• Structural Engineering and Mechanics
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• 제53권1호
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• pp.1-16
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• 2015

Due to design codes and regulations and the variety of building plans in Turkey, it is very often seen that band-type windows are left for ventilation and lightening of the basements of buildings which are used for various purposes such as workplaces and storage. Therefore when the necessary support measures cannot be given, short columns are subjected to very high shear forces and so damage occurs. One of the precautions to avoid the damage of short column mechanisms in buildings where band-type windows are in the basement is to strengthen the short columns with fiber reinforced polymer (FRP). In this study, the effect of the FRP retrofitting process of the short columns around band-windowed structures, which are found especially in basement areas, is analyzed in accordance with Turkish Seismic Code 2007 (TSC 2007). Three different models which are bare frame, frame with short columns and retrofitted short columns with FRP, are created and analyzed according to TSC 2007 performance analysis methods to understand the effects of band windows in basements and the effect of FRP retrofitting.

• Structural Engineering and Mechanics
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• 제31권4호
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• pp.423-437
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• 2009

In order to perform a step-by-step force-displacement response analysis or dynamic time-history analysis of large buildings with masonry infilled R/C frames, a continuous force-deformation model based on an equivalent strut approach is proposed for masonry infill panels containing openings. The model, which is applicable for degrading elements, can be implemented to replicate a wide range of monotonic force-displacement behaviour, resulting from different design and geometry, by varying the control parameters of the model. The control parameters of the proposed continuous model are determined using experimental data. The experimental program includes fifteen 1/3-scale, single-story, single-bay reinforced concrete frame specimens subjected to lateral cyclic loading. The parameters investigated include the shape, the size, the location of the opening and the infill compressive strength. The actual properties of the infill and henceforth the characteristics needed for the diagonal strut model are based on the assessment of its lateral resistance by the subtraction of the response of the bare frame from the response of the infilled frame.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.453-456
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• 2004

RC frames built prior to the advent of the philosophy of ductile concrete is one type of existing construction susceptible to damage. Strengthening and stiffening of such frames has been accomplished by infilled frames with cast-in-place, reinforced concrete walls. Placement of CIP shear walls within strategic bays of a structure appears to be a logical and economical method to strengthen a reinforced concrete frame and to stiffen a building in order to reduce architectural and mechanical damage. This study investigates the seismic performance of cast-in place infilled shear wall within existing frames. The object of this study is to clarify the seismic capacity and characteristics in the hysteretic behavior of bare frame, CIP infilled shear wall and CIP infilled wall reinforced diagonal bars.

• Earthquakes and Structures
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• 제9권4호
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• pp.735-752
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• 2015

The effectiveness of seismic retrofitting of RC-frame buildings by converting selected bays into new walls through infilling with RC walls was studied experimentally using a full-scale four-storey model tested with the pseudo-dynamic (PsD) method. The frames were designed and detailed for gravity loads only using different connection details between the walls and the bounding frame. In order to simulate the experimental response, two numerical models were formulated differing at the level of modelling. The purpose of this paper is to illustrate the capabilities of these models to simulate the experimental nonlinear behaviour of the tested RC building strengthened with RC infill walls and comment on their effectiveness. The comparison between the capacity, in terms of peak ground acceleration, of the strengthened frame and the one of the bare frame, which was obtained numerically, has shown a five-fold increase.

• 한국지진공학회논문집
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• 제16권1호
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• pp.47-59
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• 2012

본 연구에서는 학교건물에서 나타나는 전형적인 조적조 채움벽 골조의 내진성능을 등가 스트럿 모델을 통해 평가하였다. 순수골조모델, 중심스트럿모델 및 편심스트럿모델의 세 가지 모형화 방법을 채택하였고, 문헌상으로 얻을 수 있는 범위의 스트럿 강성과 강도를 적용하여 거동특성의 차이를 분석하였다. 역량스펙트럼에 의해 산정된 성능점에서의 변위 및 손상정도에 큰 차이가 나타났으며, 채움벽은 순수골조모델과 비교할 때 중심스트럿모델에서는 유리하게, 편심스트럿모델에서는 불리하게 작용하는 것으로 나타났다. 최종극한변위에서의 거동 또한 모형화 방법 및 재료 속성에 따라서 최대강도, 층간변위, 파괴된 부재 수 및 위치 등에 큰 차이가 나타났다.

