A cantilever riverside boardwalk has been opened to the public as shown in Figure Q.2; however, it was found that the structure experiences significant human- and traffic-induced vibrations. A harmonic oscillation test found the natural frequency of the structure to be 2.25 Hz. It is proposed to retro-fit braced struts at 5m spacing so that the natural period of vibration will be 9 Hz, Given that E 200 kN/mm and ignoring buckling effects, determine the required area of the strut. - 1 m A B 4 m 100 kg/m PROPOSED STRUT PIN Figure Q2 4 m