• Steel and Composite Structures
• /
• 제33권6호
• /
• pp.877-889
• /
• 2019

The developments of double skin composite (DSC) walls with novel enhanced C-channel connectors (DSCW-EC) were reported. Followed axial compression tests on prototype walls were carried to evaluate structural performances of this novel DSC composite structures. The testing program consists of five specimens and focused on the layout of the novel enhanced C-channel (EC) connectors, which include the web direction of C-channels, steel-faceplate thickness, vertical and horizontal spacing of C-channels. Crushing in concrete core and buckling of steel faceplate were two main observed failed modes from the compression tests. However, elastic or plastic buckling of the steel faceplate varies with designed parameters in different specimens. The influences of those investigated parameters on axial compressive behaviors of DSCW-ECs were analyzed and discussed. Recommendations on the layout of novel EC connectors were then given based on these test results and discussions. This paper also developed analytical models for predictions on ultimate compressive resistance of DSCW-ECs. Validation against the reported test results show that the developed theoretical models predict well the ultimate compressive resistance of DSCW-ECs.

• 한국터널지하공간학회 논문집
• /
• 제4권2호
• /
• pp.91-100
• /
• 2002

본 논문에서는 수평보강재로 보강된 터널막장의 거동에 관한 내용을 다루었다. 터널막장 보강공법에 있어서 보강조건이 막장의 수평변위 및 지표침하에 미치는 영향을 고찰하기 위해 축소 모형실험을 수행하였다. 실험결과 수평보강재로 터널막장을 보강할 경우 막장의 변위 및 지표침하가 현저히 감소하는 것으로 나타나 도심지 터널시공에 있어서 지반거동 억제를 위한 보조 공법으로서 효과적으로 적용될 수 있는 것으로 나타났다. 아울러 지반거동 억제 효과는 보강조건에 따라 현저히 차이를 보이는 것으로 나타났다. 본 고에서는 연구결과를 종합하여 실무 적용시 주안점을 고찰하였다.

• Structural Engineering and Mechanics
• /
• 제6권3호
• /
• pp.305-325
• /
• 1998

A method that determines the minimum stiffness of baracing to achieve non-sway buckling conditions at a given story level of a multi-column elastic frame is proposed. Condensed equations that evaluate the required minimum stiffness of the lateral and torsional bracing are derived using the classical stability functions. The proposed method is applicable to elastic framed structures with rigid, semirigid, and simple connections. It is shown that the minimum stiffness of the bracing required by a multi-column system depends on: 1) the plan layout of the columns; 2) the variation in height and cross sectional properties among the columns; 3) the applied axial load pattern on the columns; 4) the lack of symmetry in the loading pattern, column layout, column sizes and heights that cause torsion-sway and its effects on the flexural bucking capacity; and 5) the flexural and torsional end restrains of the columns. The proposed method is limited to elastic framed structures with columns of doubly symmetrical cross section with their principal axes parallel to the global axes. However, it can be applied to inelastic structures when the nonlinear behavior is concentrated at the end connections. The effects of axial deformations in beams and columns are neglected. Three examples are presented in detail to show the effectiveness of the proposed method.

• Smart Structures and Systems
• /
• 제17권4호
• /
• pp.541-557
• /
• 2016

Prefabricated bridge substructures provide new possibility for designers in terms of efficiency of creativity, fast construction, geometry control and cost. Even though prefabricated bridge columns are widely adopted as a substructure system in the bridge construction project recently, lack of deeper understanding of the seismic behavior of prefabricated bridge substructures cause much concern on their performance in high seismic zones. In this paper, experimental research works are presented to verify enhanced design concepts of prefabricated bridge piers. Integration of precast segments was done with continuity of axial prestressing tendons and mild reinforcing bars throughout the construction joints. Cyclic tests were conducted to investigate the effects of the design parameters on seismic performance. An analytical method for moment-curvature analysis of prefabricated bridge columns is conducted in this study. The method is validated through comparison with experimental results and the fiber model analysis. A parametric study is conducted to observe the seismic behavior of prefabricated bridge columns using the analytical study based on strain compatibility method. The effects of continuity of axial steel and tendon, and initial prestressing level on the load-displacement response characteristics, i.e., the strain of axial mild steels and posttensioned tendon at fracture and concrete crushing strain at the extreme compression fiber are investigated. The analytical study shows the layout of axial mild steels and posttensioned tendons in this experiment is the optimized arrangement for seismic performance.

