Earticle

본 연구의 목적은 겹침이음된 GFRP 보강근과 이형철근이 2단으로 배근된 휨부재의 구조적 거동특성을 파악하는 것이다. GFRP 보강근은 부식성, 경량, 전도등과 같은 많은 재료적인 장점을 가지고 있다. 그러나 GFRP 보강근은 항복점 없이 취성파괴로 인해 철근대용으로 사용하기가 쉽지 않다. 이형철근과 GFRP 보강근을 혼용한 휨 부재는 두 보강재료의 장점으로 인하여 우수한 구조적 성능을 보일 것으로 판단된다. 이형철근과 GFRP 보강근을 혼용한 휨부재의 구조적 거동을 파악하기 위하여 겹침이음길이와 보강근양을 주요변수로 하여 5개의 실험체를 계획하였다. 실험결과로서 첫째, 이형철근과 GFRP 보강근을 혼용한 모든 실험체는 이중선형거동을 보였다. 첫 번째 선형구간은 이형철근과 GFRP 보강근의 탄성에 의해 나타난 것이고, 두 번째 선형 구간은 GFRP 보강근의 탄성구간과 이형철근의 항복구간에 의해 나타난 것이다. 둘째 겹침이음된 GFRP 보강근이 파괴된 이후 2단에 배근된 철근이 하중을 부담함으로써 연성거동을 유지하여 결과적으로 GFRP 보강근과 이형철근을 사용한 부재가 이형철근만 배근된 RC 부재에 비해 우수한 성능을 보여주었다.

The objective of the present study is to understand the characteristics of the structural behavior of flexural members with lap-spliced glass fiber-reinforced polymer (GFRP) bars at upper layer and deformed steel bars at lower layer. A GFRP bar has many advantages such as corrosiveness, light weight, and conduction. However, it is not easy to use GFRP bars instead of steel reinforcement due to brittle failure of GFRP bars. In this study, deformed bars and GFRP bars are used together for the advantages of the both materials, such as corrosion prevention and ductile behavior. It is expected that the flexural member with both GFRP and deformed bars shows good structural performance due to the aforementioned advantages of each reinforcement. Five specimens were tested to investigate the structural behavior of the members with the two different reinforcements. The main variables were lap splice length and amount of reinforcement. As a result of the experiment, all specimens with GFRP and deformed bars indicated bi-linear behavior, where the first linear part was due to the elastic portion of both reinforcements and the second one was caused by steel yielding and the elastic portion of GFRP bars. In addition, after GFRP bars failed, deformed bars at the lower layer contributed to the ductility of the specimen. Therefore, it was found that using both GFRP bars and deformed bars significantly improved structural performance when compared with reinforced concrete members with steel bars only.

최근 들어 친환경 건축물의 관심이 고조되면서 목조 주택의 신축허가가 꾸준히 증가하는 추세에 있다. 이에 따라, 국내외 연구자들은 균질한 구조용 목재에 관한 기술개발을 진행하고 있으며, 구조용 목재를 활용한 구조물의 부재 내력향상을 위한 목구조 접합부에 과한 많은 연구가 진행되고 있다. 현재, 목조 접합부에 관한 기술은 결합철물을 이용한 방식이 일반적이며 결합철물과 볼트, 드리프트 핀을 이용한 결합 방법은 목재의 강도 차이로 인해 목재의 섬유방향 시공 시에 할렬단이 일어나며 이는 취성파괴로 이어져 접합부의 강도를 감소시키는 원인으로 작용 할 수 있다. 그리고, 철물은 수분에 노출되면 부식되어 내구성이 약해지며, 구조물의 미관을 해치게 되어 목조 구조물이 가지는 미관의 아름다움을 해치는 문제점을 가지고 있다. 이에따라, 목조 접합부에 적용 할 수 있는 새로운 보강재 및 보강공법이 필요하다고 사료된다. 최근 국내외에서는 건축 및 토목 구조물의 보수보강 공법으로 모재보다 가볍고, 자중대비 높은 강도와 내식성 등이 우수한 성질을 가지고 있는 섬유보강재(Fiber- Reinforcement)를 적용하는 사례가 늘어나고 있다. 그 중에서 유리섬유시트(Glass Fiber Sheet)는 우수한 역학적 물성과 저 단가를 갖는 재료이고, 여러 형태로 변형적용이 가능한 유용한 보강재라고 볼 수 있다. 본 연구의 진행은 첫 번째로, 유리섬유시트와 탄소강으로 이루어진 보강재(이하, 복합 보강재)를 제작하여 목조접합부에 적용 가능성을 검토하였다. 두 번째, 복합 보강재로 보강된 목조접합부의 구조적 성능평가를 위하여 무보강 실험체, 유리섬유시트 보강재와 탄소강 보강재로 보강된 실험체군으로 총 7개의 실험체를 제작하여 반복하중에 따른 각 실험체별 하중과 변위의 관계를 분석하였다. 그리고, 실험체의 최대 강도, 파괴양상, 연성능력 및 강성을 실시하였다.

