• Title/Summary/Keyword: 기둥구성

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Evaluation of Seismic Performance of Pile-supported Wharves with Batter Piles through Response Spectrum Analysis (응답스펙트럼해석을 통한 경사말뚝이 설치된 잔교식 안벽의 내진성능 평가)

  • Yun, Jung-Won;Han, Jin-Tae;Kim, JongKwan
    • Journal of the Korean Geotechnical Society
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    • v.37 no.12
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    • pp.57-71
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    • 2021
  • The pile-supported wharf is the port structure in which the upper deck is supported by piles or columns. By installing batter piles in this structure, horizontal load such as earthquake loads can be partially delivered as axial forces. The codes suggests using the response spectrum analysis as a preliminary design method for seismic design of pile-supported wharf, and suggests modeling the piles using virtual fixed points or soil spring methods for this analysis. Recently, several studies have been conducted on pile-supported wharves composed of vertical piles to derive a modeling method that appropriately simulates the dynamic response of structures during response spectrum analysis. However, studies related to the response spectrum analysis of pile-supported wharves with batter piles are insufficient so far. Therefore, this study performed the dynamic centrifuge model test and response spectrum analysis to evaluate the seismic performance according to the modeling method of pile-supported wharves with batter piles. As a result of test and analysis, it is confirmed that modeling using the Terzaghi (1955) constant of horizontal subgrade reaction (nh) most appropriately simulates the actual response in the case of the pile-supported wharf with batter piles.

A Study on the Pan-Jang in the Joseon Dynasty (조선시대 판장(板墻)에 관한 연구)

  • Oh, Jun-young;Kim, Young-mo
    • Korean Journal of Heritage: History & Science
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    • v.49 no.1
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    • pp.68-83
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    • 2016
  • Pan-jang(板墻) has become the lost facility, and the examples of its original form can be found no more due to its variable material characteristics. In order to study panjang as a lost facility, the following are needed: - To bring to light its usage and examples. - To investigate its components and structure. Panjang refers to the wall made of wooden plate and is classified as a special wall according to its material characteristics. In addition, Chinese mokyeongbyuk(木影壁) and Japanese panbyeong(板?) are similar to Korean panjang in terms of the materials, but there are clear differences in their structures. Panjang was also transformed into various types according to their materials or forms. As the wooden elements of panjang, sinbang(信防), pillars, do-ri(道里), jungbang(中枋), inbang(引枋), parn(板), dae(帶), choyeop(草葉), bangyeon(方椽), gaeparn(蓋板), pyeonggodae(平高臺), and yeonharm(椽檻) were selectively used, and they are similar, in particular, to the components of ilgakmoon(一角門). The stylobate of panjang is largely classified into three according to the kinds and structures of the wooden elements; and its frame into two according to whether sanginbang(上引枋) is used or not. The materials for the roof area include planks(蓋板) and tiles and have the distinct structural differences according to each material.

An Experimental study on the Structural Performance by the Depth Variation of Capacity of U-shaped composite Beam (U-형 복합보의 춤 변화에 따른 구조성능에 관한 실험적 연구)

  • Ha, Sang-Su
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.5
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    • pp.111-118
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    • 2020
  • The U-shaped composite beam used in this study consist of a reinforced concrete structure, a beam steel structure supporting the slab, a reinforced concrete structure, and a U-shaped steel plate. The U-shaped composite beam was developed for the purpose of using it as a parking lot because it is highly constructible and has low floor height and long span. For the improvement of constructivity, the U-shaped composite beam ends are planned with standardized H-shaped steel and connected directly to the columns, and the middle of the U-shaped composite beam consists of U-shaped steel plates folded in U-shaped form using thin steel plates (t=6) instead of H-shaped steel. In the middle of the composite beam, where U-shaped steel plates are located, the depth of U-shaped beam may be planned to be small so as to satisfy the height limit of the parking lot. It is important to grasp the structural performance according to the change of depth because low beam depth is advantageous for the reduction of the floor height, but it is a inhibitor to the structural behaviors of U-shaped composite beam. In addition, since U-shaped composite beams are a mixture of steel frame structures, reinforced concrete structures and U-shaped steel plates, securing unity has a great influence on securing structural performance. Therefore, in this study, a structural experiment was conducted to understand the structural performance according to the depth change for U-shaped composite beam. A total of three specimens were planned, including two specimens that changed the depth using a criteria specimen planned for a general parking lot. The results of the experiment showed that the specimens who planned the depth greatly had better structural performance such as yield strength, maximum strength, and energy than the standard specimen.

