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Development of Standard for Evaluating Performance of Cementitious Scagliola using Statistical Research on Generation Amount of Waste Stone and Waste Stone Powder (우리나라 폐석재, 폐석분 발생량 통계 조사 및 이를 활용한 시멘트계 인조대리석 내·외장재 개발에 따른 성능검증 시험 표준안 개발)

  • Park, Wan-Goo;Kim, Su-Ryon;Heo, Neung-Hoe;An, Ki-Won;Oh, Sang-Keun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.1
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    • pp.41-48
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    • 2013
  • Waste Stone and Waste Stone Powder are recycling some cyclic aggregate only. And the greater part of Waste Stone and Waste Stone Powder are reclaining or neglecting. To solve this problem, the government is proceeding development of cementitious scagliola using waste stone and waste stone powder. However, quality standard for cementitious scagliola using waste stone and waste stone powder has not been established. So cementitious scagliola using waste stone and waste stone powder has problem of quality assurance. Therefore in this study, developed standard for Evaluating Performance of cementitious scagliola using waste stone and waste stone powder through survey of international standard.

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A Study on the Bearing Capacity characteristics of Stone column by Numerical Analysis (수치해석에 의한 쇄석말뚝의 지지력 특성 고찰)

  • Chun, Byung-Sik;Kim, Baek-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.90-99
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    • 2004
  • Stone column is one of the soft ground improvement method, which enhances ground conditions through ground water draining, settlement reducing and bearing capacity increasing complexly by using crushed stone instead of sand in general vertical drain methods. In recent, general construction material, sand is in short of supply, because of the unbalance of demand and supply. Also, the bearing capacity improving effect of stone column method is needed in many cases so the bearing capacity estimation is considered as important point. Nevertheless, adequate estimation methods to predict bearing capacity of stone column considering stone column and improving ground behavior reciprocally is not yet prepared. To contribute this situation, bearing capacity behavior of stone column were simulated as numerically on various property cases of crushed stone and surrounded ground. Through the numerical analysis of simulation results, bearing capacity behavior prediction formula was suggested. This formula was verified by comparing the prediction result with in situ test.

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Structural Analysis of Stone Pagoda in Miruksa Temple Site using Discrete Element Method (개별요소법을 이용한 미륵사지 석탑의 구조해석)

  • Kim Ho-Soo;Jung Sung-Jin;Hong Seok-Il
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.427-434
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    • 2006
  • The stone pagoda on the Miruksa temple site has a high value as architectural history, because this stone pagoda is one of the oldest and grandest stone pagodas which remain in Korea today. However, this stone pagoda has remained only six stones of the northeastern part, becased this stone pagoda was collapsed at past. Therefore, it is important to know the original structure and form of this stone pagoda. Hypotheses about collapse cause of this stone pagoda are presented as four cases: collapse by earthquake, collapse by fragility of ground, collapse by durability reduction, and collapse by lightning, On the basis of these four collapse hypotheses in this study, we investigate collapse phenomenon through the structural analysis using discrete element method and evaluate collapse causes of this stone pagoda.

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Utilization of Stone Sludge Produced by Stone Block Manufacturing Process as Concrete Admixtures (석재 가공시 발생한 석분슬러지의 콘크리트 혼화재료로의 활용)

  • Jeong, Jin-Seob;Lee, Jong-Cheon;Yang, Keek-Young;So, Kwang-Ho
    • Journal of the Korea Institute of Building Construction
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    • v.8 no.6
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    • pp.83-89
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    • 2008
  • The stone sludge produced during the manufacturing process of stone blocks is considered as one of industrial waste materials. This stone sludge are managed to either burying under the ground or stacking in the yard, but this disposal process is required an extra costs. The stone sludge disposal like burying or stacking also cause environmental pollutions such as ground pollution and subterranean water pollution. Thus, this study was conducted to explore the possibility of recycling of stone dust sludge as a concrete mixing material in order to extend recycling methods and to solve the shortage of aggregate caused by recently increased demand in construction. Based on the experiment results on various ratios of cement to stone sludge content, the compressive strengths of concrete were recorded in the range of $20{\sim}30N/mm2$. The results did not show any decrease in compressive strength due to the stone dust content. It can be concluded that the stone sludge produced by stone block manufacturing can be sufficiently recycled as one of concrete mixing materials in the aspect of compressive strength.

