• Title/Summary/Keyword: Backfill Material

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Development of Rapid Hardening Backfill Material for Reducing Ground Subsidence (지반함몰 저감을 위한 속경형 하수관거 뒤채움재료 개발)

  • Ryu, Yong-Sun;Han, Jin-Gyu;Chae, Woo-Ri;Koo, Ja-Sul;Lee, Dae-Young
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.3
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    • pp.13-20
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    • 2015
  • Inappropriate backfill material and poor compaction cause the damage to sewer and ground settlement. To deal with such problem, flowable backfill material has attracted attention recently. A basic study was conducted in a bid to obtain optimum mixing ratio of backfill material with the characteristics of rapid hardening, pseudo-plasticity, flowability and anti washout ability and enhance the cost efficiency of backfill material. Through the test of optimal mixing ratio of rapid hardening, evaluation of optimal mixing ratio of backfill material was conducted. As a result, required performance as well as cost efficiency could be achieved by adjusting plasticizer even in case of increasing W/M of the paste of rapid hardening to 100%.

Geotechnical properties of tire-sand mixtures as backfill material for buried pipe installations

  • Terzi, Niyazi U.;Erenson, C.;Selcuk, Murat E.
    • Geomechanics and Engineering
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    • v.9 no.4
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    • pp.447-464
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    • 2015
  • Millions of scrap tires are discarded annually in Turkey. The bulk of which are currently landfilled or stockpiled. These tires consume valuable landfill space or if improperly disposed, create a fire hazard and provide a prolific breeding ground for rats and mosquitoes. Used tires pose both a serious public and environmental health problem which means that economically feasible alternatives for scrap tire disposal must be found. Some of the current uses of scrap tires are tire-derived fuel, creating barrier reefs and as an asphalt additive in the form of crumb rubber. However, there is a much need for the development of additional uses for scrap tires. One development the creation of shreds from scrap tires that are coarse grained, free draining and have a low compacted density thus offering significant advantages for use as lightweight subgrade fill and backfill material. This paper reports a comprehensive laboratory study that was performed to evaluate the use of a shredded tire-sand mixture as a backfill material in trench conditions. A steel frame test tank with glass walls was created to replicate a classical trench section in field conditions. The results of the test demonstrated that shredded tires mixed with sand have a definite potential to be effectively used as backfill material for buried pipe installations.

Application of Formed Urethane to Slope Stabilizaton and Backfill Material (발포우레탄에 의한 사면안정화 및 사면요철충진재로의 활용성 연구)

  • 정하익;조진우;구호본;정연수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.635-638
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    • 2000
  • The feasibility study on the application of formed urethane to slope stabilization and backfill material was carried out through laboratory and field test. The physical and chemical properties of formed urethane were investigated. The slope stabilization effect of urethane was examined in the field occurred slope failure. The formed urethane and sprayed urethane admixed with seed was applied to protect the slope failure in this study.

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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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Development and Application of Backfill Material for Reducing Ground Subsidence (지반함몰 저감을 위한 하수관로 뒤채움재 개발 및 현장적용성 평가)

  • Lee, Dae-Young;Kim, Dong-Min;Ryu, Yong-Sun;Han, Jin-Gyu
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.4
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    • pp.147-158
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    • 2015
  • In this study, sewer backfill material was developed to prevent sewer damage and ground subsidence. Laboratory test was performed in the field of CA replacement ratio, accelerator type and replacement ratio and W/M. The compression strength of backfill material was 0.55~0.64MPa below in W/M 70% and 0.20MPa over W/B 80%. Ice block was used to simulate the ground cavity and subsidence caused by sewer damage in application study. The existing sand compaction and the new backfill material was comparative estimated in field. The ground settlement of cross section was 23.4cm and that of longitudinal section was 27cm in sand compaction section, but the ground had not sunk in backfill material section.

