• Earthquakes and Structures
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• v.10 no.6
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• pp.1467-1486
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• 2016

This research focuses on seismic performance of a class of single pier skewed bridges with three different pier-deck connections; skew angles vary from $0^{\circ}$ to $60^{\circ}$. A well-documented four span continuous deck bridge has been modeled and verified. Seat-type connections with fixed and sliding bearings plus monolithic pier-deck connections are studied. Shear keys are considered either fully operational or ineffective. Seismic performances of the bridges and the structural components are investigated conducting bidirectional nonlinear time history analysis in OpenSees. Several global and intermediate engineering demand parameters (EDP) have been studied. On the basis of results, the values of demand parameters of skewed bridges, such as displacement and rotation of the deck plus plastic deformation and torsional demand of the piers, increase as the skew angle increases. In order to eliminate the deck collapse probability, the threshold skew angle is considered as $30^{\circ}$ in seat-type bridges. For bridges with skew angles greater than $30^{\circ}$, monolithic pier-deck connections should be applied. The functionality of shear keys is critical in preventing large displacements in the bearings. Pinned piers experience considerable ductility demand at the bottom.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.617-622
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• 2000

In this study, effective compressive strength and nodal zone of Strut-and-Tie Model are studied to propose a new design method for RC T-type pier coping for prevention of sudden brittle failure. The coping which transmits loads of bridge to pier should be properly designed to retain ductile behavior. In order to carry out this proper design using STM, tie must yield before concrete fails, and a stress at strut should not exceed a certain effective stress. Therefore, reasonable determination of the effective compressive strength of strut by considering stress states at the nodal zone exactly is very important. Since conventional STM is applied under assumption that all nodes are under hydrostatic stress state, actual non-hydrostatic stress state in nodal zone caused by geometrical characteristics, loading conditions, support conditions of structures can not be considered properly. In order to apply STM for design of RC T-type pier coping, the non-hydrostatic stress state of nodal zone is considered and effective compressive strength is proposed. Then, a new design method of RC T-type pier coping which applies the principle of superposition to obtain optimum ductile behavior is rationally designed.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.81-82
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• 2010

As a part of rapid construction technology of bridge pier caps, controversial issues for design and construction of precast pier caps were discussed. Three kinds of approaches of rapid bridge pier cap construction were proposed and discussed. Especially for an approach of precast shell type structures, experimental studies were performed to evaluate structural performance and compared with conventionally constructed reinforced concrete pier cap.

• Water for future
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• v.6 no.1
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• pp.19-28
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• 1973

Presented is the results of a model study about scouring around a bridge pier. 24 different types of piers were inestigated for the depth and width of scouring. The grain size of sand used in the experiment ranges from 0.149 to 2, 380mm, The time required to reach the stable bed formation was about 30min, with the range of Froud number from 0.58 to 0.69. It has been found that the scouring is most severe at the frontal side of the pier and decreases with decreasing a contact angle (between the center line of the pier and tangent to the frontal face). For design purposes, it is recomanded that the contact angle at the frontal face is 25 degrees for a triangular type and 40 deyrees for a circular type respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1707-1711
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• 2008

Landing pier is connect from onshore to offshore with bridge type that a coast structure. The sub-structure is consisted of vertical or batter pile and combined reinforced concrete slab. These days useful design method of quay wall of landing pier type for pile foundation analysis abide by approximate depth of pile supported method, "Harbor and port design criterion, 2005 The ministry of land transport and maritime affairs". The approximate depth of pile supported is calculated two kind of method that one is assume to below depth of 1/$\beta$ from assumed submarine surface and other is 1st fixpoint depth by Chang(1937)'s theory. By this paper, FEM dynamic analysis of 3-dimensions was achieved that it has compared pile fixed end modeling with elastic spring modeling base on winkler theory.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.4
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• pp.65-81
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• 2013

Urban sprawl has been the limits of traffic accommodate and the supply road. Thus, Light Rail Transit(LRT) has been proposed as the best alternative. Owing to landscape damage from construction of LRT, landscape planning should be considered seriously in the urban planning step. This paper therefore seeks to determine landscape improvement direction of LRT pier. First, the methods in this study shared landscape improvement direction type of LRT pier through previous studies such as planting of surface(30%, 60%, 90% planting of surface), graphic(character, commercial advertising, symbol), and surface treatment type(exposed concrete, white painting, pattern dies). Next, respondent evaluated 3D simulated landscape image accordingly shared types by preference and landscape adjectives using in streetscape evaluation. As a result, visual preference was the highest in planting type of surface and the lowest in the surface treatment type. Covering 60%(4.48) in planting type of surface was the highest. Because it is similar to the golden ratio considering the visual principle, we will need to take advantage through the result of this paper. Also, most landscape improvement direction which satisfied with significant level showed a positive effect from landscape improvement. Comprehensively based on these results, it suggests desirable landscape improvement direction of LRT pier in the city for solution of landscape inhibition problem.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.71-78
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• 1994

The main objectives of the study may be stated as follows : \circled1 the acquisition of fundamental updated data for the assessment of aged wharf structures of pier type based on systematic static/dynamic load testing \circled2 the study of techniques and methods for field testing \circled3 realistic safety and load carrying capacity assessment based on practical reliability analysis. In this study field testing of real structure is performed and the results are compared with those of the 2D and 3D linear structural analysis. It may be seen that the practical reliability methods can be applied for the safety and capacity assessment of aged wharf structures of pier type.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.99-104
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• 2006

There are several advantages to make use of a bridge pier for the tidal power generation. Current velocity increases near the pier, therefore the tidal power generation becomes more efficient because the power is proportional to the cubic of the current velocity. The pier is convenient for access and maintenance of the hydraulic turbine and the power unit. The project is now underway at the Ikitsuki Bridge in Tatsuno-Seto Strait of Nasasaki Prefecture, where the tidal current was measured by the bottom mount ADCP for almost one year. Model experiments for a Darrieus water turbine with two and three straight blades were carried out in the circulating water channel, in which the power coefficients of the turbine were obtained as a function of blade section and the attaching angle of a blade to the rotor. Those experimental results are discussed to obtain an optimum Darrieus turbine for tidal power generation.

• Earthquakes and Structures
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• v.17 no.3
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• pp.317-327
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• 2019

High-speed railway bridge piers in seismically active area may be subjected to multiple earthquakes and then produce cumulative residual deformation. To study the cumulative residual deformation of high-speed railway bridge piers under multiple earthquakes, a nonlinear numerical analytical model with multi-DOF (MDOF) system is presented and validated against two shaking table tests in this paper. Based on the presented model, a simple supported beam bridge pier model of high-speed railway is established and used to investigate the cumulative residual deformation of high-speed railway bridge pier under mainshock-aftershock sequences and swarm type seismic sequences. The results show that the cumulative residual deformation of the bridge pier increases with earthquake number, and the increasing rates are different under different earthquake number. The residual deformation of bridge pier subjected to multiple earthquakes is accumulated and may exceed the limit of code.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.341-348
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• 2000

The existing solid circular RC pier without seismic detailing is found to have poor ductility due to the premature bond failure of lap spliced longitudinal bars. The steel-jacket was introduced to prevent this unexpected type of failure. The nonlinear behavior and he seismic performance of the retrofitted pier were examined through the scale model test and compared with those of existing one. It is confirmed from the test results that the steel-jacket retrofitting can be used as an measure to improve seismic performance considerably.