• Journal of Korean Society of Steel Construction
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• v.20 no.2
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• pp.347-354
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• 2008

Steel plate-concrete (SC) structure has recently been used in nuclear power structure because of its construction efficiency. In this study, experimental and analytical study to investigate the behavior of the SC structure's wall slab connection was carried out. Experiments were performed for typical SC and RC connections in order to examine the basic difference between each structure. Finite element analysis was performed and the result of the analysis was found to closely reflect the experimental result. By varying the thickness of the shear plate and friction coefficients and the distance of applied load from the wall, the influence of the parameters on the joint strength and failure modes were examined. Finally, it was confirmed that the joint strength formula proposed in th this research gives conservative results.

• Journal of Korean Society of Steel Construction
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• v.26 no.4
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• pp.349-359
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• 2014

Until now, wall-slab plate of steel plate concrete has been constructed by joint. But, the shear plate has problems in the workability as well as structural integrity. This study investigates the behavior and strength of rib stiffened SC wall-slab connection. Seven prototype specimens of wall-slab connections were fabricated and tested. the structural safety of the specimens was confirmed through the monotonic loading test. Based on the experimental observations, this study propose the strength formula of the joint was proposed. To enhance the reliability of the proposed strength formula, analytical verification was performed through inelastic finite element analysis. Effect of parameters, such as, load point, friction coefficient, on the joint strength was examined. The proposed formula yields a conservative value for most cases.

• Steel and Composite Structures
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• v.11 no.2
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• pp.169-181
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• 2011

The behavior of connections between open sandwich slabs and double steel skin composite walls in steel plate-concrete(SC) structure is investigated by a series of experimental programs to identify the roles of components in the transfer of forces. Such connections are supposed to transfer shear by the action of friction on the interface between the steel surface and the concrete surface, as well as the shear resistance of the bottom steel plate attached to the wall. Experimental observation showed that shear transfer in slabs subjected to shear in short spans is explained by direct force transfer via diagonal struts and indirect force transfer via truss actions. Shear resistance at the interface is enhanced by the shear capacity of the shear plate as well as friction caused by the compressive force along the wall plate. Shear friction resistance along the wall plate was deduced from experimental observation. Finally, the appropriate design strength of the connection is proposed for a practical design purpose.

• Journal of Korean Society of Steel Construction
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• v.25 no.6
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• pp.623-634
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• 2013

In this study, the structure behavior of RC slab and SC shear wall connection was investigated. Also experimental study was performed to evaluate the factor of safety of demand shear connection strength in KEPIC SNG Standard. As a result, shear friction strength of connection was known about 300kN and shear strength of rebar increased according to the displacement increase. With the installment of the lower rebars, 40% shear strength increased compared to the non-rebar specimen.

• Journal of the Korean Geotechnical Society
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• v.34 no.10
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• pp.17-28
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• 2018

Important parameters for the stability checks of cantilever wall are the active earth pressure and the weight of soil above the heel of the base slab. If the heel length is so long enough that the shear zone bounded by the failure plane is not obstructed by the stem of the wall, the Rankine active condition is assumed to exist along the vertical plane which is located at the edge of the heel of the base slab. Then the Rankine active earth pressure equations may be theoretically used to calculate the lateral pressure on the vertical plane. However, in case of the cantilever wall with a short heel, the application of Rankine theory is not only theoretically incorrect but also makes the lateral earth pressure larger than the actual pressure and results in uneconomical design. In this study, for the cantilever wall with a short heel the limit analysis method is used to investigate the mechanism of development of the active earth pressure and then the magnitude and location of the resultants of the pressure and the weight of the soil above the heel are determined. The calculated results are compared with the existing methods for the stability check. In case of the cantilever wall with a short heel, the results by the Mohr circle method and Teng's method show max. 3.7% and 32% larger than those of the limit analysis method respectively.

• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.235-246
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• 1999

Some of the underground structures such as subway tunnels are constructed by open cut method, in which the ground is excavated, a structure installed, and after that the excavated space is backfilled. In this case, because of their narrow and constrained boundary conditions, the earth pressure induced by self-weight of the backfilled soil acting on the underground structures is different from that of the classical theory. The vertical and horizontal earth pressures acting on upper slab and side wall of the underground structures constructed by open cut method are affected by the backfill geometry. The laboratory model tests were performed in the conditions of a variety of the shapes of backfill geometry and wall friction. And their results were compared with those from theories. As a result, it was observed that the distribution of the earth pressure acting on the underground structure is affected by the shapes of backfill geometry, the width of backfill, the angle of excavation and the wall friction.