A Study on Friction Characteristics of Backfill Material for Heat Transport Pipeline (열 수송관로 되메움재의 마찰 특성에 관한 연구)

  • Kim, You-Seong;Park, Young-Jun;Cho, Dae-Seong;Bhang, In-Hwang
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.1
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    • pp.73-81
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    • 2013
  • The objective of this paper is to minimize installation length of pipeline and to reduce burial depth for construction by increasing the friction coefficient caused by the interface between backfill material and pipeline. And then, the sufficient friction coefficient shortens the length of expansion joint pipe and gives the life extension of expansion joint absorber for efficient procedure regarding maintenance and administration of construction. The backfill material which is developed in this study has larger and smaller friction angle than that of conventional backfill material (river sand). The backfill material with tire powder provides low friction angle at curved section when pipe diameter increases in size (38% reduction at pipe diameter in 900 mm). When using backfill material with river sand and fly-ash, the mixture mixed with 1.5% fly-ash has 30% and that with 3% fly-ash has 50% reduction effect for minimum installation length of expansion joint pipe.

The Utilization of Waste Foundry Sand as Backfill Material for Underground Electric Utility Systems (방식사의 지중 전력설비 되메움재로의 활용성 평가)

  • 이대수;홍성연;김경열;상현규
    • Journal of the Korean Geotechnical Society
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    • v.19 no.1
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    • pp.201-207
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    • 2003
  • 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 far mechanical stability, environmental hazard and power transmission capacity Also its properties are compared with those of 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.

Vertical Earth Pressure Distribution on Cantilever Retaining Wall (역 T 형 옹벽에 작용하는 연직토압분포)

  • Yoo, Nam-Jae;Lee, Myeung-Woog
    • Journal of Industrial Technology
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    • v.16
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    • pp.181-189
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    • 1996
  • Centrifuge model tests of cantilever retaining wall were performed to investigate the vertical stress distribution due to selfweight of backfill material. Model tests were carried out to find the effect of arching action on vertical stress distribution by changing the roughness of rigid boundary slope and the distance between retaining wall and boudary slope. A reduced scale model of cantilever retaining wall was made with concrete and Jumunjin Standary Sand with 80 % of relative density was used as foundation and backfill material. Centrifuge tests were performed by increasing g-level up to 40 g with measuring vertical stress induced by selfweight of backfill material. Test results on vertical stress distribution were analyzed and compared with results of Silo theory.

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An experimental study on the reduction method of earth pressure acting on the cut-and-cover tunnel lining (개착식 터널의 라이닝에 작용하는 토압경감대책에 관한 실험적 연구)

  • Kim, Sang-Yoon;Im, Jong-Chul;Park, Lee-Keun;Bautista, Ferdinand E.
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.952-957
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    • 2004
  • Cut and Cover Method is generally used in shallow tunnels and tunnel entrances with thin soil cover. In this type of cons0truction, backfilling is considered to be the most important process. In this process even though the backfill material is thoroughly compacted, compaction and self-weight due to vehicular vibration and pressure exerted by the soil cause the backfill material to undergo self-compression which leads to settlement. The settlement of the backfill material subjects the tunnel lining under excessive earth pressure which cause cracking and deformation. In the model test performed installation of geotextile on the sides and top of the tunnel was able to reduce the earth pressure acting on the tunnel lining.

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Evaluation of the Applicability of CLSM by Numerical Method and Field Test (현장시험과 수치해석에 의한 관거 뒤채움용 CLSM 적용성 평가)

  • Nam, Joongwoo;Byun, Yoshep;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.7
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    • pp.5-12
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    • 2013
  • The safety and structural integrity of buried pipes are usually at risk from constructing loading and compaction of backfill materials. The backfill material should be strong enough to help resistance and redistribute loads so that the buried pipe remains unaffected. Due to the many problems associated with buried pipes, there have been multiple studies on the development of a sustainable backfill material. In this study, a Controlled Low Strength Material made of coal ash was considered as a buried pipe backfill material. To determine the feasibility and performance of this backfill material, a numerical simulation was conducted with the results confirmed by a field test. Results showed maximum settlement to be 2 mm with the elastic strain of the buried pipe to be about 0.006.