장방형 개구부를 갖는 고강도 철근콘크리트 깊은 보에서 개구부 경사보강철근의 전단저항

양근혁,김자영,정헌수 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.1

For reinforced concrete deep beams with rectangular openings, the diagonal reinforcement around opening has greater effect on restraining the diagonal crack width and increasing the ultimate strength than the horizontal or vertical reinforcement around opening of the same steel amount The purpose of this study was to evaluate the relation between opening Size and amount of diagonal reinforcement requiring for complement of reduced strength Fifteen deep beams were examined according to the variety of the width and depth of opening as web as amount of diagonal reinforcement around opening Also, the concepts of volumetric ratio of diagonal reinforcement(Ρ_(od)) and of effective diagonal reinforcement factor around opening(ξ) were suggested Test results indicated that preservation of strength of deep beams with openings correspond to ultimate strength of solid beams calculated by strut-tie model of ACI 318-02 may be achieved by providing the effective diagonal reinforcement factor around opening of 0.05

상계치 이론을 이용한 장방형 개구부를 갖는 철근콘크리트 깊은 보의 전단내력 평가

양근혁,이영호,은희창,정헌수 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

The purpose of this study is to evaluate the failure plane and the shear capacity of reinforced concrete deep beams with rectangular openings using upper bound theorem. A numerical optimization procedure programmed to obtain the minimum value of the shear capacity by adjusting the position of the instantaneous center according to various potential failure planes. The predictions obtained from the proposed method are in good agreement with experimental results.

철근콘크리트 깊은 보의 전단거동에 대한 최소 전단철근비의 영향

양근혁,정헌수 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.3

Reinforced concrete deep beams can be designed using a strut-tie model consisting of concrete compression struts, steel tension ties, and joints referred to as nodal zones. The spreading of the compression forces in a strut gives rise to transverse tensions, which may cause the strut to crack longitudinally. To prevent progress of longitudinal cracking in a strut and to resist the tensile force due to the lateral spread of the strut forces, minimum horizontal or vertical shear reinforcement should be provided. Sixteen reinforced concrete continuous deep beams with minimum shear reinforcement recommended by ACI 318-02 were tested. From investigation of this test result and existing data, the influence of minimum shear reinforcement ratio on the shear behavior of reinforced concrete deep beams was evaluated. Also Based on strut-tie model developed by MacgreGor, this study proposed minimum shear reinforcement ratio which considered the effectiveness of horizontal and vertical shear reinforcements with shear span-depth ratio.

고층건물에서 수직 구조부재의 축소량 평가

양근혁,정헌수 중앙대학교 기술과학연구소 2002 기술과학연구소 논문집 Vol.32 No.-

철근콘크리트 구조의 고층화에 따라 수평 구조부재의 기울어짐을 유발시키는 수직 구조부재의 부등 축소량에 대한 중요성과 관심이 증가하고 있다. 부등 축소량이 발생하는 주요 원인은 기둥과 전단벽의 수직 철근비의 차이, 옹력수준의 차이, 콘크리트 강도의 차이 및 부재의 체적표면적 비의 차이 등이다. 본 연구의 목적은 고층건물에서 수직구조부재의 축소량 예측방법을 제시하고, 수직 구조부재의 축소량에 영향을 미치는 각 변수들을 분석.평가하여 고층건물 설계시 수직부재의 부등 축소량 보정을 위한 기초자료로 활용하는데 있다. 본 연구의 결과 철근콘크리트 수직 구조부재의 축소량은 탄성 변형보다는 비탄성 변형에 의해 크게 영향을 받았으며, 최대 부등 축소량은 건물의 중상층부에서 발생하였다. The effects of differential shortening of vertical structural members in reinforced concrete structures, causing significant tilt of the horizontal members, take on added significance and need special consideration in design and construction with increased height of structures. Differential shortening in concrete buildings are primarity those between isolated columns and shear walls due to different ratios of vertical reinforcement, differential stress levels, different concrete strength, and different volume-to-surface ratios. Therefore, the objective of this study are to develope prediction methods for shortening of vertical structural members, and to evaluate parameter that effect on column shortening in high-rise buildings. The results of this study indicated that shortening of vertical structural members in reinforced concrete structures was influenced significantly by inelastic defomation including creep and shrinkage rather than elastic one. Especially, the maximum differential shortening is appeared between the middle and top floor of the building.

