1.A braced frame has a 10-ft-long column. Design a tied column with reinforcing bars on two end faces only to support the following service loads and moments: PD = 150 k, PL = 200 k MD = 50 ft-k, ML =...

1.A braced frame has a 10-ft-long column. Design a tied column with reinforcing bars on two end faces only to support the following service loads and moments: PD = 150 k, PL = 200 k MD = 50 ft-k, ML = 70 ft-k If necessary, adjust the column dimensions to qualify it as a short column. The column has equal end moments and a single curvature. Use fc ' = 4,000 psi and fy = 60,000 psi. 2. A pre-stressed concrete beam, 300 mm wide and 500 mm deep, is pre-tensioned by straight wires of 260 mm2 cross-sectional area, carrying an initial force of 450 kN at an eccentricity of 50 mm. Estimate the percentage loss of stress in steel due to elastic shortening. The modulus of elasticity of steel is 195 kN/mm2 (195 GPa). The modulus of elasticity and compression strength of concrete are 28 kN/mm2 (28 GPa) and 35 MPa (35 N/mm2), respectively.