A Study on the Geogrid Reinforced Stone Column System for Settlement Reduction Effect (침하저감효과를 위한 고강도 지오그리드 보강Stone Column 공법에 관한 연구)

  • Park, Si-Sam;Lee, Hoon-Hyun;Yoo, Chung-Sik;Lee, Dae-Young;Lee, Boo-Rak
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.838-845
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    • 2006
  • Recently construction work in Korea, demands of favorable condition ground had been increased with industrialization acceleration and economic growth. However, because of limited land space, it was so hard to ensure favorable condition grounds that construction work proceeds until soft ground area on plans of road, railroad and industrial complex. In this case, soft ground improvement was required such as a stone column method. Stone column method, making a compaction pile using crushed stone, is a soft ground improvement method. However, stone column method is difficult to apply to the ground which is not mobilized enough lateral confine pressure because no bulging failure resistance. Hence, in present study, evaluates the stone columns reinforced by geogrid for settlement reduction and wide range of application of stone columns. Triaxial compression tests were conducted for evaluation which is about behavior characteristics of stone column on replacement rate. Then, 3-dimensional numerical analysis were conducted for application of stone column reinforced by geogrid as evaluate behavior characteristics and settlement reduction effect of stone column reinforced by geogrid on reinforcing depth change of geogrid.

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Stone weirs in Penghu and adaption to tourism development

  • Yu, Shyi-Liang;Chu, Ying-Chien;Tsai, Chia-Wen
    • Journal of Ecology and Environment
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    • v.38 no.2
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    • pp.257-262
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    • 2015
  • The ancient fishing methods include stone fish weir, beach seine and baulk net, but the fish catches of the stone fish weir is the most abundant. The stone fish weirs not only constitute important landscape, but also are representative of the fishery culture in Penghu, because they are fishing ground built by ancient people to take advantage of natural environment and resources. The objectives of this study is to understand the relevance of stone fish weirs in Penghu and to preserve biological diversity, as well as the value of stone fish weirs in Penghu fishery culture, and further make suggestions on the stone fish weirs. According to the present study, the marine species around the stone fish weirs tend to be diversifying, and in the future the region's economy can be revitalized by sightseeing, which may promote the ecotourism, and also volunteer tourism. In the future, stone fish weirs must be promoted as a sightseeing destination. Also, by taking into consideration the experience of the Jibei stone weir protection team, the local communities of Penghu can have their own protection team to revitalize the stone fish weirs for sustainable operation and management.

Influence of dual layer confinement on lateral load capacity of stone columns: An experimental investigation

  • Akash Jaiswal;Rakesh Kumar
    • Geomechanics and Engineering
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    • v.32 no.6
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    • pp.567-581
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    • 2023
  • Enhanced vertical load capacity of the ground reinforced with the stone columns drew great attention by the researchers as it deals with many of the geotechnical difficulties associated with the weak ground. Recently, it has been found that the stone columns are also prone to fail under the shear load when employed beneath the embankments or the foundations susceptible to lateral loads. In this study, the effect of various encasement conditions on the lateral deflection of stone columns is investigated. A method of dual layers of encasement has been introduced and its the effect on lateral load capacity of the stone columns has been compared with those of the single encased stone column and the un-encased stone columns. Large shear box tests were utilised to generate the shear deformation on the soil system under various normal pressure conditions. The stiffness of the soil-stone column combined system has been compared for various cases of encasement conditions with different diameters. When subjected to lateral deformation, the encased columns outperformed the un-encased stone columns installed in loose sand. Shear stress resistance is up to 1.7 times greater in dual-layered, encased columns than in unencased columns. Similarly, the secant modulus increases as the condition changes from an unencased stone column to single-layer encasement and then to dual-layer encasement, indicating an improvement in the overall soil-stone column system.

