• Journal of the Korean Society of Radiology
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• v.7 no.5
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• pp.359-364
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• 2013

Femur is the largest bone in the human body which supports the weight of body. A long pipeline shape of femur has little cancellous bone, so that regeneration is difficult when fracture happens. The fracture caused by an accident most frequently occurs at diaphysis. IM Nailing is the surgical method that implants an IM Nail into a medullary cavity for the fixation of fracture parts. However, a secondary fracture may happen if an IM Nail does not penetrate at the center of femur. In this study, a patient-specific femur was manufactured by a 3D printer using the computed tomography images scanned before surgery, which was used for the simulation of IM Nailing. It is expected that this result may prevent the secondary damage, reduce surgical operation time, and increase the precision.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.457-464
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• 2016

The analysis for stability of slope reinforced with soil nails need professional knowledge and skilled technology for program. So we spend a lot of money and time. In this study, we try to save it. After we analyzed the stability of reinforced slope with MIDAS GTS using shear strength reduction technique, we made charts by result. Charts created in the stydy can be used rapidly in slope disaster prevention. We try to analyze stability of slopes when we changed nail spacing, nail angle, slope type, properties of soil. We obtained relationship as follows; 1) The safety factor appears effectively when the nail angle is $10{\sim}20^{\circ}$. 2) The safety factor appears effectively when the nail spacing is 0.8~1.2m. 3) The error of Singh's and suggested chart are 3.45, 8.65, 4.35% when the slope are 1:0.5, 1:1, 1:2.

• Journal of the Korean Geotechnical Society
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• v.29 no.11
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• pp.107-118
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• 2013

Geosynthetic reinforced soil (GRS) walls have been increasingly applied recently due to its numerous geotechnical engineering applications. However failure occurs in some cases of constructed GRS walls. These GRS wall failures are mostly due to the unpredictable characteristics of intensive rainfall. Hence, the need for new and innovative ideas for rehabilitation methods has been getting attention. This paper introduces a case study for the design and restoration method of collapsed GRS wall using Limit equilibrium and Numerical Analyses. Restoration method includes: (1) soil nailing without backfill excavation and (2) reconstruction with GRS wall after collapsed backfill excavation. Analyses results show minimal horizontal displacements and shear strain on the reinforced concrete facing for the restoration case with soil nailing. On the other hand, horizontal displacements are developed in the middle of the mortar block facing and shear strains are developed at the bottom facing with spiral curves for the reconstructed GRS wall after collapsed backfill excavation. Therefore, the collapsed GRS wall was restored with the soil nailing without backfill excavation and its construction procedures are discussed in this paper.

• Journal of the Korean Geotechnical Society
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• v.19 no.3
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• pp.5-13
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• 2003

The soil nailing is one of the useful support-system in urban excavation because of the presence of other structures in the vicinity Since the soil nailing system was introduced, model experiments and theoretical studies have been performed to investigate behavior of soil nailed wall. However, there are few data in the case of multi-layered soil strata just like Seoul Metropolitan area in Korea. The feed back analyses are carried out using the measured wall displacement data for soil nailing construction sites with multi-layered strata in order to analyze the distance and the coefficients of extension zone of ground behind soil nailed wall. As a result, the distance of extension zone increased with increasing of the final excavation depth and the ratio of the distance to the final excavation depth was shown to be about 94% of the final excavation depth. Also, the coefficients of extension zone increased with enlargement of soil layer thickness and converged into constant value of 1.05. On the other hand, the maximum vertical displacements by the feed back analysis and Caspe's method were shown to be approximately 80%, 150~280% of the maximum horizontal displacement respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5963-5973
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• 2011

Current design and analyzing methods about soil nailing structures, developed on the basis of results obtained from experiments in laboratory or in field and numerical analyses, have applied different interaction mechanisms between the reinforced nails and the surrounding ground, and different safety factors against failure have been obtained. They might be proper approaches if the assumptions about rigidity of nails and ground conditions are met with actual conditions occurred in field. Otherwise, they would result in designing on analyzing in inappropriate ways so that it is needed to evaluate the validity of them. Therefore, in this research using the Centrifugal Model Testing, numerical parameters experiments about soil nailing structures' behavior and failure mechanism were performed. In the numerical parameters experiments, transmuted nail's length, setting angle, nail's front panel, stiffness variously, and increased the level of gravity until wall model was destroyed. Based on experimental results, we compared the effect, failure mechanism caused from parameters changes. By reviewing and comparing centrifugal model test results and methods currently in use, verified validity of existing methods.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.137-144
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• 2005

