HW # 4

1. Design of Concrete Structure I University of Palestine بسم الله الرحمن الرحيم HW # 4 Instructor: Eng. Mazen Alshorafa

2. Design of Concrete Structure I University of Palestine Page 1 HW # 4 Problem # 1 The cross section of a short axially loaded tied column is shown in Figure [1]. It is reinforced with 6Φ20mm bars. Calculate the design load capacity of the cross section. Use fc′=250 kg/cm2 and fy = 4200 kg/cm2. Ties Φ8@25cm 20 6Φ20 Figure [1] 50 Problem # 2 The cross section of a short spirally reinforced column is shown in Figure [2]. It is reinforced with 8Φ25mm bars. Calculate the design load capacity of the cross section. Use fc′=250 kg/cm2 and fy = 4200 kg/cm2. spiral Φ8 Pitch=3.0cm 8Φ25 Figure [2] 40

3. Design of Concrete Structure I University of Palestine Page 2 HW # 4 Problem # 3 Design a short tied column to support an axial dead load of 150 tons and an axial live load of 50 tons, Initially assume ρg=2%. Use fc′=280 kg/cm2 ,fy = 4600 kg/cm2. Problem # 4 Design a short tied column to support an axial dead load of 280 tons and an axial live load of 180 tons, with the long side equal to two times the length of the short side. Initially assume ρg=2%. Use fc′=350 kg/cm2 ,fy = 4200 kg/cm2. Problem # 5 Design the reinforcement in a short tied column of size 70x20cm, subject to an axial dead load of 110 tons and an axial live load of 60 tons. Use fc′=250 kg/cm2 and fy = 4200 kg/cm2.

4. Design of Concrete Structure I University of Palestine Page 3 HW # 4 Problem # 6 Design a short spirally reinforced column to support an axial dead load of 80 tons and an axial live load of 130 tons. Use fc′=280 kg/cm2 ,fy = 4200 kg/cm2 and Initially assume ρg=2%. Problem # 7 Design the reinforcement in a short spirally reinforced column of 55cm diameter subjected to an axial dead load of 200 tons and an axial live load of 100 tons. Use fc′=300 kg/cm2 and fy = 4200 kg/cm2