The paper introduces an experimental program for the newly developed vertical joints between Precast Concrete (PC) walls to improve their in-plane shear capacity. Compared to the existing vertical joints, two types of vertical joints were developed by increasing the transverse reinforcement ratio and improving frictional force at the joint interface. A total of four specimens including the Reinforced Concrete (RC) wall and PC walls with developed vertical joints were designed and constructed. The constructed specimens were experimentally investigated through monotonic shear tests. The observed damage, load-deformation relationship, strain and strength are investigated and compared with the cases of RC wall specimen. Experimental results indicate that the maximum force and initial stiffness of the PC wall with proposed vertical joints were decreased by comparing with those of RC wall. However, the ultimate displacement increased by up to 217.30% compared to the RC wall specimen. In addition, brittle failure did not occurred and relatively few cracks and damages occurred.

In this study, an incremental loading test of the HRS(Hybrid Rubber Slit) damper was additionally performed to define the physical characteristics according to the incremental test results, and an analytical study was performed according to the damping design procedure by selecting an example structure. As a result of performing seismic performance evaluation before reinforcement by selecting a RC structure similar to an actual school structure as an example structure, the story drift ratio was satisfied, but some column members collapsed due to bending deformation. In order to secure the seismic performance, the damping design procedure of the HRS damper was presented and performed. As a result of calculating the amount of damping device according to the expected damping ratio and applying it to the example structure, the hysteresis behavior was stable without decrease in strength, and the story drift ratio and the shear force were reduced according to the damping effect. Finally the column members that had collapsed before reinforcement satisfied the LS Level.

It is effective to apply hybrid damping device that combine separate damping device to cope with various seismic load. In this study, HRS hybrid damper(hybrid rubber slit damper) in which high damping rubber and steel slit plate are combined in parallel was proposed and structural performance tests were performed to review the suitability for seismic performance. Cyclic Loading tests were performed in accordance with criteria presented in KDS 41 17 00 and MOE 2019. As a result of the test, the criteria of KDS 41 17 00 and MOE2019 was satisfied, and the amount of energy dissipation increased due to the shear deformation of the high-damping rubber at low displacement. Result of performing the RC frame test, the allowable story drift ratio was satisfied, and the amount of energy dissipation increased in the reinforced specimen compared to the non-reinforced specimen.

본 연구에서는 실대형 실험과 구조해석을 통해서 현장에서 사용되는 가새 시스템을 적용한 강관 골조 플라스틱 연동온실 의 횡하중 가력시험을 수행하고 성능을 분석하였다. 횡강성 과 응력을 분석하기 위해 실험체에 변위와 변형률계를 각각 9 개소 및 16개소 설치하였으며 가새의 설치 유무에 따른 성능 을 비교하기 위해 구조해석을 수행하였다. 실대형 실험과 가 새의 설치 유무에 따른 구조해석 결과 비교에서 구조물의 횡 강성이 많은 차이를 보였다. 실험체의 측고 부근에서 측정한 횡강성은 가새 시스템을 설치함으로 강성을 최대 44%까지 증 가시켰다. 현장에서 사용하는 가새의 접합부가 충분한 강성 을 확보하지 못함으로써 외력을 전체 구조물에 적절히 전달하 지 못하여 횡강성이 구조해석 결과보다 많이 저하되는 현상이 나타났다. 따라서 온실 설계 시 구조성능의 신뢰성을 높이기 위해서 가새 시스템의 연결방법, 설치위치, 부재의 최대길이 등 온실의 접합부에 대한 명확한 시공방법과 설계기준이 정립 되어 온실 설계가 이루어져야 할 것으로 판단된다.

본 논문에서는 프리팹 구조물의 품질관리를 위한 딥러닝 및 비전센서 기반의 조립 성능 평가 모델을 개발하였다. 조립부 검출을 위 해 인코더-디코더 형식의 네트워크와 수용 영역 블록 합성곱 모듈을 적용한 딥러닝 모델을 사용하였다. 검출된 조립부 영역 내의 볼트 홀을 검출하고, 볼트홀의 위치 값을 산정하여 k-근접 이웃 기반 모델을 사용하여 조립 품질을 평가하였다. 제안된 기법의 성능을 검증 하기 위해 조립부 모형을 3D 프린팅을 이용하여 제작하여 조립부 검출 및 조립 성능 예측 모델의 성능을 검증하였다. 성능 검증 결과 높은 정밀도로 조립부를 검출하였으며, 검출된 조립부내의 볼트홀의 위치를 바탕으로 프리팹 구조물의 조립 성능을 5% 이하의 판별 오차로 평가할 수 있음을 확인하였다.

본 연구는 콘크리트구조기준(KDS 14-2021)을 적용한 RC보와 ACI 440.1R-15를 적용한 FRP 콘크리트의 비교 연구를 수행하였다. 파라미터 변수로 피복두께, FRP의 탄성계수 및 극한변형률 그리고 보강량 4가지로 설정하여 비교, 분석을 수행하였 다. 파라미터 연구 분석 결과 FRP의 탄성계수와 극한 변형률이 클수록 FRP 콘크리트의 휨성능이 우수하지만, 극한 응력이 동일 할 때 극한 변형률보다 탄성계수를 크게 하는 것이 유리하다. FRP 콘크리트가 인장지배 단면이나 변화구간 일 때 극한 변형률 증가에 휨성능이 비례해서 증가하지만 압축지배 단면일 경우에는 극한 변형률이 증가해도 휨성능은 증가하지 않는다. 또한, FRP 콘크리트는 최소 피복두께가 필요하지 않아 추가적인 휨성능이 17∼33% 증진 효과가 나타났다.

Tuned mass damper (TMD) is widely used to reduce dynamic responses of structures subjected to earthquake loads. A smart tuned mass damper (STMD) was proposed to increase control performance of a traditional passive TMD. A lot of research was conducted to investigate the control performance of a STMD based on analytical method. Experimental study of evaluation of control performance of a STMD was not widely conducted to date. Therefore, seismic response reduction capacity of a STMD was experimentally investigated in this study. For this purpose, a STMD was manufactured using an MR (magnetorheological) damper. A simple structure presenting dynamic characteristics of spacial roof structure was made as a test structure. A STMD was made to control vertical responses of the test structure. Two artificial ground motions and a resonance harmonic load were selected as experimental seismic excitations. Shaking table test was conducted to evaluate control performance of a STMD. Control algorithms are one of main factors affect control performance of a STMD. In this study, a groundhook algorithm that is a traditional semi-active control algorithm was selected. And fuzzy logic controller (FLC) was used to control a STMD. The FLC was optimized by multi-objective genetic algorithm. The experimental results presented that the TMD can effectively reduce seismic responses of the example structures subjected to various excitations. It was also experimentally shown that the STMD can more effectively reduce seismic responses of the example structures conpared to the passive TMD.