Most reinforced concrete (RC) school buildings constructed in the 1980s have seismic vulnerabilities due to low transverse reinforcement ratios in columns and beam-column joints. In addition, the building structures designed for only gravity loads have the weak-columnstrong- beam (WCSB) system, resulting in low lateral resistance capacity. This study aims to investigate the lateral resistance capacities of a two-story, full-scale school building specimen through cyclic loading tests. Based on the experimental responses, load-displacement hysteresis behavior and story drift-strain relationship were mainly investigated by comparing the responses to code-defined story drift limits. The test specimen experienced stress concentration at the bottom of the first story columns and shear failure at the beam-column joints with strength degradation and bond failure observed at the life safety level specified in the code-defined drift limits for RC moment frames with seismic details. This indicates that the seismically vulnerable school building test specimen does not meet the minimum performance requirements under a 1,400-year return period earthquake, suggesting that seismic retrofitting is necessary.

In this study, static and dynamic analyses were conducted on three atypical building models to evaluate the displacement response reduction performance based on the outrigger system installation location in a atypical building that incorporated both tapered and twisted shapes. Three 60-story models were developed with a fixed 3-degree taper and twist angles of 1, 2, and 3 degrees per story. Outrigger systems were installed at 10-story intervals and additionally between the 20th and 40th floor at 1-story intervals. The results indicated that, although there were variations depending on the seismic loads, the displacement response reduction performance was generally most effective when the outriggers were installed in the upper stories (41st to 60th floors) of the analytical models.

This paper aims to quantify the retrofit effect of the Bolt Prefabricated Concrete-Filled Tube reinforcement method on non-seismic school reinforced concrete building through static cyclic loading experiments. To achieve the objective, two-story specimens including a non-retrofitted frame(NRF) and a Bolt Prefabricated Concrete-Filled Tube Reinforcement Frame(BCRF) were tested under static cyclic loading, and the lateral resistant capacities were compared in terms of maximum strength, initial stiffness, effective stiffness, and total energy dissipation. In addition, the load-displacement curves were compared to the story drift limit specified in Seismic Performance Evaluation and Retrofit Manual for School Facilities to investigate if the retrofitted frame was satisfied in target performance(life safety). Experimental results showed that BCRF successfully met the target performance, with a 200% increase in maximum strength and a 300% increase in energy dissipation capacity. Additionally, both initial stiffness and effective stiffness improved by more than 30% compared to NRF. Furthermore, BCRF exhibited an effect that delayed the occurrence of bond failure.

This study was conducted through experiments by producing an image output evacuation guide light linked with a smoke detector. To summarize the results, first, the biggest recognition distance of the door at 30% smoke concentration was found to be the image output evacuation guide light. This is because of visual impairment and fear caused by indoor smoke, and in the process of finding the light of the emergency exit, accurate recognition of the evacuation behavior was searched even at the farthest distance, and it is judged that the time required for evacuation was short. Second, the biggest recognition distance of the door at 70% smoke concentration was the image output evacuation guide light, which showed the longest recognition distance. It is judged that even in smoke with many evacuees, the door is accurately recognized while seeing the light of the image output evacuation guide light and exits safely. Third, when the smoke concentration was 100%, the smoke rose and the evacuation guide light at the top of the door was not identified as thick smoke, and the image output evacuation guide light was displayed on the bottom of the passage, indicating that the evacuee accurately recognized the door and escaped safely to the outside even from a long distance.

