• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.5
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• pp.11-21
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• 2007

Currently in the country, the necessity of seismic analyses is increasing due to the increase of demand and interest in seismic design. Especially, shear wall apartments are constructed mostly for a residental building so seismic analyses for the apartment are actively executed. For the seismic analysis of the shear wall apartment, it may be not efficient in time and effort to model the entire structure by a finite element mesh. Therefore, an equivalent model is needed to simulate the dynamic behavior of the structure by decreasing the number of degrees of freedom. In this study, a method to form an equivalent model that is simple and easy to use was proposed utilizing effective mass coefficient that is highly correlated to mode shape of the structure. This equivalent model was obtained by replacing a shear wall structure with an equivalent frame structure having beams and columns. This model can be used very effectively when excessive seismic analyses are necessary in a short period because it can be operated in any commercial program and reduce the analysis time. Also, it can model floor slabs so it can represent the actual behavior of shear wall apartments. Furthermore, it is very excellent since it can represent the asymmetry of the structure.

• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.636-646
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• 2017

This thesis aims to create a new technique by applying traditional ceramics technique. As a matter of fact, on the toremi plate of the sieve-frame skein technique, the weld on which various patterns are squeezed, is attached to the cylinder made of clay on the spinning wheel. And it is the concept that maximizes aesthetic beauty by expressing distorted pattern and free dismantling of existing pattern by pushing it out from inside by the turn of electric spinning wheel for the first time.The main point of view of this aesthetic source is that most of the surface of the ceramics is a spherical curved surface and looks distorted like an indicator drawn on a globe. The researcher created a dynamic and humorous technique of expression through the free dismantling of the squashed shapes and the distorted patterns and called it the bating sealing weld outer wall extension technique.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.579-585
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• 2017

Development of a facade system that can reduce load factor and costs in high-rise building construction is required. The proposed cable wall system is used as a structural support by the glass-cable and can increase openness on lower elevations and the lobby area. Its use in high-rise buildings can reduce construction costs. Without transferring directly a strong initial tension of the cable to the building frame is connected to the steel member and the reinforced concrete structures, by absorbing the initial tension of the cable, it is possible to control the occurrence of a strong concentrated loads to the structure. Comparison of load-displacement test results from the numerical analysis with the test results showed reasonable agreement, Therefore, the proposed numerical results confirm good prediction of cable behavior for the facade system.

• Structural Engineering and Mechanics
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• v.27 no.6
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• pp.713-739
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• 2007

Nowadays computers can perform symbolic computations in addition to mere number crunching operations for which they were originally designed. Symbolic computation opens up exciting possibilities in Structural Mechanics and engineering. Classical areas have been increasingly neglected due to the advent of computers as well as general purpose finite element software. But now, classical analysis has reemerged as an attractive computer option due to the capabilities of symbolic computation. The repetitive cycles of simultaneous - equation sets required by the finite element technique can be eliminated by solving a single set in symbolic form, thus generating a truly closed-form solution. This consequently saves in data preparation, storage and execution time. The power of Symbolic computation is demonstrated by six examples by applying symbolic computation 1) to solve coupled shear wall 2) to generate beam element matrices 3) to find the natural frequency of a shear frame using transfer matrix method 4) to find the stresses of a plate subjected to in-plane loading using Levy's approach 5) to draw the influence surface for deflection of an isotropic plate simply supported on all sides 6) to get dynamic equilibrium equations from Lagrange equation. This paper also presents yet another computationally efficient and accurate numerical method which is based on the concept of derivative of a function expressed as a weighted linear sum of the function values at all the mesh points. Again this method is applied to solve the problems of 1) coupled shear wall 2) lateral buckling of thin-walled beams due to moment gradient 3) buckling of a column and 4) static and buckling analysis of circular plates of uniform or non-uniform thickness. The numerical results obtained are compared with those available in existing literature in order to verify their accuracy.