Recently a pressurized grouting soil nail is demanded due to problems beyond of economical and engineering purpose. In this study, a newly modified soil nailing technology named as the PGSN (Pressurized Grouting Soil Nailing) system is respected to reduced displacements of nails and increase of global slope stability. And effects of various factors related to the design of the PGSN system, such as the length of the soil nail, injected pressure and W/C ratio of cement grout in the pressurized grouting soil nail are examined throughout a series of the displacement-controlled field pull-out tests. Displacement-controlled field pull-out tests are performed in the present study and the volume of grouting are also evaluated based on the measurements. In addition, both short-term and long-term characteristics of pull-out deformations of the newly proposed PGSN system are analyzed and compared with those of the general soil nailing system by carrying out the stress-controlled field pull-out tests. From the pull-out characteristics of pressurized grouting soil nails, it is found that the effect of the length of the soil nail, injected pressure and W/C ratio of cement grout are important parameters.

• Clinics in Shoulder and Elbow
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• v.18 no.1
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• pp.47-51
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• 2015

Iatrogenic damage of the rotator cuff followed by postoperative shoulder function loss is a potential complication after antegrade intramedullary nailing (AIN) for a humeral fracture. The authors present a case of arthroscopic rotator cuff repair and subacromial decompression of a non-healed rotator cuff tendon (mainly supraspinatus) and secondary impingement syndrome caused either by the tear or a proud nail after AIN for a mid-shaft humeral fracture. At presentation, the patient complained of right shoulder pain and 'snapping', especially during forward elevation and abduction of the shoulder, of 4 years duration. Right shoulder pain started sometime after pain due to the humeral shaft fracture, operation had subsided, and persisted after nail removal. Arthroscopic findings showed a longitudinal rotator cuff tear at the nail entry point that had not healed and severe fibrous hypertrophy on the acromion underspace, which is a unique finding since most longitudinal splits of tendon fibers are more likely to heal than conventional rotator cuff tears detached from bone. The torn rotator cuff was repaired after debridement and placing side-to-side sutures. At his 34-month follow-up after rotator cuff repair, the patient showed complete recovery and had excellent clinical scores.

• Journal of the Korean GEO-environmental Society
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• v.2 no.2
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• pp.23-32
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• 2001

A soil wall reinforced by soil nailing is excavated in the typical soil conditions which are consisted of weathered soil, weathered rock and soft rock. The resulting nail loads computed are compared to loads measured by utilizing strain gauges during construction. The wall deflection at two locations are related to construction events and specific soil conditions, providing an understanding of the behavior of soil nailed walls. The load distribution along the nail indicated relatively high loads close to the wall. The mobilized load on the nail is proportional to the wall deflection showing the maximum value at the surface of the wall. The construction monitoring for this project provided valuable information in understanding the behavior of soil nailed walls.

• 기술발표회
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• s.2006
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• pp.135-145
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• 2006

Soil nailing systems are generally many used in underground excavations and reinforcements of slopes since the first construction as a temporary retaining wall in 1993, Korea. In recently, they are many attempts to expand the permanent reinforcements of slopes However, experimental studies related to soil nailing systems are insufficient Specially, there are no researches related in the large scaled load tests of soil nailed walls in Korea In this study, a case study on the large scaled load tests of soil nailed walls is introduced and the behavior characteristic of them is investigated Also, they are proposed allowable deformation corresponding to the serviceability limit of soil nail walls and ultimate deformation corresponding to the collapse state of the walls. These results can be applied to the maintenance management of soil nailed walls And analysis on the required minimum factor of safety of soil nailed walls using the relation curve of load ratio and deformation ratio are carried out

• Journal of the Korean Geotechnical Society
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• v.28 no.7
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• pp.5-16
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• 2012

Soil-nailing is the most popular method of reinforcing for slope stability. In general, two factors are considered as failure modes during the soil-nailing design stages: pullout failure mode and shear failure mode that will occur on the most probable failure plane. In many cases, however, shallow failure can also occur when the ground near the slope face is swept away by the horizontal stress release during the staged top-down excavation. In this paper, an optimized soil-nailing design methodology is proposed by considering the three failure modes mentioned above: pullout failure; shear failure; and shallow failure. The variables to be optimized include the bonded length and number of soil-nailings, and the confining pressure that should be applied at the slope face. The procedure to obtain the optimized design variables is as follows: at first, optimization of soil-nailings, i.e. bonded length and number, against pullout and shear failure modes; and then, optimization of confining pressure at each excavation stage that is needed to prevent shallow failure. Since the two processes are linked with each other, they are repeated until the optimized design variables can be obtained satisfying all the constrained design requirements in both of the two processes.