Evanescent-mode Waveguide Band-pass Filter Applied by Novel Metal Post Capacitor (새로운 금속막대 커패시터를 적용한 감쇄모드 도파관 대역통과 여파기)

  • Kim, Byung-Mun;Yun, Li-Ho;Lee, Sang-Min;Hong, Jae-Pyo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.5
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    • pp.775-782
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    • 2022
  • In this paper, a novel small-diameter cylindrical post capacitor inserted into an evanescent-mode rectangular waveguide (EMRWG) is proposed for easier tuning. In order to feed the EMRWG, the proposed structure uses a single ridge rectangular waveguide with the same width and height as the waveguide at the input and output ends. The inserted post capacitor are made up a circular groove formed in the center of the lower part of the broad wall of the EMRWG, and a concentric cylindrical post inserted into the upper part. First, the equivalent circuit model for the proposed structure is presented. When the EMRWG and the single ridge waveguide are combined, the joint susceptance and the turns ratio of the ideal transformer are calculated by two simulations using HFSS (3d fullwave simulator, Ansoft Co.) respectively. The susceptance and resonance characteristics of the inserted post were analyzed by using the obtained parameters and the characteristics of the EMRWG. A 2-post filter with a center frequency of 4.5 GHz and a bandwidth of 170 MHz was designed using a WR-90 waveguide, and the simulation results by using the HFSS and CST, equivalent circuit model were in good agreement.

Structural Performance Evaluation of Anchors for Power Equipment Electrical Cabinets Considering On-Site Installation Conditions (현장 설치 조건을 고려한 발전설비 전기 캐비닛 정착부 앵커의 구조성능 평가)

  • Lee, Sang-Moon;Jung, Woo-Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.6
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    • pp.709-719
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    • 2023
  • In general, most of the electrical equipment responsible for control within power plants is housed in self-standing cabinets. These cabinets are typically fixed to a slab using post-installed anchors. Although the fixation method of using post-installed anchors provides stability, there is a risk of conductor failure due to external forces, including moments. However, the performance assessment of current anchors is only evaluated through uniaxial material tests. Therefore, the primary purpose of this study is to compare the static performance of post-installed anchors, considering on-site installation conditions, with their performance in material tests and to analyze the behavioral characteristics of the anchors. While conducting experiments using actual cabinets would be ideal, practical and spatial constraints make this approach difficult. As an alternative, experiments were conducted using a test specimen consisting of a steel column and a support. As a result, the pull-out performance of anchors reflecting on-site installation conditions was measured to be about 10% higher than that observed in material tests. The trends in load reduction and the point of maximum performance for the anchors also differed. To verify the reliability of the experimental study, a 3D FEM analysis was performed, which will provide predictive information on the loads transferred to the post-installed anchors for structural performance evaluations of electrical cabinets using shaking table test in the future.

A Study on the Gungwi Perception of Year, Month, Day and Hour in the East (동양의 연월일시 궁위 인식에 관한 고찰)

  • Sun-Ok Shin;Hyeok-Jin Na
    • Industry Promotion Research
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    • v.9 no.1
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    • pp.167-177
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    • 2024
  • The purpose of this paper is to restore the academic status of Gungwi perception a little. The symbolism of Gungwi, or Year Month Day Hour, likened to Geun Myo Hwa Sil, is not just a technique of interpretation. Recognizing that it corresponds to Saju's most fundamental Mingli principle, the study was conducted to the effect that more academic research should be conducted in the future. The intrinsic idea that constitutes Saju is the yin-yang and the five elements, the letters recorded are twelve-dimensional, and the elements in charge of the space and time are Cheongan, Jeeji, and Gungwi, which are woven into four pillars. Through this consideration of Gungwi's perception, we presented the "spectrum of time" phenomenon that past time and information pass through the point of time, spread like a spectrum, and lead future time and action at the time when humans are born, that is, the energy of the universe is formatted throughout the brain and body. We discussed the change point of Eight Trigrams used by Lim Cheol Cho as a basis for explaining 'Won Hyong I Jeong' and the assumption that the time change or distortion of the two cones penetrating the present, which is assumed in parallel theory, one of the modern cosmologies, leaves an afterimage in the future universe as Gungwi's deductive basis.

