In this study, as a part of the BCP (Business Continuous Plan), the performance tests of the rocking wall and the steel damper were carried out. The rocking wall was made of concrete block. The concrete block was connected to the floor by two hinges. However, in the performance test, the hinge part was destroyed and the experiment was finished. This will be due to the fact that the hinge has not rotated, and will be retested after reinforcement of the concrete block.

In this study, literature review on the method of reinforcing the special shear wall boundary element was carried out. As a reviewing results of two studies, it was evaluated that it is possible to reinforce the boundary element using rectangular steel pipe, H-shaped section steel and lattice material.

기존 골조구조물의 횡 변위 조절이 가능한 댐퍼 시스템을 개발하기 위한 목적으로 상세개발 및 성능실험을 실시하였다. 개발 상세는 기둥간 보의 변형을 방지하기 위하여 고안된 ALD및 층간변위를 제어하기 위하여 고안된 AWD로 구분되며, 기존 연구결과의 비보강 BF를 비교대상으로 사용하였다. 파괴양상, 하중-변위 곡선, 포락선, 최대강도, 강성저하 및 에너지 소산능력 등을 비교 평가하였으며, ALD 및 AWD 의 내진보강효과를 확인할 수 있었다. 또한 아라미드 시트로 기둥을 구속하는 공법이 내진성능 향상에 매우 우수함을 확인하였다.

In this study, seismic strengthening method using precast concrete rocking wall is considered in the literature studies. As a result of reviewing the two studies, it is considered necessary to develop a sequential study on development of lightweight precast wall panel, application of post-tension method, and development of location and shape of energy dissipation devices.

In this study, the seismic retrofitting effect of existing frame was evaluated. The strength and energy dissipation capacities of three reinforcement methods were evaluated based on the existing literatures. In the case of strength and energy dissipation capacity, it was evaluated that reinforcing effect of specimen reinforced with damper by installing K brace inside the frame was excellent. Also, it was evaluated that there is an effect of seismic reinforcement in the external retrofitting case. Therefore, proper seismic retrofit planning is expected to ensure the seismic safety of buildings.

In this study, it was evaluated the detection results of ground penetration radar (GPR) by using pixel difference. Experimental tank was made for this purpose. Concrete hume pipe and PE pipe were buried in the tank. The pavement finish of the surface was classified 4th cases. In the case of non-reinforcement concrete pavement, the buried pipe detection was easy than other pavement cases. And it was easy to detect the buried pipe by the difference of the color pixels rather than the black and white pixels.

This study summarizes the results of the research results published by the researchers after the 2016 Gyeongju earthquake and will be reflected in the development of the seismic control system to be conducted in the future. Although various researchers' seismic analysis and effective frequency analysis for Gyeongju earthquake have been proposed, it is necessary to present the certified seismic records to evaluate the proper seismic response of the structure.

In this study, the behavior of column rebar in non-reinforced specimens (BF) was evaluated as part of the development of seismic retrofitting systems for public buildings such as school buildings. This is a very useful work because it can show the deformation state of the main bars according to the hysteretic behavior of lateral loads. When yielding the specimen, the main bar was yielded. and the deformation of stirrup at the inflection point position hardly occurred. These results will be used as a key index to evaluate the yield state of the structure from the deformation comparison of the reinforced specimens.

본 연구의 목적은 지반침하를 방지하기 위하여 지반에 매립된 파이프 및 공동의 패턴 데이터베이스를 구축하는데 있다. 이를 위하 여 Open CV를 이용한 패턴 템플레이트 알고리즘을 개발하였으며, 이를 토조 GPR 탐사결과에 적용하였다. 그 결과 적절한 패턴 데이터베이스 구축이 가능하였다. 본 연구결과는 제한적인 실험결과만을 근거로 한 것이기 때문에, 향후 다양한 현장자료 및 대규모 테스트베드의 탐사결과 등이 보완되면 보다 실증적인 자료가 구축될 것으로 판단된다.

