• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.117-120
• /
• 2008

The bridge bearings are devices absorbing the displacements of the superstructure. KS F 4420 relative to the design of elastomeric bearings in Korea allows shear deformation up to 70% of total rubber height. For the elastomeric bearings to fulfill their shear function required in the design, the stability of allowable shear strain of elastomeric bearings relative to the shear failure should be guaranteed. Moreover considering the possibility that elastomeric bearings are applied to the seismic design together with isolation devices, elastomeric bearings is supposed to display higher shear performance. In this paper ultimate shear performance tests were performed. The measured ultimate shear strains were over 200%. Therefore an allowable shear strain provision becomes safe. But elastomeric bearings expected to show their performance in one united body reveled the separation of components near 200% shear strain. These separation in elastomeric bearing can cause unexpected impact or concentrated stress to bridge system considering to application of seismic design. Therefore provision relevant to separation problem is necessary.

• Journal of Korean Society of Steel Construction
• /
• v.11 no.3 s.40
• /
• pp.291-299
• /
• 1999

In this paper, an experimental study have been many studies on the propriety of block shear design code. according to limited state design criteria of steel structures recently established in Korea, by an experiment on the joint of H-Beam Flange tension members. The objects of this study were to compare with the results of other studies on block shear rupture mode and ultimate capacity, and to evaluate the propriety of the design criteria. The result is that the joint happened, two types, tension yield-shear ruptures and shear yield-tension ruptures, and the experimental rupture load was 23% higher than the capacity entered in the criteria design code In this criteria, it was found that ultimate strength of block shear of H-Beam Flange was lowly estimated. Therefore, we emphasize the need of estimates on the block shear rupture by carrying out many studies in this field.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.6 s.67
• /
• pp.611-620
• /
• 2003

Shear studs with a diameter of 19mm or 22mm are typically used in steel-concrete composite bridge. For the simplification of details in steel bridges, the convenience of removing concrete slab, and the efficient distribution of shear pockets for precast decks, large studs can be an excellent alternative. Through push-out tests on large stud shear connectors that transcend the limitation of current design codes, static behavior was investigated and comparisons with design equations performed. The shear stiffness of the connectors in elastic range and trilinear load-slip curves were proposed after shear tests on 25mm, 27mm, and 30mm studs. The ultimate slip capacity and ultimate strength of large studs were also evaluated, with the test results revealing conservative values for the design shear strength in Eurocode-4. For 30mm stud shear connectors, the welding quality and bearing capacity of concrete slab should be improved.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.1A
• /
• pp.55-64
• /
• 2012

Experimental investigation on the structural behavior of steel fiber-reinforced ultra high performance concrete (UHPC) beams subjected to shear are presented. Six tests carried out on simply supported I-beams under concentrated loads are presented. The parameters varied were the volume fraction of the fibers (1.0, 1.5 and 2.0%) and shear span-effective depth ratio (2.5, 3.4). The test results indicated that ultimate shear strength increased with increasing fiber volume, and that ultimate shear strength decreased with increasing shear span-effective depth ratio. In addition, applicability of predictive equations for evaluating the ultimate shear strength of steel fiber-reinforced UHPC beams are estimated based on the test results. The comparison between computed values and the experimentally observed values are shown to validate the proposed theoretical equations. It is found that predictions by using AFGC and JSCE recommendations provide the most accurate estimates of shear strength of steel fiber-reinforced UHPC beams.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.2 s.48
• /
• pp.1-10
• /
• 2006

Reinforced concrete bridge columns with relatively small aspect ratio show flexure-shear behavior, which is flexural behavior at initial and medium displacement stages and shear failure at final stage. Since the columns with flexure-shear failure have lower ductility than those with flexural failure, shear capacity curve models shall be applied as well as flexural capacity curve in order to determine ultimate displacement for seismic design or performance evaluation. In this paper, a modified shear capacity curve model is proposed and compared with the other models such as the CALTRANS model, Aschheim et al.'s model, and Priestley et al.'s model. Four shear capacity curve models are applied to the 4 full scale circular bridge column test results and the accuracy of each model is discussed. It may not be fully adequate to drive a final decision from the application to the limited number of test results, however the proposed model provides the better prediction of failure mode and ultimate displacement than the other models for the selected column test results.

