims to investigate the characteristics of vertical vibration in terms of the transfer of horizontal directions on the rahmen building structures. In order to examine the characteristics of vertical vibration, the modal test and the impact (heel-drop and hammer) excitation experiments were conducted several times on three building structures. The results from the experiments are analyzed and compared. with the results. The results of this study suggest that the characteristics of vertical vibration transfer in horizontal way are effected from the fundamental frequency of the slabs and excitation forces.

• Smart Structures and Systems
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• 제9권3호
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• pp.207-230
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• 2012

Full-scale shake table seismic experiments and low-amplitude vibration tests on a masonry building are carried out to assess its seismic performance as well as study the effectiveness of a new multifunctional textile material for retrofitting masonry structures against earthquakes. The un-reinforced and the retrofitted with glass fiber reinforced polymer (GFRP) strips masonry building was subjected to a series of earthquake excitations of increasing magnitude in order to progressively induce various small, moderate and severe levels of damage to the masonry walls. The performance of the original and retrofitted building states is evaluated. Changes in the dynamic characteristics (lowest four modal frequencies and damping ratios) of the building are used to assess and quantify the damage states of the masonry walls. For this, the dynamic modal characteristics of the structure states after each earthquake event were estimated by performing low-amplitude impulse hammer and sine-sweep forced vibration tests. Comparisons between the modal results calculated using traditional accelerometers and those using Fiber Bragg Grating (FBG) sensors embedded in the reinforcing textile were carried on to investigate the reliability and accuracy of FBG sensors in tracking the dynamic behaviour of the building. The retrofitting actions restored the stiffness characteristics of the reinforced masonry structure to the levels of the original undamaged un-reinforced structure. The results show that despite a similar dynamic behavior identified, corresponding to reduction of the modal frequencies, the un-reinforced masonry building was severely damaged, while the reinforced masonry building was able to withstand, without visual damage, the induced strong seismic excitations. The applied GFRP reinforcement architecture for one storey buildings was experimentally proven reliable for the most severe earthquake accelerations. It was easily placed in a short time and it is a cost effective solution (covering only 20% of the external wall surfaces) when compared to the cost for full wall coverage by GFRPs.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.367-374
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• 1999

this paper focuses on the dynamic characteristics of full-scale viscoelastic dampers through the experimental study. Viscoelastic dampers which dissipate the response energy of a building under earthquake excitation make a role of increasing damping capacity of the building. Therefore it is important to recognize the damping behavior of viscoelastic dampers. Full-scale viscoelastic dampers are made of three types of rubbers for experimental test. The hysteretic behavior is obtained through the load-deformation experiment over the various loading frequencies and damper strains The experimental results show the good performance of viscoelastic dampers under earthquake excitations,

• 한국공간구조학회논문집
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• 제9권3호
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• pp.59-66
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• 2009

구조물이 건전한 상태에서 진동계측을 통한 고유진동수와 감쇠율과 같은 동적특성의 분석에 대하여 국내 외적으로 많은 연구가 진행되어 왔다. 그러나 실물 구조물에 대하여 파괴 직전까지의 큰 손상 후에 진동계측을 통한 동적특성에 대한 연구는 상대적으로 매우 미약한 실정이다. 따라서 본 연구는 3층 철근콘크리트조 건물에 엑츄에이터로 하중을 주어 건물에 손상을 준 후에 손상 전 후의 진동계측을 통하여 동적특성을 파악하였다. 손상 전 후에 대한 고유진동수 및 감쇠율을 산정하였으며, 이 결과를 국외의 기존 연구와 비교하였다. 상시진동계측 및 인력가진을 통한 계측방법을 실시하였으며, 계측 전에 고유치 해석을 선행하여 계측치와 비교분석을 하였다. 120mm의 수평변위를 준 결과 구조물의 파괴 직전 손상 전 후에 장변과 단변의 고유진동수는 각각 34.3%, 33.7% 감소하였고, 감쇠율은 각각 36.5%, 19.5% 감소하였다. 기존 국외의 연구결과와의 비교를 한 결과 고층형 건물보다 강성의 변화가 크게 감소됨을 확인할 수 있었으며, 저층형 구조물에 대한 안정성 검토가 시급함을 확인할 수 있다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.39-40
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• 2018

The goal of site layout planning(SLP) is to maximize the productivity and efficiency of the construction by reducing travel distance and material handling cost and manpower. However, SLPs are static layout schemes, which cannot be reorganized during the construction process to correspond with errors, phase transition, changing working environments on the site. To solve this problem, researches on dynamic site layout planning(DSLP) are emerging. This preliminary study clarifies characteristics of temporary facility's variables to develop the vertical DSLP algorithm of high-rise building construction.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.676-681
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• 2002

System Identification is carried out for a full scale five-story builing to design a vibration controller. Dynamic characteristics such as natural frequencies, damping ratios, and modes are obtained from the input/output information by both sine-sweep method and white noise method. The active mass driver installed on the five floor is applied as external loading to move the building and each floor acceleration is measured and processed for the system identification. The identified building will be experimentally investigated again with viscoelastic dampers installed at inter-stories to obtain the response behavior. Corresponding result will be presented soon.

• 국제초고층학회논문집
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• 제9권4호
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• pp.369-376
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• 2020

Given the importance of quickly recovering livelihoods and economic activity after an earthquake, the seismic performance of the pile foundation is becoming more critical than before. In order to promote seismic retrofit of the pile foundations, it is necessary to develop a method for evaluating the seismic performance of the pile foundation based on the experimental data. In this paper, we focus on the building that was suffered severe damage to the pile foundation, conduct simulation analyses of the building, and report the results of evaluating the dynamic characteristics when piles are damaged using a system identification method. As a result, an analysis model that can accurately simulate the behavior of the damaged building during an earthquake was constructed, and it was shown that the system identification method could extract dynamic characteristics that may damage piles.

• 한국지진공학회논문집
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• 제23권4호
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• pp.221-229
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• 2019

Several water tanks installed in the building were damaged during the Gyeongju earthquake (2016) and the Pohang earthquake (2017). Since a water tank for fire protection is very important component, seismic safety should be ensured. In this study, an interaction between a water tank and a building was studied by the dynamic analysis of the RC building with the water tank. In case the water tank was installed on the roof of the RC building, it was confirmed that it did not significantly affect the response of the building. Based on the result, dynamic response characteristics of the water tank in the building were studied using two SDOF models represented dynamic behavior of the water tanks under earthquake. An earthquake time-history analysis was carried out with variables of aspect ratio of the tank, story of the building, and installed location in the building using three kinds of earthquakes.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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• pp.482-489
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• 2000

The cyclic extrusion damper, Lead Extrusion Damper, was invented by the W H Robinson in order to produce the isolated buildings and bridges the damping force. Recently, LED was applied to reduce the vibration of the tall building. In this study, to verify the dynamic characteristics of LED, the tests to find out the dependences on the velocity, displacement, repeated cycle, and temperature were performed at structural lab of Unison Industrial Co. Ltd. Through the result of the dynamic characteristics. we`ll define the design parameters and apply the appropriate parts.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.772-775
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• 2005

Most engineers, related to soil and civil dynamic field, have been interested in the direct dynamic design of building transmitted from soil and rock to structure due to blasting. However it is not easy to estimate the dynamic response of structures due to blasting by using analytical method because of difficulties of soil modeling, prediction of excitation force and so on. In this paper, dynamic analysis have been performed to predict vibration level and evaluate dynamic safety of structure adjacent to tunnel blast and the semi empirical method, which is based on vibration measurement data, has been employed to consider blast vibration characteristics.