Characteristics of finishing materials used in tomb No.1 of the Songje-ri, in Naju (나주 송제리 고분군 1호분에 사용된 마감재의 재료적 특성)

  • KIM Eunkyung;KANG Soyeong
    • Korean Journal of Heritage: History & Science
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    • v.57 no.3
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    • pp.56-67
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    • 2024
  • This study aims to characterize the material of the finishing materials used in the No.1 stone chamber tomb of the Baekje-era tumuli in Songjeri, Naju with mineralogical, chemical, and physical analyses. The finishing material is a mixture of white lumps and fragments, presumed to be shells, that remain on the surface and between the gaps of the stone walls inside the tomb. The analysis results revealed that the main constituent mineral of the finishing material is calcite. Infrared spectroscopy showed peaks due to calcium carbonate, and thermal reaction decarbonation in the 700~800℃ range, high calcium content, and loss on ignition were confirmed. Therefore, the main material of the finishing materials was determined to be lime, and since no aggregates such as sand or gravel were found, it was identified as lime paste. The shell fragments mixed into the lime paste appear dark blue or grayish-white in color, with no original shape remaining. The surface has a layered structure, and microscopic observations revealed prismatic layers with a columnar structure and nacreous layers with a consistent orientation, suggesting that the shells are from bivalve mollusks. Additionally, X-ray imaging of the shell fragments showed holes and tunnels caused by boring marine organisms both on the surface and inside, and radiocarbon dating results confirmed that the dating of the shells was consistent with the construction period of the tomb. It is concluded that the finishing material used in Tomb No. 1 in Songje-ri, Naju, was lime paste mixed with shell fragments, and the lime was made using the shells of bivalve mollusks as the raw material.

Broadening the Understanding of Sixteenth-century Real Scenery Landscape Painting: Gyeongpodae Pavilion and Chongseokjeong Pavilion (16세기(十六世紀) 실경산수화(實景山水畫) 이해의 확장 : <경포대도(鏡浦臺圖)>, <총석정도(叢石亭圖)>를 중심으로)