• Structural Engineering and Mechanics
• /
• v.59 no.2
• /
• pp.291-312
• /
• 2016

Seismic performance evaluation of shear wall is essential as it is the major lateral load resisting member of a structure. The ultimate load and ultimate drift of the shear wall are the two most important parameters which need to be assessed experimentally and verified analytically. This paper comprises the results of monotonic tests, quasi-static cyclic tests and shake-table tests carried out on a midrise shear wall. The shear wall considered for the study is 1:5 scaled model of the shear wall of the internal structure of a reactor building. The analytical simulation of these tests is carried out using micro and macro modeling of the shear wall. This paper mainly consists of modification in the hysteretic macro model, developed for RC structural walls by Lestuzzi and Badoux in 2003. This modification is made by considering the stiffness degradation effect observed from the tests carried out and this modified model is then used for nonlinear dynamic analysis of the shear wall. The outcome of the paper gives the variation of the capacity, the failure patterns and the performance levels of the shear walls in all three types of tests. The change in the stiffness and the damping of the wall due to increased damage and cracking when subjected to seismic excitation is also highlighted in the paper.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.10a
• /
• pp.389-396
• /
• 2000

Fatigue behavior of shear joints between combined reinforced concrete(RC) and reinforced steel fiber concrete(RSFC) specimens has been experimentally investigated. Experimental parameters used are the amount of steel fiber and the type of shear joint. 6 specimens have been tested under static load, and 8 specimens have been subjected to the fatigue load in a range of 50% and 5 % of the ultimate static load. The purpose of this research is to propose an empirical formula for fatigue shear behavior of combined RC and RSFC structures on the basic of experimental result. It can be observed from experimental result that addition of steel fibers to concrete specimen increases the static ultimate load by approximately 25%, enhances the fatigue behavior, and also reduces vertical and lateral displacements at the shear joint for a given load cycle after the occurrence of first crack.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.05a
• /
• pp.853-858
• /
• 2001

Experimental studies were peformed to investigate variations in ductility of shear wall with length of boundary confinement. Eight specimens containg different lengths of confinment zone, which model compressive zone in plastic regions of shear walls, were tested against eccentric vetical load. Stress-strain model for confined concrete was used to predict strength and ductility of the specimens, which was compared to the test results. The results obtained show that failure of the compressive zone occurs in a brittle manner when the stress of unconfined zone softened after the ultimate strength were reached. To enhance the ductility of shear walls with concentrated confinement zone such as barbell-type walls, the ultimate strength of the confinement zone needs to be increased, and for shear walls with distributed confinement zone the length of the confinement zone needs to be extended.

• Journal of the Korean Society for Railway
• /
• v.3 no.4
• /
• pp.194-202
• /
• 2000

Fatigue behavior of shear joints between the combined reinforced concrete(RC) and the reinforced steel fiber concrete(SFRC) specimens has been experimentally investigated. Experimental parameters used are the amount of steel fiber and the type of shear joint. Six specimens have been tested under static load, and eight specimens have been subjected to the fatigue load in a range of 50 % and 5 % of the ultimate static load. The purpose of this research is to propose an empirical formula for fatigue shear behavior of the combined RC and SFRC structures on the basis of experimental result. It can be observed from experimental results that addition of steel fibers to concrete specimen increases the static ultimate load by approximately 25 %, enhances the fatigue behavior, and also reduces vertical and lateral displacements at the shear joint for a given load cycle after the occurrence of first crack.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.93-96
• /
• 2005

Since the columns with flexure-shear failure have lower ductility than those with flexural failure, shear capacity curve models shall be applied as well as flexural capacity curve in order to determine ultimate displacement for seismic design or performance evaluation. In this paper, a modified shear capacity curve model is proposed and compared with the other models such as the CALTRANS model, Aschheim et al.'s model, and Priestley et al.'s model. Four shear capacity curve models are applied to the 4 full scale circular bridge column test results and the accuracy of each model is discussed. It may not be fully adequate to drive a final decision from the application to the limited number of test results, however the proposed model provides the better prediction of failure mode and ultimate displacement than the other models for the selected column test results.