• 제목/요약/키워드: Anchor stability

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A Case Study on The Stability and Reinforcement Method at a Rock Slope (암반사면의 안정성검토 및 보강방안에 관한 사례연구)

  • Chun, Byung-Sik;Lee, Seung-Eun;Kong, Jin-Young;Lim, Joo-Heon
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1369-1375
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    • 2006
  • This study analyzes stability and the reason of slope failure about cut slope on stony mountain in Acheondong, Guri and suggests the reasonal reinforce method. Based on the results of the subsurface exploration, laboratory tests, and the numerical analysis of finite element method, the potentials of plane and wedge failure are highly estimated. The safety factor was 1.2 under dry and 1.06 wet condition. The most proper reinforce method to raise the safety factor more than 1.5 was the way to control displacement by using step retaining wall, earth anchor, wire mesh, and rock anchor.

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Lateral Load Test on the Bar-type Anti-buoyancy Anchors in the Weathered Rock (풍화암에 시공된 Bar Type 부력앵커의 수평재하시험)

  • Park, Chan-Duk;Lee, Kyu-Hwan;Ryu, Nam-Jae;Lee, Song
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.4
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    • pp.165-174
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    • 2004
  • This study is about a horizontal load test of buoyance anchor installed in the section where underground water level happens in the depth of 5m under the ground when the ground is excavated, because the section as a excavation section of high speed railway ${\bigcirc}{\bigcirc}$ station is near a rivers and because the section always has a reservoir of full water level on the left. Therefore, in this study we will appraise the long-term stability of the structure permanently being taken buoyance by the underground water level, through the spot test of the buoyance anchor installed in the section where underground water level happens. For that, Bar Type anchor is used, which can get enough pulling-out force by a method to resist buoyance by using friction force against the ground by high strength steel rod or steel wire. Anti-buoyance anchor is installed on the bottom slab of underground structure being taken horizontal force by the braking and accelerating of high speed train. And, It is aimed to analyze and grasp the review result of stability for the horizontal force that happens at the parking and stopping of high speed train, by executing horizontal load test for the grasping of the movements characteristic of buoyance anchor.

Behaviour of Ground Anchor According to Period Characteristic of Seismic Load Using Numerical Analysis (수치해석을 통한 지진하중의 주기특성에 따른 그라운드 앵커의 거동)

  • Oh, Dong-Wook;Jung, Hyuk-Sang;Yoon, Hwan-Hee;Lee, Yong-Joo
    • Tunnel and Underground Space
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    • v.28 no.6
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    • pp.635-650
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    • 2018
  • Many people have been recognized that the Korean Peninsula is no longer safe area from the earthquake by the recent earthquakes occurred in the country. The earthquakes that occurred at Pohang and Gyeongju appeared differently from them considered in the seismic design and researches on the seismic design method have been also conducted by many researchers. Studies on seismic loads are mainly focused on existing superstructures, and research involving them has been actively carried out in reality. However, paper regarding structural stability of reinforcement from seismic load such as soil-nails, rock-bolts, ground anchors which were constructed to ensure stability of serviced structure have been published rarely. In this study, ground anchor been effected by static load and seismic load which is settled in the weathered rock is analyzed. Results for static load are obtained from field test and seismic load is from numerical analysis. In this study, the behavioral characteristics of the ground anchor were analyzed by numerical analysis in case of seismic loading based on the result of the in-situ tensile test of the ground anchor settled weathered rock. As a result, settlement of concrete block due to application of tension force for ground anchor occurred as well as following loss of axial force for ground anchor. Also, as bond length and period of seismic load are longer, increasement of displacement is greater.

Comparison of Safety factor for an Anchored Slope in Accordance with the Effects of Load Transfer (앵커 하중전이에 따른 사면의 안전율 비교 연구)

  • Kim, Sung-Kyu;Kim, Wak-Kyung;Park, Jong-Sik;Joo, Yong-Sun;Kim, Tae-Hoon
    • Journal of the Korean Geotechnical Society
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    • v.24 no.11
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    • pp.55-60
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    • 2008
  • This paper presents how the load transfer mechanism of the ground anchor affects on the stability analysis of anchored slope. The finite element analysis and the conventional limit equilibrium analysis on the anchored slope were performed and compared. The limit equilibrium analysis of the anchored slope is widely used in design practice due to the easiness of the analysis. However, the load transfer mechanism is not considered properly for the analysis. When the failure surface passes through the bonded length of an anchor, the anchor load is disregarded and the factor of safety for the anchored slope is smaller than it should be. In this study, the load transfer distribution was incorporated into the limit equilibrium stability analysis of the anchored slope and the results were compared with those of finite element analysis.