This study aims to model an accident that occurred at building demolition work sites in Gwangju in 2021 by using functional resonance analysis method(FRAM) and to understand a range of factors contributing to the accident based on the concepts and principles of FRAM and Safety-II. The nature of building demolition works needs to be understood from the viewpoint of socio-technical systems. Not only technical factors but also non-technical factors, including human, organizational, and political factors, and their complicated interrelationships should be considered in the modeling and analysis of accidents happening in the works. Because of the inherent complexity of a demolition works, it is unlikely to specify all of the necessary activities to be conducted in the works and their accountable actors. Additionally, unexpected situations are likely to happen and therefore some activity procedures cannot be followed in a prescribed way, which means that workers sometimes should conduct their activities in an improvisional way. Those characteristics of building demolition works indicate that a traditional accident analysis method based on a linear cause-effect relationship would be inadequate, and that more systemic approaches that can deal with the socio-technical complexities and characteristics of demolition works should be used. With this in mind, we applied FRAM to the accident happening in Gwangju in 2021 and attempted to understand the accident based on the concepts and principles of FRAM and Safety-II (e.g. a functional variablity and its propagation to another function). Lastly, we also suggested ways to enhance the safety of building demolition working sites.

본 연구에서는 재건축사업에 의하여 이주한 노인을 대상으로 재건축사 업 추진과정에서 발생한 외상이 정신건강에 미치는 영향을 살펴보고, 이 요인 간의 관계에서 정주환경 포용성의 완충효과를 규명하고자 하였다. 이를 위하여 재건축구역에 거주했던 186명에게 설문조사를 진행하였고, 자료분석을 위하여 IBM SPSS Statistics ver. 27.0을 사용하였다. 주요 연구결과는 다음과 같다. 첫째, 조사대상자의 외상 수준은 높았으며, 정 신건강과 정주환경 포용성은 양호하지 못한 것으로 나타났다. 둘째, 조사 대상자의 정신건강에는 외상, 재건축 구역의 거주기간, 사회적 포용성, 재건축사업 정책의 신뢰 정도가 크게 영향을 주는 것으로 나타났다. 셋 째, 외상과 정신건강의 관계에서 사회적 포용성과 공간적 포용성은 각각 완충효과를 갖는 것으로 나타났다. 이러한 연구결과는 재건축사업에 의 하여 이주한 노인이 외상에서 벗어나 양호한 정신건강을 회복하여 의욕 하는 삶을 향유하는데 기여할 것이다. 나아가, 재건축사업과 관련한 법· 제도의 미진한 부분을 보완하여 이주한 노인의 건강권 및 주거권을 보장 하는데 필요한 근거자료를 제공했다는 점에서 연구 의의가 있다.

Digital restoration of non-verbal expressions is difficult to trust unless the documentation. The purpose of this study is a new documentation methodology that can intuitively confirm the basis for restoration. The technical method utilized the BIM program function by referring to Italia's VRIM and Korea's HBIM cases. And the direction of documentation distinguishes between 'positivism' based on archaeological data and 'interpretivism' based on hypotheses. Specifically, it was applied to the 'Mireuksa Restoration Project' and tried to document it experimentally. This documentation proposed a framework for recording evidence according to sources based on the context of regions. Technically, the data organized in the Excel DB were directly input into the 3D model using the BIM program function. So, the user was able to intuitively review by matching the absence of the model and document information. The documenting method of this study is flexible to modify the restoration information whenever new evidence is found. And it has the advantage of being able to easily inform by converting it to IFC format.

In the Joseon Dynasty, ‘Bocheom’ had the function of a shade, but in that it was a building that applied the construction method, it had a different structure and character from the shade as a simple facility. If Bocheom was placed on all four sides of the main building, the roof would be structured as a double-layer, making the entire building grand and splendid, so it was mainly adopted in authoritative architecture. The materials of Bocheom was significantly smaller than that of the main building, and it had square rafters on the roof, and no beams were installed between the Bocheom and the main building. Bocheom is an additional architectural element that is clearly distinct from the main building, and it is different from architecture where the roof is formed in layers and the floor plan is composed of the inner and outer floor. The outer and inner floor constitute a single building, but Bocheom is distinct from the main building. If the outer floor are removed, the building cannot be established, but even if Bocheom is removed, the proportions and function of the main building are maintained. Bocheom is an additional architectural element that makes the building grand and splendid and helps with the conduct of ceremonies, and for this reason, it was adopted in authoritative architecture of the Joseon Dynasty.

