• Archives of Reconstructive Microsurgery
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• v.15 no.1
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• pp.17-25
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• 2006

Twelve cases in eleven patients with segmental bone defects were treated with contralateral fibula free flap and ipsilateral island fibula flap in an antegrade, retrograde or bidirectional flow fashion. Five cases were managed with free flaps and seven were with ipsilateral fibula island transfer. Among seven cases, antegrade fashion was three, retrograde was three, and bidirectional was one. All patients were related with open tibial fractures and its sequelae except one who had open foot bone fracture. According to Gustilo's classification, ten patients were type IIIb and one was type IIIc. Basically, antegrade-flow flaps based on the peroneal vessels as in the conventional free flap were used for the proximal or middle one-third tibial defects. On the contrary, retrograde-flow flaps based on the communicating branch between the peroneal and posterior tibial vessels were used for the middle or distal one-third of the tibia. Bidirection-flow flap based on intact peroneal vessels were used for the middle portion of the tibia. The patients who have undergone ipsilateral fibula island flap had one of the following problems: a previously failed free flap, below-knee amputation of the opposite leg because of open tibial fracture, refusal to use the contralateral sound leg, or poor general condition to stand a lengthy operation. Six of the patients who have got ipsilateral fibula island flap also had an associated fibula fracture on the same leg, which was ultimately used as one of the osteotomy sites. The follow-up period was from 1 to 10 years. Two cases of free flap were failed: one patient had below-knee amputation and the other patient had ipsilateral fibula transfer. Other cases were successful and excellent hypertophy of the transferred fibula was achieved. Time to bone union ranged from 4 to 11 months. Time to full weight bearing was from 5 to 13 months after surgery. All of the transferred fibulas showed hypertrophy after weight bearing. In one case, stress fracture was developed during ambulation, which was healed conservatively. Nonunion occurred in two cases, which were treated with a long leg cast and cancellous bone graft, respectively. Length discrepancy of the legs was noted. The limb was shorter by an average 0.5 cm in three cases, longer by 1.1 cm in one case. In the case of island fibula transfer, limited arc of rotation was not a problem. Other disabling complications were not seen. We believe that these diverse modalities using a vascularized fibula will make us more comfortable to handle major bone defects.

• Journal of Korean Society of Steel Construction
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• v.26 no.4
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• pp.323-334
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• 2014

In this paper, experimental program and associated numerical study were carried out to evaluate the fire resistance of unprotected concrete-filled rectangular steel tubular (CFT) columns subjected to the standard fire. The key testing parameters included the length effect, the load ratio, and the sectional dimensions of the CFT columns. Temperature distribution and axial deformation of the CFT column specimens were measured and analyzed. Rather early local buckling of steel tubes was observed in all the specimens. This caused subsequent load transfer from steel tube to concrete, and eventually triggered concrete crushing, or complete loss of the load bearing capacity of the column. This implies that the limit state of local buckling as well as overall flexural buckling should be incorporated in fire design procedure. As expected, the fire resistance time of specimen with higher load ratio consistently lessened. The prediction of fire resistance time of unprotected CFT columns based on the limiting steel temperature in current design codes or the formula proposed by previous studies is slightly conservative compared to the fire test results available. To establish the finite element analysis model that can be used to predict the thermal and structural behaviour of unprotected CFT columns in fire, the fully coupled thermal-stress analysis was also tried by using the commercial code ABAQUS. The numerical results showed a reasonable global correlation with the experimental results.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.5
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• pp.124-135
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• 2011

The capacity of bearings installed at abutments and piers for continuous bridges is usually determined by the magnitude of the maximum vertical reaction at each support and the capacity of bearings placed at piers is higher than that at abutments. In this study, the possibility of the improved seismic performance of base-isolated continuous skew bridges was investigated by analysing the variation of the seismic behavior of them according to three arrangements of bearings. Based on the conventional arrangement of bearings(Case A), three arrangements of bearings such as Case A, Case B and Case C were selected considering the variation of the horizontal stiffness of the lead rubber bearing(LRB) installed at the pier. The seismic behavior of the total 36 skew bridges was investigated by conducting the response spectrum analysis using the hybrid response spectrum considered the effect of LRB's damping. Results of analyses show that a more desirable seismic behavior of base-isolated continuous skew bridges can be obtained by reducing the magnitude of the horizontal stiffness of LRB placed at the pier to similar to or less than that of LRB installed at abutments. The variation of LRB's stiffness at the pier brings about period elongation and the change of mode shapes of base-isolated skew bridges and results in the reduction of the total base shear, the maximum base shear at the pier and the girder stresses. Although positive effects on the seismic behavior of base-isolated skew bridges caused by the change of arrangement of bearings decreased slighty with an increase in the flexibility of the substructure, the proposed arrangements of bearings bring about the improved seismic performance of base-isolated continuous skew plate girder bridges with less than 10m height of piers.