Structural Analysis of a Cable Anchor System for a Cable-Stayed Bridge over the Sea (해상 사장교의 Pipe형 케이블 정착구에 관한 구조해석)

  • KONG BYUNG-SEUNC;HONG NAMSEEG
    • Journal of Ocean Engineering and Technology
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    • v.19 no.5 s.66
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    • pp.34-42
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    • 2005
  • The cable connection zone of the cable-stayed bridge transfers deal-load, live-load, and second-load to the cables on the structural joint zone of the cables and the main girders are the most critical parts in which big cable tensile forces are generated by those loads. Therefore, it is necessary to thoroughly check the main girder, structurally to secure the required stability. Because of the heavy tensile force of cables linked in the connection zone of the cable-stayed bridge, locally concentrated stress, as well as the dispersion of stress, occurs in the structurally contacted point of cable and main girder thus, we need to make a thorough investigation through a detailed structural analysis. Directly delivering the tensile force to the connection zone of the cable, the consequently big effect in the tensile force fluctuation caused by the live-load will make it necessary to review the fatigue strength. As the connection zone of the cable is designed to resist the tensile force of the cable, which is applied to a connecting section as a concentrated force, thick plates are used. These plates are frequently made of welded structure, thus, the investigation of the welding workability is inevitable.

Evaluation on Stability of Reinforced Earth Wall using Geosynthetic Strip with Rounded Band Anchor (띠형 섬유보강재가 적용된 블록식 보강토옹벽의 안정성 평가)

  • Lee, Kwang-Wu;Cho, Sam-Deok;Han, Jung-Geun;Hong, Ki-Kwon
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.3
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    • pp.43-51
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    • 2012
  • This paper describes the stability evaluation of reinforced earth wall using geosynthetic strip based on field test. The wall facing, which is applied in field, is able to present excellent scenery, and the reinforcement has improvement effect of pullout resistance based on rounded band anchor. The measurement is conducted according to construction elapsed time of structure for earth pressure, horizontal displacement of wall facing and reinforcement strain in field test. The evaluation results show that the measured earth pressure is less than theoretical earth pressure due to dispersion effect of earth pressure by geosynthetic strip. The horizontal displacement of wall facing is also satisfied a empirical criteria. The measured strain of reinforcement had nearly no effect on stability of the reinforced earth wall. Therefore, the geosynthetic strip with rounded band anchor can be applied in the reinforced earth wall, and the reinforced earth wall with geosynthetic strip can be commonly used in field because it has a structural stability.

Performance Evaluation of the Cast-in-place Anchor Bolt in Non-cracked Concrete used in Power Plant Facilities (비균열 콘크리트에 매립된 발전설비 정착부 선 설치 앵커의 구조성능 평가)

  • Kim, Dong-Ik;Jong, Woo-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.11
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    • pp.250-258
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    • 2019
  • The seismic performance and stability of operating facilities installed in domestic power plants need to be verified because of the increased incidence of earthquakes resulting in power plant damage due to the overturning failure of electric operating facilities. In this study, a structural performance evaluation of the anchor bolts constructed to setup the operating facilities on concrete slabs was carried out through an on-site inspection of power plants, called Daechung-Dam. M10 J hook and M12 J hook anchor bolts were installed in the field unit. According to the ASTM E 488-96 specifications, anchor bolt pullout and shear tests were carried out and compared with the anchor-bolt design standards. The results from the tension and shear pullout tests showed that the M10 and M12 J hook anchor bolts had higher performance than the required design load. Thus, they were found to be safe enough. Nevertheless, more research in the field of analytical study will be needed in the near future.

