Discussion of Principles of Structural Analysis and Design problems in preparation for Civil Engineering Licensure Examination.
Curated by: Engr. Harf Miranda (Sir Harf Engineering Tutorial) (125 videos)
SITUATION: The flooring of a warehouse is made up of double-tee joists (DT) as shown in Figure LPT-012. The joists are simply supported on a span of 7.5m and are pre tensioned with one tendon in each stem with an initial force of 745 kN each, located at 75 mm above the bottom fiber, loss of stress at service load is 18%. Load imposed on the joists are: Dead load = 2.3 kPa (does not include self -eight) Live load = 6 kPa Properties of DT: A = 200,000 mm² yt = 88 mm I = 1880 x 10^6 mm^4 yb = 267 mm 7. Compute the stress at the top fiber of the DT at mid-span due to the initial pre stressing force and self-weight. A. 4.36 (T) C. 17.11 (C) B. 9.67 (T) D. 20.84 (C) 8. Compute the resulting stress at the bottom fiber of the DT at mid-span due to the service loads and final pre-stressing force. A. 14.74 (C) C. 6.45 (T) B. 9.75 (T) D. 28.19 (C) 9. What additional super imposed load can the DT carry such that the resulting stress at the bottom fibers at mid-span is zero? A. 7.33 kPa C. 14.76 kPa B. 6.15 kPa D. 4.07 kPa