Characteristics of Plantable Concrete Using Waste Stone and Stone Dust (폐석과 석분을 사용한 식생 콘크리트의 특성)

  • 성찬용;윤준노
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.3
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    • pp.85-91
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    • 2002
  • This study is performed to evaluate characteristics of plantable concrete using waste stone and stone dust. The test result shows that the void ratio is decreased as the size of waste stone smaller and the content of stone dust increased. The strength of neutralized plantable concrete is decreased by approximately 4∼5% than that of the normal plantable concrete. The reduction effect of pH value is achieved by chemical treatment. Also, the plant is grown well with increase of the void ratio and size of waste stone.

Analysis of work times and postures occurring relating to stone channel work in forest engineering (돌수로공의 작업시간 및 작업자세 분석에 관한 연구)

  • Yeom, In-Hwan;Choi, Yeon-Ho;Kim, Myeong-Jun;Kweon, Hyeong-Keun;Lee, Joon-Woo;Kim, Je-Su;Park, Bum-Jin
    • Korean Journal of Agricultural Science
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    • v.38 no.1
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    • pp.101-108
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    • 2011
  • In forest work, working conditions are very hard to improve. The proper distribution of work time and good posture is believed to bring about direct improvements such as accident prevention. On this, this study has analyzed forest workers' posture and their working hours in order to improve their working conditions in stone channel work. Authors has chosen several core elements of stone channel work to focus on, which include stone masonry, excavation of bed, moving stone, directing work, choosing stone, and breaking stone. The ratio of real working time over total working time was shown as 84.6%. As for the time ratio of each elemental work over the real working time, the stone masonry was 60.4%, the directing work was 15.1%, moving stone was 12.1%, choosing stone was 7.1%, breaking stone was 3.3%, and excavation of bed was 2.0%. According to the analytical results provided by OWAS, the ratio of category III (Work posture has a distinctly harmful effect on the musculoskeletal system) has shown that moving stone turned out 65.2%, choosing stone was 61.5%, stone masonry was 46.1%, breaking stone was 14.3%, excavation of bed was 12.5% and directing work was 6.8%. Furthermore, the ratio of category IV (Work posture with an extremely harmful effect on the musculoskeletal system) has shown that excavation of bed turned out 37.5%, breaking stone was 28.6%, stone masonry was 27.3%, choosing stone was 7.7%, moving stone was 6.1% and directing working was 4.5%. These results are expected to be utilized for the improvement with respect to both working methods in the stone channel work and the workers' working posture.

A Starting Point of Formation and Development of Baekje-style Stone Stupa (백제양식석탑의 형성과 전개의 시발점(始發點))

  • Jun, Ji Hye
    • Korean Journal of Heritage: History & Science
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    • v.42 no.4
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    • pp.172-197
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    • 2009
  • The stone stupas of the Mireuk Temple Site and Jeongnim Temple Site were the beginning of Korean stone stupa and the unique ones stemming from the Baeje period. Therefore, the work of investigating the characteristics of these two stone stupas would give us a basis for understanding Korean stone stupas in a large scale and Baekje-style stone stupas in a narrow sense. As shown in some records, the excellent architectural skills of Baekje could be known by the fact that Abiji was invited to the building of Hwangryong Wooden stupa, one of the national undertakings of Shilla and the skills and styles related to stone stupas were thought to be disseminated in this process. However, it has not been very convincing that the stone stupas with Baekje styles were disconnected in an instant with the unification of Shilla, in terms that culture and art would inherited and developed. The current academic circle set a frame and defined all these types of stone stupas as Baekje-system stone stupas built in Goryeo period and put them in a uniformly chronological order. The popularization of Buddhism, support of regionally powerful clans and cultural revival were suggested as the factors of their appearance, but it seemed difficult to be assured that these led Baeje-style stone stupas to reappear in a moment by breaking the gap of about 300 years. Of course, it has not been active in Gyeongju area, but they have greatly influenced the stone stupas of Shilla; therefore, it would be possible to consider that they were developed but limited to certain areas. This study focused on the starting point of such development and investigated the formation of Baeje-style stone stupas through the stone stupas of the Mireuk Temple Site and Jeongnim Temple Site and their subsequent development through Wanggung-ri Stone Stupa.