題組內容

(20%) 2. A two-story building has steel columns AB in the first floor and BC in the second floor. The roof load P1 equals 400 kN and the second-floor load P2 equals 720 kN. Each column has length L = 3.75 m. The cross-sectional areas of the first- and second-floor columns are 11,000 mm2and 3900 mm2, respectively.
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(b) How much additional load P0 can be placed at the top of the column (point C) if the total shortening 612743e1bc9d2.jpg is not to exceed 4.0 mm? (10%)