개구부 폭과 깊이 변화에 따른 철근콘크리트 깊은 보의 파괴모드 및 내력 평가에 관한 연구

양근혁,이영호,은희창,정헌수 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

The purpose of this study is to investigate the failure mode and the shear strength of reinforced concrete deep beams with rectangular openings. Fourteen deep beams which shear span-to-depth ratio(a/h) is 0.5 were tested and an equation to predict the ultimate shear strength of deep beams with rectangular openings was established by the test results.

냉동 건조 탈회 동종골 이식후 골막이 골 형성 과정에 미치는 영향에 관한 실험적 연구

이동근,엄인웅,민승기,권혁도 大韓顎顔面成形再建外科學會 1995 Maxillofacial Plastic Reconstructive Surgery Vol.17 No.4

Periosteum in general is described as a specialized fibrous membrane of mesenchymal origin consisting of two basis layers : outer fibrous layer consists of irregularly arranged dense connective-tissue with fibroblasts, and inner osteogenic or cambial layer is composed of more loosely arranged fibers, greater vascularity and flatted spindle-shaped pre-osteoblasts. This periosteum may serve in controlling bone growth, especially mandibular growth has been emphasized. But, the periosteum enwrapping the facial skeleton have been studied for many years leaving a controversy in opinion regarding the function of these structures. We evaluated the bone formation activity of te periosteum in allogeneic bone grafts which bones are made of freeze-dried preparation preoperatively. We made the calvarial bone defects, 5×7mm sized, amd grafted with allogeneic bone in rats, which a half of specimens has dissected the overlying periosteum and a rest intacted. After bone grafting, we evaluated the capacity ofbone formation of periosteum, 1, 2, 4, 6, 8 weeks postoperatively. There are subtle differences of bone formation during early healing period after demineralized allogeneic bone grafting between control groups with periosteum and experimental groups without periosteum.

一部地域 老人들의 主權的 建康水潗에 영향을 미치는 IADL에 관한 硏究

김근조,박흥기,권혁수,배수찬 대한정형물리치료학회 2001 대한정형도수물리치료학회지 Vol.7 No.1

This research have been made to define how the IADL (Instrumental Activity of Daily Living) performance and the subjective health index of the Aged are affected by their residential circumstance, gender and age, and how deeply these two factors are related and interact. For the period of June 1 to July 31, 2000, we had conducted a questionnaire and direct interview with 693 persons over age sixty-five (65) in Daejon and in other adjacent area, grouping into three different residential types The Aged living at home, The Aged living at welfare facilities and The Aged living alone, and studied on how the IADL performance and the subjective health index of the Aged are influenced and interact as per their characteristics, daily activity and mentality. We had analyzed all the data obtained through this research by the method of : - analysis of frequency as per specific factors by SPSS 10.0/PC+, - x^2 test, - t - test, - ANOVA, - multiple regression analysis by factors. The research concludes followings : a. It appears that the three (3) factors such as gender, age and residential circumstance of the Aged deeply affect the IADL performance and subjective health index of the Aged. (p<0.01) b. With regard to IADL performance of the Aged by the gender, it was analyzed that the female-Aged gains 23.8 point on average, which shows the performance of the female-Aged is less independent. (p<0.01). In addition, it was also found that the IADL performance is becoming less and less independent following their age increasing. In analyzing IADL performance by the residential type, it appears that the Aged living at welfare facilities gains the lowest 21.5 points and is least independent. It was also found that the Aged living at welfare facilities need some assistances from others for their performing IADL. (20-24 point) (p<0.001) c. With regard to the subjective health index of the all-Aged participated in this research, the analysis indicates 8.8 point and this is considered as a point of general standard (7-10 point). In analyzing this index by the gender, the female-Aged gains only 8.6 point which explains a lot of female-Aged consider they are not really healthy. (p<0.001) In analyzing this index by the residential type, the Aged living at welfare facilities and the Aged living alone gain the comparatively lower point, - respectively 8.4 point for the Aged living at welfare facilities and 8.8 point for the Aged living alone. The Aged living at these two residential types express they are obviously in a bad situation of health. (p<0.001) d. With regard to the factors affecting the IADL performance and the subjective health index of the Aged, it was analyzed that the IADL performance can largely be affected by the factors such as depression, frequency of going-out and age rising, and that the subject health index can also deeply be affected by depression, pain and by how much they are satisfied with their current living conditions. e. It was analyzed that the interacting between the IADL performance and the subjective health index is not that strong but even weak. As a result, we were able to conclude that the IADL performances is less independent in case of the female-Aged, the Aged living at welfare facilities, and following the age rising. As for the subjective health state the Aged themselves are aware of, we concluded that the female-Aged, the Aged living at welfare facilities and the Aged living alone, are more critical about their health. From this research, we were able to realize that, when the OMT (Orthopedic Manual Therapy) needed, the physical therapists are really required to have a correct and cautious understanding of the situation in which the aged persons are, and take care of them with more concerns and more improved treatment.