• Journal of the Korean GEO-environmental Society
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• v.7 no.6
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• pp.101-111
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• 2006

In case of drilled shafts installed by drilling through soft overburden onto a strong rock, the piles can be regarded as end-bearing elements and their working load is determined by the safe working stress on the pile shaft at the point of minimum cross-section or by code of practice requirements. Drilled shafts drilled down for some depth into weak or weathered rocks and terminated within these rocks act partly as friction and partly as end-bearing piles. The base resistance component can contribute significantly to the ultimate capacity of the pile. However, the shaft resistance is typically mobilized at considerably smaller pile movements than that of the base. In addition, the base response can be adversely affected by any debris that is left in the bottom of the socket. The reliability of base response therefore depends on the use of a construction and inspection technique which leaves the socket free of debris. This may be difficult and costly to achieve, particularly in deep sockets, which are often drilled under water or drilling slurry. As a consequence of these factors, shaft resistance generally dominates pile performance at working loads. The efforts to improve the prediction of drilled shaft pile performance are therefore primarily concerned with the complex mechanisms of shaft resistance development. In this study, the numerical analyses are carried out to investigate the behavior characteristics of side of rock socketed drilled shafts varying the loading condition at the pile head. The difference of behavior characteristics of side resistance is also evaluated with the effects of modelling of asperity.

• Journal of the Korean Geotechnical Society
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• v.15 no.3
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• pp.41-70
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• 1999

The benefits of utilizing internal reinforced members, such as soil nails and ground anchors, in maintaining stable excavations and slopes have been known among geotechnical engineers to be very effective. Occasionally, however, both soil nails and ground anchors are simultaneously used in one excavation site. In the present study, a method of limit equilibrium stability analysis of the excavation zone reinforced with the vertically or horizontally mixed nail-anchor system is proposed to evaluate the global safety factor with respect to a sliding failure. The postulated failure wedges are determined based on the results of the $FLAC^{2D}\; 및\; FLAC^{3D}$ program analyses. This study also deals with a determination of the required thickness of the shotcrete facing. An excessive facing thickness may be required due to both the stress concentration and the relative displacement at the interface zone between the soil nailing system and the ground anchor system. A simple finite element method of analysis is presented to estimate the corresponding relative displacement at the interface zone between two different support systems. As an efficient resolution to reduce the facing thickness, the modified bearing plate system is also proposed. Finally with various analysis related to the effects of design parameters, the predicted displacements are compared with the results of the $FLAC^{2D}$ program analyses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.577-584
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• 2019

Recently, CSB(Cable-Stayed Bridge) have been attempted to be atypical forms for landscape elements in Korea. CSB with new geometry need to analyze their characteristics clearly to ensure structural safety. This study's bridge is the S-shaped curved pedestrian CSB that has a girder with S-shape plane curve and reverse triangular truss cross section, inclined independent pylon, modified Fan type main cable and vertical backstay cable. Curved CSB can have excessive lateral displacement and moment when the tension is adjusted, focusing only on longitudinal behavior, such as a straight CSB. In order to analyze the effect of the cable on the lateral behavior of bridges, the cable is divided into two groups according to the lateral displacement direction of the pylon due to tension. The influence of the combination ratio of GR1 and GR2 on the girder, bearing, pylon, and vertical anchor cable was analyzed. When the tension applied to the bridge is 1.0GR1 plus 1.0GR2, In the combination of 1.2GR1 plus 0.8GR2, the stress on the left and right upper member of the truss girder and the deviation of the both were minimized. In addition, the horizontal force of the bearing, the lateral displacement and moment of the pylon, and the tension of the vertical backstay cable also decreased. This study is expected to be used as basic data for determination of tension of CSB with similar geometry.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.1
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• pp.17-32
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• 2021

