• 한국지반환경공학회 논문집
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• 제9권1호
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• pp.5-10
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• 2008

본 연구에서는 표면거칠기와 근입비, 직경에 따른 파이프형 앵커의 인발거동을 평가하기 위하여 실내모형실험이 시행되었다. 수직방향의 지반 변형에서 매입된 파이프형 앵커의 설계는 파이프에 부과된 힘의 크기에 의해 지배받는다. 본 논문에서는 모형실험의 분석을 통하여 파이프 직경과 표면 거칠기, 근입비와 지반상태로 야기된 파이프형 앵커의 변위 특성과 극한 저항력을 비교하고 평가하였다. 실험결과는 상대밀도의 증가에 따라 극한 인발력이 20%가량 증가하고 있음을 보여주고 있다. 지반의 상대밀도와 파이프의 지름, 표면거칠기의 변화에 따른 파이프형 앵커의 파괴시 변위는 근입비가 2에서 8로 증가함에 따라 약 5배 정도의 증가 경향을 보였다. 또한 앵커이론에 근거한 이론식들은 인발계수를 과대평가하는 것으로 나타났다.

• 한국구조물진단유지관리공학회 논문집
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• 제15권4호
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• pp.212-220
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• 2011

최근 들어 인천대교 등 다수의 사장교가 공용 또는 시공 중에 있으며 이러한 시점에서 국내 사장교의 기술력을 살펴본다면 시공기술은 눈에 띄게 발전하였지만 설계기술은 아직 국외 의존도가 매우 높은 실정이다. 사장교 핵심설계요소들 중 케이블 정착구조는 강력한 케이블 장력의 작용으로 국부적인 응력집중현상이 발생하므로 안전성 확보를 위해서는 반드시 국부상세해석에 의한 설계가 요구된다. 하지만 명확한 설계기준이나 이론적 설계 없이 유한요소해석에만 의존하여 설계하는 실정이며 정착구조의 이론적 기본메커니즘을 이해하지 못한 채 유한요소해석 결과에만 의존, 엔지니어의 판단력이 흐려지는 부작용을 가져오고 있다. 이에 따라 본 연구에서는 케이블 정착구조 가이드 파이프앵커 형식 중 정착강관의 기존 이론적인 설계절차를 나타내고 추가적으로 고려해야 할 사항들을 국내외 설계기준에 따라 정리하고 보완 설계절차를 제시하였다.

• 한국해양공학회지
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• 제16권5호
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• pp.49-55
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• 2002

The compression anchor is characterized by decrement of progressive failure, simple site work, economy and durability compared with tension anchor. In this paper, compression anchor is analysed through the laboratory element tests. The formula to be estimate the grout strength in fixed part of compression anchor and the effective reinforcement method for several types of soil were suggested. The following conclusions were made from this study : (1) A formula, which is able to calculate the grout strength in the fixed part of the compression anchor, is suggested. (2) The strength increment ratios( $R_{si}$) are 100％, 132％, 147％, 217％ according to the reinforcement method of grout. The reinforcement method is Non, Outside spiral, Inside-Outside spiral, Steel pipe, respectively. (3) The strength increment ratios( $R_{si}$) by reinforcing can be 8.23 times the strength increment effect according to the reinforcement types and ground confining pressure. (4) The steel pipe reinforcement is most effective in decomposed soil while, in the case of hard rock ground, high confining pressure is exerted on the grout, so there is no need to use reinforcements.

• Geomechanics and Engineering
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• 제35권4호
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• pp.395-409
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• 2023

Long-span suspension bridges have tunnel anchor systems to maintain stable cables. More investigations are required to determine how closely tunnel excavation beneath the tunnel anchor impacts the stability of the tunnel anchor. In order to investigate the impact of the adjacent tunnel's excavation on the stability of the tunnel anchor, a large-span suspension bridge tunnel anchor is utilised as an example in a three-dimensional numerical simulation approach. In order to explore the deformation control mechanism, orthogonal tests are employed to pinpoint the major impacting elements. The construction of an advanced pipe shed, strengthening the primary support. Moreover, according to the findings the grouting reinforcement of the surrounding rock, have a significant control effect on the settlement of the tunnel vault and plug body. However, reducing the lag distance of the secondary lining does not have such big influence. The greatest way to control tunnel vault settling is to use the grout reinforcement, which increases the bearing capacity and strength of the surrounding rock. This greatly minimizes the size of the tunnel excavation disturbance area. Advanced pipe shed can not only increase the surrounding rock's bearing capacity at the pipe shed, but can also prevent the tunnel vault from connecting with the disturbance area at the bottom of the anchorage tunnel, reduce the range of shear failure area outside the anchorage tunnel, and have the best impact on the plug body's settlement control.

