Piloti-type structures with vertical irregularity are vulnerable to earthquakes due to the soft structure of the first story. Structural characteristics of buildings can significantly affect the seismic loss function, calculated based on seismic fragility, and therefore need to be considered. This study investigated the effects of the number of stories and core locations on the seismic loss function of piloti-type buildings in Korea. Twelve analytical models were developed considering two variations: three stories (4-story, 5-story, and 6-story) and four core locations (center core, x-eccentric core, y-eccentric core, and xy-eccentric core). The interstory drift ratio and peak floor acceleration were assessed through incremental dynamic analysis using 44 earthquake records, and seismic fragility was derived. Seismic loss functions were calculated and compared using the derived seismic fragility and repair cost ratio of each component. The results indicate that the seismic loss function increases with more stories and when the core is eccentrically located in the piloti-type structure model. Therefore, the uncertainty due to the number of stories and core location should be considered when deriving the seismic loss function of piloti-type structures.

In this study, we investigated the dynamic characteristics of three irregular building models to analyze the effectiveness of displacement response control with Tuned Mass Damper (TMD) installation in twisted irregular buildings. The three irregular models were developed with a fixed angle of twist per story at one degree, subjected to three historical seismic loads and resonant harmonic loads. By designing TMDs with linear and dashpot attributes, we varied the total mass ratio of the installed TMDs from 0.00625% to 1.0%, encompassing a total of 10 values. Two TMDs were installed at the center of the top story of the analysis model in both X and Y directions to evaluate displacement response control performance based on TMD installation. Our findings suggest that the top displacement response control performance was most effective when a 1.0% TMD was installed at the top layer of the analysis model.

It is very important to evaluate how the functions of products, facilities, and spaces affect human life. The evaluation of these actions has legal regulations such as certification, inspection, and diagnosis, and the degree of quality, safety, and excellence of the results is announced. This study sought to secure safety through efficient system operation by reviewing safety-related certification systems established and implemented by each government department in Korea and analyzing the characteristics of each system and similarities between systems. There was also an aspect of cross-checking safety through the certification and diagnosis system implemented by each ministry, but it was confirmed that the efficiency of the system should also be considered in terms of overlapping application. Therefore, when securing safety is confirmed based on each safety-related law, active alternatives such as exemption, substitution, delegation, etc. should be presented.

하브라켄(N. John Habraken) 교수는 2023년 10월 21 일에 별세했다. 그는 1928년 인도네시아 반둥에서 태어 난 네덜란드 건축가, 교육자, 이론가이다. 그의 이론적 공헌은 대량 주택에 대한 사용자 참여 및 사용자와 거 주자를 설계 프로세스에 통합한 것이다. 그의 이론이 추 구하는 시각적 결과물은 생동감 넘치는 다양성의 건축 이다. 하브라켄은 그의 􋺷주거대(Support)􋺸에서, 주거 설 계에서 주거대(住居帶: support = base building)를 ‘내 장품(內裝品: detachable unit = infill)’1)과 분리하여 주 민들이 설계 과정에서 의미 있는 참여 역할을 할 수 있 도록 제안했다. 하브라켄은 제2차 세계대전 중에 일본제국주의 강제 수용소에 3년간 억류된 경험을 했고, 그 후에 네덜란드 의 델프트 공대에서 건축을 공부했다. 그는 1965∼1975 년 SAR(Foundation for Architects Research)의 소장을 역임했으며, 1967년 아인트호벤 공대의 건축학과를 신 설하고, 초대 학과장의 중책을 맡았다. 1975∼1981년 하 브라켄은 MIT 건축대학의 학과장으로 재직했고, 1989 년 퇴임하고 명예교수로 은퇴할 때까지 MIT에서 학생 들을 가르쳤다. 2016년에 나는 그가 설계해 살고 있던 네덜란드 아펠도른(Apeldoorn)의 집을 방문했다. 당시 그는 노쇠했으나, 정신은 매우 명료했다. 이후 다시 가 보려고 했는데, 이젠 지난 소망이 되었다. ―하브라켄 교수님의 명복을 빕니다. 하브라켄의 서거를 접하고, 내게 특별한 의미가 있는 하 브라켄의 논문 한 편을 번역해 공개한다. 그는 MIT에 서 나의 석사과정과 박사과정의 지도 교수였으며, 여기 번역한 글은 박사과정 중에 출간되었다. 1991년에 나는 써머슨(J. Summerson)의 논문 ｢The case for a theory of modern architecture｣를 그에게 소개했고, 우리는 그 내용에 대해 토의했다. 하브라켄은 4쪽, 각주 3에 써머 슨의 논문을 인용했다는 노트를 적은, 내가 번역한 영문 논문을 내게 주면서, “네가 즐겁게 읽어주었으면 좋겠 다”는 메모를 남겼다. 벌써 30년이 지났지만, 나는 이 글의 주장이 현재에도 유효하다고 생각한다. 나는 이 번 역이 하브라켄의 학문 세계를 이해하는데 작은 도움이 되기를 소망한다. 하브라켄의 글에는 현학적이거나 어려운 단어가 거의 없다. 포괄적 추상 개념을 지시하는 정신(Geist), 공간 (space), 표상(representation), 미학(Aesthetics) 등과 같 은 난해한 어휘도 없다. 그는 평이한 문장으로 자신의 주장과 논리를 전개하는 탁월한 능력을 가진 지적 거인 이다. 그리고 그는 특정 개념에 대해 동일한 명사를 일 관되게 사용한다. 영어 원문에 대한 이해와 참조를 위 해, 내가 일관되게 번역해 사용한 단어와 구는 다음과 같다.