  • Lee, Soomi
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.96
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    • pp.18-53
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    • 2019
  • The paintings Gyeongpodae Pavilion and Chongseokjeong Pavilion were recently donated to the National Museum of Korea and unveiled to the public for the first time at the 2019 special exhibition "Through the Eyes of Joseon Painters: Real Scenery Landscapes of Korea." These two paintings carry significant implications for understanding Joseon art history. Because the fact that they were components of a folding screen produced after a sightseeing tour of the Gwandong regions in 1557 has led to a broadening of our understanding of sixteenth-century landscape painting. This paper explores the art historical meanings of Gyeongpodae Pavilion and Chongseokjeong Pavilion by examining the contents in the two paintings, dating them, analyzing their stylistic characteristics, and comparing them with other works. The production background of Gyeongpodae Pavilion and Chongseokjeong Pavilion can be found in the colophon of Chongseokjeong Pavilion. According to this writing, Sangsanilro, who is presumed to be Park Chung-gan (?-1601) in this paper, and Hong Yeon(?~?) went sightseeing around Geumgangsan Mountain (or Pungaksan Mountain) and the Gwandong region in the spring of 1557, wrote a travelogue, and after some time produced a folding screen depicting several famous scenic spots that they visited. Hong Yeon, whose courtesy name was Deokwon, passed the special civil examination in 1551 and has a record of being active until 1584. Park Chung-gan, whose pen name was Namae, reported the treason of Jeong Yeo-rip in 1589. In recognition of this meritorious deed, he was promoted to the position of Deputy Minister of the Ministry of Punishments, rewarded with the title of first-grade pyeongnan gongsin(meritorious subject who resolved difficulties), and raised to Lord of Sangsan. Based on the colophon to Chongseokjeong Pavilion, I suggest that the two paintings Gyeongpodae Pavilion and Chongseokjeong Pavilion were painted in the late sixteenth century, more specifically after 1557 when Park Chung-gan and Hong Yeon went on their sightseeing trip and after 1571 when Park, who wrote the colophon, was in his 50s or over. The painting style used in depicting the landscapes corresponds to that of the late sixteenth century. The colophon further states that Gyeongpodae Pavilion and Chongseokjeong Pavilion were two paintings of a folding screen. Chongseokjeong Pavilion with its colophon is thought to have been the final panel of this screen. The composition of Gyeongpodae Pavilion recalls the onesided three-layered composition often used in early Joseon landscape paintings in the style of An Gyeon. However, unlike such landscape paintings in the An Gyeon style, Gyeongpodae Pavilion positions and depicts the scenery in a realistic manner. Moreover, diverse perspectives, including a diagonal bird's-eye perspective and frontal perspective, are employed in Gyeongpodae Pavilion to effectively depict the relations among several natural features and the characteristics of the real scenery around Gyeongpodae Pavilion. The shapes of the mountains and the use of moss dots can be also found in Welcoming an Imperial Edict from China and Chinese Envoys at Uisungwan Lodge painted in 1557 and currently housed in the Kyujanggak Institute for Korean Studies at Seoul National University. Furthermore, the application of "cloud-head" texture strokes as well as the texture strokes with short lines and dots used in paintings in the An Gyeon style are transformed into a sense of realism. Compared to the composition of Gyeongpodae Pavilion, which recalls that of traditional Joseon early landscape painting, the composition of Chongseokjeong Pavilion is remarkably unconventional. Stone pillars lined up in layers with the tallest in the center form a triangle. A sense of space is created by dividing the painting into three planes(foreground, middle-ground, and background) and placing the stone pillars in the foreground, Saseonbong Peaks in the middle-ground, and Saseonjeong Pavilion on the cliff in the background. The Saseonbong Peaks in the center occupy an overwhelming proportion of the picture plane. However, the vertical stone pillars fail to form an organic relation and are segmented and flat. The painter of Chongseokjeong Pavilion had not yet developed a three-dimensional or natural spatial perception. The white lower and dark upper portions of the stone pillars emphasize their loftiness. The textures and cracks of the dense stone pillars were rendered by first applying light ink to the surfaces and then adding fine lines in dark ink. Here, the tip of the brush is pressed at an oblique angle and pulled down vertically, which shows an early stage of the development of axe-cut texture strokes. The contrast of black and white and use of vertical texture strokes signal the forthcoming trend toward the Zhe School painting style. Each and every contour and crack on the stone pillars is unique, which indicates an effort to accentuate their actual characteristics. The birds sitting above the stone pillars, waves, and the foam of breaking waves are all vividly described, not simply in repeated brushstrokes. The configuration of natural features shown in the above-mentioned Gyeongpodae Pavilion and Chongseokjeong Pavilion changes in other later paintings of the two scenic spots. In the Gyeongpodae Pavilion, Jukdo Island is depicted in the foreground, Gyeongpoho Lake in the middle-ground, and Gyeongpodae Pavilion and Odaesan Mountain in the background. This composition differs from the typical configuration of other Gyeongpodae Pavilion paintings from the eighteenth century that place Gyeongpodae Pavilion in the foreground and the sea in the upper section. In Chongseokjeong Pavilion, stone pillars are illustrated using a perspective viewing them from the sea, while other paintings depict them while facing upward toward the sea. These changes resulted from the established patterns of compositions used in Jeong Seon(1676~1759) and Kim Hong-do(1745~ after 1806)'s paintings of Gwandong regions. However, the configuration of the sixteenth-century Gyeongpodae Pavilion, which seemed to have no longer been used, was employed again in late Joseon folk paintings such as Gyeongpodae Pavilion in Gangneung. Famous scenic spots in the Gwandong region were painted from early on. According to historical records, they were created by several painters, including Kim Saeng(711~?) from the Goryeo Dynasty and An Gyeon(act. 15th C.) from the early Joseon period, either on a single scroll or over several panels of a folding screen or several leaves of an album. Although many records mention the production of paintings depicting sites around the Gwandong region, there are no other extant examples from this era beyond the paintings of Gyeongpodae Pavilion and Chongseokjeong Pavilion discussed in this paper. These two paintings are thought to be the earliest works depicting the Gwandong regions thus far. Moreover, they hold art historical significance in that they present information on the tradition of producing folding screens on the Gwandong region. In particular, based on the contents of the colophon written for Chongseokjeong Pavilion, the original folding screen is presumed to have consisted of eight panels. This proves that the convention of painting eight views of Gwangdong had been established by the late sixteenth century. All of the existing works mentioned as examples of sixteenth-century real scenery landscape painting show only partial elements of real scenery landscape painting since they were created as depictions of notable social gatherings or as a documentary painting for practical and/or official purposes. However, a primary objective of the paintings of Gyeongpodae Pavilion and Chongseokjeong Pavilion was to portray the ever-changing and striking nature of this real scenery. Moreover, Park Chung-gan wrote a colophon and added a poem on his admiration of the scenery he witnessed during his trip and ruminated over the true character of nature. Thus, unlike other previously known real-scenery landscape paintings, these two are of great significance as examples of real-scenery landscape paintings produced for the simple appreciation of nature. Gyeongpodae Pavilion and Chongseokjeong Pavilion are noteworthy in that they are the earliest remaining examples of the historical tradition of reflecting a sightseeing trip in painting accompanied by poetry. Furthermore, and most importantly, they broaden the understanding of Korean real-scenery landscape painting by presenting varied forms, compositions, and perspectives from sixteenth-century real-scenery landscape paintings that had formerly been unfound.