• Structural Engineering and Mechanics
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• v.51 no.3
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• pp.487-502
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• 2014

In buildings structures, the flexural stiffness reduction of beams and columns due to concrete cracking plays an important role in the nonlinear load-deformation response of reinforced concrete structures under service loads. Most Seismic Design Codes do not precise effective stiffness to be used in seismic analysis for structures of reinforced concrete elements, therefore uncracked section properties are usually considered in computing structural stiffness. But, uncracked stiffness will never be fully recovered during or after seismic response. In the present study, the effect of concrete cracking on the lateral response of structure has been taken into account. Totally 120 cases of 3 Dimensional Dynamic Analysis which considers the real and accidental torsional effects are performed using ETABS to determine the effective structural system across the height, which ensures the performance and the economic dimensions that achieve the saving in concrete and steel amounts thus achieve lower cost. The result findings exhibits that the dual system was the most efficient lateral load resisting system based on deflection criterion, as they yielded the least values of lateral displacements and inter-storey drifts. The shear wall system was the most economical lateral load resisting compared to moment resisting frame and dual system but they yielded the large values of lateral displacements in top storeys. Wall systems executes tremendous stiffness at the lower levels of the building, while moment frames typically restrain considerable deformations and provide significant energy dissipation under inelastic deformations at the upper levels. Cracking found to be more impact over moment resisting frames compared to the Shear wall systems. The behavior of various lateral load resisting systems with respect to time period, mode shapes, storey drift etc. are discussed in detail.

• Journal of architectural history
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• v.23 no.1
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• pp.7-19
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• 2014

This study considers the proper repair techniques by examining the most representative repair cases of the Korean arch bridges and proposes the constructional manual which can apply similar occasions. The cases are Seonamsa Seungseongyo and Songgwangsa Geukrockgyo where this researcher had taken part in the repair works. This Study proposes the maintenance construction manual about the performance degradation drew by performance degradation of the both Korean arch bridges in the maintenance process. First, arch bridge maintenance should be carried out in the dry season, when water is impermeable in the bottom surface of the bridge. Moreover, risk factors of the maintenance should be excluded to secure the water vally flow, the bypass and the temporary bridge. Second, prior to repair, it has to precede (1)3D shooting (2)formal examination (3)structure safety test (4)geological and lithic surveys (5)arch curvature establishment and makeshift frame settlement before transformation (6)relationship expert comments. Third, if the baduk and the foundation stones are inevitable to replace due to performance degradation on the foundation, it should use the high quality stones and secure greater stress by extending the standard range. The foundation on irregular rock needs to be flattened and underside on the replaced materials require Grengyijil to deliver the equal loads. Fourth, In the process of dismantling the stones of the arched bridge, it could make heavy weathering degree and not reuse the materials. Charge should converge the expert advices to choose the reuseable, the conservate and the alternative materials, and increase the reutilization of the raw materials by preservation and reinforcement treatments. Fifth, the side wall should be repaired by the rubble work technique which is not able to pile compost satiety, so it must use long depth of masonary stones for reinforcement. It is considered to reinforce the stone wall in shore as much as possible and protect the abutment and the side wall on the upstream for the arch bridge maintenance works.

• Wind and Structures
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• v.28 no.3
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• pp.181-190
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• 2019

Light-frame wood structures have the ability to carry gravity loads. However, their performance during severe wind storms has indicated weakness with respect to resisting uplift wind loads exerted on the roofs of residential houses. A common failure mode observed during almost all main hurricane events initiates at the roof-to-wall connections (RTWCs). The toe-nail connections typically used at these locations are weak with regard to resisting uplift loading. This issue has been investigated at the Insurance Research Lab for Better Homes, where full-scale testing was conducted of a house under appropriate simulated uplift wind loads. This paper describes the detailed and sophisticated numerical simulation performed for this full-scale test, following which the numerical predictions were compared with the experimental results. In the numerical model, the nonlinear behavior is concentrated at the RTWCs, which is simulated with the use of a multi-linear plastic element. The analysis was conducted on four sets of uplift loads applied during the physical testing: 30 m/sincreased by 5 m/sincrements to 45 m/s. At this level of uplift loading, the connections exhibited inelastic behavior. A comparison with the experimental results revealed the ability of the sophisticated numerical model to predict the nonlinear response of the roof under wind uplift loads that vary both in time and space. A further component of the study was an evaluation of the load sharing among the trusses under realistic, uniform, and code pressures. Both the numerical model and the tributary area method were used for the load-sharing calculations.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.96-105
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• 2002

