• Title/Summary/Keyword: Punching

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The Original Form and Meaning of the Gilt Bronzed Crown in Naju Bogam-ri Jeongchon Tombs (NBJ) (나주 복암리 정촌고분 금동관의 원형과 의미)

  • Yi, Gunryoung
    • Korean Journal of Heritage: History & Science
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    • v.53 no.3
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    • pp.202-223
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    • 2020
  • This purpose of this article is to identify the original form of the gilt-bronze ornamental pieces unearthed from the east part of the third wooden coffin in the Naju Bogam-ri Jeongchon (NBJ) tombs. The gilt-bronze ornamental pieces were all small, measuring less than 3cm in size and about 0.2cm in thickness, and only 19 or more small pieces were identified. In each piece of gilt decoration, a circular perforation, convex pattern, leaf-shaped spangle (瓔珞), 2 small holes for attaching spangles and gilt-bronze thread, 2 small holes for unknown purposes, and a continuous dot pattern of about 0.05 cm can be observed. As a result, it was judged that the gilt-bronze pieces excavated from the NBJ No. 1 chamber were part of the Headband Crown. Therefore, type 1 and type 3 of the gilt-bronze pieces were determined to be part of the Headband, and type 2 to be part of the Vertical Ornaments. Based on previous results, two types of restoration were proposed for NBJ No. 1 tomb gilt-bronze ornaments. In the first restoration proposal, there are wave-shaped dot patterns on the top and bottom of the crown, and the middle decoration is a spangle, circular perforation and spangle and a convex-pattern. In the second restoration plan, one row of convex patterns was added among the decorations in the middle of the first. The same type of vertical ornament was found in the Sochang (小倉) collection crown, but the overall structure and shape of the crown were completely different. On the other hand, the use of small holes of unknown use, as seen in the crown, was presumed to represent holes for fixing to a cap of organic matter. The restored NBJ No. 1 tomb gilt-bronze crown is characterized by circular punching, which makes it difficult to find an analogy in the other Three Kingdoms-period crowns. Unlike the existing halls in Gaya, Mahan, and Baekje, each district has a unique shape and decoration. The gilt-bronze crown excavated from NBJ No. 1 tomb is thought to reflect these characteristics.

Analysis on Seismic Resistance Capacity of Hollow Concrete Block Reinforced Foundation Ground by Using Shaking Table Test (진동대 시험을 이용한 중공블록 보강 기초의 내진성능분석)

  • Shin, Eun-Chul;Lee, Yeun-Jeung;Yang, Tae Chul
    • Journal of the Korean Geosynthetics Society
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    • v.20 no.4
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    • pp.85-93
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    • 2021
  • The seventy percentage of Korean Peninsular is covered by the mountainous area, and the depth of west sea and south sea is relatively shallow. Therefore, a large scale land reclamation from the sea has been implemented for the construction of industrial complex, residental area, and port and airport facilities. The common problem of reclaimed land is consisted of soft ground, and hence it has low load bearing capacity as well as excessive settlement upon loading on the ground surface. The hollow concrete block has been used to reinforce the loose and soft foundation soil where the medium-high apartment or one-story industrial building is being planned to be built. Recently the earthquakes with the magnitude of 4.0~5.0 have been occurred in the west coastal and southeast coastal areas. Lee (2019) reported the advantages of hollow concrete block reinforced shallow foundation through the static laboratory bearing capacity tests. In this study, the dynamic behavior of hollow concrete block reinforced sandy ground with filling the crushed stone in the hollow space has been investigated by the means of shaking table test with the size of shaking table 1000 mm × 1000 mm. Three types of seismic wave, that is, Ofunato, Hachinohe, Artificial, and two different accelerations (0.154 g, 0.22 g) were applied in the shaking table tests. The horizontal displacement of structure which is situated right above the hollow concrete block reinforced ground was measured by using the LVDT. The relative density of soil ground are varied with 45%, 65%, and 85%, respectively, to investigate the effectiveness of reinforcement by hollow block and measured the magnitude of lateral movement, and compared with the limit value of 0.015h (Building Earthquake Code, 2019). Based on the results of shaking table test for hollow concrete block reinforced sandy ground, honeycell type hollow block gives a large interlocking force due to the filling of crushed stone in the hollow space as well as a great interface friction force by the confining pressure and punching resistance along the inside and outside of hollow concrete block. All these factors are contributed to reduce the great amount of horizontal displacement during the shaking table test. Finally, hollow concrete block reinforced sandy ground for shallow foundation is provided an outstanding reinforced method for medium-high building irrespective of seismic wave and moderate accelerations.