• Geomechanics and Engineering
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• 제34권3호
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• pp.251-265
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• 2023

In urban construction projects, it is crucial to evaluate the impacts of excavation-induced ground movements in order to protect surrounding structures. These ground movements resulting in damages to the neighboring structures and facilities (i.e., parking basement) are of main concern for the geotechnical engineers. Even more, the danger exists if the nearby structure is an ancient or masonry brick building. The formations of cracks are indicators of structural damage caused by excavation-induced ground disturbances, which pose issues for excavation-related projects. Although the effects of deep excavations on existing brick masonry walls have been thoroughly researched, the impact of twin excavations on a brick masonry wall is rarely described in the literature. This work presents a 3D parametric analysis using an advanced hypoplastic model to investigate the responses of an existing isolated brick masonry wall to twin perpendicular excavations in dry sand. One after the other, twin perpendicular excavations are simulated. This article also looks at how varying sand relative densities (D_r = 30%, 50%, 70%, and 90%) affect the masonry wall. The cracks at the top of the wall were caused by the hogging deformation profile caused by the twin excavations. By raising the relative density from 30% to 90%, excavation-induced footing settlement is greatly minimized. The crack width at the top of the wall reduces as a result of the second excavation in very loose to loose sand (D_r = 30% and 50%). While the crack width on the top of the wall increases owing to the second excavation in medium to very dense sand (D_r = 70% and 90%).

• 건축역사연구
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• 제15권2호
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• pp.7-22
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• 2006

The Industrial Revolution brought a variety of new forms of structure, and as a group they are usually called 'industrial architecture'. Steam engines contributed greatly to architecture with a unique structure called 'water tower' to provide water for steam engines, especially the adoption of it. This study is to examine the changes of the building materials and architectural features of the water towers of railway stations built in the early twentieth century in South Korea. This study also attempts to describe the modern features of the industrial architecture, which did not get a chance to be noticed. Through this examination on water tower, which is a part of industrial architecture with sheer integration of function and pure geometric form, we would like to find the meaning of modern architecture in Korea. As we can see in the Korean oldest railway station water tower constructed in masonry at Yeonsan Station in 1911, early water towers were divided into the masonry machine room and the steel water tank. However, the masonry structure was soon turned into concrete structure with its formal features maintained as it was. The steel water tank was also replaced with concrete structure. As a result, while its basic structure remained, concrete structure had substituted for the every components of water tower. Concrete-built water towers were the high-tech architecture of that time and the most perfect structures built in concrete. Nevertheless, the perfection of the water tower form and the technology it attained were not transferred to other modern and contemporary architecture in South Korea. Since the subject to railway station water towers was the Japanese government, and steam engines were replaced with diesels in the midst of a complicated domestic situation after the independence, the need for water towers in railway stations disappeared and therefore, it became ignored and was difficult to look over the architectural features and values of early railway station water towers.

• 한국지진공학회논문집
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• 제8권5호통권39호
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• pp.1-14
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• 2004

본 연구는 우리나라에서 저층 주거용 건물로 널리 사용되고 있는 2층 규모의 비보강조적조 의 1/3 축소 모델에 대한 진동대 실험을 수행한 것이다. 본 연구의 주목적은 내진설계가 이루어지지 않은 조적조 건물의 내진거동을 살펴보고, 실험적 자료를 확보하는데 있다. 실험대상구조물은 횡방향으로는 대칭이지만 종방향으로는 약간 비대칭이고, 비교적 강한 다이어프램을 나타내는 콘크리트 슬래브로 되어있다. 실험체에 대한 모의 지진하중은 가속도를 점차 증가시켜가면서 종방향으로 가력하였다. 실험에서 얻은 구조물의 동적 응답자료는 진동대의 입력지진과 연관지어서 분석하였다. 더욱이 성능기초설계를 위한 성능수준을 제시하였다. 실험결과 1층에서의 전단파괴가 지배적이고 상부층은 강체거동을 보여주었다. 또한 균열 발생후에도 상당한 강도와 변형능력을 보유하고 있는 것으로 나타났다.

• 지구물리
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• 제9권1호
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• pp.63-71
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• 2006

When surveying the cultural heritages especially in the case of stone structures, preserving their originalstate is of primary importance. For the effective assessment of survey results of stone structure, thedynamic characteristics of that system should be considered. Dynamic characteristics of stone masonry structures depend on several factors such as coefficients of friction, contact conditions, and number of layers of bonding stones. These factors can be estimated by using the dynamic analysis results. This paper describes a method for natural frequency determination of traditional stone arch bridge subjected to compressive force. For this purpose, multi-layered granite brick models of for arch bridge were made and fundamental frequencies corresponding increasing axial forces were measured.

• 한국터널지하공간학회 논문집
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• 제4권4호
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• pp.319-332
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• 2002

국내 조적식 철도터널의 라이닝은 적벽돌이나 화강암의 석재블럭 또는 석축으로 구성되어 있다. 조적식라이닝은 지진하중에 대한 고려가 없이 시공이 되어 있어 지진시 거동에 대한 연구가 필요하다. 따라서 본 연구에서는 철도터널내 조적식 라이닝에 대한 물성평가 및 내진 해석기법을 개발하여 내진성능을 평가할 수 있도록 하였다. 적벽돌 조적식 라이닝은 배열이 지반조건에 따라 3~5층으로 구성 되어 있으며 벽돌과 벽돌은 모르터로 부착이 되어 있다. 본 연구에서는 조적식 라이닝의 거동분석 및 내진성능 평가를 위해 적벽돌, 횡줄눈, 종줄눈과 배면줄 눈을 각각 고려한 모형을 개발하였다. 내진해석은 구조물의 고유주기 뿐만 아니라, 지반과의 상호 작용을 고려한 전체계의 주기 등을 고려하는 응답스펙트럼해석을 실시하였다. 또한 라이닝과 지반조건변화에 따른 거동을 분석하고, 보강공법에 따른 거동을 분석하여 합리적인 보강공법을 유도하였다.