Arthroscopic Capsulolabral Repair Using Absorbable Suture-Anchor for the Traumatic Anterior Instability of Shoulder (흡수성 suture-anchor를 이용한 견관절 전방 불안정성의 재건술)

  • Kim Seung-Ki;Song In-Soo;Seo Hyun Mo;Moon Myung-Sang;Lin Guang
    • Clinics in Shoulder and Elbow
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    • v.7 no.2
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    • pp.65-69
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    • 2004
  • Purpose: The purpose of this study is to evaluate the short-term clinical outcome of the capsulolabral repair using absorbable suture anchor in traumatic anterior instability of shoulder. Materials and Methods: From June 2000 to September 2001, 15 shoulders with recurrent anterior instability were operated with arthroscopic Bankart repair using absorbable suture-anchor 'PANALOK' (Mitek, westwood, MA), and were followed up over 1 year (average; 13 months). The mean age was 23-years. There were fourteen males and one female. The mean duration from the initial symptoms to the operation was 24 months. Associated pathologies were Hill-Sachs defect in 12 cases, SLAP in 6 cases, and partial rotator cuff tear in 2 cases. The results were evaluated by patien's satisfaction, Modified Rowe Score in regard to joint stability, mobility, pain and function in comparison with the preoperative ones, and other complications. Results: At the last follow-up, the total Rowe Score increased from 38 points to 92 points. There were no recurrence and 14 patients among 15 patients gained pre-operative level of sports activity and no other complications. Conclusion: Effective capsulolabral repair could be obtained by the absorbable anchoring without any untoward complications. This procedure is simple and safe one and this system can be a good substitute for the metallic anchor.

Clinical and Radiological Outcomes of Modified Phemister Operation with Coracoclavicular Ligament Augmentation Using Suture Anchor for Acute Acromioclavicular Joint Dislocation

  • Cho, Nam Su;Bae, Sung Ju;Lee, Joong Won;Seo, Jeung Hwan;Rhee, Yong Girl
    • Clinics in Shoulder and Elbow
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    • v.22 no.2
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    • pp.93-99
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    • 2019
  • Background: Modified Phemister operation has been widely used for the treatment of acute acromioclavicular (AC) joint dislocation. Additionally, the use of suture anchor for coracoclavicular (CC) fixation has been reported to provide CC stability. This study was conducted to evaluate the clinical and radiological results of a modified Phemister operation with CC ligament augmentation using suture anchor for acute AC joint dislocation. Methods: Seventy-four patients underwent the modified Phemister operation with CC ligament augmentation using suture anchor for acute AC joint dislocation and were followed-up for an average of 12.3 months. The visual analogue scale (VAS), range of motion, Constant score, and Korean shoulder scoring system (KSS) were used for clinical assessment. Acromioclavicular interval (ACI), coracoclavicular distance (CCD), and acromioclavicular distance (ACD) were obtained to evaluate the radiological assessments. Results: At the last follow-up, the mean VAS Score was 1.7 points, the mean joint range of the forward flexion was $164.6^{\circ}$, external rotation at the side was $61.2^{\circ}$ and internal rotation to the posterior was a level of T12. The mean Constant score and the mean KSS was 82.7 points and 84.2 points, respectively. At the mean ACI, CCD, and ACD, significant differences were found preoperatively and at the last follow-up. When the ACI, CCD, and ACD were compared with the contralateral unaffected shoulder at the last follow-up, the affected shoulders had significantly higher values. Conclusions: The modified Phemister operation with CC ligament augmentation using suture anchor is clinically and radiologically effective at acute AC joint dislocation.

Evaluation of Characteristics of Ground Anchor Using Large Scale Laboratory Test (실규모 실험을 이용한 그라운드 앵커의 거동 특성 평가)

  • Sangrae Lee;Seunghwan Seol
    • Journal of the Korean GEO-environmental Society
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    • v.24 no.11
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    • pp.19-24
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    • 2023
  • Ground anchor has been widely used specially for maintaining stability on reinforced cut slope in expressway. While the durability of the ground anchors should be ensured over the service life. However, the long-term loss of tensile force has occurred in most of field-installed anchors. Main causes are not clearly identified and very few studies have been made for analyzing long-term behavior of ground anchor in slopes. In this study, full-scale model tests and long-term measurements were made to obtain the load-displacement data and identified the causes of the long-term behaviors of ground anchor. As a result, the bond strength decreases exponentially with increasing water-binder ratio. Especially, groundwater is the most influencing factor to the bond strength. In the long-term behavior, the load decreases sharply until the initial settlement stabilized, and thereafter the tension force decreases constantly.