• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.520-526
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• 2019

I-type girders are widely applied as very economical sections in plate girder bridges. There has been research on developing composite laminated panels, curved plates reinforced with closed-end ribs, and new forms of ribs and compression flanges for steel box girders. However, there is a limitation in analyzing the exact cause of local buckling caused by an I-type girder's webs. Therefore, an I-type girder's web was modeled using the finite element analysis program LUSAS 17.0 before and after reinforcement. We checked for the minimum thickness criteria presented in the Korea highway bridge design code, and the cause of buckling after performing a linear elastic buckling analysis of dead and live loads was analyzed. Before reinforcement, an eigenvalue (λ₁) at the 1st mode was 0.7025, the critical buckling load was smaller than the applied load, and there is a buckling. After reinforcement, when applying vertical and horizontal stiffeners to the web part of the girder at support, a Nodal line was formed, the eigenvalue was 1.5272, and buckling stability was secured. To improve buckling trace of the girder at the support, an additional plate was applied to the web at the support to ensure visual and structural safety, but buckling occurs at center of web. The eigenvalue (λ₁) was 3.5299, and this method is efficient for reinforcing the web of the support.

• Korean Journal of Heritage: History & Science
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• v.37
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• pp.65-89
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• 2004

Up to now, the studies for a pond of ancient palace of Korea are mainly achieved in a landscape architectural field. In fact, we can't grasp the general aspects but we are only heard about the fragmentary ruins and remains by the people who are in charge of an archaeological excavation. In this thesis, therefore, I attempt to grasp the relational categories of the ponds of an ancient palace of Korea, and find out the ideological backgrounds of the ponds of a palace construction through classify them excavated so far. The ancient ponds of Korea are divided to the class of square ponds(I) and curved ponds(II) according a shapes of planes. The class of square ponds(I) are subdivided to the form IA of the class of square ponds and form IB of the class of square ponds by whether it has an island, artificial hill and ornamental stone or not. And the class of the curved ponds(II) are divided to the form IIC that is only composed of curves in shore and the form IID that is composed of curves and straight lines. According the size, it is divided to a small size that is below the maximal diameter, 20m, and a large size that is more than 45m, after all, the ponds of the ancient palaces are devided to IAa, IAb, IBa, II Ca, IICb, IIDa. The square ponds and the curved ponds are co-exist from the initial stage when a pond of a place was found in our country and are succeeded or changed after Silla unified the three Kingdoms. In other words, we can infer a continuity from the earlier stage from the fact that there is a flat figure ground mainly constituted by the ponds of a palace mixed up of a straight line and a curved line in United Silla Kingdom while it succeeds the ponds of a palace that has a square form of Goguryo in Balhai. Different from the successional relation of the flat figure grounds, in an aspect of the elements of the construction, the site of the arbor at the top of the island and the bridge facilities in a field of a palace those are not exist in three Kingdoms period are appeared in United Silla Kingdom. The point that this aspect is simultaneously appeared in a neighboring country, or Japan, allows us to infer that there may be some motivations cause the changes in a construction of the ponds of a palace of Korea, China and Japan from the latter half of the 7th century to the first half of the 8th century. The ideological backgrounds of the ponds of a palace construction are divided roughly into Taoism and Buddhism. We can recognize that the ponds of a palace made up of the islands, the artificial hills and the garden rocks reflect Taiosm, considering the records of the ponds a palace of Korea and China are all use the term, Taoism, or the concrete statement represents that the islands, the artificial hills and the garden rocks are used in the description of the ponds of a palace of Korea. Both two are, therefore, obviously differentiated from the ponds of a palace that doesn't include them. We can conclude that the ponds of a palace that doesn't include them are colored by Buddhism since they are overtly distinguished from the class of curved ponds that reflect Taoism at the same period and they are identical with the site of an ancient temples in an aspect of their type and construction.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.633-640
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• 2023