This is a study about a strengthened material for wooden joint section. Although carbon steel is mainly used for wooden joint section, but this material has the weakness of corrosion. In order to improve this problem , this study intended to use the glass-fiber sheet, a kind of fiber-reinforced sheet which is an alternative material replacing the carbon steel as the strengthened material. As the glass-fiber sheet has a strong brittleness attribute, so this study produced a new complex material utilizing the glass-fiber sheet in order to complement this problematic attribute and the carbon steel and conducted an experiment with the new complex material as the strengthened material for wooden joint section. For this experiment, total 7 specimens being made of non-reinforced steel, carbon steel, complex-material and glass fiber sheets were produced with setting the reinforced material’ thickness changes as the variable, and the experiment was conducted. From the results of experiment, it is judged that the complex strengthened material for wooden joint section being proposed in this study generated some effective effect.

This is an experimental study on the structural behavior of reinforced concrete beams using of the oyster shells as a substitute fine aggregate of concrete. In this study, the main factors consist of the grain sizes, the percentage of substitution of oyster shells to fine aggregate and the water cement ratio in the same size beams. The results of the study showed as followed. The initial load value of them represented similar constant within 10% of the maximum load value in each test beam. But the maximum load value and the ultimate load value decreased with increased grain size and the rate of substitution. As the grain size of oyster shells became smaller, the load values of them were somewhat higher. The deflection of reinforced concrete beams with oyster shells represented typical curve like that of normal reinforced concrete beam. In the deformation of the steel and concrete, the deformation was proportionated to the load until the yield point and after the yield point it was approached the ultimate load point.: One type was typical curve of the load and the deformation and the other type irregularly was changed to very small deformation with the load increase centering around load axis. It also has proved the good coincidence between the results of the experiment and them of the theory. After analyzing the structural behavior about the above mentioned test beams, the most excellent grain size of oyster shells represented 5.0mm and less with taking the uniform quantity, and the percentage of practicable substitution of them to fine aggregate was about 30% in other to make superior reinforced concrete beams containing oyster shells.

중공 부재는 자중, 경제적, 그리고 환경적인 측면에서 만흥 장점을 자지고 있고, GFRP 보강근은 비부식성과 강도대비 높은 강도를 가지고 있다. 따라서 본 연구의 목적은 GFRP 보강근으로 배근된 중공 빔의 휨 거동을 파악하기 위한 것이며, 또한 GFRP 중공 빔의 구조적 거동을 평가하고 이론적인 휨 내력식을 제안하기 위한 것이다. 본 연구에 제안된 휨 내력식은 ACI 440.1R-06에 제시된 이론식을 바탕으로 하여 수정된 것이다. 이러한 연구목표를 달성하기 위하여 보강근비, 중공비, 그리고 이형철근의 유무 등을 변수로 하여 6개의 실험체를 제작하고 실험을 수행하였다. 실험 결과, GFRP 보강근과 이형철근을 혼용하여 사용된 실험체의 휨 성능이 GFRP 보강근만 배근된 실험체에 비해 매우 우수하게 나타났으며, 제안된 휨 내력식에 의한 예측값이 실험값과 매우 유사한 결과를 보여주었다.

