In this study, The recent national interest is focused on the welfare of the people, and new projects in the construction sector are being reduced, and the aging of infrastructure is not getting attention. In domestic case, most of the infrastructures were built in the 1970s to 1980s, and the road extension is also steadily increasing. Therefore, the costs to bridge maintenance from around 2010 by a similar route to that of advanced countries are also 4 times And it is time to pay attention to maintenance as well as construction. Therefore, a study was carried out on the valuation method considering bridge condition evaluation, which is a part of BIM library building and assembly program development. The proposed value evaluation method will be used as an index of the existence of bridges by comparing the cost required for maintenance and reinforcement of the target bridges and the costs required for dismantling and disposal in the bridge management system of the future program

In this study, to develop the basis of damage prediction system for abutment type rigid-frame bridge, measurement data is generated by artificially expressing damage by Abaqus, a commercial structural analysis program, and applied to machine-learning. The rigid-rame bridge structural analysis model is expressed as closely as possible to the actual bridge condition considering the specification, damage expression, analysis method, boundary condition, and load. CNN(Convolutional Neural Network), one of the neural network algorithm, is used for machine-learning and accuracy is confirmed when there was no measurement error as a result of machine learning.

Since 1990’s, many researches about ultra high performance concrete have been conducted. Compare to conventional concrete, it shows significantly high compressive and tensile strength so that leads to reduce the self weight of structures. However, the use of slender member may meet the buckling failure that is not common phenomenon in concrete structures so far. Most design codes have not suggested any provisions for buckling limit states and very few of researches have been conducted for buckling of concrete girders. In this study, a number of finite element analysis were carried out to investigate the buckling behavior of UHPC I-shaped girders.

This study investigates characteristics on inelastic flange local buckling of ultra high performance concrete (UHPC) plate supported by one edge. The UHPC plate were modeled using 3D shell elements (S4R) and analyzed using by geometric and material nonlinear analysis. The plates for FE analysis were supported by pined and fixed boundary conditions to considering constrained effects of one web. The inelastic local buckling strength from the FE analysis were evaluated according to the flange slenderness ratios. The results shows that material non-linearities of tensile behavior of UHPC highly affects the inelastic local buckling of UHPC plate.

This study investigates elastic flange local buckling of ultra high performance concrete (UHPC) I-girders. The girders were modeled using 3D shell elements (S4R) and analyzed by eigenvalue analysis. Then, the flange local buckling strength from the FE analysis were evaluated according to the flange and web slenderness ratios and compared to the local buckling strength of steel girders. The results shows that the flange local buckling of UHPC I-girders are underestimated compared to the strength of steel girders which has same geometric cross sections and further studies needed related to this field.

This study investigates the flexural shear strength of ultra high performance concrete I-girder. The effect of aspect ratio on the flexural - shear strength of UHPC was analyzed using finite element analysis. The UHPC I-type girder was modeled using 3D shell elements and analyzed using geometric and material nonlinear analysis. The boundary condition is simple support condition and a displacement load is applied to the center of the upper flange. The results shows that shear strength decreased as the aspect ratio increased and the bending-shear failure of UHPC I-girder does not occur even at larger moment than ordinary concrete due to the cross-linking action of steel fiber.

Prestress is a reinforcement method to control crack due to moment on concrete girders with low tensile strength. In the existing literature, it is mentioned that prestress for ordinary concrete affects not only crack control but also shear strength enhancement. As the construction material improves, UHPC(Ultra-HIgh Performance Concrete) with excellent strength and ductility has been developed by combining ultra-high strength concrete and steel fiber. However, study on the effect of prestress on the shear strength of UHPC with different material properties from ordinary concrete is lacking. Therefore, in this paper, the effect of prestress on the shear behavior of UHPC I-girder is studied by finite element analysis. As a result of the analysis, it has been confirmed that the prestress increases crack strength and shear strength of UHPC.