For the use of recycled aggregate concrete, the early strength is evaluated. The test variables are replacement ratio of recycled aggregate, steel fiber and blast furnace slag powder. For this, 6th concrete mixing plan is prepared. As a result, it is evaluated that the early strength depends on the steel fiber volume fraction and replacement ratio of blast furnace slag powder.

The aim of this study is a large amount use of recycled aggregates. The considering recycled aggregates replacement ratio is 50% that of natural aggregates. In order to increase the shear capacity of beams, that may be weaken by use of recycled aggregates, steel fibers are reinforced. The main variables are steel fiber volume fractions such as 0%, 0.5%, 0.75% and 1.0%. After the test, it could confirm that the strength and deformation capacity of beams with the steel fiber content values of 0.5% and 0.75% are comprehensively enhanced compared to non reinforcement. After evaluating the shear strength by using shear strength equations of previous researches, it concluded that the strength equation of Oh et al. (2008) is able to predict the shear strength of SFRC beams on the safety side.

For the use of recycled aggregate concrete, the early strength is evaluated. The test variables are replacement ratio of recycled aggregate, steel fiber and blast furnace slag powder. For this, 6th concrete mixing plan is prepared. As a result, it is evaluated that the early strength depends on the steel fiber volume fraction and replacement ratio of blast furnace slag powder.

This study is to determine the predictability of the ground cavitation by GPR (ground penetrating radar) equipment. Hume pipe, PE pipe, Steel Pipe and EPS (expanded polystyrene) are buried in the test bed. According to detection results, the EPS was not well detected. It received a lot of interference signal of other buried things. Otherwise the buried pipes were well detected.

The purpose of this study is a image processing program development to consider the domestic situation of GPR detection. Therefore the image processing program will be developed to extract and to visualize the measured raw data.

The purpose of this study is an GPR image processing program (GPRiPP) development. And the developed GPRiPP has many image processing functions such as background removal, stacking and Gain function. With the GPR detection results of such as test bed, GPRiPP will be tested and modified in the near future.

To get the empirical data of GPR detection and to develop the image prosessing program of GPR detection data, GPR detection were proceed by the underground pipes and cavities buried in the Chamber. In the case of non pavement and asphalt pavement, water filled cavity that was buried in 0.7m depth was able to detection. But in the case of 1.0 m and 1.3 m buring depth, water filled cavity was not able to detection. In the case of non-reinforced and reinforced concrete pavement, it was difficult to detect the cavity caused by signal interference. GPRiPP programs was developed for image processing of the GPR detection data. The major processing algorithm were background removal, stacking and gain function. With proper image processing of gain function and background removal in GPRiPP program, it was showed that similar results can be obtained with conventional image processing program.

This study evaluates the material performance of slump value and compressive strength of the concrete which was made by recycled sand and blast furnace slag powder(BFSP). The main variables are replacement ratio of BFSP. As a result, it was evaluated that more detailed evaluation is needed in long-term strength development and the compensation of slump value to the replacement ratio of BFSP.

In this study, Cavities in Specimens were find using GPR equipment. Results of exploration deadline for plain concrete, reinforced concrete, asphalt, gravel, depending on the type, asphalt pavement was most clearly exploration. Developed GPRiPP can represent a good cavitation through the image processing with the background removal.

본 연구에서는 토조에 설치한 관의 종류 및 매립 깊이, 공동 깊이 및 포장 조건 등에 대한 GPR(Ground Penetrating Radar) 탐사를 진 행하여 매립관의 종류 및 공동 탐사 능력을 실험적으로 규명하였다. 아스팔트 포장 및 비포장의 경우, 콘크리트 포장 및 철근 콘크리트 포장 대 비 매립관의 탐사가 용이한 것으로 평가되었다. 또한 공기 공동의 경우, 매립 깊이 1 m에서는 탐지가 가능한 것으로 평가되었다.

So far, various experiments were carried out and published on recycled aggregates. But the structural use of recycled aggregates were very limited. To use a recycled coarse aggregate as structural materials, evaluation of compressive strength and splitting tensile strength were proceed according to replacement ratio of recycled coarse aggregate.