• Journal of the Korean Professional Engineers Association
• /
• v.34 no.1
• /
• pp.23-26
• /
• 2001

Seohae Grand Bridge is a part of the new West Coast Highway(353km) under construction, which connects Inchon and Mokpo. It is the longest bridge in Korea (7.31 km), and has 97 spans of 60m each precast segmental approach bridges, 2 main spans of 165m each free cantilever segmental bridge(500m), and 1 stay cable bridge of 990m In total length. During the seven year long construction period, many new construction technologies and methods were utilized for the first time in Korea, and gave invaluable opportunities to experience and master these in completing the project on time with safety and precision. I am proud of being a member of this project, and wish to express deep appreciations to those who participated in the project.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2007.09a
• /
• pp.39-52
• /
• 2007

A new type bridge combining an integral bridge and a pair of geosynthetic-reinforced soil (GRS) retaining walls having full-height rigid (FHR) facings, called the GRS integral bridge, is proposed. The geosynthetic reinforcement layers are connected to the FHR facings (i.e., RC parapets) that are integrated with a girder without using any girder-support. GRS integral bridges are basically much more cost-effective in construction and long-term maintenance while having a much higher seismic stability than conventional-type bridges having a girder via movable and fixed supports on a pair of cantilever abutments. GRS integral bridges are better than bridges using GRS retaining walls as abutments and also than conventional integral bridges with unreinforced backfill. To validate the above, a series of static cyclic lateral loading tests of the facing and a series of shaking table tests were performed on smallscaled models of different bridge types.

• 한국방재학회:학술대회논문집
• /
• 2008.02a
• /
• pp.63-66
• /
• 2008

The bridge deck section composed of a concrete slab resting on two I-beam girders are known to be susceptible to flutter instability and vortex shedding. Moreover, the cable stayed bridge in construction is more vulnerable to wind rather than in service when the free cantilever construction method is applied. This paper describes the effect of the dynamic wind loads on the bridge during construction and the effect of alternative temporary stabilizing measures. Therefore, a series of wind tunnel tests and numerical analysis were carried out to determine if any countermeasures were required.

• Journal of Korean Society of Steel Construction
• /
• v.18 no.1
• /
• pp.33-45
• /
• 2006

Cable-stayed bridges are more inherently vulnerable to wind during the erection stages than when they are already being used. Even if a bridge that is already being used is aerodynamically stable, it is prone to having aerodynamic instabilities within the design wind speed during construction. Therefore, when the bridge's designers deliberate on the method they will use in constructing the bridge, they must likewise come up with a suitable plan to ensure the stability of the bridge during its erection (e.g., conducting a wind-tunnel investigation). This paper describes the aeroelastic full-bridge model tests that were conducted to investigate the aerodynamic behavior of the bridge during erection, with emphasis on aerodynamic stability and the mitigation of the buffeting response through temporary stabilization. The aerodynamic performance of a cable -stayed bridge with a main span of 50 m was studied in its completed stage and in two erection stages, corresponding 50% and 90% completion, respectively. In the 50% erection stage tests, a balanced cantilever configuration, with wind cable and temporary support at the tower, was conducted. The system that was determined to be most effective in reducing wind action on the bridge during construction was proposed in the paper, based on the results of the comparative study that was conducted.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.05a
• /
• pp.279-284
• /
• 2002

Prestressed concrete(PSC) bridge structures with a number of continuous spans has been segmentally built in many countries. These methods include incremental launching method, movable scaffolding method, full staging method and balanced cantilever method. In these segmentally constructed prestressed concrete bridges, many construction joints exist and these construction joints are weak points in PSC bridges. The prestress force can be introduced prestress force continuously through the construction joints of PSC bridge superstructure using tendon couplers. The main objective of this study is to evaluate the structural behavior and ultimate flexural strength of construction joints in PSC girder bridge members. To this end, a comprehensive experimental program has been set up and a series of full-scale tests have been performed. Ultimate flexural strength of construction joint in PSC members with tendon couplers is decreased by approximately 10% for non-coupled members.

• Structural Engineering and Mechanics
• /
• v.46 no.3
• /
• pp.433-445
• /
• 2013

Vibration-based structural identification has become an important tool for structural health monitoring and safety evaluation. However, various kinds of uncertainties (e.g., observation noise) involved in the field test data obstruct automation system identification for accurate and fast structural safety evaluation. A practical way including a data preprocessing procedure and a vector backward auto-regressive (VBAR) method has been investigated for practical bridge identification. The data preprocessing procedure serves to improve the data quality, which consists of multi-level uncertainty mitigation techniques. The VBAR method provides a determinative way to automatically distinguish structural modes from extraneous modes arising from uncertainty. Ambient test data of a cantilever beam is investigated to demonstrate how the proposed method automatically interprets vibration data for structural modal estimation. Especially, structural identification of a truss bridge using field test data is also performed to study the effectiveness of the proposed method for real bridge identification.

• Journal of the Korean Society of Safety
• /
• v.31 no.4
• /
• pp.104-110
• /
• 2016

The effect of a partially earth anchored cable system on the structural safety of a long span cable-stayed bridge under seismic and wind loads are examined during construction process. By assuming the FCM (free cantilever method) construction stages with structural vulnerability, a multi-mode spectral analysis and a multi-mode buffeting analysis are performed for specific seismic load and wind load, respectively. Results show that the wind load dominates the structural safety of a cable-stayed bridge during construction. And, the application of a partially earth anchored cable system can enhance structural safety under wind load since the maximum pylon moment in the model with partially earth anchored cable system is reduced by 49% under wind load. In contrast, the maximum pylon moment occurred by seismic load is only decreased by 8%.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05a
• /
• pp.534-537
• /
• 2006

The jacking of cantilever before key segment closure has been introduced to offset the long term forces caused by creep and shrinkage. In this paper, the behavior of structural system with the jacking force in approach bridge of Incheon Bridge was reviewed. The introduction of jacking force effectively offset the long term horizontal forces and allows economic substructure member design.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.23 no.4
• /
• pp.417-424
• /
• 2010

This study proposes a parametric modeling method for efficient preliminary design of FCM(Free Cantilever Method) bridge. The method is capable of automatic fitting of cross section according to variation of span length of box girder which has variational section. Parameters for forming longitudinal geometry of box girder are defined, then implicit and explicit constraints, and functional relations among them are defined by applying statistics of parameters used in FCM bridge designs. The constraints and relations are applied to a sample bridge for verifying applicability of parametric modeling. In addition, material quantity of the sample model generated by parametric modeling is estimated and compared to the quantity of the real designed model to check the accuracy of the automatically designed parametric model.

• The magazine of the Korean Society for Advanced Composite Structures
• /
• v.5 no.3
• /
• pp.53-64
• /
• 2014