ANALYSIS AND DESIGN OF FOOTINGS | Wall Footing скачать в хорошем качестве

ANALYSIS AND DESIGN OF FOOTINGS | Wall Footing

Sample problems for wall footings: PROBLEM 3. A 400 mm masonry wall supports a dead load of 200 kN/m and a live load of 158 kN/m. The allowable soil bearing pressure is 220 kPa. The bottom of the footing is 1.20 m below the natural ground line. Unit weight of concrete is 24 kN per cu.m. and unit weight of soil is 16 kN per cu.m. The thickness of footing is 300 mm with an effective depth of 225 mm. Use 𝑓𝑐′ = 20.7 MPa and fy = 345.6 MPa. a) Determine the width of the wall footing. b) Determine the nominal shear stress of the wall footing. c) Determine the spacing of 16 mmØ bars of the wall footing. PROBLEM 4. A footing supports a 300-mm thick concrete wall which carries an axial loads and moments as indicated below. Axial load: P_DL=200 kN/m, P_LL=180 kN/m Moment: M_DL=30 kN∙m/m, M_LL=50 kN∙m/m, M_EL=60 kN∙m/m The thickness of the wall footing is 500 mm with an effective depth of 430 mm. The bottom of the footing is 1.20 m below the ground surface. Unit weight of soil is 15 kN/m3, unit weight of concrete is 23.45 kN/m3, f’c = 20.7 MPa, fy = 415 MPa. The allowable soil bearing pressure is 200 kPa. At ultimate conditions, U = 1.2DL + 1.6LL U = 1.2D + LL + EL a) Determine the width of the wall footing. b) Determine the nominal shear stress at the critical section. c) Determine the design moment.