A Study on the Optimal Limit State Design of Reinforced Concrete Flat Slab-Column Structures (한계상태설계법(限界狀態設計法)에 의한 철근(鐵筋)콘크리트 플래트 슬라브형(型) 구조체(構造體)의 최적화(最適化)에 관한 연구(研究))

  • Park, Moon Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.4 no.1
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    • pp.11-26
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    • 1984
  • The aim of this study is to establish a synthetical optimal method that simultaneously analyze and design reinforced concrete flat slab-column structures involving multi-constraints and multi-design variables. The variables adopted in this mathematical models consist of design variables including sectional sizes and steel areas of frames, and analysis variable of the ratio of bending moment redistribution. The cost function is taken as the objective function in the formulation of optimal problems. A number of constraint equations, involving the ultimate limit state and the serviceability limit state, is derived in accordance with BSI CP110 requirements on the basis of limit state design theory. Both objective function and constraint equations derived from design variables and an analysis variable generally become high degree nonlinear problems. Using SLP as an analytical method of nonlinear optimal problems, an optimal algorithm is developed so as to analyze and design the structures considered in this study. The developed algorithm is directly applied to a few reinforced concrete flat slab-column structures to assure the validity of it and the possibility of optimization From the research it is found that the algorithm developed in this study is applicable to the optimization of reinforced concrete flat slab column structures and it converges to a optimal solution with 4 to 6 iterations regardless of initial variables. The result shows that an economical design can be possible when compared with conventional designs. It is also found that considering the ratio of bending moment redistribution as a variable is reasonable. It has a great effect on the composition of optimal sections and the economy of structures.

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Evaluation of Hydrogeologic Seal Capacity of Mudstone in the Yeongil Group, Pohang Basin, Korea: Focusing on Mercury Intrusion Capillary Pressure Analysis (포항분지 영일층군 이암층의 수리지질학적 차폐능 평가: 수은 모세관 압입 시험의 결과 분석을 중심으로)

  • Kim, Seon-Ok;Wang, Sookyun;Lee, Minhee
    • Economic and Environmental Geology
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    • v.53 no.1
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    • pp.23-32
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    • 2020
  • Geological CO2 sequestration is a global warming response technology to limit atmospheric emissions by injecting CO2 captured on a large scale into deep geological formations. The presented results concern mineralogical and hydrogeological investigations (FE-SEM, XRD, XRF, and MICP) of mudstone samples from drilling cores of the Pohang basin, which is the research area for the first demonstration-scale CO2 storage project in Korea. They aim to identify the mineral properties of the mudstone constituting the caprock and to quantitatively evaluate the hydrogeologic sealing capacity that directly affects the stability and reliability of geological CO2 storage. Mineralogical analysis showed that the mudstone samples are mainly composed of quartz, K-feldspar, plagioclase and a small amount of pyrite, calcite, clay minerals, etc. Mercury intrusion capillary pressure analysis also showed that the samples generally had uniform particle configurations and pore distribution and there was no distinct correlation between the estimated porosity and air permeability. The allowable CO2 column heights based on the estimated pore-entry pressures and breakthrough pressures were found to be significantly higher than the thickness of the targeting CO2 injection layer. These results showed that the mudstone layers in the Yeongil group, Pohang basin, Korea have sufficient sealing capacity to suppress the leakage of CO2 injected during the demonstration-scale CO2 storage project. It should be noticed, however, that the applicability of results and analyses in this study is limited by the lack of available samples. For rigorous assessment of the sealing efficiency for geological CO2 storage operations, significant efforts on collection and multi-aspect evaluation for core samples over entire caprock formations should be accompanied.