• Structural Engineering and Mechanics
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• v.34 no.5
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• pp.563-580
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• 2010

Composite beams using bolts to attach steel plates to the side faces of existing reinforced concrete (RC) coupling beams can enhance both their strength and deformability. The behavior of those composite beams differs substantially from the behavior of typical composite beams made up of steel beams and concrete slabs. The former are subjected to longitudinal, vertical and rotational slips, while the latter only involve longitudinal slip. In this study, a mixed analysis method was adopted to develop the fundamental equations for accurate prediction of the load-carrying capacity of steel plate strengthened RC coupling beams. Then, a rigid plastic analysis technique was used to cope with the full composite effect of the bolt group connections. Two theoretical models for the determination of the strength of medium-length plate strengthened coupling beams based on mixed analysis and rigid plastic methods are presented. The strength of the strengthened coupling beams is derived. The vertical and longitudinal slips of the steel plates and the shear strength of the anchor-bolt connection group is considered. The theoretical models are validated by the available experimental results presented in a companion paper. The strength of the specimens predicted from the mixed analysis model is found to be in good agreement with that from the experimental results.

• International Journal of Concrete Structures and Materials
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• v.10 no.4
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• pp.451-460
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• 2016

An anchorage system is necessary in most reinforced concrete structures for connecting attachments. It is very important to predict the strength of the anchor to safely maintain the attachments to the structures. However, according to experimental results, the existing design codes are not appropriate for large anchors because they offer prediction equations only for small size anchors with diameters under 50 mm. In this paper, a new prediction model for breakout shear strength is suggested from experimental results considering the characteristics of large anchors, such as the prying effect and size effect. The proposed equations by regression analysis of the derived model equations based on the prying effect and size effect can reasonably be used to predict the breakout shear strength of not only ordinary small size anchors but also large size anchors.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.87-88
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• 2009

In this research project, 24 tests are performed to find out a behavior and shear breakout capacity of large anchor system exceeding 2 inch(50mm) in anchor bolt diameter($d_0$) and 25 inch(635mm) in effective embedment($h_{ef}$) not addressed by ACI 349-01 Appendix B (ACI 349 2001). On this report, analysis results are presented that this variables influence on behavior and shear breakout strength through those of test results.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.129-132
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• 2008

All bearing device should be examined to determine that they are functioning properly. Small changes in other portions of the structure, such as pier or abutment settlement, may be reflected in the bearings. Bearings should be checked to see that they can move freely and are clear of all foreign material. Shoes should be in proper position relative to the temperature at the time of the inspection. Check anchor bolts for any damage and to see that nuts are secure. See that anchor bolt nuts are properly set on the expansion bearings to allow normal movement. In this paper, rehabilitation method for damaged bearings is proposed and damage example of the skewed bridge is illustrated

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.234-237
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• 2003

Previous researches about headed reinforcement have not been concerned about bond failure which is quite important is some cases. In this paper, failure mechanism including bond failure was presented in order to define the contribution of bond stress at the time failure occurs. Examined with design codes and test results, it is proved to be rational to consider the contribution of bond stress in determining the ultimate pull-out capacity of headed reinforcement. Direct adaptation of design code for anchor bolt without modification for the contribution of bond stress will lead to underestimate the capacity of headed reinforcement.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.845-850
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• 1998

Flexural tests on 3.0m reinfored concrete beams with epoxy and anchor bolt bonded CFRF-Grid reported in these tests. The selected experimental variables are concrete compressive strength, strengthening length and strengthening method. The effects of these variables in overall behavior are discussed. The results generally shown that the main flexural mode of strengthened beams is separation failure. The strengthening of the chipping by the tensile bar is really necessary in order to prevent CFRP-Grid from rip-off failure.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.44-51
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• 2002

The construction road and addition work are increasing now. Therefore, slope stability is important in construction slope on the fault and fractured zone. Rock bolt method, soil nailing method and anchor method are applied to reinforcement method of slope. This paper is the study for construction management on reinforcement method of slope.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.121-124
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• 2006

This study focuses on the flexural behavior of RC beam with externally bonding FRP reinforcement. FRP-plate strengthening system is mainly installed with an anchor-bolt. But the installation with it has several disadvantage as a complicated work, a high labor costs. To complement these disadvantage, the test is performed about improved FRP-plate strengthening system.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.620-627
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• 2006

강재기둥으로부터 전달되어 내려오는 모멘트 하중에 의한 베이스판의 변형을 고려한 앵커볼트의 설계방법에 대해 소개하였다. 기둥-베이스판 접합부의 설계를 위해 간략해석 모델 (Simple Beam Model) 이 개발되었으며 인장력과 모멘트 하중에 동시에 저항하는 앵커볼트의 설계를 위해 국부 메카니즘 개념이 도입되었다. 제안된 새로운 설계법을 적용하여 앵커볼트와 베이스판 사이의 최대지압력을 계산할 수 있었으며 이를 바탕으로 앵커볼트의 사이즈를 결정할 수 있었다. 본 논문에서는 상기 간략히 소개된 앵커볼트 설계법을 보다 상세히 기술하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.7
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• pp.875-881
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• 2013

The failure of a bolted joint owing to stress corrosion cracking (SCC) has been considered one of the most important structural integrity issues in a nuclear power plant. In this study, the failure possibility of bolting, which is used to support the steam generator of a pressurized water reactor, owing to SCC and brittle fracture was evaluated in accordance with guidelines proposed by the Electric Power Research Institute, which are called the Reference Flaw Factor method. For this evaluation, first, detailed finite element stress analyses were conducted to obtain the actual nominal stresses of bolting in which either service loads or bolt preloads were considered. Based on these nominal stresses, the structural integrity of bolting was addressed from the viewpoints of SCC and toughness. In addition, the accuracy of the EPRI Reference Flaw Factor for assessing bolting failure was investigated using finite element fracture mechanics analyses.