Hollow flexural members such as slabs and beams have many advantages in terms of weight, economy, and environment. Glass fiber reinforced polymer (GFRP) reinforcement has attracted designers due to its corrosion resistance and high strength-to-weight ratio. Therefore, the objectives of this study are to evaluate structural behavior of hollow beams with GFRP reinforcing bars and to propose theoretical equations for predicting flexural strength of such hollow beams. The proposed equations were derived through modification of existing ones suggested by ACI 440.1R-06. To achieve the goals, six beam specimens were manufactured and examined with variables such as hollow ratio, GFRP reinforcement ratio, and presence of deformed steel rebar. The test results showed that using both GFRP and steel reinforcements was more effective than GFRP reinforcements only from the standpoint of stiffness and strength. In addition, the estimated results using the proposed equations were in good agreement with the experimental ones.

Purpose: The purpose of this study was to explain the health promotion behavior of Chinese international students in Korea using a structural equation model including acculturation factors. Method: A survey using self-administered questionnaires was employed. Data were collected from 272 Chinese students who have resided in Korea for longer than 6 months. The data were analyzed using structural equation modeling. Results: The p value of final model is .31. The fitness parameters of the final model such as goodness of fit index, adjusted goodness of fit index, normed fit index, non-normed fit index, and comparative fit index were more than .95. Root mean square of residual and root mean square error of approximation also met the criteria. Self-esteem, perceived health status, acculturative stress and acculturation level had direct effects on health promotion behavior of the participants and the model explained 30.0% of variance. Conlcusions: The Chinese students in Korea with higher self-esteem, perceived health status, acculturation level, and lower acculturative stress reported higher health promotion behavior. The findings can be applied to develop health promotion strategies for this population.

본 연구는 베트남 소비자의 그린구매행동에 관한 구조적 모형과 구매능력이 가지는 조절효과를 중점적으로 살펴본 연구이다. 베트남의 중산층 인구는 2012년 12백만 명에서 2020년에는 33백만 명으로 증가할 것으로 예상되고 이에 따른 소비패턴 변화가 예상되고 있으며, 최근 산업화와 내구재 소비증가로 인해 환경문제에 대한 관심이 증가하고 있다(Koning et al., 2016). 이에 따라 그린 제품구매 관련 문헌고찰을 통해 베트남 소비자들의 그린 구매행동 관련 가설 및 모형을 제시하고 실증 자료를 통해 가설을 검증하였다. 연구모형을 검증하기 전에 측정문항의 신뢰성과 타당성분석을 실시하였으며 연구변수간 선․후행 관계검증을 위해 구조방정식 모형분석을 실시하였고 구매능력의 조절효과검증은 개별모수 차이검증을 통해 실시되었다. 실증분석결과는 다음과 같다. 먼저 생태적 관심과 집단주의는 그린구매행동에 관한 태도에 긍정적인 영향을 미치는 것으로 나타났으나 생태적 지식은 유의한 영향을 미치지 않았다. 둘째, 그린구매행동에 대한 태도는 그린구매행동의도에, 그린구매행동의도는 그린구매행동에 유의한 영향을 미치는 것으로 나타나 계층적 효과모형과 일관된 결과를 보여주었다. 셋째, 구매능력은 구매의도와 실제 구매행동 간의 관계를 조절하는 것으로 나타났다. 이러한 연구결과에 기반하여 이론적, 실무적 시사점을 제시하였다.

This research suggests a structural model of green purchase behavior, focusing on the moderating effect of affordability. Affordability means buying power or ability to buy products. Based on the literature review, a research model of behavior of buying green products was proposed and tested empirically using the field study. To examine the proposed research model, the reliability and validity verifications on measurement items were carried out and then the structural equation model analysis was applied to test the model. Lastly, to test the moderating effect of affordability, a two-group model(using Amos program) was used subsequently so that it could be determined whether or not there was any significant difference in structural parameters between the high affordability group and the low affordability group. The empirical results are as follow: Firstly, green purchase attitude is influenced by ecological concern and collectivism, then green purchase attitude has an impact on green purchase intention, and in turn, green purchase intention affects green purchase behavior. Secondly, affordability significantly moderates the relationship between green purchase intention and green purchase behavior. These results are consistent with the past researches and based on them, some managerial implications are given.