All structures can not be perfect due to geometric or material initial imperfections. Initial imperfections are an important factor in determining the buckling mode and are known to be important factors in evaluating the actual buckling strength. The DNV-RP-C202 design standard limits the longitudinal stiffener spacing. However, the criteria for the stiffener spacing presented in DNV-RP-C202 is a guideline derived from the curved panel theory of perfect cross-sectional shape without initial imperfections. In this study, considering geometric initial imperfections, the transition point of stiffener spacing where longitudinal stiffeners affect the buckling strength of reinforced steel wind turbine tower is analyzed using finite element analysis program. The results of finite element analysis compared with theoretical results based on the perfect shape. As a result, a more reasonable stiffener spacing considering the initial imperfections was suggested.

Wind tower structure has relatively simple shape compared to other structures, but due to its characteristics, various and irregular environmental loads are applied. These loads cause vibrations at tower, and can cause failure of the structure if over vibration occurs. Vibration occurred at structures is gradually exhausted by damping of the structures, and if high damping is ensured, the failure of the structure due to over vibration can be prevented. In this study, the vibration reduction effects are to be analyzed through FEM analysis by examining the top displacement, bottom moment, and bottom fatigue damage of the structure depending on damping ratio of the wind tower structure.

Recently, for efficiency increase of the wind turbine tower, turbine has been enlarged and installation location has been transferring to offshore. The importance of the support structure is emphasized when a wind turbine tower is installed on offshore. The support structure is influenced not only by the system operating loads but also by various marine condition loads. Accurate and safe design is essential because the connection between the support structure and the wind tower can be relatively fragile. In particular, the type of foundation pile and sleeve grout connection were adapted from DNV, API, and ISO that are typically used for wind towers, and they have been continuously studied by many researchers. However, the experimental results by researchers are different from the design equations, and it needs to modify the formula according to connection properties and material. Therefore, this study investigates the design equation presented in existing design criteria and the results of research conducted by existing researchers, and analyzes ultimate strength and failure modes.

For the purpose of economic growth in the nineteenth century, social infrastructures have been rapidly aging since the 21st century, Currently, many of the existing infrastructure has been aged, and many national costs have been spent on safety Inspection and maintenance. It is expected that more maintenance will be costly in the future, and maintenance cost can be expected to be reduced due to safety inspection and repair and reinforcement measures in a timely manner. The measures provided in the national and international safety inspection and maintenance manual reduce the efficiency of the work by repeating document work. In addition, due to lack of information sharing among practitioners performing inspection and maintenance, it is considered that incomplete work or incurring additional costs will lead to a large national loss. Building Information Modeling (BIM) can manage all the information generated during the whole life cycle of social infrastructures. Domestic institutions are increasing the use of BIM, and the Public Procurement Service is obliged to design BIM. We expect to increase the work efficiency of practitioners by reducing repetitive document work using BIM, It will make the integrated management information enable bi-directional communication among practitioners. First of all, building a library of social infrastructures and standardizing the information classification system and procedures for BIM application should be essential. As a result, standardization studies on standard information classification system and procedures based on representative bridges among social infrastructures were conducted.

The present study analyzes the flexure behavior of the circular CFT member through experiment and numerical analysis. Through comparison between experimental and numerical results, whether or not the member was a full composite have little effect on the behavior. There circular CFT’s flexure behavior when considering pure moment is almost similar regardless of the interface characteristics between the steel and concrete. This is because there is no difference in the neutral axis of the full-composite and non-composite circular CFT member.

Two types of connection between the abutment and CFT pile were proposed for the sub-structure of the integral abutment bridge. One was a bolt connection (Type-A) and the other was a hook connection (Type-B). To analyze the performance of connection Type-A and Type-B, a quasi-static experiment was carried out. According to experimental results, the destruction occurred at the connection point and so both type A and type B need to have a reinforced design as the link between the abutment and CFT pile. However, when the load resistance performance and energy dissipation capacity was analyzed, the performance of connection Type-B was superior to the performance of connection Type-A.

In this study, a quasi-static experiment was conducted on the connection performance between the integral abutment bridge and CFT pile. Six experiment specimen were manufactured and were divided into type A and type B. Experiment specimens of Type A were connected with bolts and experiment specimens of Type B were connected with hooks. In the experiment results the connection performance of Type B showed excellent performance more than that of Type A.