• Title/Summary/Keyword: backfill

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A Study on the Recycling of Coal Ash as Fill Materials (석탄회 자원의 채움재로서의 활용에 관한 연구)

  • 천병식;고용일;송경율;이준기
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.513-520
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    • 1999
  • 20 million tons of coal ash has been produced in Korea annually. This causes the environmental problems and the cost of land for ash pond. However the amount of coal ash for recycling is small because of the low level of recycling technology and the ignorance. As the coal ash has the significant engineering properties, it can be utilized as soft ground stabilizer, backfill materials and so forth. The purpose of this paper is to summarize some of the recycling methods of coal ash. One is structural backfill materials, the other is flowable fill. Optimal mixture ratio(fly ash : bottom ash) is determined for structural backfill materials and the model test is performed. The model test accompanied with physical tests were executed for identifying that the flowable fly ash can be used as fill materials such as trench back filling.

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A Study on the Thermal Resistance Characteristics of Backfill Concrete for Underground Power Cables (지중송전 케이블 되메움 콘크리트의 열 저항 특성에 관한 연구)

  • 정원섭;권기주;김대홍
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.397-402
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    • 2001
  • Due to the recent economic growth and the subsequent increase in demand of electricity, the construction of underground transmission line is also on the rise. Especially, in the metropolitan area, we have much obstruction in laying the line to the central district because of difficulties in procurement of construction land and the increase in the construction cost. Therefore, the necessity of increasing the capacity of transmission line has been suggested. In order to increase the capacity, the electric voltage and current intensity in size-limited lines should be also increased. But, eventually, it leads to the generation of unnecessary heat and the heat radiates through insulation cables and backfill concrete. So we need to develop the material that has good heat radiation characteristics. In this study, we developed and tested backfill concrete that can be a substitute for previously used backfill sand.

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Estimation of field application for the PHC pile backfill recycling In-site soil (현장 발생토를 재활용한 PHC파일 채움재의 현장 적용성 평가)

  • Choi, Hee-Bok;Noh, Chang-Suck;Han, Byung-Kwon;Lee, Hong-Gyu
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05b
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    • pp.63-66
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    • 2011
  • The aim of this study is to estimate the field applicability of PBFM to replace in-site soil with pile backfill used to replace the existing cement paste. As results, the flowability, segregation and bleeding, and bond strength of PBFM was a good performance than that of the existing cement paste. But the skin friction of pile by Pile Driving Analyzer (PDA) and compressive strength was slightly decreased than that of the existing cement paste. However, as pile backfill materials, and in terms of economics and environment, the applicability of PBFM is considered very effective.

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Evaluation of Construction Applicability for Slurry Backfill Materials of Underground Power Cable (지중송전관로 유동화 뒷채움재의 시공성 평가)

  • Kim, Dae-Hong;Cho, Hwa-Kyung;Oh, Gi-Dae;Lee, Dae-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1068-1075
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    • 2006
  • Flow-able backfill is known as soil-cement slurry, void fill, and controlled low-strength material (CLSM). The benefits of CLSM include reduced equipment costs, faster construction, re-excavation in the future, and the ability to place material in confined spaces such as narrow parts nearly impossible for compaction or perimeter of underground power cables. A review of some recent full-scale tests carried out by KEPRI on slurry backfill materials for application in underground power cable was presented. Based on this research, applicability was assessed and compare to results of laboratory tests for improved slurry materials with optimal mixture contents.

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Failure Probability Model of Buried Pipeline (매설배관의 파손 확률 모델)

  • Lee, Eok-Seop;Pyeon, Jang-Sik
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.11
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    • pp.116-123
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    • 2001
  • A failure probability model based on Von-Mises failure criterion and the standard normal probability function is proposed. The effects of varying boundary conditions such as nearby cavity, backfill, load cycle and corrosion on failure probability of the buried pipes are systematically investigated. The location of cavity is found to affect failure probability of buried pipeline within a certain limit. It is noted that the flexibility of backfill plays a great role to change the failure probability of buried pipeline. Furthermore, the corrosion gives less effects than other boundary conditions such as cavity, load as cavity, load cycle, and backfill to the failure probability of buried pipeline.

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Deformation Characteristics of Subgrade Materials and Soil at Abutment (노상토 및 보조기층 재료의 변형특성)

  • Song, Chang-Seop;Lim, Seong-Yoon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.52 no.3
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    • pp.105-111
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    • 2010
  • It is very important to select carefully backfill materials and build for the structural integrity of abutment in bridge. In general, backfill materials of unbound crushed stones (SB-1) are used to provide the safety of abutment structure and to reduce differential settlement around abutment that is significantly related with performance of road pavement under working conditions. In this study, to evaluate the compatibility of backfill materials at abutment and to develop the abutment design program, i) basic properties of subgrade soils in Korea, ii) evaluation of deformational characteristics of backfill materials from RC/TS tests, cyclic TX tests and Creep tests were accomplished.

A Study on the Utilization of Waste Foundry Sand as Backfill Material for Underground Electric Utility Systems (방식사의 지하 전력시설용 되메움재 활용에 관한 연구)

  • 이대수;홍성연;김경열
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.665-672
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    • 2002
  • In this paper, the utilization of waste foundry sand produced in the molding process is studied as a backfill material for underground electric utility systems such as concrete box structures and pipe lines for power supply. The physical, chemical and thermal properties for waste foundry sand are investigated for mechanical stability, environmental hazard and power transmission capacity. Also its properties are compared with the natural river sand. The test results show that waste foundry sand can be utilized for underground concrete box structures as a backfill material; however, it can not be applied to underground pipe lines due to high thermal resistivity or low power transmission capacity.

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Backfill and subsoil interaction effects on seismic behavior of a cantilever wall

  • Cakir, Tufan
    • Geomechanics and Engineering
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    • v.6 no.2
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    • pp.117-138
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    • 2014
  • The main focus of the current study is to evaluate the dynamic behavior of a cantilever retaining wall considering backfill and soil/foundation interaction effects. For this purpose, a three-dimensional finite element model (FEM) with viscous boundary is developed to investigate the seismic response of the cantilever wall. To demonstrate the validity of the FEM, analytical examinations are carried out by using modal analysis technique. The model verification is accomplished by comparing its predictions to results from analytical method with satisfactory agreement. The method is then employed to further investigate parametrically the effects of not only backfill but also soil/foundation interactions. By means of changing the soil properties, some comparisons are made on lateral displacements and stress responses. It is concluded that the lateral displacements and stresses in the wall are remarkably affected by backfill and subsoil interactions, and the dynamic behavior of the cantilever retaining wall is highly sensitive to mechanical properties of the soil material.

A Study on the optimal selection of backfill method using VE/LCC Analysis for Urban Underground Railway (VE/LCC 분석을 통한 도시철도 지하구조물 상부 되메우기의 최적대안 선정에 관한 연구)

  • Kim, Kyong-Ho;Shin, Min-Ho;Park, Jong-Kwan
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.100-106
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    • 2008
  • Road on the urban underground railway has been repaired for several years right after completion caused by the settlement of backfill and the damage of utility lines, which demands the practical application of life-cycle cost on design of backfill. This study perform the VE and LCC Analysis to select a optimal method of backfill and present the models and factors of VE process in the consideration of specialists' opinion and judgement on the category of critical maintenance items.

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