This study focuses on importance of perceptions of election polls published by mass media and their effects on the support for election poll censorship. Two hypothetical models using SEM technique are tested against survey data from a sample of 422 residents of Ulsan metropolitan city in S. Korea. One model predicts that the biased media perception affects the support for censorship through mediating third person effect and sincere vote, while the other model predicts that horse race reporting affects the support for censorship through mediating third person effect and strategic vote. Two models fit well with the data. In both models the third person effects were found to play key roles in the mediation processes. We discussed several unexpected findings from the data analysis and their implications for the Korean Election Act, Article 108 by which the media publication of election poll results is prohibited during the last 6 days before the election date.

본 연구는 미취학 아동 어머니의 양육행동에 영향을 미치는 요인을 확인하고 이들 요인들 간의 직 · 간접적 관계와 영향력을 검정함으로써 부정적 양육행동을 예방하고 바람직한 양육행동을 증진하기 위한 간호중재개발에 대한 기초자료를 제공하고자 수행되었다. 본 연구의 가설적 모형은 양육스트레스, 부모역할만족도,양육효능감, 양육행동 4개의 변수를 주요개념으로 제시하였다. 또한 양육행동에 영향을 미치는 조절요인으로 아동 관련변인(성별, 연령), 모성 관련변인(연령, 교육수준, 취업여부, 완벽주의), 가정 관련변인(가족월수입)을 포함하여 이러한 개념들과 4개의 주요개념들 간의 상호작용을 토대로 양육행동을 설명하는 가설적 모형을 구축하였다. 그 결과 미취학 아동 어머니의 양육행동에 대한 변수들의 영향력을 살펴보면 양육효능감과 양육스트레스는 양육행동을 12.5% 설명하였고 그 중 양육효능감의 영향력이 가장 컸고 양육스트레스는 양육효능감을 매개로 하여 양육행동에 간접적인 영향을 미치는 것으로 나타났다. 그 밖에 양육행동 관련 변수들이 양육행동에 영향을 미칠 때 모성 관련변인 중 자기 지향적 완벽성과 가정 관련변인 중 가족월수입에 따라 차이가 있는 것으로 나타났다. 결론적으로 미취학 아동 어머니의 양육행동에 영향하는 주요 변인은 양육효눙감임이 확인되었고 양육스트레스, 어머니의 자기 지향적 완벽성, 가족월수입도 고려해야 할 영향변인임이 확인되었다. 이러한 결과는 양육효능감 증진과 양육스트레스 감소 뿐 아니라 어머니의 성격적 특성과 현실적인 보육료 부담을 고려한 양육프로그램이 미취학 아동 어머니의 긍정적인 양육행동을 증진시키기 위한 효과적인 간호중재 방안으로 활용될 수 있음을 나타낸다.

Purpose: This study was done to build and test a theoretical model that could be used to explain and predict parenting behavior of mothers with preschool children. Methods: The participants were 298 mothers with preschool children. Data were analyzed using the SAS (Statistical Analysis System) and AMOS (Analysis of Moment Structures) programs. Results: Parenting stress showed a direct effect on parenting satisfaction. Parenting efficacy showed a direct effect on parenting behavior. Parenting stress showed an indirect effect on parenting behavior. Parenting efficacy was found to mediate the relationship between parenting stress and parenting behavior. Income and mother’s perfectionism had an impact on parenting behavior. Conclusion: The outcomes of this study indicate the necessity of designing intervention programs that emphasize increasing parenting efficacy in order to increase positive parenting behavior.

Purpose: This study was conducted to verify model for predicting health promotion behavior and the health status of child care teachers based on Pender's health promotion model and Dahlgren and Whitehead's health determinants model. Methods: The data was collected from January to February 2018 from 205 child care teachers in day care centers in Seoul. Results: This model was suitable to explain the health status and health promotion behavior of child care teachers. In this study, health promotion behavior had the most direct affect on the health status of child care teachers. Health promotion behavior was directly affected by social support, self-efficacy, and depression. Job stress had an indirect affect on health promotion behavior. Conclusion: Considering the factors identified in this study that influence the health promotion behavior of child care teachers, we propose the development of interventions to improve the health status of child care teachers.

