• Earthquakes and Structures
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• v.7 no.2
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• pp.217-231
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• 2014

Ancient masonry towers are regarded as among the most important historical heritage structures of the world. These slender structures typically have orthogonal and circular geometry in plane. These structural forms are commonly installed with adjacent structures. Because of their geometrical shapes and structural constraints, ancient masonry towers are more vulnerable to earthquake damage. The main goal of the paper is to investigate the seismic behavior of Erzurum Clock Tower under earthquake loading and to determine the contribution of the castle walls to the seismic performance of the tower. In this study, four three-dimensional finite element models of the Erzurum Clock Tower were developed and the seismic responses of the models were investigated. Time history analyses were performed using the earthquakes that took place in Turkey in 1983 near Erzurum and in 1992 near Erzincan. In the first model, the clock tower was modeled without the adjacent walls; in the second model, the clock tower was modeled with a castle wall on the south side; in the third model, the clock tower was modeled with a castle wall on the north side; and in the last model, the clock tower was modeled with two castle walls on both the north and south sides. Results of the analyses show that the adjacent walls do not allow lateral movements and the horizontal displacements decreases. It is concluded that the adjacent structures should be taken into consideration when modeling seismic performance in order to get accurate and realistic results.

• Journal of the Korea Concrete Institute
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• v.27 no.3
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• pp.207-214
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• 2015

This study examined the feasibility of wire ropes as lateral reinforcement at the boundary element of heavyweight concrete shear walls. The spacing of the wire ropes varied from 60 mm to 120 mm at an interval of 30 mm, which produces the volumetric index of the lateral reinforcement of 0.126~0.234. The wire ropes were applied as a external hoop and/or internal cross-tie. Five shear wall specimens were tested to failure under constant axial load and cyclic lateral loads. Test results showed that with the increase of the volumetric index of the lateral reinforcement, the ductility of shear walls tended to increase, whereas the variation of flexural capacity of walls was minimal. The flexural capacity of shear walls tested was slightly higher than predictions determined from ACI 318-11 procedure. The displacement ductility ratio of shear walls with wire ropes was higher than that of shear wall with the conventional mild bar at the same the volumetric index of the lateral reinforcement. In particular, the shear walls with wire rope index of 0.233 achieved the curvature ductility ratio of more than 16 required for high-ductility design.

• Wind and Structures
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• v.39 no.3
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• pp.223-242
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• 2024

Wind comfort in cold climates is one of the most essential factors for urban planners. This issue is particularly important for sidewalks that are in line with the prevailing wind flow and surrounded by high-rise buildings. Imam Street near the University Square in Tabriz is one of the passages that struggle with uncomfortable wind speeds. The aim of this study is to investigate the role of sidewalk walls on pedestrian wind comfort. These multifunctional walls not only serve as street furniture, but also reduce wind speed at pedestrian level. In this work, all simulations are performed using the RWIND tool and validated by wind tunnel experiments at the Architectural Institute of Japan. The main objective of this study is to evaluate the effects of the angle, height and spacing of the walls on wind attenuation at pedestrian level. The results show the effect of multifunctional walls on pedestrian-level wind mitigation. By rotating the windbreak walls from 0 to 60 degrees along the street, the average wind speed decreases by 30% to 46% compared to a situation without this type of wall. Increasing the wall height from 1.5 to 2 meters reduces the urban wind speed by 39-46%. However, increasing the distance between the sidewalk walls from 3.5-9.5 meters reduces the speed in the models from 46% to 32.7%. Finally, it has been demonstrated that sidewalk walls with a height of 2 meters, a rotation angle of 60° and a distance of 3.5 meters are the optimal choice for wind attenuation at pedestrian level.

• Computers and Concrete
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• v.2 no.2
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• pp.111-123
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• 2005

The ductility of reinforced concrete bearing walls subjected to high axial loading and moment can be enhanced by improving the deformability of the compression zone or by reducing the neutral axis depth. The current state-of-the-art procedure evaluating the confinement effect prompts a consideration of the spaces between the transverse and longitudinal reinforcing bars, and a provision of tie bars. At the same time, consideration must also be given to the thickness of the walls. However, such considerations indicate that the confinement effect cannot be expected with the current practice of detailing wall ends in Korea. As an alternative, a comprehensive method for dimensioning boundary elements is proposed so that the entire section of a boundary element can stay within the compression zone when the full flexural strength of the wall is developed. In this comprehensive method, the once predominant code approach for determining the compression zone has been advanced by considering the rectangular stress block parameters varying with the extreme compression fiber strain. Moreover, the size of boundary elements can also be determined in relation to the architectural requirement.

• Journal of the Korean Society for Advanced Composite Structures
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• v.1 no.4
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• pp.6-12
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• 2010

This study investigates how to apply composite material to the blast loading protection devices, mainly used for military purpose. Traditionally, earth-filled blast walls have been used for protecting important parts of military facilities and personnels. However these types of blast walls show difficulty in fabrication and portability because of their nature of heavy weight. Composite materials are known to have relatively higher specific stiffness and strength than any other metallic and earth-filled materials such as sand and gravels. Totally 4 times of TNT blast experiments were performed on the carbon/epoxy blast walls. After the end of each test, the improvement of blast wall was implemented to the structure. The test results show that the use of composite material in the blast protecting area is the one of very effective and reliable alternatives.