Recently, the occurrence frequency of earthquake has increased in Korea, and the interests for seismic reinforcement of existing school buildings have been raised. To this end, the seismic performance evaluations for school buildings that did not accomplish the seismic design are required. In particular, this study checks the eigenvalue analysis, pushover curves, maximum base shears, performance points and story drift ratios, and then analyzes the seismic performance characteristics according to bracing configuration of steel frame system reinforcement. Also, this study presents the practical field application methods through the comparison of analysis results for the seismic performance characteristics.

Due to the aging of a building, 38.8% (about 2.82 million buildings) of the total buildings are old for more than 30 years after completion and are located in a blind spot for an inspection, except for buildings subject to regular legal inspection (about 3%). Such existing buildings require users to self-inspect themselves and make efforts to take preemptive risks. The scope of this study was defined as the general public's visual self-inspection of buildings and was limited to structural members that affect the structural stability of old buildings. This study categorized possible damage to reinforced concrete to check the structural safety of buildings and proposed a checklist to prevent the damage. A damage assessment methodology was presented during the inspection, and a self-inspection scenario was tested through a chatbot connection. It is believed that it can increase the accessibility and convenience of non-experts and induce equalized results when performing inspections, according to the chatbot guide.

Existing reinforced concrete buildings with seismically deficient details have premature failure under earthquake loads. The fiber-reinforced polymer column jacket enhances the lateral resisting capacities with additional confining pressures. This paper aims to quantify the retrofit effect varying the confinement and stiffness-related parameters under three earthquake scenarios and establish the retrofit strategy. The retrofit effects were estimated by comparing energy demands between non-retrofitted and retrofitted conditions. The retrofit design parameters are determined considering seismic hazard levels to maximize the retrofit effects. The critical parameters of the retrofit system were determined by the confinement-related parameters at moderate and high seismic levels and the stiffness-related parameters at low seismic levels.

This study proposes a methodology for the regional seismic risk assessment of structural damage to buildings in Korea based on evaluating individual buildings, considering inconsistency between the administrative district border and grid lines to define seismic hazard. The accuracy of seismic hazards was enhanced by subdividing the current 2km-sized grids into ones with a smaller size. Considering the enhancement of the Korean seismic design code in 2005, existing seismic fragility functions for seismically designed buildings are revised by modifying the capacity spectrum according to the changes in seismic design load. A seismic risk index in building damage is defined using the total damaged floor area considering building size differences. The proposed seismic risk index was calculated for buildings in 29 administrative districts in 'A' city in Korea to validate the proposed assessment algorithm and risk index. In the validation procedure, sensitivity analysis was performed on the grid size, quantitative building damage measure, and seismic fragility function update.

