• Steel and Composite Structures
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• v.31 no.4
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• pp.329-340
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• 2019

An innovated type of the flat steel plate-lightweight aggregate concrete hollow composite slab was presented in this paper. This kind of the slab is composed of flat steel plate and the lightweight aggregate concrete slab, which were interfaced with a set of perfobond shear connectors (PBL shear connectors) with circular hollow structural sections (CHSS) and the shear stud connectors. Five specimens were tested under static monotonic loading. In the test, the influence of shear span/height ratios and arrangements of CHSS on bending capacity and flexural rigidity of the composite slabs were investigated. Based on the test results, the crack patterns, failure modes, the bending moment-curvature curves as well as the strains of the flat steel plate and the concrete were focused and analyzed. The test results showed that the flat steel plate was fully connected to the lightweight aggregate concrete slab and no obvious slippage was observed between the steel plate and the concrete, and the composite slabs performed well in terms of bending capacity, flexural rigidity and ductility. It was further shown that all of the specimens failed in bending failure mode regardless of the shear span/height ratios and the arrangement of CHSS. Moreover, the plane-section assumption was proved to be valid, and the calculated formulas for predicting the bending capacity and the flexural rigidity of the composite slabs were proposed on the basis of the experimental results.

• Steel and Composite Structures
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• v.38 no.4
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• pp.431-445
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• 2021

This paper presents experiments and theoretical analysis on shear behavior of eight concrete-encased square concrete-filled steel tube (CECFST) specimens and three traditional reinforced concrete (RC) specimens. A total of 11 specimens with the test parameters including the shear span-to-depth ratio, steel tube size and studs arrangement were tested to explore the shear performance of CECFST specimens. The failure mode, shear capacity and displacement ductility were thoroughly evaluated. The test results indicated that all the test specimens failed in shear, and the CECFST specimens enhanced by the interior CFST core exhibited higher shear capacity and better ductility performance than that of the RC specimens. When the other parameters were the same, the larger steel tube size, the smaller shear span-to-depth ratio and the existence of studs could lead to the more satisfactory shear behavior. Then, based on the compatible truss-arch model, a set of formulas were developed to analytically predict the shear strength of the CECFST members by considering the compatibility of deformation between the truss part, arch part and the steel tube. Compared with the calculated results based on several current design specifications, the proposed formulas could get more accurate prediction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2406-2413
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• 2014

Since clear span-to-depth ratio is used to define what is so called a deep beam, it is an important parameter ratio for study about deep beam. Deep beams can be designed by flexure design method, and shear provided by concrete ($v_c$) and by steel ($v_s$) for deep flexure members are provided in ACI 318-99 [1]. But in later version of ACI (from ACI 318-02) it is not provided and deep beams shall be designed either by taking into account nonlinear distribution of strain or by Appendix A of Strut-and-Tie Models (STM). The trend of deep beam design seems to be familiar with strut-and-tie model, but ACI traditional design is not forgotten. By comparing these two method, there should a point which definitely explain the different between the two methods. In this study, 68 samples result of steel, after reinforcement arrangement, are taken to be analyzed.

• Journal of Korean Association for Spatial Structures
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• v.12 no.4
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• pp.109-118
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• 2012

The large-space single-layer lattice dome is relatively simpler in terms of the arrangement of the various framework members and of the design of the junction than the multi-layered lattice dome, can reduce the numbers and quantity of the framework members, and has the merit of exposing the beauty of the framework as it stands. The single-layer lattice dome, however, requires a stability investigation of the whole structure itself, along with an analysis of the stress of the framework members, because an unstable phenomenon called "buckling" occurs when its weight reaches critical levels. Many researchers have systematically conducted researches on the stability evaluation of the single-layer lattice dome. No construction case of a single-layer lattice dome with a 300-m-long span, however, has yet been reported anywhere in the world. The large-space dome structure is difficult to erect due to the gigantic span and higher ceiling compared with other common buildings, and its construction cost is generally huge. The method of erecting a structure causes major differences in the construction cost and period. Therefore, many researchers have been conducting various researches on the method of erecting such structure. The step-up method developed by these authors can reduce the construction cost and period to a great extent compared with the other general methods, but the application of this method inevitably requires the development of system supports in the center section as well as pre-existing supports in the boundary sections. In this research, the safety during the construction of a single-layer lattice dome with 300-m-long span using pre-existing materials was examined in the aspect of structural strength, and the basic data required for manufacturing the supports in the application of the step-up method developed by these authors during the erection of the roof structure were obtained.