• Journal of the Korea Concrete Institute
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• v.25 no.6
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• pp.649-656
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• 2013

Coupled shear walls can provide an efficient structural system to resist lateral force. However, the reinforcement detail for diagonally reinforced coupling beams required by ACI-318 often causes the difficulties in construction due to the reinforcement congestion and interference among reinforcement. This paper is to evaluate cyclic behavior of High-Performance Fiber-Reinforced Cement Composite (HPFRCC) coupling beams having reduced transverse reinforcement around the beam perimeter. Experimental test was conducted using three specimens having a beam aspect ratio 2.0. Test results showed that HPFRCC coupling beams with half of transverse reinforcement required by ACI-318 provided similar energy dissipation capacities compared with the coupling beams having reinforcement satisfy the requirement of ACI-318.

• Journal of architectural history
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• v.30 no.6
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• pp.71-80
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• 2021

This study tries to shed light on character and architectural features of the 2nd construction of Bunhwangsa temple in the mid-8th century. The site of Bunhwangsa Temple is divided into upper and lower areas based on retaining walls running from northwest to southeast, and the main area of the temple centered on Geumdang(the main hall) is located in the upper area. Space composition of the lower area including Wonji(a garden pond) and Gangdang(a lecture hall), is noteworthy in that Bunhwangsa Temple was constructed in a deviating way from rigorous constructional disciplines and used their space efficiently. The Geumdang in the 2nd construction was the largest worship hall with 7×6 bays. The hall was designed to divide its space into two ; the core space was surrounded by outer space. Each gap between columns in the hall was narrowed from center to outer. The main construction of the Geumdang was built as a stable structure with lead-to corridors. This was a much-advanced style than Geumdang at Hwangnyongsa Temple. The Gangdang is presumed to be a large building site as a typical Gangdang style in the Silla era. It was built in the late 9th century and was located in the northern part of the retaining walls. The composition of the middle gate and southern corridors were in double and long corridor style and they were located in front of the 2nd construction. This style coincided in the form of the architectural style of the Hwangnongsa Temple. The 2nd construction of the Bunhwangsa Temple was smaller than the Hwangnongsa Temple. However, it was a prestigious architecture.

• Journal of KIBIM
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• v.12 no.1
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• pp.42-54
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• 2022

BIM facilitates data transparency and consistency through three-dimensional parametric modeling and promotes the accurate managing and sharing of project information. In Korea, however, BIM-based detailed design of architectural interior finishes required during the Construction Documents phase increases the burden on architectural firms due to frequent design changes and manual workload. Therefore, the purpose of this study was to establish rule-based modules using parametric modeling that automates repetitive tasks that occur during the detailed design of interior finishing. Interviews with practitioners were conducted to analyze the major finishing elements. Of these floors, walls, and ceilings, which were the most rudimentary and common items, were selected as the subjects of the study. The modules developed in this study have two functions. One is to create new finish types, and the other is the automatic modeling of new types into rooms. For these functions, parameters that belonged to each finish and room element in a BIM model were analyzed and valid parameters directly used for parametric modeling were derived. Then, based on these parameters, rule-based modules for three elements, I.e., floors, walls, and ceilings were constructed with Revit Dynamo, and the effectiveness of the modules was verified with a pilot test. In conclusion, this study suggested a series of processes for automatic finishing to improve the efficiency of BIM-based architectural detailed design of finishes and to contribute in solving the chronic problems occuring during current design processes.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.47-55
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• 2009

As a conventional line-fitting method, the Bouwer and Rice method has been popularly adopted to estimate the hydraulic conductivity of an aquifer through a slug test. Because a vertical cutoff wall is usually very compressible and features a small wall thickness, the Bouwer and Rice method should be carefully applied to analyzing slug test results to estimate the hydraulic conductivity of vertical cutoff walls. In addition, a relatively impermeable layer, called a filter cake, formed at the interface between the cutoff wall and the natural soil formation makes it difficult to use the Bouwer and Rice method directly. In order to overcome such limitations, the original Bouwer and Rice method has been modified by incorporating the concept of the flow net method. In this modification, the geometry condition of cutoff walls including the filter cake is effectively considered in evaluating the hydraulic conductivity of a vertical cutoff wall.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.2
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• pp.93-101
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• 2024

Code-compliant seismic design should be essentially applied to realize the so-called emulative performance of precast concrete (PC) lateral force-resisting systems, and this study developed simple procedures to design precast industrial buildings with intermediate precast bearing wall systems considering both the effect of seismic and blast loads. Seismic design provisions specified in ACI 318 and ASCE 7 can be directly adopted, for which the so-called 1.5S_y condition is addressed in PC wall-to-wall and wall-to-base connections. Various coupling options were considered and addressed in the seismic design of wall-to-wall connections for the longitudinal and transverse design directions to secure optimized performance and better economic feasibility. On the other hand, two possible methods were adopted in blast analysis: 1) Equivalent static analysis (ESA) based on the simplified graphic method and 2) Incremental dynamic time-history analysis (IDTHA). The ESA is physically austere to use in practice for a typical industrial PC-bearing wall system. Still, it showed an overestimating trend in terms of the lateral deformation. The coupling action between precast wall segments appears to be inevitably required due to substantially large blast loads compared to seismic loads with increasing blast risk levels. Even with the coupled-precast shear walls, the design outcome obtained from the ESA method might not be entirely satisfactory to the drift criteria presented by the ASCE Blast Design Manual. This drawback can be overcome by addressing the IDTHA method, where all the design criteria were fully satisfied with precast shear walls' non-coupling and group-coupling strength, where each individual or grouped shear fence was designed to possess 1.5S_y for the seismic design.