• KCI Concrete Journal
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• 제11권3호
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• pp.153-164
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• 1999

The objective of this research is to observe the actual response of a low-rise nonseismic moment-resisting masonry-infilled reinforced concrete frame subjected to varied levels of earthquake ground motions. The reduction scale for the model was determined as 1 : 5 considering the capacity of the shaking table to be used. This model was, then, subjected to the shaking table motions simulating Taft N2IE component earthquake ground motion, whose peak ground acceleration(PGA) was modified to 0.12g, 0.2g, 0.3g, and 0.4g. The g1oba1 behavior and failure mode were observed. The lateral accelerations and displacements at each story and local deformations at the critical portions of the structure were measured. Before and after each earthquake simulation test, free vibration tests and white noise tests were performed to find the changes in the natural period of the model. When the results of the masonry-infilled frame are compared with those of the bare frame, it can be recognized that masonry infills contribute to the large increase in the stiffness and strength of the g1oba1 structure whereas it also accompanies the increase of earthquake inertia forces. However, it is judged that masonry infills may be beneficial to the performance of the structure since the rate of increase in strength appears to be greater than that of the induced earthquake inertia forces.

• 한국해양공학회지
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• 제26권3호
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• pp.1-5
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• 2012

A complex energy saving device has been developed for middle class vessels. The propulsive performance of the developed device is described through a model test. The pre-swirl stator, which recovers the rotational energy of the propeller slipstream, is a well-known energy saving device for large vessels. The pre-swirl stator for a large vessel is usually cast as a part of the stern frame and has a high cost. The manufacture of a cast stator for an existing vessel is almost impossible. The complex device that was developed can be fitted on astern frame by welding. The model tests show a 4-6% efficiency gain for middle class vessels with the developed appendages compared to those with bare hulls.

• Earthquakes and Structures
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• 제4권1호
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• pp.85-108
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• 2013

The research presented in this paper deals with the seismic protection of existing frame structures by means of passive energy dissipation. A displacement-based procedure to design dissipative bracings for the seismic protection of frame structures is proposed and some applications are discussed. The procedure is based on the displacement based design using the capacity spectrum method, no dynamic non linear analyses are needed. Two performance objective have been considered developing the procedure: protect the structure against structural damage or collapse and avoid non-structural damage as well as excessive base shear. The compliance is obtained dimensioning dissipative braces to limit global displacements and interstorey drifts. Reference is made to BRB braces, but the procedure can easily be extended to any typology of dissipative brace. The procedure has been validated through a comparison with nonlinear dynamic response of two 2D r.c. frames, one bare and one infilled. Finally a real application, on an existing 3D building where dissipative braces available on market are used, is discussed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.129-132
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• 2005

The primary purpose of this investigation is to find out the shear behavior and the shear capacity of RC bare frames, brick-infilled RC frames, and damper-retrofitted RC frames and to evaluate the average shear strength of brick--infill wall. The main variables art the absence of brick infill wall and steel plate slit damper. The test results show that the shear capacity of specimen IF-DR is 2.8 times as high as that of the specimen BF and it presents the fact that the retrofitting effect and the possibility of RC frame reuse with changing the slit damper is verified. And the average shear strength of the brick infill wall is figured to be at $5.0 kgf/cm^2$.

• Structural Engineering and Mechanics
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• 제26권3호
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• pp.231-250
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• 2007

The influence of masonry infills with eccentric openings on the seismic performance of reinforced concrete (r/c) frames that were designed in accordance with current code provisions are investigated. Eight 1/3-scale, single-story, single-bay frame specimens were tested under cyclic horizontal loading up to a drift level of 4%. In all examined cases the shear strength of columns was higher than the cracking shear strength of solid infill. The parameters investigated include the shape and the location of the opening. Assessment of the behavior of the frames is also attempted, based on the observed failure modes, strength, stiffness, ductility, energy dissipation capacity and degradation from cycling loading. Based on these results there can be deduced that masonry infills with eccentrically located openings has been proven to be beneficial to the seismic capacity of the bare r/c frames in terms of strength, stiffness, ductility and energy dissipation. The location of the opening must be as near to the edge of the infill as possible in order to provide an improvement in the performance of the infilled frame.