• 대한조선학회 특별논문집
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• 대한조선학회 2011년도 특별논문집
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• pp.55-62
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• 2011

Although the performance of the commercial vessel has been dramatically improved through innovations, there has been no big changes on the traditional anchoring method of commercial vessels, both on design and operation until now. In this paper, two cases of design modifications were introduced for optimized design of pocket type anchor handling, which resulted in improved performance of the vessel's anchoring. From the first time fully balanced type anchors were applied on vessels in Korean shipyard, main design problem on this application was that the anchor doesn't normally slide into the pocket when the anchor fluke is not in line with pocket, as the anchor freely rotates by the swivel on forerunner. In order to prevent the problem, swivel has been deleted on the forerunner to prevent anchor rotation until now, but this solution caused problems such as twist lock of anchor chain, restriction of windlass direction, etc. On this paper, one of the solution is introduced to overcome the design problem by tilting the hawse pipe to some extent, which makes anchor turned at the time anchor ring touches the pocket skirt and that it properly slides into the pocket. Secondly, one of the solution is introduced to overcome misalignment problem between anchor chain cable and roller of chain compressor, which has been frequently occurred, by modification of roller design.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.125-128
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• 2002

The uplift capacity and displacement of an earth anchor for improving the wind resistance of the 1-2W type plastic film pipe on greenhouse was tested using the steel circular vertical earth anchor with various diameters and embedded depths (L) in dry sand. The diameter (B) of the model anchor is 90mm, 120mm, 150mm, respectively. The model tests were performed embedded depth ratios (L/B) ranging from $1{\sim}3$ in loose density. In the case of diameter 90mm, as the uplift loading increased, the uplift capacity also increased until the loading was reached to ultimate uplift capacity. After that, the uplift capacity was continually increased or decreased until the experiment was finished. In general, the ultimate uplift capacity was different depending upon the anchor diameter and embedded depth ratios.

• 한국지반공학회지:지반
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• 제14권6호
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• pp.139-151
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• 1998

SI 앵커는 지반개량 앵커를 의미한다. 이는 앵커를 지지하는 지반을 JSP로 개량한 것으로, SI 앵커체는 80cm 정도의 직경을 가지게 된다. SI 앵커는 앵커체와 지반사이의 마찰저항력과 앵커체 앞면의 지압저항력으로 인해 높은 인발저항력을 발휘하게 되는데, 특히 마찰저항력은 JSP로 개량된 앵커체의 직경의 증대로 인해 상당히 증가하게 된다. 본 연구에서는 SI 앵커의 인발저항기구를 분석하기 위해 실내 모형실험과 현장실험을 실시하였다. 공기건조 모래지반 내에서의 실내 모형실험을 통해 SI 앵커 주변지반의 변형률장을 분석하였는데, 이는 토조 벽면에 설치된 라텍스 멤브레인을 이용한 사진 분석법을 통해 이루어 졌다. 10매의 변형률게이지가 부착된 특수 설계된 PVC 파이프를 앵커체 내에 설치하고 변형률을 측정하여 현장실험의 결과를 분석하였는데, 역시 실내 모형실험과 같이 앵커체 내에서의 변형률을 측정하였다.

• Geomechanics and Engineering
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• 제9권6호
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• pp.757-774
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• 2015

Reinforcing soils with the geosynthetics have been shown to be an effective method for improving the uplift capacity of granular soils. The pull-out resistance of the reinforcing elements is one of the most notable factors in increasing the uplift capacity. In this paper, a new reinforcing element including the elements (anchors) attached to the ordinary geogrid for increasing the pull-out resistance of the reinforcement, is used. Thus, the reinforcement consists of the geogrid and anchors with the cylindrical plastic elements attached to it, namely grid-anchors. A three-dimensional numerical study, employing the commercial finite difference software FLAC-3D, was performed to investigate the uplift capacity of the pipelines buried in sand reinforced with this system. The models were used to investigate the effect of the pipe diameter, burial depth, soil density, number of the reinforcement layers, width of the reinforcement layer, and the stiffness of geogrid and anchors on the uplift resistance of the sandy soils. The outcomes reveal that, due to a developed longer failure surface, inclusion of grid-anchor system in a soil deposit outstandingly increases the uplift capacity. Compared to the multilayer reinforcement, the single layer reinforcement was more effective in enhancing the uplift capacity. Moreover, the efficiency of the reinforcement layer inclusion for uplift resistance in loose sand is higher than dense sand. Besides, the efficiency of reinforcement layer inclusion for uplift resistance in lower embedment ratios is higher. In addition, by increasing the pipe diameter, the efficiency of the reinforcement layer inclusion will be lower. Results demonstrate that, for the pipes with an outer diameter of 50 mm, the grid-anchor system of reinforcing can increase the uplift capacity 2.18 times greater than that for an ordinary geogrid and 3.20 times greater than that for non-reinforced sand.

• 한국관개배수논문집
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• 제10권2호
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• pp.55-61
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• 2003

Bench scale experiments have been carried out to evaluate the adaptability of the anchor for improving the uplift capacity of foundation of pipe framed greenhouse which is typically adopted in conventional plastic film glazing greenhouses, such as 1-2W ty

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.329-333
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• 1995

The usual methods for the temperature control of mass-concrete structures include the use of low-heat cement, pre-cooling, or pipe-cooling. In order to control the heat of hydration of mass-concrete structures such as massive pier or anchor block, and mat foundation, the pipe cooling method is widely acceptable for pratical use. In this paper, method of analysis using the Finite Element Method was applied to analyze the heat exchange on the field of three dimensional thermal conduction. The result of analysis Well agreed with experimentally measurement data by "KUMATANI". The method of this analysis will be used widely to control the heat of hydration by the pipe cooling in mass-concrete.-concrete.