• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.36 no.4
• /
• pp.123-133
• /
• 2020

The purpose of this study is to analyze the method of retrofitting flexural strength and the flexural performance of retrofitted shear walls. There are various ways to reinforce the flexural strength of reinforced concrete shear wall structural systems that have already been built, in the case of that, the external force is increased, and the internal force is insufficient. However, there are various problems, such as excessive flexural stiffness after reinforcement and increasing the thickness and length of the wall. We have developed a retrofit method to solve these problems. The wall end is excavated to place the required vertical rebars, and concrete is poured after placing rebars. This is the same concept as creating wall end boundary elements later on. We also studied the anchorage method of reinforcement and the interaction method between the retrofitting end and the existing wall. The flexural test results for the reinforced concrete shear wall using the studied retrofit method can be predicted according to the sectional analysis and FEM analysis, and there are differences in the plastic hinge length, crack propagation, stiffness degradation and energy dissipation due to the bending depending on the vertical rebar ratio of wall end.

• Korea-Australia Rheology Journal
• /
• v.20 no.2
• /
• pp.51-58
• /
• 2008

This paper describes a two-step Tikhonov regularization procedure for converting the steady shear data generated by parallel-disk viscometers, in the presence of wall slip, into a shear stress-shear rate function and a wall shear stress-slip velocity functions. If the material under test has a yield stress or a critical wall shear stress below which no slip is observed the method will also provide an estimate of these stresses. Amplification of measurement noise is kept under control by the introduction of two separate regularization parameters and Generalized Cross Validation is used to guide the selection of these parameters. The performance of this procedure is demonstrated by applying it to the parallel disk data of an oil-in-water emulsion, of a foam and of a mayonnaise.

• Computers and Concrete
• /
• v.3 no.5
• /
• pp.285-299
• /
• 2006

The free vibration of stiffened and damaged coupled shear walls is investigated using the mixed finite element method. The anisotropic damage model is adopted to describe the damage extent of the reinforced concrete shear wall element. The internal energy of a locally damaged shear wall element is derived. Polynomial shape functions established by Kwan are used to present the component of displacements vector on each point within the wall element. The principle of virtual work is employed to deduce the stiffness matrix of a damaged shear wall element. The stiffened system is reinforced by an additional stiffening beam at some level of the structure. This induces additional axial forces, and thus reduces the bending moments in the walls and the lateral deflection, and increases the natural frequencies. The effects of the damage extent and the stiffening beam on the free vibration characteristics of the structure are studied. The optimal location of the stiffening beam for increasing as far as possible the first natural frequency of vibration is presented.

• Structural Engineering and Mechanics
• /
• v.5 no.2
• /
• pp.167-175
• /
• 1997

A new seismic energy dissipation shear wall structure is proposed in this paper. The new shear wall is one with purposely built-in vertical slits within the wall panel, and various seismic energy dissipation devices are installed in the vertical slits so that the dynamic characteristics of the structure (for instance, lateral stiffness, ductility and fundamental period) can be controlled. In order to verify this concept, shaking table tests of two 10-story shear wall models were carried out, and the seismic behavior of the two models are studied by analyzing the test data and computing the nonlinear seismic response of the models.

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

• Journal of the Korea Institute of Building Construction
• /
• v.2 no.2
• /
• pp.175-180
• /
• 2002

"Samsung Composite Shear Wall System" has its basis on "Samung Able System". "Samsung Able System" has some problems not only in the connection structure but also in waterproofing and soundproofing. We developed "Samsung Composite Shear Wall System" in order to solve these matters and expand PC system. "Samsung Composite Shear Wall System" is the compromise and complement of all the merits of full PC, half PC and in-situ concrete system.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1993.04a
• /
• pp.141-148
• /
• 1993

In this paper, TVLEM is selected for the shear wall model which was proposed by Kabeyasawa and the characteristics of spring models composing TVLEM was studied. In axial stiffness spring model, the horizontal displacements when Kabeyasawa model and simple axial stiffness hysteresis model were used, were closely similar. When the large shear-displacement was occured, stiffness degrading model was more adquate to the shear wall modelling than OOHM. Also for the purpose of modelling the horizontally continuous wall, the seperational method for TVLEM was used. The results of nonlinear analysis by this method were closely similar to experimental results .

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.9 no.3
• /
• pp.213-220
• /
• 2005

Recently, a concern to verify the displacement capacity of shear wall has been arised to produce suitable data for the performance based design. In this paper, a process is presented to evaluate the displacement capacity of shear wall. The displacement of shear wall is expressed as the superposition of shear and flexural deformation. Variable crack angle truss model with a modification and sectional analysis method are used in calculating shear and flexural displacement, respectively. In addition, the effect of axial force and the contribution of vertical and horizontal reinforcements in wall are considered in the analysis. The accuracy of proposed method is evaluated by the comparison calculation results with previous test results. From the comparison, it was shown that the hysteretic behavior of shear wall could be well predicted by using the process. In the case with flange wall, however, the method overestimates the contribution of flange wall for strength and stiffness and underestimates for displacement capacity.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2006.04a
• /
• pp.865-872
• /
• 2006

Recently, many apartment buildings in the shear wall system often has pilotis in the lower story to meet the architectural needs. If the lateral force resisting system consists of shear walls supported by columns and beams. the discontinuity at the lowest level with pilotis results in the vertical irregularity with strength and stiffness. So, there are needs to be considered tile analysis and design about column and beam bellow shear walls and the behavior and stress condition of structure by stiffness change being generated at shear walls. The purpose of this paper is to investigate the behavior of shear wall structures with pilotis using the floors modeled as rigid diaphragm or semi rigid diaphragm. Through analyses, after estimating values of the story drift, natural period, stress condition of shear walls and the forces of column, we inferred how the behavior of shear wall structures with pilotis was influenced by the floor stiffness.

• Journal of Industrial Technology
• /
• v.3
• /
• pp.103-116
• /
• 1983

Recent developments in multi-storey buildings for residential purpose have led to the extensive use of shear walls for the basic structural system. When the coupled shear wall system is used, joined together with cast-in-place concrete or mortar (or grout), the function of the continuous joints is a crucial factor in determining the safety of L.P. Precast concrete shear wall structures, because the function of the continuous joints(Vertical wall to wall joints) is to transfer froces from one element(shear wall panel) to another, and if sufficient strength and ductility is not developed in the continuous joints, the available strength in the adjoining elements may not be fully utilized. In this paper, the influence of the stiffness of vertical joints(wet vertical keyed shear joints) on the behaviour of precast shear walls is theoretically investigated. To define how the stiffness of the vertical joints affect the load carrying capacity of L.P.Precast concrete shear wall structure, the L.P.Precast concrete shear wall structure is analyzed, with the stiffness of the vertical joints varying from $K=0.07kg/mm^3$(50MN/m/m) to $K=1.43kg/mm^3$(1000MN/m/m), by using the continuous connection method. The results of the analysis shows that at the low values of the vertical stiffness, i.e. from $K=0.07kg/mm^3$(50MN/m/m) to $K=0.57kg/mm^3$(400MN/m/m), the resisting bending moment and shearing force of precast shear walls, the resisting shearing force of vertical joints and connecting beams are significantly affected. The detailed results of analysis are represented in the following figures and Tables.