구속된 고강도 콘크리트 기둥의 휨 거동에 관한 실험적 연구

양근혁,이영호,곽노현,정헌수 중앙대학교 기술과학연구소 1998 기술과학연구소 논문집 Vol.28 No.-

본 실험적 연구의 목적은 콘크리트 강도, 띠근 배근형태, 띠근 량, 축하중비가 축하증과 횡하증을 받는 구속된 콘크리트 기둥의 휨 내력과 연성에 미치는 영향을 팡가하기 위한 것이다. 구속된 기둥의 휨 거동을 시험하기 위하여 200×200×800mm 크기의 시험체 14개를 2축 하중하에서 실험하였다. 시험결과로서, 저축력에서 콘크리트 구속으로 인한 휨 강도의 증가는 비교적 작게 있지만, 고축력에서 콘크리트 구속으로 인한 휨 강도 증가는 크게 있다. 그리고, 고축력, 고강도 콘크리트에서 내부 cross-ties가 있으면 휨 연성의 증가가 보였으며, 구속된 콘크리트 기둥의 연성은 단순한 띠근 량보다는 구속지수에 관계되었다. The purpose of this experimental study was to investigate the effects of concrete strength, the configuration of lateral ties, the amount of lateral ties, and level of axial loads on flexural strength and ductility of confined of reinforced concrete columns subjected to combined axial and lateral loads. To simulate the flexural behavior of confined columns, fourteen reinforced concrete columns, 200×200×800mm, were tested under bi-axial loads. Test results indicate that for low axial load levels, the enhancement of the flexural strength due to concrete confinement is relatively small, but that for high axial load levels, the enhancement of the flexural strength due to concrete confinement can be very high. Considerable enhancement of ductility was observed in columns confined by cross-ties, even for high strength concrete columns and under high axial loads. Ductility of confined columns are found to be more related to confinement index (ρ??f??/??) than the amount of lateral ties(ρ??)

구조용 데크플레이트를 사용한 연속 합성슬래브 부모멘트 영역의 균열거동

양근혁,고영우,정헌수 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.1

The objective of this study W3" to evaluate the flexural cracking behavior in the negative moment region of continuous composite slabs reinforced with structural steel decking Main experimental variables were slab thickness and top bar ratio The slabs were tested in 2 continuous span with fixed-ends to get easy access to the negative moment region Also, Based on the distribution of interfacial bond stresses along a segment between two adjacent cracks was assumed as sin function, a simple method for predicting the spacing and width of cracks was suggested Results showed that crack spacing and width m the negative moment region of composite slabs depend mainly on the top bar ratio rather than slab thickness The predictions obtained from the proposed method arc m good agreement With experimental results

구조용 데크플레이트를 사용한 연속 합성슬래브 시스템의 모멘트 재분배 및 소성회전능력

정헌수,은희창,양근혁 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.2

The objective of this study is to evaluate the moment redistribution and plastic rotation of continuous one-way composite slabs reinforced with structural steel decking. A total of 8 two-span continuous slabs with fixed-ends were tested and compared with limit analysis approaches. Theoretical moment capacity and curvature for section subjected to positive or negative moment were calculated by section laminae method. Test results showed that flexural behavior and rotation were greatly influenced by the amount of top bar in negative moment region. Also, the welded wire fabric used as top bar in negative moment region could result in decreasing total load capacity of slabs due to impairing moment redistribution. The predictions, maximum load and plastic rotation capacity, obtained from proposed analysis method were in good agreement with the test results.