Shear wall is the most important component resisting lateral loads imposed to a building by wind or earthquake. In shear walls, lateral load applied to framing is transmitted to sheathing panel through nailed joints between sheathing and framing so that the load is resisted by in-plane shear strength of sheathing. Therefore, nailed joints are the most basic and important component in the viewpoint of stiffness and strength of shear walls. In this study, stiffness and strength of single nailed joint were measured by single shear tests of nailed joints and used as input for theoretical models developed to estimate racking behavior of shear walls. And shear walls were tested to check the accuracy of theoretical models estimating racking resistance of shear walls. Stiffness of nailed joint was affected by grain direction of stud but direction of sheathing panel had little effect. Behavior of nailed joint and shear walls under lateral loads could be represented by three lines. Theoretical model II was more accurate than theoretical model I in estimating racking behavior of shear wall under loads.

• Structural Engineering and Mechanics
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• v.85 no.6
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• pp.793-808
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• 2023

Türkiye is located in a region where destructive earthquakes are frequently experienced due to its geological characteristics and geographical location. Therefore, considering the possibility of a devastating earthquake at any time, determining the reinforced concrete (RC) building seismic safety, constructed before or after the current seismic buildings code, is one of the most important issues to be completed firstly. For this purpose, rapid assessment methods developed to quickly determine the seismic safety of buildings are available in the literature. Comparison of the principles of Principles of the Determination of Risky Structures-2019, Column and Wall Index Method, P25 Scoring Method and Improved Discriminant Analysis Method, which are among these methods, have been aimed within the scope of this study. Within the scope of this paper, a total of 43 buildings in the Yalova/Çınarcık region of Türkiye that the damage level was determined by street observation method immediately after the 1999 Kocaeli (Izmit) Earthquake; 15 buildings with heavy damage and 28 buildings with moderate damage were examined by rapid assessment methods. Although the risk detection difference was not separated as a clear line in any of the methods used, the results obtained from the rapid assessment methods are evaluated as being compatible with the detected after earthquake structural seismic behavior of the buildings. The PDRS-2019 and column and wall index method gave the most approximate results. In the results obtained from the analyzes; structural features such as number of floors, frame continuity, soft/weak story irregularity, effective shear strength area, existence of heavy overhangs in plan, type of structural system have been found to be significantly effective on the earthquake behavior of buildings.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.118-128
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• 2012

As the bearing wall structure, which has been widely applied to domestic apartment buildings since the 1980s, cause many problems during remodeling of buildings, the government encourages constructors to adopt flat plate or rahmen structure through legal incentives. In line with such a trend, the green frame, an eco-friendly rahmen structure that has removed the shortcomings of previous structures, was developed to enhance structural safety, constructability, and eco-friendliness. The construction of green frame can reduce the labor cost and facilitate the composition of iron bars to reduce rebar loss through calculating the quality and establishing the bar bending schedule automatically on the precast concrete member data collected over the design phase. Therefore, the purpose of this study is to develop the algorithm to automate the calculation of iron bar volume for the green frame designed on composite precast concrete members. Automated algorithm to calculate concrete structural design information and design information. Practices through the application site should prove efficacy. The database established by the developed algorithm will automate the establishment of iron bar processing map and bar cutting list and the calculation of optimal composition and order volume to minimize the rebar loss. This will also reduce the expenses on management staff and overall construction cost through the minimization of rebar loss.