CIV2235—STRUCTURAL MATERIALS
Week 10 Practice Class
Actions and Action combination
Part I. Actions
Assume that you are designing an office building of 10 stories. The floor plan is given in Fig 1 and the cross sections are shown in Fig 2. The data for the problem is:
n Density of concrete: 2500 kg/m3
n Superimposed dead load: 1.5 kPa
n g = 9.8 m/s2
n The distance from top of slab to top of slab is 3.5 meters
n The floors and roofs thickness is 150 mm
n All beams are 300 mm wide and 500 mm deep
n All columns are 350 x 350 mm2
n Beam supports are assumed to be simple supports (easy for moment calculation).
Fig 1. Floor plan.
Fig 2. Cross sections at AA, BB and CC.
Question 1. Prove the conversion formula shown in Figs 3 and 4 (20 marks).
Fig 3. Conversion formula: from triangular load to UDL.
Fig 4. Conversion formula: from trapezoidal load to UDL.
Question 2. Determine the dead load and live load in the slab (10 marks).
Question 3. Determine the dead load and live load in the beam B1 (30 marks).
Question 4. Determine the live load in the beam B2 (10 marks).
Part II. Action combinations
Consider the frame. given in Fig. 5. Determine the maximum and minimum design bending moment at the midspan from the following load cases:
n 1.35G
n 1.2G+1.5Q
n 1.2G+w+0.4Q
n 0.9G+w
For wind load w, consider two cases w1 and w2.
Fig 5. Frame. and actions.