• 한국공간구조학회:학술대회논문집
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• 한국공간구조학회 2005년도 춘계학술발표회 및 정기총회 2권1호(통권2호)
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• pp.108-115
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• 2005

Maintenance and reinforcement are very important especially in the case of the hybrid structures. In this paper, we introduce the maintenance and reinforcement design method of cable dome structures. In the case of the Olympic fencing stadium structural system has the stiffness in dependence of the initial tension force. Therefore, the verification of this phenomenon is very important. The result shows that the final tension force which is measured is almost reached to the calculated aim tension force after the maintenance ana reinforcement works is confirmed.

• Structural Monitoring and Maintenance
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• 제2권2호
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• pp.133-143
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• 2015

Civil engineering infrastructure is aging and requires cost-effective maintenance strategies to enable infrastructure systems operate reliably and sustainably. This paper presents an approach for determining risk-cost balanced repair strategy of corrosion damaged reinforced concrete structures with consideration of uncertainty in structural resistance deterioration. On the basis of analytical models of cover concrete cracking evolution and bond strength degradation due to reinforcement corrosion, the effect of reinforcement corrosion on residual load carrying capacity of corroded reinforced concrete structures is investigated. A stochastic deterioration model based on gamma process is adopted to evaluate the probability of failure of structural bearing capacity over the lifetime. Optimal repair planning and maintenance strategies during the service life are determined by balancing the cost for maintenance and the risk of structural failure. The method proposed in this study is then demonstrated by numerical investigations for a concrete structure subjected to reinforcement corrosion. The obtained results show that the proposed method can provide a risk cost optimised repair schedule during the service life of corroded concrete structures.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.759-764
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• 2005

With the tunnel to case of the construction slope it executes the periodic maintenance due to an objectivity standard. But, the standard connected with construction slope is not integrated with the important public paper organic enemy and it is duplicated and the standards which conflict are being scattered. Also, it is referred to some specifications simply and the feature which is diffuse appears. Therefore, there is a necessity which it investigates the problem point of the maintenance civil official and it improves rationally and it takes a triangular position a confusedly be standard system. In this research which it sees accomplished the fundamental research against the inspection item classified by reinforcement method for the construction slope maintenance.

• Geomechanics and Engineering
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• 제2권3호
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• pp.161-176
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• 2010

Discrete Element Method (DEM) simulations were developed to investigate the effectiveness of geosynthetic reinforcement and the effectiveness of maintenance techniques performed on a simulated ballast bed subjected to dynamic loading. The results from four samples subjected each one to a total of 425 load cycles are presented: one unreinforced and unmaintained sample, one unmaintained but reinforced sample, one unreinforced sample subjected to maintenance in the form of stoneblowing after 200 load cycles, and one unreinforced sample subjected to maintenance in the form of tamping after 200 load cycles. The obtained values of permanent deformation as a function of the applied number of load cycles for the four cases are presented together allowing a comparison of the effectiveness of each technique. Moreover, snapshots of the simulated track sections are presented at different moments of the simulations. The simulations indicated that the geosynthetic reinforcement may not be beneficial for the analyzed case while stoneblowing was the most effective maintenance technique.

• 한국철도학회논문집
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• 제3권2호
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• pp.68-76
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• 2000

Such traditional construction methods as the interchange or improvement of railway subbase maintenance and reinforcement have many problems in the matters of construction period, constructive and economical efficiency aspects. This paper will describe the alternative railway subbase reinforcement method based on geosynthetics system. It is presently very popular in Germany and Japan. In summary it is to say, that geosynthetics used at fine grained subsoils to a strong improvement of the whole railroad system.

• 한국구조물진단유지관리공학회 논문집
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• 제10권3호
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• pp.211-218
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• 2006

본 연구에서는 거주형 무량판 구조의 뚫림 전단을 방지하기 위한 연속 절곡된 전단 보강근을 개발하였다. 이를 적용한 슬래브-기둥 접합부에 있어 개발 전단 보강근의 뚫림 전단 성능을 평가하기 위하여, 구조 성능 실험을 수행하였다. 실험 변수는 전단보강근이 없는 경우, 개발 전단보강근을 사용한 경우, 헤드 스터드를 사용한 경우이다. 수평하중에 대한 저항성능을 평가하기 위하여 일정축력하에서의 이력 하중 실험을 수행하였다. 실험결과는 전체 변위 및 접합부 강도 등으로 평가되었다. 이러한 결과로부터, 개발된 전단보강근이 층간변위비 거동에 있어 우수한 성능을 보유함을 확인할 수 있었다.

