The column base may yield even if the building is designed to perform the beam yielding mechanism. Nevertheless, the yielding of the column base leads to instability of the overall structure. This project thereby develops the mid-story pin system to control the distribution of bending moment between the top and bottom column in the first story. Additionally, the ultimate seismic capacity of steel moment-resisting frames with the system is assessed experimentally and analytically.

 

Clarifying the structural performance of steel piles is highly demanded to secure building safety. The current seismic guideline does not precisely grasp the ultimate state of actual steel piles, such as the interaction between the steel piles and infilled concrete. In addition, the piles can originate the flexural buckling in the liquefied soil since the bracing force from the soil decreases tremendously. This project constructs the ultimate design method of steel piles by revealing the dynamic buckling behavior based on centrifuge tests.

 

The lateral buckling of steel beams is critical, particularly for large-span structures. Moreover, the non-structural members such as purlin and folded-plate roof are usually attached to the beams. Thus, the lateral buckling strength increases compared with bare steel members. This project invents the evaluation method of lateral buckling strength of large-span beams through the theoretical induction, loading tests, and finite element analyses.

 

Recently, braced steel structures have prevailed since they can reduce structural damage even in a huge earthquake. However, the appropriate design of the surrounding frame is necessary to maximize the efficiency of the damper, which dissipates the energy of vibration. Furthermore, the concrete slab is generally settled above the beam, differentiating the stress transfer path and structural capacity. The current design provisions have not clarified this complex phenomenon fluctuating during earthquakes. This project creates the seismic design method of structural members in the braced frames considering the composite effect.