This study attempted to examine the relationship between traditional architecture and its corresponding modern architecture by using the dynamic characteristics of text linguistics. The study assumed that past and present buildings, which maintain some kind of relationship, were a single text, and explored its internal structure that generated continuous textuality. As a case study, the buildings by Wang Shu and Kuma Kengo was reinterpreted using the techniques of cohesive structure to analyze their continuity with each tradition. The results showed that both architects used a variety of strategies to inherit tradition, but there were also differences in applying expressive and semantic aspects. Wang Shu attempted a modern reinterpretation of its architectural expressions at various levels, while Kuma actively borrowed traditional materials, structures, and patterns allowing various alteration in their meanings. We found that some concepts of text linguistics could be applicable as a meaningful perspective for analyzing and evaluating modern architecture that inherits tradition. We hope that our approach will develop into a comprehensive methodology for architectural analysis through more diverse attempts in the future.

According to literature, Chengdu was built in the ancient Shu period, and Chengdu experienced nearly 3,000 years of history in this region. After the city was founded in the Qin Dynasty, there were never any natural disasters such as floods in Chengdu for more than 2,000 years. Although there were no natural disasters, due to its central location in the southwest of China, wars were frequent. Thus, how to effectively suppress the rebellion in the southwest and how to rebuild the city after the wars became the top attention of the governments of Chengdu in the successive dynasties. At the beginning of the Qing Dynasty, the government followed the Yuan and Ming systems, and the layout and architectural style of the city was similar to the previous dynasties. With the gradual recovery of the economy, Chengdu became a military center in southwest China and a military base was built in the city. Since then, Chengdu has gradually broken the original city style. Therefore, in this study, through archeological and literature sources, we analyzed the spatial structural evolution of Chengdu city in the historical background, focusing on the urban space and major building structures of Chengdu during the Qing Dynasty, which was relatively rich in information.

Piloti-type buildings are widely constructed in urban areas of South Korea. Due to stiffness irregularities, piloti-type buildings are vulnerable to lateral loads such as earthquakes. Although seismic retrofitting is necessary for piloti-type buildings, many of these structures are privately owned, and the extensive number of buildings creates significant challenges in terms of cost and time for regional seismic performance evaluation. This study proposes a methodology for determining the seismic performance of multiple piloti-type buildings within a region by utilizing structural parameters. Information on piloti-type buildings is classified into public building data and exterior building data, which are integrated to define structural parameters for estimating the first natural period of the buildings. Linear regression analysis was performed to develop a regression equation correlating structural parameters with the natural period. Additionally, the natural period and structural parameters are used to perform another linear regression analysis to estimate the yield and ultimate points of the capacity curve. The capacity curves derived from the regression equations facilitate seismic performance evaluation based on structural parameters.

Structures compromised by a seismic event may be susceptible to aftershocks or subsequent occurrences within a particular duration. Considering that the shape ratios of sections, such as column shape ratio (CSR) and wall shape ratio (WSR), significantly influence the behavior of reinforced concrete (RC) piloti structures, it is essential to determine the best appropriate methodology for these structures. The seismic evaluation of piloti structures was conducted to measure seismic performance based on section shape ratios and inter-story drift ratio (IDR) standards. The diverse machine-learning models were trained and evaluated using the dataset, and the optimal model was chosen based on the performance of each model. The optimal model was employed to predict seismic performance by adjusting section shape ratios and output parameters, and a recommended approach for section shape ratios was presented. The optimal section shape ratios for the CSR range from 1.0 to 1.5, while the WSR spans from 1.5 to 3.33, regardless of the inter-story drift ratios.

