• Journal of Korean Society of Steel Construction
• /
• v.16 no.5 s.72
• /
• pp.661-669
• /
• 2004

In the steel structure of high-rise buildings, a connection analysisand a column design have been made after welding and bolting suitable gaps. Each country, however, has different codes, and such differences are very big. American steel has been designed according to a code that all axial loads can be carried from the upper parts to the lower parts as determined by the designer, but Korean and Japanese steel have been designed by 1/4 of the standard of all axial loads. In this paper, a metal touch experiment was done as an intermediation parameter with a connecting location and a connecting method for economic and constructive efficiency. Every specimen is tested by a low-to-high displacement control to grasp ultimate strength, displacement, the connection's lateral deflection, and stress. The results of the test were compared and analyzed.

• Journal of the Korean GEO-environmental Society
• /
• v.20 no.3
• /
• pp.21-30
• /
• 2019

Composite pile, which is composed of the steel pipe pile in which the large horizontal force acts and the PHC pile in which the small horizontal force acts by a special connecting devices, is being commercialized as a base material for civil engineering structures. The core of such a composite pile can be said to be a design criterion for estimating the joint position and stability of the connection device between steel pipe pile and PHC pile. In Korea, there is no precise specification for the location of composite pile joints. In the LH Design Department (Korea Land & Housing Corporation, 2009), "Application of composite pile design and review of design book marking" was made with reference to Road Design Practice Volume 3 (Korea Expressway Corporation, 2001). this is used as a basis of the design of the composite pile. It can not be regarded as a section change of the composite pile, so it has a limitation in application. Therefore, In this study, we propose a design criterion for the location of the section of the composite pile (joint of steel pipe pile and PHC pile) and evaluate the stability and economical efficiency of it by using experimental method and analytical method. Analysis of composite pile design data installed in 79 domestic bridges abutment showed that the stresses, bending moments, and displacements acting on the pile body and connection of the pile were analyzed. Through the redesign process, it was confirmed that the stresses generated in the connecting device occur within the allowable stress values of the connecting device and the PHC pile. In conclusion, the design proposal of composite pile joint location through empirical case study in this study is an improved design method considering both stability and economical efficiency in designing composite pile.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.306-309
• /
• 2010

강철도 플레이트거더교의 경우 일반적으로 레일의 폭보다 거더 사이의 폭이 넓기 때문에 거더에 편심이 작용하게 된다. 이러한 편심 영향으로 거더 내측 상부플랜지에 휨변형이 일어나게 되어, 상부플랜지와 수직보강재 용접이음부에 반복하중에 의한 피로균열이 발생되고 있는 것으로 보고되고 있다. 본 연구에서는 공용중인 강철도 플레이트거더교를 대상교량으로 하여 공용하중에 대한 구조해석을 실시하였다. 대상교량에 대한 현장계측을 기초로 구조모델링을 검증하였고, 검증된 구조모델링을 사용하여 열차하중 하에서의 상부플랜지와 수직보강재 용접연결부에서의 피로균열 보강방안에 대한 구조해석을 실시하였다. 또한 상부플랜지와 수직보강재 용접이음부 상세해석을 통하여 피로균열 발생위치를 확인하고 연결이음부의 적절한 보강방안을 제시하고자 한다.

• Journal of Korean Society of Steel Construction
• /
• v.23 no.3
• /
• pp.367-375
• /
• 2011

In this study, structural behavior of bolted joints which were important elements in plate girder design was analyzed using commercial FE analysis program. Also, the numerical analysis method that simply showed behavior of bolts was proposed using the connector element of ABAQUS, nonlinear FE program. Numerical analysis was conducted to verify the proposed numerical analysis method on the basis of the experiment of previous study. In order to investigate effects of action force which was changed by locations of the bolted joints, the three different models were developed by the locations of the bolted joints and behavior for the each model was compared and analyzed by various design parameters (area of splice plates, stiffness of splice plates, and stiffness of bolts). The moment-displacement relations of structures for the various design parameters were investigated to analyze effects of each parameter in ultimate behavior of the structures. Also, the effects of each parameter were compared by force.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.04a
• /
• pp.303-306
• /
• 2002

변위가 발생한 해안도로 옹벽에 대한 원인을 규명하기 위하여 기반암과 매립부 지반에 대한 조사를 실시하였다. 연구지역에서 지질구조선의 발달은 관찰되지 않고 지표에서 기반암의 거동은 낙석의 형태로 나타난다. 기반암은 생교란작용의 유무에 따라 상, 하부지층이 구분되며 하부 지층은 신선한 상태로 이완된 불연속면은 나타나지 않는다. 변위는 옹벽의 이음부에 집중되며 옹벽의 운동방향은 우향이동과 좌향이동이 반복되며 최초 변위 발생지점 (시 점부)에서 멀어짐에 따라 장력에 의한 확장 (벌어짐)이 우세하며 종점부에서 회전운동이 수반된다. 이음부의 확장과 회전은 최초 발생 지점에서 응력이 전달되는 과정에서 나타난 것으로 해석된다. 매립부 지반의 전기비저항탐사에서 상부의 매립층은 높은 전기비저항을 가지는 것에 반해 하부는 매우 낮은 전기비저항 값을 보여준다. 이는 매립부의 하부지반이 해수면 이하에 위치하여 해수와 같은 유체의 영향을 받으나, 상부는 유체의 영향을 거의 받지 않는 것으로 추정된다. 반면 최초 변위가 발생한 지점의 매립부 지반은 하부와 같이 낮은 전기비저항 값을 보여준다. GPR 탐사에서 최초 변위 발생 지점에서 매질의 이완 내지 공동으로 추정되는 구조가 관찰된다.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.9 no.4
• /
• pp.537-544
• /
• 2021

