Experiment of Friction-type Reinforcing Members for Upgrading Wind-Resistant Performance of Transmission Towers

송전철탑의 내풍성능 향상을 위한 마찰형 보강기구 실험

A friction-type reinforcing member(FRM) is proposed for the purpose of upgrading wind resistant performance of a transmission tower and verified through cyclic loading tests. First, suitable install scheme of the FRM is investigated through numerical analysis. Main-post-reinforcing type and X-brace type installation schemes are examined, and numerical analysis shows that the former is more effective due to the vertical cantilever type behavior of the transmission tower. Based on this result, two types of the FRM's, dissipating energy in slotted belted connections, are proposed. The one utilizes the relative displacement between the FRM and the main post, and the other utilizes that between the separated angles consisting of the FRM as a slip deformation of the slotted bolted connection. Proposed FRM's are installed on each main post of the 1/2 scale substructure models of an actual transmission tower body. From cyclic loading tests, the latter type of the proposed FRM's dissipates energy more effectively and its slip load is controlled by applied torque well, and shares considerable amount of the axial force in the main post.