• Corrosion Science and Technology
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• v.7 no.5
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• pp.283-287
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• 2008

The drag reduction agency (DRA) for gas pipeline, a novel method used for reducing friction or drag on a gas flowing to increase the transmission efficiency of gas pipeline, is a more flexible and economical technology than internal flow efficient coatings. In this paper, an effective DRA has been developed in Authors' Institute by analyzing the hydrodynamic friction resistance on internal gas pipeline and then studying the work mechanism and molecular structure of DRA. In the meantime, a group of property test for selecting DRA material has been determined, including viscosity, contact angle, volatility, corrosion, slab extending, and flow behavior in horizontal tube. The inhibition efficiency and drag reduction efficiency of the developed DRA have been investigated finally based on the relevant test methods. Results of corrosion test show that the developed DRA has very good inhibition effect on mild steel by brushing a thin layer of DRA on steel specimens, giving inhibition efficiency of 91.2% and 73.1% in 3%NaCl solution and standard salt fog environment respectively. Results of drag-reducing test also show that the Colebrook formula could be used to calculate friction factors on internal pipes with DRA as the Reynolds number is in the range of $0.75\times10^5\sim2.0\times10^5$. By comparing with normal industrial pipes, the friction resistance coefficient of the steel pipe with DRA on internal wall decreases by 13% and the gas flux increases by 7.3% in testing condition with Reynolds number of $2.0\times10^5$.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.513-518
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• 1998

In Half Precast Concrete Method, such as composite slab and composite wall, Interface between half PC plate and cast-in-place concrete is occurred. And this interface endure lastly in-plane shear which is occurred by external force. Therefore, test was executed to study in-plane shear strength of interface between half PC plate and cast-in-place concrete. In this test, Experimental parameters are finishing condition of the interface, cohesion of concrete, existence and nonexistence of re-bar truss, and angle and direction of lattice of re-bar truss. Comparing and analyzing experimental results, conclusions are obtained as follows. (1) In-plane shear strength of wide interface in composite plate is more affected by the roughness of interface than re-bar truss. And cohesion of concrete contribute to increasing in-plane shear strength. Therefore it seems that the interface should be roughen and kept clean to improve in-plane shear strength. (2) It seems that shear friction equation in ACI code can be sagely available for design of in-plane shear of composite plate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.15-20
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• 2019

This paper evaluated the construction costs of 11 design cases to decrease the horizontal forces applied to the abutment. They include two abutment types, which are to improve backfill materials for a reversed T-shaped abutment and geosynthetic Reinforced Abutment for Railways (RAR). The first type of economic analysis was that the internal friction angles of backfill materials were increased from Φ=35° to Φ=40° and 50° for a reversed T-shaped abutment. In addition, the second type was the cases with the design of geosynthetic RAR. When friction angles of 40° or 50° were applied through the improvement of the backfill material, the decrease in construction cost of the abutment was not large (2.0~3.9%), even though the horizontal forces applied to the abutment had decreased to 18~48%. In the case of applying the RAR, however, a maximum 30% cost reduction was evaluated by the decrease in horizontal force to "0" theoretically. The cost reduction resulted from the decrease in wall thickness, base slab size, and number and material change of pile foundation for the abutment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.3
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• pp.87-98
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• 1990

The present Study dealt with the earthquake-resistant design of cantilever retaining walls supporting cohesionless soils. With design examples of three different types of cantilever retaining walls, the factors of safety against sliding were computed at various values of horizontal acceleration coefficient and compared with each other. The horizontal inertia effect due to the weights of concrete wall itself and a portion of backfill was taken into account in the analyses, and also Mononobe-Okabe pseudo-static solution method was modified to deal with various states different from limiting equilibrium state. From the analyses of safety against sliding, it was found that a cantilever retaining wall with sloped base was the most efficient type in earthquake resistant design. It was also found that by sloping the base, the width of the base slab could be reduced, resulting in the least volume of concrete, excavation and backfill as compared to the other types of walls. In the case of a cantilever retaining wall with sloped feel, the efficiency similar to that of a wall with sloped base could be expected under static loading as well as at relatively low level of earthquake loading. However, this efficiency became vanished with the increase of horizontal acceleration coefficient, since the rate of reduction in developed earth pressures on the heel became smaller. In addition, the design charts with different soil friction angles as well as with different earthquake resistant design criteria of safety factor against sliding were presented for the design of cantilever retaining walls sith sloped base.