Faculty of Civil Engineering, UiTM

1. Unbraced Column Column Buckling Curve P Pcr Buckling strength L P2 Unbraced length P1 Existing member BRACE FORCE FORMULA Where P is the axial compression load Δ0 is the initial imperfection e0 is the load eccentricity βi is the ideal bracing stiffness, β is the provided bracing stiffness, Mechanical bracing Bracing member ENHANCEMENT OF STRUCTURAL CAPACITIES IN LATTICE TOWER USING MECHANICAL JOINTED BRACING Faculty of Civil Engineering, UiTM PM Ir. Dr. Sooi Took Kowng, En. Yong Chua Bon, Prof. Wan Mahmood Wan Abd Majid and Ir. Hj. Shan Bin Suleiman. Faculty of Civil Engineering, UiTM OBJECTIVES ABSTRACT As the telecommunication and electrical transmission industries expand, the strength of the existing lattice tower needs to be upgraded. This research focuses on the effectiveness of mechanical jointed bracings for strengthening existing lattice towers and developing design guidelines for a mechanical jointed bracings. Thirty-two numbers of equal angle columns were tested with and without single or double bracings. The results show that the jointed bracing system is effective in enhancing the column strength. The bracing members forces are higher than that suggested by the design recommendation of 2.5 %. A proposed analytical model based on eccentricity loadings and inelastic buckling is developed to predict the bracing forces. The predicted bracing forces show good correlation with the measured forces. • To study the effectiveness of mechanical jointed bracings for strengthening existing lattice towers. • To develop design guidelines for the mechanical jointed bracings. LITERATURE REVIEW • Lowers overall infrastructure cost. • New towers need not be built to cater for the next generation of telecommunication and transmission requirements. METHODOLOGY • Pending patent application. • Mechanical bracings have been used successfully to strengthened several existing towers. PROBLEM STATEMENT • Allows for continuous operation of the tower, while upgrading works are being carried out. • Allows existing tower to cater extra loading. • No site welding or drilling required. • Great potential for commercial applications. ENGINEERING PRINCIPLES/THEORETICAL BACKGROUND Bracings reduce column length & increase buckling resistance Column Buckles Braced Column 4Pcr Brace force Fbr L1 L2 L2 L1 RESULTS, ANALYSIS & DISCUSSION CONCLUSION ACKNOWLEDGEMENTS • RMI, UiTM • Faculty of Civil Engineering, UiTM