KDS 41 12 00의 풍하중 관련 식은 정형적인 건축물에 대한 수많은 연구를 통해 만든 경험식이다. 따라서 비정형 건축물에 대하여 KDS 41 12 00에 따라 풍하중을 산출하면 건축물의 형상이 반영되지 않아 실제 풍하중과 상이할 수 있다. 이에 Y자형 건축물 에 대하여 풍동실험에 따른 풍하중과 KDS 41 12 00에 따른 풍하중을 산출하고 비교하고자 하였다. 이를 위해 풍력실험을 수행하였고 최종적으로 두 가지 방법에 따른 풍하중의 비율을 산출하고 이를 풍하중 증감계수로 도출하고자 하였다. 본 연구에서 제시하는 풍하 중 증감계수를 KDS 41 12 00에 따라 풍하중 산출 과정에 적용한다면 보다 합리적으로 Y자형 건축물에 대한 풍하중을 산출할 수 있 을 것으로 사료된다.

In this study, in order to establish a strategy for developing an fire following earthquake risk assessment method that can utilize domestic public databases(building datas, etc.), the method of calculating the ignition and fire-spread among the fire following earthquake risk assessment methodologies proposed by past researchers is investigated After investigating and analyzing the methodology used in the HAZUS-MH earthquake model in the United States and the fire following earthquake risk assessment methodology in Japan, based on this, a database such as a domestic building data utilized to an fire following earthquake risk assessment method suitable for domestic circumstances (planned) was suggested.

Existing reinforced concrete (RC) frame buildings have seismic vulnerabilities because of seismically deficient details. In particular, since cumulative damage caused by successive earthquakes causes serious damage, repair/retrofit rehabilitation studies for successive earthquakes are needed. This study investigates the repair effect of fiber-reinforced polymer jacketing system for the seismically-vulnerable building structures under successive earthquakes. The repair modeling method developed and validated from the previous study was implemented to the building models. Additionally, the main parameters of the FRP jacketing system were selected as the number of FRP layers associated with the confinement effects and the installation location. To define the repair effects of the FRP jacketing system with the main parameters, this study conducted nonlinear time-history analyses for the building structural models with the various repairing scenarios. Based on this investigation, the repair effects of the damaged building structures were significantly affected by the damage levels induced from the mainshocks regardless of the retrofit scenarios.

Following the social requirement to strengthen field supervision of the asbestos containing materials (ACM) abatement process with regard to asbestos school buildings, this study was conducted to understand the status and characteristics of airborne asbestos that may potentially occur after the ACM abatement process is completed. In the area where a series of asbestos abatement processes were finally completed, comprehensive area air sampling was performed. For sample analysis, Transmission Electron Microscopy (TEM) was used according to The Asbestos Hazard Emergency Response Act (AHERA) method and Phase Contrast Microscopy (PCM) analysis was also performed. Airborne asbestos was detected in 29.5% of the total samples, and the average concentration was 0.0039 ± 0.0123 s/cc (12.3 ± 38.9 s/mm2). 4.5% of the total samples exceeded the AHERA standard (70.0 s/mm2) and the average concentration was 0.0528 ± 0.0256 s/cc (167.2 ± 82.0 s/mm2). Airborne asbestos was no longer detected at the point when AHERA is exceeded after re-cleaning. Most of the detected asbestos was chrysotile (94.4%) and the structure types of asbestos were Matrix (41.4%), Fiber (39.9%), Bundle (10.8%), and Cluster (7.8%). Among the asbestos structures detected through transmission electron microscope analysis, the asbestos structures satisfying PCM-equivalent structures were found to be 6% of the detected asbestos, indicating that there is a limitation of the PCM analysis to check the airborne asbestos in that area. As a result of reviewing the status of airborne asbestos that may potentially occur and the type and dimensions of asbestos structure detected in the area, since the airborne asbestos exposure caused by poor field supervision for the ACM abatement process could not be ruled out, thorough management is necessary. In addition, the result of this study could be used as scientific evidence for establishing and strengthening policies related to ACM abatement, including cases of school buildings.