Purpose: The purpose of this study was to construct and test a hypothetical model of exercise behavior in patients with Heart Failure (HF) based on the Information-Motivation-Behavioral skills (IMB) model, and the IMB model including depression (IMBD). Methods: Data collection was conducted from February 1 to March 15, 2019. A total of 306 patients who were diagnosed with HF and were receiving outpatient treatment at the D University hospital and S hospital located in B city were included in the final analysis. The collected data were analyzed using SPSS 24.0 and AMOS 25.0 program. Results: The IMB model (x 2 /df=2.45, SRMR=.07, RMSEA=.07, GFI=.98, AGFI=.94, TLI=.93, CFI=.97) and IMBD model (x 2 /df=0.79, SRMR=.02, RMSEA=.003, GFI=.99, AGFI=.97, TLI=.98, CFI=.97) were a good fit for the data. In the exercise behavior IMB model, exercise behavior was explained by 55.1% by information, personal motivation, and behavioral skills. In the exercise behavior IMBD model, exercise behavior was explained by 60.4% by information, personal motivation, behavioral skills, and depression. Conclusion: The IMBD model showed high predictive power of exercise behavior. Therefore, in order to improve HF patients’ exercise behavior, it is necessary to identify and manage patients who experience depression. The development and application of integrated interventions to provide appropriate information, motivation, and confidence in exercise can be an effective strategy in increasing exercise compliance, and ultimately contribute to improving the health outcomes of patients with HF.

Purpose: This study was conducted to construct and test a hypothetical model for alcohol abstinence behavior of patients with chronic liver diseases (CLD). The model was based on the theory of planned behavior. Methods: Participants consisted of 240 adult patients with CLD who had regular visits to Busan medical center and Kyungsang universisty hospital from February 12 to March 14, 2014. Data were collected using self-report questionnaires. Collected data were analyzed using SPSS 18.0, AMOS 21.0 programs. Results: The modified model was a good fit for the data. The model fit indices were x2/df=1.78, GFI=.86, AGFI=.90, RMR=.08, RMSEA=.05, NFI=.88, TLI=.92, CFI=.87, PNFI=.70. Alcohol abstinence intention (β=.56) had significant direct effects on alcohol abstinence behavior in patients with CLD. This variable explained 32% of the variance in alcohol abstinence behavior. Attitude (β=.47), perceived behavioral control (β=.41) and subjective norms (β=.25) had direct effects on alcohol abstinence intention. These variables explained 46% of the variance in alcohol abstinence intention. Conclusion: Findings suggest that the intention of alcohol abstinence is important for patients with CLD to engage in alcohol abstinence behavior. It provides the basis for developing an intervention program to induce alcohol abstinence in patients with CLD.

The purpose of this study was to test hand hygiene behavior model of hospital nurses, based on theory of planned behavior. Methods: Data were collected from 253 nurses from four university hospitals for the period of December 2010 to January 2011. Data were analyzed using of SAS (ver.9.1). Fitness of the study model was identified with SAS PROC CALIS. Results: The overall fitness was x2=57.81 (df=13, p<.001), GFI=.99,AGFI=.99, CFI=.95, NFI=.93. The variance of actual implementation of hand hygiene by predictor variables was 11.0% and the variance of intention to hand hygiene was 53.5%. Variable that had a direct effect on hand hygiene behavior was intention. Perceived behavior control and attitude affected hand hygiene behavior indirectly. Control belief had a direct effect on perceived behavior control and had an indirect effect on intention and behavior. Behavioral belief had a direct effect on attitude and an indirect effect on intention and behavior. Conclusion: The study provides basic information for understanding nurses’ hand hygiene behavior. Further testing of the model will indicate which variables can contribute to improved hand hygiene.

