These researches results are analyzed and verified by various methodologies such as non-linear finite element analysis and scaled model experiment. Not only conducting those researches for academic purpose, we are striving to apply those research results to industry in reality by consistently participating in setting Korean Building Code(KBC), Korea Concrete Institute Standard(KCI), Performance-based design standard, and many other seismic design-related standards. We are publishing many papers, patents, institution activities and in active exchange with engineers. Our goal is contributing to Korea’s construction industry and development of companies in the perspective of global competitiveness.

The research topics that were performed in the past include the followings :

material model for concrete under various stress states, development of geopolymer concrete and Hwangto concrete, development of composite beams and columns, beam-column connections, slab-column connections, development of earthquake design/analysis method, applicability of high strength concrete and high strength reinforcing steel bars, soil-structure interaction of building under earthquake. The research topics being performed today are the followings : design method of nuclear plant wall structures with high-strength reinforcing bars, seismic performance and retrofit of small-scale buildings concerned with current issues on expanded coverage of seismic design provisions, shear resistance of RC beams in the view of economical design, development of details and verification of structural performance for steel-reinforced concrete columns and angle-truss composite beams with high-strength steel, researches on heavyweight impact sound of residential structures, development of non-cement binder and concrete using industrial by-product.

The main research topics that are performed recently includes the followings:

• 1) Corner steel plate-reinforced core wall system

  For better structural performance and constructability, a new composite core wall system using steel plate columns at the corners of the core section was developed. When compared to traditional RC core walls, the use of the corner steel plate columns provided better structural capacity, which allows less wall thickness and re-bars. Further, due to such effects, the construction cost and time can be reduced despite the use of steel plate columns.

• 2) Evaluation of load carrying capacity of wall with 700MPa reinforcing bar

  As the demand force is increased by earthquake load, high-strength reinforcing bars can be used for economic design of the wall. In the preset study, load carrying capacity of wall with 700 MPa rebars was investigated. Further, on the basis of the strain-based strength prediction model, evaluation method to accurately predict the strength of wall with 700 MPa bars was suggested.

• 3) Development of seismic fragility analysis for structures in nuclear power plants for SPRA applications

  Recent earthquakes such as Tohoku earthquake (Japan) and North Anna earthquake (U.S.) have resulted in the emergence of safety issues in nuclear power plants (NPPs) owing to increasing seismic demands (i.e., beyond design basis earthquakes (DBEs)). Therefore, seismic probabilistic risk assessment (SPRA) is performed to re-evaluate the seismic safety of operational NPPs based on the increased site-specific seismic demands.

• 4) Development of seismic performance evaluation technology of nuclear structures for excessively design high frequency earthquake

  In recent years, earthquakes of magnitudes 5.8 (Gyeong-Ju) and 5.4 (Po-Hang) had occurred in Korea. These earthquakes were reported to contain high-frequency contents. Thus, concerns about the safety of nuclear power plants under high-frequency earthquakes have increased. In this study, the reinforced concrete wall which is main structural element is evaluated about high-frequency earthquakes analytically and experimentally.

• 5) The study of hinge-frame retrofitting methods for reinforced concrete moment frames (especially in school building)

  As the Gyeongju Earthquake (2016) and Pohang Earthquake (2017) occur, the social concern and demand for securing sufficient safety of structures during earthquakes have increased greatly. Although many seismic retrofit methods have been developed for reinforced concrete moment frames, there are not clear methods that correctly proved seismic performance, joint performance, and design method. In this study, the seismic performance of the internal steel frame-retrofitting method was investigated through the two-story frame cyclic lateral loading test for almost real scale.