Objectives The present study was designed to find out the therapeutic effects and possible underlying mechanism of Buja-tang, a herbal complex formula on experimental monosodium iodoacetate (MIA)-induced osteoarthritis. Methods Osteoarthritis models were created via intra-joint injection of MIA (50 μL with 80 mg/mL) in rats. Rats were divided into five groups and each group consisted of seven. Normal group was not injected MIA and did a normal diet. Control group injected MIA and received distilled water. Indo injected MIA and oral administration of 5 mg/kg of indomethacin. BJTL injected MIA and oral administration of 100 mg/kg of Buja-tang. BJTH injected MIA and oral administration of 200 mg/kg of Buja-tang. We analyzed weight-bearing ability of hind paws, oxidative stress related factor, antioxidant protein, inflammatory protein, inflammatory messenger and cytokine in joint tissue. Pathological observation of knee cartilage tissue structures was also performed with hematoxylin & eosin and safranin-O chromosomes. Results Weight-bearing ability of hind paws showed a tendency to reduce pain. The incidence of nicotinamide adenine dinucleotide phosphate oxidase and p22phox in articular tissue was significantly reduced, and the incidence of nuclear factor-erythroid 2-related factor 2 and heme oxygenase-1 and superoxide dismutases was significantly increased. The incidence of phosphorylated inhibitor of κBα, nuclear factor-kappa B p65, inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor alpha, interleukin (IL)-6, and IL-1β decreased significantly. In pathological observation, cartilage tissue damaged by MIAs in biopsy has significantly recovered from Buja-tang administration. Conclusions Buja-tang has anti-inflammation, antioxidation and pain relief effects. So this is thought to inhibit the progress of osteoarthritis in rat caused by the MIA.

• Geotechnical Engineering
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• v.12 no.6
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• pp.185-198
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• 1996

EPS is increasingly used as a filling material in soft ground. The beneficial effects of the use of EPS derive from minimizing the stress increment, which, in turn, increases the bearing capacity and reduces the settlement. EPS can also be used as a backfill material for retaining walls and abutments to reduce the horizontal earth pressure. However, there is no rational application for the selection of the EPS fill which is essential to the selection of the filling configuration and the settlement calculation. In this paper, therefore, the nonlinear numerical model developed from the results of triaxial compression tests is applied to the construction of EPS and verified through the comparison between the prediction and in-situ measurements.

• Geotechnical Engineering
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• v.1 no.2
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• pp.17-26
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• 1985

This study was carried out for the purpose of comparing in reference to sand drain in the next three different cases. First, The case of drain material (sand pile) has some rigidity during embankment and consolidation. Second, In usual case of no rigidity as a paper drain without permeability during embankment and consolidation Third, Check up clay behavior when above the two cases carried out respectively. This FEM analysis is consisted with Biot's consolidation equation when it is used for Christian Boehmer's numerical technique. The main results are obtained from above the Analysis When sand drain has some rigidity, the lateral and vertical deformation of clay foundation is restrained considerable amount and .exhibited bearing capacity of load as a pile According to the foundation in drained condition and untrained condition, the results are much variable in this analysis method. Also, The behaviors of stress path and pore water pressure met our expectation during , consolidation. This analysis should be considered to put into use of sand drain and design in future.

• The Journal of Korean Medicine
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• v.25 no.4
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• pp.43-50
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• 2004

Objective : Obesity is associated with degenerative arthropathy giving stress on joints. It also amplifies loads of weight bearing joints by changing the gravity line of the body. Our aim is to investigate the correlation between obesity and lumbar lordosis in obese pre-menopausal Korean females. The hypothesis was tested that there is a correlation between obesity and lumbar lordosis. Methods : A cross-sectional evaluation of 44 Females (baseline age 30.77 ± 6.46) with BMI 31.53 ± 3.82 (kg/㎡) was done. Body composition was measured using bio-impedance analysis (BIA), and anthropometry was done by the same observer. A lateral whole spine X-ray was taken in standing position to measure the lumbar lordotic angle (LLA), Ferguson angle (FA) and lumbar gravity line (LGL). A Pearson correlation was used to measure the correlation between obesity and lumbar lordosis (SPSS 10.0 for windows). Results : Body mass index (BMI kg/㎡) had a negative relationship with LLA((equation omitted)=-0.469), FA((equation omitted) =-0.347) and LGL((equation omitted)=-0.389). Body fat rate had a negative relationship with LLA only(γ=-0.385). Waist circumference had a negative relationship with LLA((equation omitted)=-0.345) and LGL((equation omitted)=-0.346). WH ratio had no relationship with lumbar lordosis. Conclusion : These data show that obesity is related to mechanical structures, such as lumbar lordosis. BMI was the most useful index, which reflects a change of mechanical structure of lumbar, more than other variables in this study.