우리나라는 삼면이 바다이며 북쪽과 동쪽으로 산지가 위치하고 서쪽으로는 평탄한 지리적 특성을 가진다. 또한 계절풍, 태풍 등의 바람이 지리적 특성으로 인하여 지역마다 풍향별 풍속이 다르다. 그러나 건축구조기준(이하 KDS 41 12 00: 2019)은 전풍향에 대 해 동일한 풍속을 적용한다고 규정하였고, 이것은 상대적으로 약한 풍향에 대해 과다한 풍속을 적용할 수 있다. 이런 점을 고려하여 건 축구조기준(이하 KDS 41 12 00: 2022)에서는 합리적인 설계를 위해 풍향계수를 적용한다. 본 연구는 8개소를 대상으로 10년간의 자 료를 수집하여 사용성 평가를 위한 1년 재현기대풍속과 풍향계수를 산출하였다. 선행 연구된 논문에서 사용성 평가를 위한 1년 재현 기대풍속과 풍향계수를 산출하였으나, 이는 기상청에서 제공하는 일최대풍속으로 산출하였기 때문에 누락되는 풍속이 있을 수 있다고 판단되었다. 따라서 분풍속을 이용하여 모든 풍향의 일최대풍속을 구하였고, Weibull 분포를 통해 재현기대풍속을 산출하였다. 최종적 으로 기상청에서 제공하는 일최대풍속으로 구한 풍향계수와 분풍속으로 구한 일최대풍속의 풍향계수를 비교하여 지역별 풍향계수의 경향 및 두 방법의 차이점에 대해 분석하였다.

Structures of high-rise buildings are less prone to earthquake damage. This is because the response acceleration of high-rise buildings appears to be small by generally occurring short-period ground motions. However, due to the increased construction volume of high-rise buildings and concerns about large earthquakes, long-period ground motions have begun to be recognized as a risk factor for high-rise buildings. Ground motion observed on each floor of the building is affected by the eigenmode of the building because the ground motion input to the building is amplified in the frequency range corresponding to the building's natural frequency. In addition, long-period components of ground motion are more easily transmitted to the floor or attached components of the building than short-period components. As such, high-rise buildings and non-structural components pose concerns about long-period ground motion. However, the criteria (ASCE 7-22) underestimate the acceleration response of buildings and non-structural components caused by long-period ground motion. Therefore, the characteristics of buildings’ acceleration response amplification ratio and non-structural components were reviewed in this study through shake table tests considering long-period ground motions.

Existing reinforced concrete building structures constructed before 1988 have seismically-deficient reinforcing details, which can lead to the premature failure of the columns and beam-column joints. The premature failure was resulted from the inadequate bonding performance between the reinforcing bars and surrounding concrete on the main structural elements. This paper aims to quantify the bond-slip effect on the dynamic responses of reinforced concrete frame models using finite element analyses. The bond-slip behavior was modeled using an one-dimensional slide line model in LS-DYNA. The bond-slip models were varied with the bonding conditions and failure modes, and implemented to the well-validated finite element models. The dynamic responses of the frame models with the several bonding conditions were compared to the validated models reproducing the actual behavior. It verifies that the bond-slip effects significantly affected the dynamic responses of the reinforced concrete building structures.

In this study, an incremental loading test of the HRS(Hybrid Rubber Slit) damper was additionally performed to define the physical characteristics according to the incremental test results, and an analytical study was performed according to the damping design procedure by selecting an example structure. As a result of performing seismic performance evaluation before reinforcement by selecting a RC structure similar to an actual school structure as an example structure, the story drift ratio was satisfied, but some column members collapsed due to bending deformation. In order to secure the seismic performance, the damping design procedure of the HRS damper was presented and performed. As a result of calculating the amount of damping device according to the expected damping ratio and applying it to the example structure, the hysteresis behavior was stable without decrease in strength, and the story drift ratio and the shear force were reduced according to the damping effect. Finally the column members that had collapsed before reinforcement satisfied the LS Level.