Purpose: The purpose of this study was to explain fall prevention behaviors of community-dwelling elderly with osteoarthritis based on the Health Belief Model. Methods: A total of 200 older adults with osteoarthritis residing in community was recruited from July 10 to August 30, 2013. The direct and indirect effects of perceived fall risk, perceived benefits and barriers, and self efficacy of fall prevention were examined on fall prevention behaviors. Data were collected with structured questionnaires and analyzed using SPSS/WIN 20.0 and AMOS 20.0 program. Results: The hypothetical model was a good fit for the data based on the model fit indices. Among socio-demographic variables, age and fall knowledge showed significant direct effects on fall prevention behaviors. The constructed model explained 34.2% of the variance of fall prevention behaviors, including perceived fall risk and efficacy of fall prevention behaviors as significant predictors. Conclusion: The findings revealed the need to develop an effective nursing intervention to promote fall prevention behaviors of community-dwelling elderly with osteoarthritis by focusing on perceived fall risk and efficacy of fall prevention behaviors. Knowledge about fall can also be increased by an age-based education program.

본 연구는 부모양육태도와 청소년기 문제행동의 관계에서 자아탄력성 및 공감능력 관련 변인간의 구조모형을 확인하기 위해 구조방정식 분석을 진행하였다. 부모양육태도, 자아탄력성, 공감능력을 주요 변인으로 변인들 간의 직·간접 효과를 분석하여 매개효과를 확인하였다. 자료는 서울, 경기, 전남 지역의 고등학생 512명을 대상으로 자기보고식 설문지를 통해 수집하였다. 그 결과 첫째, 부모양육태도는 자아탄력성과 공감능력, 문제행동에 각각 직접효과가 있었고, 자아탄력성은 공감능력과 문제행동에, 그리고 공감능력은 문제행동에만 직접효과가 확인되었다. 둘째, 부모양육태도는 자아탄력성과 공감능력 둘 다 매개하여 문제행동에 간접효과가 확인된 반면 자아탄력성은 공감능력을 매개로 문제행동에 간접효과는 없었다. 이러한 결과 모든 변인들이 청소년기 문제행동 감소를 위해 중요하다는 것을 관계구조모형을 통해 확인 하였다.

This study conducted a structural equation analysis to confirm the structural model for variables related to problem behavior in adolescents. The mediating effect was confirmed by analyzing the direct/indirect effect among the following main variables: setting the parental attitude, ego resiliency, and empathic ability. Data was collected through a self-report questionnaire targeting 512 high school students in Seoul, Gyeonggi, and Jeonnam. As a result, first, the parental attitude had a direct effect on ego resiliency, empathic ability, and problem behavior. Second, ego resiliency had a direct effect on empathic ability and problem behavior. Third, empathic ability directly affected problem behavior. Fourth, parental attitude indirectly influenced problem behavior by mediating both ego resiliency and empathic ability. Fifth, ego resiliency did not indirectly affect problem behavior via empathic ability. Although no indirect effect was revealed, this study confirmed that ego resiliency has a direct effect on problem behavior via empathic ability, confirming the relation structure model that all variables are important in reducing problem behaviors adolescents.

최근들어 싱크홀과 같은 지반의 국부적인 침하가 빈번히 발생하고 있다. 매립 배관 시스템은 국부적인 지반침하와 같은 대변 형에 의해 피해를 입을 수 있다. 벨로우즈 신축이음관은 높은 변위 순응력을 갖으며 대변형에 의한 매립 배관의 손상을 효과적 으로 저감시킬 수 있다. 그러나 배관 시스템이 매립된 지반의 기계적 특성은 지반 침하에 따른 매립 배관 시스템의 구조적 거동 에 영향을 미칠 수 있다. 따라서 본 연구는 지반-배관 시스템 상호작용을 고려한 유한요소 모델을 구축하였으며 사질토 및 점토 의 재료특성에 따른 배관 시스템의 구조적 거동을 비교하였다.