• Journal of Korean Association for Spatial Structures
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• v.17 no.2
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• pp.21-32
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• 2017

The objective of this study is to analysis the mechanical characteristics on the geometric nonlinear behavior of radial cable roof systems for long span retractable cable roof structures. The retractable roof is designed as a full control system to overcome extreme outdoor environments such as extreme hot or cold weather, strong wind or sunlight, and the cable roof greatly can reduce roof weight compared to other rigid structural system. A retractable cable roof system is a type of structures in which the part of entire roof can be opened and closed. The radial cable roof is an effective structural system for large span retractable roofs, the outer perimeter of the roof is a fixed membrane roof and the middle part is a roof that can be opened and closed. The double arrangement cables of a radial cable truss roof system with reverse curvature works more effectively as a load bearing cables, the cable system can carry vertical load in up and downward direction. In this paper, to analyze the mechanical characteristics of a radial cable roof system with central posts, the authors will investigate the tensile forces of bearing cables, stabilized cables, ring cables, and the deflection of roof according to the height of the post or hub that affects the sag ratio of cable truss. The tensile forces of the cables and the deflection of the roof are compared for the cases when the retractable roof is closed and opened.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.3
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• pp.250-258
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• 2018

Free Standing Hybrid Riser (FSHR) is comprised of vertical steel risers and Flexible Jumpers (FJ). They are jointly connected to a submerged Buoyancy Can (BC). There are several factors that have influence on the behavior of FSHR such as the span distance between an offshore platform and a foundation, BC up-lift force, BC submerged location and FJ length. An optimization method through a parametric study is presented. Firstly, descriptions for the overall arrangement and characteristics of FSHR are introduced. Secondly, a flowchart for optimization of FSHR is suggested. Following that, it is described how to select reasonable ranges for a parametric study and determine each of optimal configuration options. Lastly, numerical analysis based on this procedure is performed through a case study. In conclusion, the relation among those parameters is analyzed and non-dimensional parametric ranges on optimal arrangements are suggested. Additionally, strength analysis is performed with variation in the configuration.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.379-384
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• 2001

This paper presents the experimental result of composite basement wall in which H-pile and reinforced concrete wall are combined using shear connector. Twelve specimens are tested to evaluate the shear capacity of the wall. Main variables in the test are composite ratio, arrangement of shear connector, thickness of wall, shear span ratio, and shear reinforcement. Test results indicate that the shear capacity of test specimens varies with the foregoing variables except the composite ratio. The results are compared with strengths predicted using the equations of ACI 318-99, Zsutty, and Bazant. Based on this investigation, a method for predicting the shear strength of composite basement walls is proposed.

• Steel and Composite Structures
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• v.16 no.1
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• pp.1-21
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• 2014

Knee Braced Frame (KBF) is a special form of ductile eccentrically braced frame having a diagonal brace connected to a knee element, as a hysteretic damper, instead of beam-column joint. This paper first presents an experimental investigation on cyclic performance of two knee braced single span one-story frame specimens. The general test arrangement, specimen details, and most relevant results (failure modes and hysteretic curves) are explained. Some indexes to assess the seismic performance of KBFs, including ductility; response reduction factor and energy dissipation capabilities are also subsequently discussed. Experimental results indicate that the maximum equivalent damping ratios achieved by test frames are 21.8 and 23% for the specimens, prior to failure. Finally, a simplified analytical model is derived to predict the bilinear behavior of the KBFs. Acceptable conformity between analytical and experimental results proves the accuracy of the proposed model.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.1
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• pp.61-71
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• 2004

The performance evaluation and deflection of 3 spans concrete simplicity slab bridge analyzed by non-destructive and loading test. Compressive strength of slab and pier appeared in the range of each 353∼366 kgf/$cm^2$ and 152∼215 kgf/$cm^2$ in rebound number test. Also, it appeared that concrete quality of slab was good after performance improvement. The average compressive strength of slab by core picking appeared 229 kg/$cm^2$. In reinforcing bar arrangement test of span and member, it appeared that horizontal and vertical reinforcing bar was arranged to fixed interval. The value of calculation deflection that carried structural analysis with deflection analysis wave in static loading test appeared higher than that of experimental deflection and it appeared that hardness of this bridge was good. Maximum impact factor that estimated from deflection by running speed in dynamic loading test appeared by 0.216 in 10 km/hr running speed.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1043-1049
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• 2008

Trouble by excessive axial stress in CWR layed on a bridge is frequently happen, and this problem is induced from lack of considering on the track/structure interface on preliminary design stage. In this study, the sensitivity evaluation for the major influencing parameters, that is, expansion length of span, stiffness of super structure, arrangement of bearing, and strength of sub-structure, to the axial force in CWR on a bridge is conducted. From the sensitivity study, the guideline to reduce axial force efficiently in CWR for bridge engineer was suggested. The suggested guideline may not applicable for every case, but it is helpful for preliminary design of bridge.