The primary purpose of this study is to develop system modules of school buildings and the seismic loss function of the system modules for regional loss assessment of school buildings. System modules of school buildings were developed through statistical analysis of school facilities in Korea. The structural system of school buildings with non-seismic details is defined as reinforced concrete with partially masonry walls (RCPM), and 27 system modules of RCPM were developed considering the number of stories, spans, and the age of the building. System modules were designed to assess the structural behavior by applying the shear spring model and the shear failure of the columns of the school building. Probabilistic seismic demand models for each component of system modules were derived through nonlinear dynamic analysis to determine the relationship between seismic intensity, drift ratio, and peak floor acceleration of system modules. The seismic loss function was defined as the total damage ratio, which is the ratio of replacement cost to repair cost to evaluate the seismic loss quantitatively. The system module-based seismic loss well predicted the observed data. It will be possible to help many stakeholders make risk-informed decisions for a region through the regional loss assessment of school buildings in Korea.

In densely populated urban areas, reinforced concrete residential buildings with an open first floor and closed upper floors are preferred to meet user demands, resulting in significant vertical stiffness irregularities. These vertical stiffness irregularities promote the development of a soft-story mechanism, leading to concentrated damage on the first floor during seismic events. To mitigate seismic damage caused by the soft-story mechanism, stiffness-based retrofit strategies are favored, and it is crucial to determine an economically optimal level of retrofitting. This study aims to establish optimal seismic retrofit strategies by evaluating the seismic losses of buildings before and after stiffness-based retrofitting. An equivalent single-degree-of-freedom model is established to describe the seismic response of a multi-degree-of-freedom model, allowing for seismic demand analysis. By convolving the seismic loss function with the hazard curve, the annual expected loss (EAL) of the building is calculated to assess the economic losses. The results show that stiffness-based retrofitting increases first-story lateral stiffness by 20-40%, enhancing structural seismic performance, but also results in a rise in EAL compared to the as-built state, indicating lower cost-effectiveness from an economic perspective. The research concludes that retrofit options that increase first-story lateral stiffness by at least 60% are more appropriate for reducing financial losses.

The diagrid structural system has a braced frame that simultaneously resists lateral and vertical loads, and is being applied to many atypical high-rise buildings for aesthetic effects. In this study, a 60-story structure with twisted degrees of 0° to 180° was selected to determine seismic response control performance of twisted high-rise structures whether the diagrid system was applied and according to the reduction of braced frame material quantity. For this purpose, ‘Nor’ model without the diagrid system and the ‘DS’ model with the diagrid system, which was modeled by reducing braced frame member section to 700~400, were modeled. As a result, the 'DS' model showed an seismic response control effect in all Twisted models even when the quantity was reduced, and especially, the Twisted shape model was found to have an superior response control effect compared to the regular structure. In addition, the ‘600DS’ analysis model, which matched the ‘Nor’ model by 99.0% in quantity, showed an increase in seismic response control performance as the rotation angle increased.

This study analyzed displacement records of Sungnyemun Gate's primary structural members, such as columns, beams, and hip rafters, over approximately ten years from 2013 to 2023. Through this, we attempted to examine the behavior of wooden architectural heritage in detail and infer the factors influencing structural change through the deformation revealed during the displacement accumulation process. As a result of the analysis, it was quantitatively confirmed that the prominent structural members of the Sungnyemun gate, including the columns, beams, and hip rafters, continued to move and that the accumulated displacements from the movement led to the structure's deformation. It was also confirmed that member displacements accumulate in a specific direction. In the case of the Sungnyemun gate, even after the structure was stabilized, the columns were tilting inward toward the building, and the ends of the hip rafters and the centers of the beams were moving downward continuously. Furthermore, the behavior of wooden architectural heritage, in which damage accumulates as it undergoes repeated transformation and recovery according to seasonal changes, was also revealed in detail. The deformation of the Sungnyemun gate members shows a common pattern of relatively large behavior in the summer. However, seasonal deformation did not appear the same in all members. Even the same member has an uneven drying speed due to differences in the amount of sunlight received depending on the location, leading to uneven distribution of deformation. This study, while acknowledging its limitations, is significant in that it attempts to examine the behavior of our wooden architectural heritage in detail and discuss its characteristics and influencing factors based on quantitative results of long-term measurements.