• 한국구조물진단유지관리공학회 논문집
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• 제4권4호
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• pp.121-128
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• 2000

When RC beams are strengthening in flexure with steel plate, they have initial strain due to dead load. Strain of steel used in strengthening member is zero. The effect of strengthening in flexure at member changes in accordance with the quantity of initial strain. But in most cases, Quantity of reinforcement is determined without regard to the difference of initial strain when there are calculated the strengthening in flexure at beams. Such method is possible to suggest inadequate quantity of reinforcement. Thus, the object of the study is to suggest practical design equation and reinforcement proposal using comparison and analysis reinforcement efficiency about fexural strength in case with regard and without regard to the initial strain when Re beams are strengthening in flexure with steel plate.

• 한국구조물진단유지관리공학회 논문집
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• 제21권2호
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• pp.60-68
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• 2017

본 연구에서는 지내력이 기초판에 미치는 영향을 충분히 고려할 수 있도록 현장여건과 동일한 옥외의 지반에서 실험할 수 있는 시스템을 구축하였으며, 대상 실험체는 경제성 및 시공성 향상을 위하여 강판을 "ㄷ"자형으로 절곡하여 단면 2차모멘트를 극대화 하고 현장조립이 가능하도록 제안 하였다. 대상 실험체는 무보강 실험체 1개, 강판 두께를 동일하게 하여 보강 길이를 달리한 실험체 3개, 강판 두께를 달리하고 위험단면 부근에 스티프너 보강한 실험체 2개 총 6개의 실험체를 대상으로 비교 검토 한다. 실험 결과 스티프너 보강에 의한 효과는 없는 것으로 나타났으며, 전단보강재의 보강길이는 확장된 위험단면에서 전단력을 지내력으로 나타낸 값과 위험단면에서 보강재가 받을 수 있는 전단내력을 지내력으로 환산여하여 두 선의 교차점을 유효보강 길이로 산정하는 강판두께별 유효보강길이 산정방법을 제안하였다.

• Smart Structures and Systems
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• 제30권6호
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• pp.571-582
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• 2022

Optimal life-cycle management is a challenging issue for deteriorating regional bridges. Due to the complexity of regional bridge structural conditions and a large number of inspection and maintenance actions, decision-makers generally choose traditional passive management strategies. They are less efficiency and cost-effectiveness. This paper suggests a deep reinforcement learning framework employing double-deep Q-networks (DDQNs) to improve the life-cycle management of deteriorating regional bridges to tackle these problems. It could produce optimal maintenance plans considering restrictions to maximize maintenance cost-effectiveness to the greatest extent possible. DDQNs method could handle the problem of the overestimation of Q-values in the Nature DQNs. This study also identifies regional bridge deterioration characteristics and the consequence of scheduled maintenance from years of inspection data. To validate the proposed method, a case study containing hundreds of bridges is used to develop optimal life-cycle management strategies. The optimization solutions recommend fewer replacement actions and prefer preventative repair actions when bridges are damaged or are expected to be damaged. By employing the optimal life-cycle regional maintenance strategies, the conditions of bridges can be controlled to a good level. Compared to the nature DQNs, DDQNs offer an optimized scheme containing fewer low-condition bridges and a more costeffective life-cycle management plan.

• 한국구조물진단유지관리공학회 논문집
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• 제16권6호
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• pp.1-8
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• 2012

이 연구는 횡보강근의 배근형상에 따른 횡구속된 콘크리트의 성능을 평가하였다. 주요 변수는 횡보강근의 항복강도와 횡보강근의 배근형상으로 하였다. 총 27개의 직사각형 형태의 실험체를 제작하였으며, 단조 집중하중상태에서 실험을 수행하였다. 이 연구에서는 배근형상을 사각형인 R-type, 원형인 C-type 및 이 연구에서 제안한 사각과 팔각이 혼합된 O-type으로 계획하였다. 실험결과, 이 연구에서 제안한 배근형상이 사각형 나선철근과 비교하여 뛰어난 연성능력을 가짐을 확인할 수 있었다.