• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.3
• /
• pp.49-57
• /
• 2016

This study intended to analyze reinforcement effects of PSC I girder bridges to which prestresses are introduced using V type of external strands. So that series of bridge loading tests are carried out on existing PSC I girder bridge for the cases of before-reinforcement and reinforcement. The measured results from tests being analyzed and compared with the ones from MIDAS structural analyzing program, the reinforcing effects of the reinforcement system adopted in this study were investigated. It is found out that when the V type systems are applied to the bridge girders, the slope of load distribution factor curves become lower improving soundness of bridge upper structure. And also it is confirmed that the reinforcement system in this study can be taken as helpful for improvement of both flexural and shear ability of PSC I girder bridges, as well as dynamic behavior. Furthermore it is found when the elastic pads are applied to the system, dynamic reinforcing effects are maximized.

• Journal of the Korea Institute of Building Construction
• /
• v.12 no.1
• /
• pp.98-107
• /
• 2012

Reinforcing bars (rebar) comprise an integral part of a concrete structure, and play a major role in the safety and durability of the building. However, the actual placement or installation of rebar is not planned and controlled by the detailer. Recently, 4D simulations, using 3D model and scheduling software, have been used to improve the efficiency of the construction phrase. However, 4D simulators have not been introduced at the detailed level of work, such as rebar placement. Therefore, this paper suggests a BIM-based simulator for rebar placement to determine the sequence with which rebar is placed into the form. The system using Autodesk Revit API automatically generates rebar placement plans for a building structure, and labels the placement sequence of each individual bar or set of bars with ascending numbers. The placement sequence is then visualized using Autodesk Revit Structure 2012. This paper provides a short description of a field assessment and limits.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1989.04a
• /
• pp.44-49
• /
• 1989

The primary purpose of using bracings is to improve tile lateral rigidity of main structural system, i.e., columns and beams, by reinforcing them with much smaller members. Conventional design methods consider bracings as tension-only mambers, since difficulties arise in the analysis to consider the P - effects and post-buckling behaviour of the bracing members. This is particulary true for X-bracings. Recently, however, both analytical and experimental studies have been conducted to investigate the more precise and real behaviour of bracing members, especially for the nonlinear un plastic behaviour under cyclic loads. In this study, an analytical model is proposed to investigate the nonlinear behavior of steel bracing members subjected to cyclic loads. Results of tile analysis were compared with previous experimental results, and good agreements were obtained between these results.

• Computers and Concrete
• /
• v.14 no.4
• /
• pp.387-403
• /
• 2014

The aim of this study is to assess the structural performance of deteriorated reinforced concrete bridge piers, and to provide method for developing improved evaluation method. For a deteriorated bridge piers, once the cover spalls off and bond between the reinforcement and concrete has been lost, compressed reinforcements are likely to buckle. By using a sophisticated nonlinear finite element analysis program, the accuracy and objectivity of the assessment process can be enhanced. A computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), is used to analyze reinforced concrete structures. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. Advanced deteriorated material models are developed to predict behaviors of deteriorated reinforced concrete. The proposed numerical method for the structural performance assessment of deteriorated reinforced concrete bridge piers is verified by comparing it with reliable experimental results. Additionally, the studies and discussions presented in this investigation provide an insight into the key behavioral aspects of deteriorated reinforced concrete bridge piers.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.532-535
• /
• 2004

This paper presents a nonlinear finite element analysis procedure for the prediction of shear strength of reinforced concrete deep beams. A computer program, named RCAHESTC(Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile. compressive and shear models of cracked concrete and a model of reinforcing steel. The smeared crack approach is incorporated. The proposed numerical method for the prediction of shear strength of reinforced concrete deep beams is verified by comparison with the reliable experimental results.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.6
• /
• pp.901-907
• /
• 2013

The development of high-rise firefighting vehicles warrants thorough structural analysis for ensuring vehicle stability. A few structural analyses were carried out using CAD data, material properties, load conditions, and boundary conditions for evaluating the structural stability of an overloaded multi-aerial platform for firefighting and rescue. Structural analysis was performed with an analytical model consisting of a turntable, six booms, two jib booms, and a basket structure. This model was operated in eight modes. All simulation was performed using NASTRAN, a commercial code. As a result, we confirm that the position of local stress exceeds that of the yield strength. Therefore, stress concentration relaxation is possible by introducing reinforcing boom structures, changing the shape, or imparting a larger moment of inertia to the booms' cross sections.

• Computers and Concrete
• /
• v.9 no.1
• /
• pp.63-79
• /
• 2012

The purpose of this study is to evaluate the behavior and strength of prestressed concrete deep beams using nonlinear analysis. By using a sophisticated nonlinear finite element analysis program, the accuracy and objectivity of the assessment process can be enhanced. A computer program, the RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), was used for the analysis of reinforced concrete structures. Tensile, compressive and shear models of cracked concrete and models of reinforcing and prestressing steel were used to account for the material nonlinearity of prestressed concrete. The smeared crack approach was incorporated. A bonded or unbonded prestressing bar element is used based on the finite element method, which can represent the interaction between the prestressing bars and concrete of a prestressed concrete member. The proposed numerical method for the evaluation of behavior and strength of prestressed concrete deep beams is verified by comparing its results with reliable experimental results.

• Architectural research
• /
• v.10 no.2
• /
• pp.27-35
• /
• 2008

Because of several advantages of mortar-filled sleeve splice in reinforced concrete buildings, this method is being applied increasingly at construction sites and various methods of the splice have been developed in Korea and other countries. In order to apply this system in the field, studies on mortar-filled sleeve splice have been mainly experimental research focused on overall structural performance. However, for understanding the structural characteristics of this splice more accurately, we need to study the confining effect of sleeve, which is known to affect bond strength between filling mortar and reinforcing bar, the most important structural elements of the bar splice. Thus, in order to examine the confinement effect of mortar-filled steel pipe sleeve splice, the present study prepared actual-size specimens of steel pipe sleeve splice, and conducted a loading. Using the test results, we analyzed how the confining effect of steel pipe sleeve affects the bond strength of this splice and obtained data for developing more reasonable methods of designing the splice of reinforcement.

• Journal of Korean Library and Information Science Society
• /
• v.30 no.2
• /
• pp.29-53
• /
• 1999

Today, the central government and an autonomies make an attempt to contracting out, restructuring, and renaming for public libraries in Korea. These attempts are plot for a disorganization of public libraries. The purpose of this study is to analyze an entity of the plot and to extricate from the disorganization crisis. Based of the analysis, the best alternatives to extricate the crisis are reinforcing the basis of popular support, establishing the identity for public library, finding out opposing logic, taking a legal actions, pressing for a formation of local committee of library development, and overthrowing the confusion of library administrative system.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.480-488
• /
• 2010

The CGS method is non-discharge replacement method improving ground stiffness by the effect of static compaction with injecting very low slump mortar into ground, and is applied for increasing bearing capacity and filling ground cavity by lifting or restoring differential settled structures and preventing differential settlement. This paper suggests design of ground improvement and construction case history for civil engineering structures by CGS method. This method can be used for reinforcing soft ground and liquefaction of loose sandy soil. This method was used in SongDo area in Incheon Economic Free Zone due to its low vibration of ground while it can improve the soft soil where underground structures(subway and box culvert) are already existed.