• 건축역사연구
• /
• 제21권1호
• /
• pp.83-98
• /
• 2012

The starting point of this study is the concerning of simple behavioral pattern that whoever enters the inner space with taking off his shoes should go out from the position where he laid his shoes. The using of Ondol (floor heating room) and Maru (lifted wood floor) had changed the architectural space from chair-sitting to floor-sitting space, and it also made the behavior of taking off the shoes at the entrance of building and stepping on the lifted floor. This simple behavior has possibility to make lots of changes to the culture of architectural design. With this noticeable point, this paper is talking about the cultural feature of Korean traditional architecture, especially about the influence of tanking off and putting on shoes. The matter of shoes has changed diverse aspects of building and layout planning. It maximized the difference between front and rear part of building and characterized the lateral extension of Korean traditional house. The ritual space also had evolved from chair-sitting to floor-sitting space according to the type of ritual behavioral pattern. The change on the single building level had influenced on the layout planning of architectural complex. For examples, the parallel layout of ChangDeok-gung palace and the long sequential process to the main pavilion of Buddhist temple are the result of the matter of shoes. And NuGak(樓閣), the double-storied pavilion, on the axis of entering sequence's node is one of the unique planning elements that makes possible to go through the building without taking off the shoes and also makes upper level space for staying. In short, Korean traditional architecture that has the chair-sitting spatial origin of the East Asian cultural sphere has pursued new architectural issues and planning methods according to evolution to the floor-sitting culture.

• 한국전통조경학회지
• /
• 제32권3호
• /
• pp.130-138
• /
• 2014

본 연구는 중국 원림의 조경기법에서 배치, 축 대칭, 주종(主從) 관계, 공간 대조, 경관 은폐 등으로 나타나고 있는 풍수지리사상인 "혈효응(穴效應)", "용사효응(龍砂效應)" 및 "수구효응(水口效應)" 의 이론을 파악하고 원림 공간에서의 표현 방식에 대해 고찰하고자 하였다. 배치 방식을 증명하기 위하여 사합원(四合院)과 소주 망사원(網師園)을 대상으로 하였으며, 축 대칭과 주종(主從) 관계를 증명하기 위하여 명 청대 북경성과 자금성, 운남성 선위시(宣威市) 도시 광장 설계를 대상으로 분석하였고, 공간 대조와 경관 은폐 방식을 증명하기 위하여 소주 유원(留園)과 창랑정(滄浪亭), 졸정원(拙政園), 태안시 남호공원을 대상으로 분석하였다. 연구 방법은 문헌조사와 현지답사 및 사례 분석으로 나누어 진행하였으며 연구 결과는 다음과 같다. 첫째, 배치 방식은 사합원, 소주 망사원 등에서 중국 풍수지리사상의 "혈효응"이 적용되었으며, 둘째, 축 대칭과 주종관계는 명 청대 북경성의 도시 계획과 자금성 공간 배치에서 풍수지리사상의 "용사효응"이 적용되었으며, 운남성 선위시 도시 광장 설계 등 중국 현대 조경 설계기법에도 풍수지리사상을 도입하고 있다. 셋째, "수구효응"은 공간 대조 기법과 경관 은폐 기법에서 나타나고 있다. 이는 소주 유원(留園), 창랑정(滄浪亭), 졸정원(拙政園), 태안시 남호공원 등의 설계에 도입되었다.

