While the subduction zone earthquakes have long ground motion durations, the effects are also not covered in seismic design provisions. Additionally, the collapse risk of steel frame buildings subjected to long-duration ground motions from subduction earthquakes remains poorly understood. This paper presents the influence of ground motion duration on the collapse risk of steel frame buildings with special concentrically braced frames in chevron configurations. The steel buildings considered in this paper are designed at a site in Seattle, Washington, according to the requirements of modern seismic design provisions in the United States. For this purpose, the nonlinear dynamic analyses employ two sets of spectrally equivalent long and short-duration ground motions. Based on the use of high-fidelity structural models accounting for both geometric and material nonlinearities, the estimated collapse capacity for the modern code-compliant steel frame buildings is, on average, approximately 1.47 times the smaller value when considering long-duration ground motion record, compared to the short-duration counterpart. Due to the sensitivity to destabilizing P-Delta effects of gravity loads, the influence of ground motion duration on collapse risk is more profound for medium-to-high-rise steel frame buildings compared to the low-rise counterparts.

대법원은 최근 바닥면적 300㎡ 미만 소매점에 대한 편의시설 설치의무를 면제한 장애인등편의법 시행령 별표 1을 장기간 개선하지 않은 것이 위법한 행정입법부작위에 해당한다고 보아 국가배상책임을 인정하였다. 위 대법원 판결의 1심 판결은 GS리테일 주식회사에 대하여 바닥면적의 크기나 설치시 점과 상관없이 편의점에 편의시설을 설치할 것 등을 명하면서 300㎡ 미만 편의점의 편의시설 설치의무를 면제한 위 규정은 위헌·위법하여 무효라고 보았다. 이후 장애인등편의법 시행령 개정으로 소매점 등의 편의시설 설치기준이 50㎡ 이상으로 하향되었으나, 여전히 50㎡ 미만 소매점 등에는 편의시설 설치의무가 전적으로 면제된다. 특히 위 개정 시행령의 시행일 전에 설치된 기존 시설에는 적용되지 않아 이로 인한 장애인 접근성 보장 수준의 향상은 미미하였다. 시설물에서의 편의제공의무 관련하여 장애인차별금지법 시행령 의 근본적인 문제점도 여전히 유지되고 있다. 즉 장애인차별금지법 시행령 은 여전히 편의시설 외의 설비, 인적 서비스를 포괄하는 ‘편의제공의무’를 물리적인 차원의 ‘편의시설 설치의무’로 축소해 규정하고 있고, 편의제공의 무를 지는 시설물의 시간적 적용범위를 2009년 이후 신축·증축·개축된 시설 로 제한하여 기존 시설에 대한 편의제공의무를 전적으로 배제하고 있다. 비교법적으로도, 미국장애인법(ADA)과 독일 바이에른주 건축법은 시행 전 건물에도 기술적·경제적 가능성을 고려해 접근성 개선의무를 부과하는데, 한국은 장애인등편의법, 장애인차별금지법 모두 법 시행 전에 설치된 기존 시설의 편의시설 설치의무를 건물의 ‘변경’ 등의 사정이 없는 한 영구적으로 면제하고 있다. 장애인의 시설물 접근성을 제대로 보장하기 위해서는 장애 인차별금지법 시행령에 편의시설 외의 설비, 인적 서비스를 포괄하는 ‘편의 제공의무’에 관한 규정을 장애인차별금지법의 위임 취지에 맞게 추가하고, 편의시설의 경우 바닥면적의 크기나 설치시점과 무관하게 단계적으로 일정한 수준의 편의시설 설치의무를 부과하여야 한다. 후속연구를 통해 이 문제 를 해결할 구체적인 장애인등편의법(시행령, 시행규칙 포함) 및 장애인차별 금지법(시행령 포함) 개정안을 만들어 제시할 필요가 있다.

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 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.

저층 건축물의 횡-비틀림 거동은 고차모드 효과를 증폭시킬 수 있으며, 내진성능평가 시 관련 기준은 고차모드 지배 구조물에 대해 비선형정적해석과 함께 선형동적해석을 추가로 수행하도록 규정하고 있다. 선형동적절차에는 상당한 안전계수가 적용되므로, 이는 과도한 내진보강설계로 이어질 수 있다. 이를 방지하기 위해 엔지니어들은 내진보강 시 고차모드 효과를 줄이기 위해 시행착오법을 사용해 왔다. 그러나 시행착오법에는 많은 시간과 노력이 소요되며, 결정된 보강안이 최적인지 확인하기 어렵다. 본 연구는 저층 건 축물의 수학적 모델을 수립하고 응답스펙트럼해석을 통해 고차모드 효과에 비틀림이 독립적으로 미치는 영향을 파악하였다. 이를 바탕으로 효율적인 내진보강 설계를 위해 활용될 수 있는 도표와 절차를 제시하였다. 제시된 절차를 통해 최소한의 내진보강으로 횡- 비틀림 거동하는 저층 건축물의 고차모드 효과를 효율적으로 감소시킬 수 있음을 확인하였다.

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.

Steel brace is a popular option among seismic rehabilitation methods for school buildings, but it has a weakness in that the section area must be large enough to prevent buckling, so stiffness and strength are highly increased locally, and foundation reinforcing is required. On the contrary, BRB has strength that the steel core may be negligible since buckling is restrained, so the increase of stiffness and strength is insignificant, and foundation reinforcing may not be required. This study compared the effectiveness of both reinforcing methods for the seismic performance of school buildings by conducting both pushover and nonlinear dynamic analyses. Steel brace and BRB reinforcing may not be satisfied by nonlinear dynamic analysis, even by pushover analysis. This result is due to the school buildings' low lateral resistance and high column shear strength ratio. Suppose BRB can be regarded as a general rehabilitation method. In that case, BRB reinforcing is a favorable and economical option for school buildings with low column shear strength ratio since it can better satisfy performance objectives than steel brace by pushover analysis with a small steel core and no foundation reinforcing.

The precast concrete (PC) method allows for simple assembly and disassembly of structures; however, ensuring airtight connections is crucial to prevent energy loss and maintain optimal building performance. This study focuses on the analytical investigation of the shear capacity of precast ultra-high-performance concrete (UHPC) ribs combined with standard concrete PC cladding walls. Five specimens were tested under static loading conditions to evaluate their structural performance and the thermal behavior of the UHPC rib shear keys. Test results indicated that the specimens exhibited remarkable structural performance, with shear capacity approximately three times greater than that of standard concrete. Numerical models were subsequently developed to predict the shear capacity of the shear keys under various loading conditions. A comparison between the experimental results and finite element (FE) models showed a maximum strength difference of less than 10% and a rib displacement error of up to 1.76 mm. These findings demonstrated the efficiency of the FE model for the simulation of the behavior of structures.