• Computers and Concrete
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• 제32권5호
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• pp.455-464
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• 2023

Seismologists now suggest that the earth has entered an active seismic period; many earthquake-related events are occurring globally. Consequently, numerous casualties, as well as economic losses due to earthquakes, have been reported in recent years. Primarily, significant and colossal damage occurs in reinforced concrete (RC) buildings with masonry infill wall systems, and the construction of these types of structures have increased worldwide. According to a report from the Ministry of Education in the Republic of Korea, many buildings were built with RC frames with masonry infill walls in the Republic of Korea during the 1980s. For years, most structures of this type have been school buildings, and since the Pohang earthquake in 2017, the government of the Republic of Korea has paid close attention to this social event and focused on damage from earthquakes. From a long-term research perspective, damage from structural collapse due to the short column effect has been a major concern, specifically because the RC frame with a masonry infill wall system is the typical form of structure for school buildings. Therefore, the short column effect has recently been a major topic for research. This study compares one RC frame with four different types of RC frames with masonry infill wall systems. Structural damage due to the short column effect is clearly analyzed, as the result of this research is giving in a higher infill wall system produces a greater shear force on the connecting point between the infill wall system and the column. The study is expected to be a useful reference for research on the short column effect in RC frames with masonry infill wall systems.

• Earthquakes and Structures
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• 제12권5호
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• pp.489-499
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• 2017

The effects of past earthquakes have demonstrated the seismic vulnerability of confined masonry structures (CMSs) to earthquakes. The results of experimental analysis indicate that damage to these structures depends on lateral displacement applied to the walls. Seismic evaluation lacks an analytical approach because of the complexity of the behavior of this type of structure; an empirical approach is often used for this purpose. Seismic assessment and risk analysis of CMSs, especially in area have a large number of such buildings is difficult and could be riddled with error. The present study used analytical and numerical models to develop a simplified nonlinear displacement-based approach for seismic assessment of a CMS. The methodology is based on the concept of ESDOF and displacement demand and is compared with displacement capacity at the characteristic period of vibration according to performance level. Displacement demand was identified using the nonlinear displacement spectrum for a specified limit state. This approach is based on a macro model and nonlinear incremental dynamic analysis of a 3D prototype structure taking into account uncertainty of the mechanical properties and results in a simple, precise method for seismic assessment of a CMS. To validate the approach, a case study was considered in the form of an analytical fragility curve which was then compared with the precise method.

• Structural Engineering and Mechanics
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• 제64권5호
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• pp.653-660
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• 2017

The aim of this study is to accurately estimate seismic damage and the collapse mechanism of the historical stone masonry minaret "Hafsa Sultan", which was built in 1522. Surveying measurements and material tests were conducted to obtain a 3D solid model and the mechanical properties of the components of the minaret. The initial Finite Element (FE) model is analyzed and numerical dynamic characteristics of the minaret are obtained. The Operational Modal Analysis (OMA) method is conducted to obtain the experimental dynamic characteristics of the minaret and the initial FE model is calibrated by using the experimental results. Then, linear time history (LTH) and nonlinear time history (NLTH) analyses are carried out on the calibrated FE model by using two different ground motions. Iron clamps which used as connection element between the stones of the minaret considerably increase the tensile strength of the masonry system. The Concrete Damage Plasticity (CDP) model is selected in the nonlinear analyses in ABAQUS. The analyses conducted indicate that the results of the linear analyses are not as realistic as the nonlinear analysis results when compared with existing damage.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.117-118
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• 2020

The masonry structure is constructed by cement mortar binding material of brick objects and uses reinforced hardware (connected hardware or wall tie) together when building. However, over time, the corrosion of reinforced steel and the deterioration of joint mortar as well as bricks cause the risk of collapse. In particular, when the externally decorated brick wall is installed on the concrete girder for each floor, the angle bracket is not constructed or corroded, the full-layer weight load is applied to the wall of 0.5B, which is an example of full-scale or collapse. The purpose of this study is to provide numerical information on the reinforcement design by experimentally studying the structural performance of concrete reinforcement brackets that reinforce the vertical load of the exterior wall.

• Earthquakes and Structures
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• 제18권1호
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• pp.57-72
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• 2020

This paper presents the results of a monodirectional shaking table test on a full-scale unreinforced masonry cross vault characterized by asymmetric boundary conditions. The specimen represents a vault of the mosque of Dey in Algiers (Algeria), reproducing in detail the mechanical characteristics of masonry, and the constructive details including the presence of some peculiar wooden logs placed within the vault's abutments. The vault was tested with and without the presence of two steel bars which connect two opposite sides of the vault. The dynamic behaviour of both the vault's configurations were studied by using an incremental dynamic analysis up to the collapse of the vault without the steel bars. The use of an innovative high-resolution 3D optical system allowed measure displacement data of the cross vault during the shake table tests. The experimental results were analysed in terms of evolution of damage mechanisms, and in-plane and out-of-plane deformations. Moreover, the dynamic properties of the structure were investigated by means of an experimental modal analysis.