구조물에 복합재료를 사용한 보강과 복구에 대한 사용이 증가하고 있는 상황에서 갑작 스러운 강도저하로 발생되는 재난을 피하기 위하여 임시 보강하고자 탄소섬유 판을 이용 하여 기존금속재와 접합(접착방식)을 통한 강도증진효과를 연구하였다. 특히 실험을 통 하여 강-탄소섬유보강재로 이루어진 복합 재 거동을 파악하였으며 여기에 적절한 시험을 위한 새로운 형태의 시험편을 제작하였다. 접합재로 레진을 접착하는 부착 면을 달리하 여 거동을 비교하기 위하여 표면처리가 다른 시험편을 각각 고려하여 시험한 결과 강성 보강효과는 물론 일체거동의 특성이 잘 나타남을 알 수 있었다.

The use of advanced composite materials in strengthening and repair of existing structures is increasing rapidly. This paper describes an effectiveness of a bonding of carbon fiber reinforced sheets to corroded steel members for the repair. Three types of surface treatment, what we call cleaning, of corroded plate are chosen as parameters. They are “without cleaning”,“removal of painting by brushing” and “complete removal of painting”. From the experimental study, the following findings are obtained. 1) When the steel plate is subjected to tensile force, carbon fiber sheets adhered to the painted steel gives a higher strength against peeling compared to that of the plate without painting, 2) The grade of surface treatment, or cleaning of the corroded steel plate affects the strengthening effect.

The arched ancient tomb structures have occupied the most parts among the Korean ancient tomb types. It is important to analyze the structural behavior characteristics of composed members due to the upper loads and soil pressures for the preservation of these structures. But, it is not easy to find out exactly the internal structural shape such as the corved soil thickness and side wall width. Therefore, this study selects the representative ancient tomb model and presents the modified structural model, and then performs the discrete element analysis according to the various design variables. Also, this study evaluates the structural behavior characteristics of the arched ancient tomb structures through the analysis results.

지반 침하와 같은 지반 대변형은 매설배관 시스템에 심각한 손상을 야기할 수 있다. 특히, 지반의 대변형으로 인해 매설 배관 사이의 연결부 혹은 구조물과 배관의 연결부에 손상이 집중된다. 따라서 큰 변위용량을 갖는 연결부를 적용하여 대변형으로 인한 매설 배관 시스템의 손상은 저감될 수 있다. 본 연구는 기하학적 특성으로 인하 큰 변위용량을 갖는 벨로우즈 신축이음관 의 단조 휨 성능을 평가하기 위한 실험적 연구를 수행하였으며 실험 데이터를 기반으로 유한요소 모델을 구축하였다. 단조 휨 하중을 받는 200A 벨로우즈 신축이음관은 약 425mm의 변위에서 누출이 발생하였으며 131kN의 하중이 발생하였다. 유한요 소 해석에서 425mm의 변위에서 하중은 140kN으로 나타났다. 실험 및 해석결과 사이의 일부 오차는 세 겹으로 적층된 강판 사이의 접촉거동에 기인한 것으로 판단된다. 추후연구에서 구축된 유한요소 모델을 이용하여 반복하중을 받는 벨로우즈 신축 이음관의 구조적 거동을 분석하고자 한다.

본 연구에서는 프리스트레스트 강합성 거더의 콘크리트 케이싱 분절부 상세에 따른 연결부 성능 평가를 위해 각각 다른 분절부를 가진 실험체를 제작하여 실험하였다. 분절부가 없는 일반 강합성 거더와 분절부에 이음철근 보강 유무 및 이음철근 상세를 변수로 하는 총 4본의 비교 실험체를 제작하여 구조적 거동 평가하였다. 또한, 분절형 강합성 거더의 비균열등급 설계 가능 여부 및 균열발생 후 루프철근 상세에 따른 강성과 강도 영향에 대해 분석하고, 매립강판면과 타설접합면에 따른 균열폭 제어 적정성을 평가하였다.

This study was evaluated in the performance of the connection according to the details of the concrete casing segment in the prestressed composite girder by fabricating and testing specimens with different segments. A total of four comparative specimens were fabricated by using the variables of general composite girders, reinforcement or non-reinforcement, and details of reinforcing bars in the segments so as to evaluate the structural behavior of steel girders. In addition, the possibility of non-cracking grade design of segmented composite girders as well as the effects of stiffness and strength according to the loop connection types after cracking were analyzed, and the appropriateness of the crack width control both the embedded steel plate and the concrete surface were evaluated.