In this study, numerical analysis was performed based on field investigation to derive an appropriate reinforcement method by analyzing the displacement behavior characteristics of concrete blocks generated in the direct fixation track on the bridges of the serviced light rail transit. The track of this study was a direct fixation track on a sharp curved track, and the problem of movement of the concrete blocks installed on the bridge deck in the longitudinal and lateral directions occurred. In this study, based on the finite element model using 3D solid elements, the behavior of the direct fixation track that could be occurred under operating load conditions was analyzed. In addition, the reinforcement effect of various reinforcement methods was analyzed. As a result of analyzing the lateral displacement before and after reinforcement, it was analyzed that the maximum lateral displacement after reinforcement under the extreme lateral wheel loads significantly decreased to about 3% (about 0.1mm) compared to before reinforcement. In addition, as a result of examining the generated stress of the filling mortar, bridge decks, and reinforcing bar, it was analyzed that all of them secured a sufficient safety factor of 2.6 or higher, and the optimal conditions for the reinforcement method were derived. Therefore, it is judged that the number of anchoring reinforcements and symmetrical anchor placement reviewed in this study will be effective in controlling the occurrence of lateral displacement of concrete blocks and securing the structural integrity of bridges and concrete blocks.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.4
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• pp.1-8
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• 2002

The place of South Weol Dynastys authorities exhumed in the region of KangChoWu, China lies adjacent to a stone ditch through which water streams crookedly, and a dark trough of stone pond in the north side. There is a sharply curved stone ditch and a crescent-shaped water entrance made by stones. The place was separated by using stone columns and stone walls. There is a beam of ditch, a crooked entrance, a flat bridge of slate, a stepping-stone, a sluice gate, and a crooked corridor. There are big and small artificial islands, and reinforcing stone drainage way in the palace pond recently exhumed at the building site for the pavilion of Hwang-Yong Temple in Kuhwang-Dong, Gyeongju city, Korea. There are four facilities assumed to be entrance and exits at four corners and an open space on which gravel was spread extensively. A narrow road and a middle road with indefinite curves at the south of Asukakyoseki exhumed by the first, second and third and two stone buckets which one is to fill with water and the other is to drain water off like fountain are there, and besides wave protecting dam and north pond and the part that water pass were excavated. Palace ponds that were extensively distributed at old residential cities are a general phenomenon of countries in eastern Asia. Anap pond of Silla and Gungnam pond of Baekje were in Kroea. We believe that Asutnkyoseki is on the extension. Although more investigations in the background of thought and the genealogical relation about the palace pond are required, it seems that an idea was surely received from China.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.6
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• pp.1395-1404
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• 1994

Transverse bed slope in bend is a subject of scientific investigation since it provides the necessary information for channel design and protection of hydraulic structures (bank, bridge, etc), and study of river morphology. In this paper, selected models were examined and compared for the value of prediction of the transverse bed slope in curved alluvial channels(project area), by using field data, and fitting model was proposed. All models that related the local transverse bed slope to mean flow characteristics were alike in the sense that they predicted the local transverse bed slope to be proportional to the ratio between depth and radius of curvature. The difference among the models was related with the factor of proportionality, K. Also, measured transverse bed slope was correlated to mean velocity, maximum depth, and density Froude number in channel bend. In this paper selected models were compared for the prediction of the transverse bed slope using Odgaard's experiment (obtained in Sacramento River bend), so Odgaard89 model was closely related with real transverse bed slope.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.41-46
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• 2017

The coefficient of derailment and the rate of wheel load reduction were used as the index of train running safety that was directly affected the train derailment safety. In aspects of track, the train running safety depends on the complex interaction between wheel and rail, and the track-vehicle conditions (i.e., the curvature, cant, track system, vehicle speed and the operation conditions, etc). In this study, the relationship between the train running safety and the track curvature and vehicle speed for direct fixation concrete tracks currently employed in Korean light rapid transit was assessed by performing field tests using actual vehicles running along the service lines. The measured dynamic wheel load, lateral wheel load and lateral displacement of rail head were measured for same train running on four tested tracks under real conditions, which included curved and tangent tracks placed on the tunnel and bridge, thus increasing the train speed by approximately maximum design speed of each test site. Therefore, the measured dynamic track response was applied to the running safety analysis in order to evaluate the coefficient of derailment, the rate of wheel load reduction and the track gauge widening at each test site, and compare with the corresponding Korean train running safety standard. As the results, the lateral track response of direct fixation concrete track appeared to increase with the decreased track curvature; therefore, it was inferred that the track curvature directly affected the train running safety.