In order to describe the fill-up stages of a near-surface disposal facility vault, a mock-up test is performed, and its behavior during the fil l -up stages is investigated. On an in-site concrete foundation with a l ength of 6600mm, a width of 6600mm and a thickness of 400mm, a reinforced concrete disposal vaul t is manufactured with 4 precast (PC) corner wal l s and 8 PC side wal l s. 36 wasted drums are pl aced on the 1st fl oor in 6 by 6, and then the empty space is fil l ed with grout fil l er. These processes are repeated up to the 5th floor, and the verticality and the joint gaps are measured for each fill-up stage. The verticality is measured using a level at 6 positions on each side wall (3 positions on the left and right sides, respectivel y), i.e. a total of 24 positions on the 4 side wal l s. The joint gaps are measured at 9 positions on each side wal l (3 positions on the left, center and right sides, respectively), I.e. a total 36 positions on the 4 side walls. To measure the joint gaps, crack tips are installed on the left and right sides of every joint gap, and vernier calipers are used. The measured verticality obtained through the mock-up test was found to be ±0.1° based on the initial stage (ST0), and the result of the joint gap was up to 0.38mm. This appears to have a negligible effect on the structure.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.5 s.66
• /
• pp.531-539
• /
• 2003

Unlike field-welded moment frames damaged during the Northridge earthquake, a column-tree moment frame has a tool to control and reduce its seismic behavior. The tool is the girder splice. Girder splices could be designed to be sufficiently ductile and to have a prescribed bending moment capacity. In such a design, during earthquakes, the girder splices would act as ductile "fuses" and limit the magnitude of forces including the bending moment that could be developed in the frame. In Korea, most moment frames arc composed of a column-tree moment frame. Therefore, the elasto-plastic behavior of steel beams with high strength bolted friction splice should be clarified. Furthermore, structural capacities, including energy absorption capacity, must be quantitatively found. This paper discusses an experimental study to clarify elasto-plastic behavior of steel beams with high strength bolted friction splices. A total of 5 specimens were tested. A specimen was fabricated to have a beam splice designed by a full strength method. Other specimens were fabricated to have beam splices with 75%, 50% and 0% capacities compared with the specimen.

• Journal of Korean Society of Steel Construction
• /
• v.16 no.4 s.71
• /
• pp.407-414
• /
• 2004

Bridges in common use are expected to have more varieties of load in their connected members and bolts than in construction. Faults in connection members or bolts occur so often according to the time flow. One of the purposes of this study is to find out the behavior and structural features of high-tension bolted joints with faults that are very difficult and cost much to find out through experimentation with finite element analysis. Another purpose of this study is to provide sufficient data, estimated experimental results, and the scheme of the test plate for an economical experimental study in the future. Surveys of bridges with a variety of faults and statistical classifications of their faults were performed, as was a finite element analysis of the internal stress and the sliding behavior of standard and defective bridge models. The finite element analysis of the internal stress was performed according to the interval of the bolt, the thickness of the plate, the distance of the edge, the diameter of the bolt, and the expansion of the construction. Furthermore, the analysis explained the sliding behavior of high-tension bolt joints and showed the geometric non-linear against the large deformation, and the boundary non-linear against the non-linear in the contact surface, including the material non-linear, to best explain the exceeding of the yield stress by sliding. A normally bolted high-tension bolt joint and deduction of bolt tension were also analyzed with the finite element analysis of bridge-sliding behavior.

• Journal of Korean Society of Steel Construction
• /
• v.20 no.5
• /
• pp.633-644
• /
• 2008

The structural framework design uses high-strength bolts and welding in column splices. However, for the column under high compression, the number of the required high-strength bolts can be excessive and the increase of welding results in difficulty of quality inspection, the transformation of the structural steels, and the increase of erection time. According to the AISC criteria, when columns have bearing plates, or they are finished to bear at splices, there shall be sufficient connections to hold all parts securely in place. The Korean standard sets the maximum 25% of the load as criteria. Using direct contact makes it possible to transfer all compressive force through it. The objective of this study is to examine the generally applied stress path mechanism of welded or bolted columns and to verify the bending moment and compression transfer mechanism of the column splice according to metal touch precision. For this study,22 specimens of various geometric shapes were constructed according to the change in the variables for each column splice type, which includes the splice method, gap width, gap axis, presence or absence of splice material, and connector type. The results show that the application of each splice can be improved through the examination of the stress path mechanism upon metal contact. Moreover, the revision of the relative local code on direct contact needs to be reviewed properly for the economics and efficiency of the splices.

• Journal of Korean Society of Steel Construction
• /
• v.10 no.3 s.36
• /
• pp.355-367
• /
• 1998

To evaluate the mechanical behavior and the compressive stress distribution in high tension bolted joints according to the size of bolt hole, the experimental and analytical studies are performed with enlarging bolt hole size. In experimental study, the static test is performed to measure the slip coefficient, and the fatigue test is also performed to evaluate the fatigue strength and failure pattern of fatigue crack. In analytical study, the compressive stress distribution is investigated by using the finite element analysis. From the result of experimental study, the slip coefficient and fatigue strength of the high tension bolted joints with oversize hole are not much different but somewhat it has decreased. These are because the size of bolt hole is larger than the holes of nominal size, therefore the width of clamping force is decreased and the compressive stress distribution area is smaller, this is certificated in the finite element analysis. In addition, the origin of fatigue crack in the oversize holes is closer to the hole than in the holes of nominal size, consequently it is investigated that the origin of fatigue crack is intimately associated with the compressive stress distribution which is formulated by the clamping force in both base metal and splice plate.