• Steel and Composite Structures
• /
• 제37권4호
• /
• pp.405-418
• /
• 2020

The application of double-skin composite wall should meet different layout plans. However, most available research focused on the rectangular section with uniform axial compression. In this research, the structural behavior of double-skin composite wall with L section was studied. Due to the unsymmetric geometric characteristics, the considered loading condition combined the axial compression and biaxial bending. Five specimens were designed and tested under eccentric compression. The variables in the test included the width of the web wall, the truss spacing, the thickness of the steel faceplate, and the thickness of the web wall. The test results were discussed in terms of the load-displacement responses, buckling behavior, stiffness, ductility, strength utilization, strain distribution. Two modern codes were employed to predict the interaction between the axial compression and the biaxial bending. The method to calculate the available bending moment along the two directions was proposed. It was found that CECS 159:2004 offers more suitable results than AISC 360.

• Nuclear Engineering and Technology
• /
• 제47권5호
• /
• pp.633-645
• /
• 2015

In order to analyze the mechanical properties of two-way different configurations of prestressed concrete members subjected to axial loading, a finite element model based on the nuclear power plant containments is demonstrated. This model takes into account the influences of different principal stress directions, the uniaxial or biaxial loading, and biaxial loading ratio. The displacement-controlled load is applied to obtain the stress estrain response. The simulated results indicate that the differences of principal stress axes have great effects on the stress-strain response under uniaxial loading. When the specimens are subjected to biaxial loading, the change trend of stress with the increase of loading ratio is obviously different along different layout directions. In addition, correlation experiments and finite element analyses were conducted to verify the validity and reliability of the analysis in this study.

• Structural Engineering and Mechanics
• /
• 제70권6호
• /
• pp.781-791
• /
• 2019

Earthquakes most often induce damage to structures, resulting in the degradation or deterioration of integrity. In this paper, based on the experimental study on 5 RC frames with different span length and different layout of buckling-restrained braces, the seismic damage evaluation law of RC frame with buckling-restrained braces was analyzed, and then the seismic damage for different specimens was calculated using different damage models to study the damage evolution. By analyzing and comparing the observation in test and the calculated results, it could be found that, damage evolution models including Gosain model, Hwang model as well as Ou model could better simulate the development of damage during cyclic loading. Therefore, these 3 models were utilized to analyze the development of damage to better demonstrate the evolution law for structures with different layout of braces and under different axial compression ratios. The results showed that from all layouts of braces studied, the eccentrically braced frame behaved better under larger deformation with the damage growing slowly. It could be deduced that the link beam benefited the seismic performance of structure and alleviated the damage by absorbing high values of energy.

• Advances in concrete construction
• /
• 제8권3호
• /
• pp.173-185
• /
• 2019

This article presents a comparative study of the effect of steel layouts on the seismic behavior of transition steel-concrete composite connections, both experimental and analytical investigations of concrete filled steel tube-reinforced concrete (CFST-RC) and steel reinforecd concrete-reinforced concrete (SRC-RC) structures were conducted. The steel-concrete composite connections were subjected to combined constant axial load and lateral cyclic displacements. Tests were carried out on four full-scale connections extracted from a real project engineering with different levels of axial force. The effect of steel layouts on the mechanical behavior of the transition connections was evaluated by failure modes, hysteretic behavior, backbone curves, displacement ductility, energy dissipation capacity and stiffness degradation. Test results showed that different steel layouts led to significantly different failure modes. For CFST-RC transition specimens, the circular cracks of the concrete at the RC column base was followed by steel yielding at the bottom of the CFST column. While uncoordinated deformation could be observed between SRC and RC columns in SRC-RC transition specimens, the crushing and peeling damage of unconfined concrete at the SRC column base was more serious. The existences of I-shape steel and steel tube avoided the pinching phenomenon on the hysteresis curve, which was different from the hysteresis curve of the general reinforced concrete column. The hysteresis loops were spindle-shaped, indicating excellent seismic performance for these transition composite connections. The average values of equivalent viscous damping coefficients of the four specimens are 0.123, 0.186 and 0.304 corresponding to the yielding point, peak point and ultimate point, respectively. Those values demonstrate that the transition steel-concrete composite connections have great energy dissipating capacity. Based on the experimental research, a high-fidelity ABAQUS model was established to further study the influence of concrete strength, steel grade and longitudinal reinforcement ratio on the mechanical behavior of transition composite connections.