Question

Q4 Design of isolated footings A 500 mm x 250 mm reinforced concrete column carries unfactored dead load of 1400 kN and unfactored dead load of 600 kN. The column is supported by a rectangular footing located 2.00 meters below ground level where the allowable soil bearing capacity is 292.4 KPa and unit weight is 20 kN/m2. Concrete compressive strength is 35 MPa and reinforcing steel yield strength is 420 MPa. 1. Calculate the required dimensions of a 600 mm deep rectangular footing to prevent excessive settlement under the column such that the ratio of the long side to short side of the footing is 2:1. 2. Determine whether the footing dimensions determined in (1) above are safe against two- way shear failure assuming No.16 reinforcing bars. Assume the supported column is that the long side (500 mm side) is parallel to the short side of the oriented so supporting footing. 3. Determine the required number of No. 16 reinforcing bars placed parallel to the long direction of the footing and validate the appropriateness of the spacing. Assume the supported column is oriented so that the long side (500 mm side) is parallel to the long side of the supporting footing. 4. Calculate the development length of No. 16 zinc-coated (galvanized) bars in the longitudinal direction and indicate whether the available footing dimension is appropriate.

Answer 1

G ven 5 00 mn xIp mm Size of Column 0ad dead 400 K 600 iv load - So heoring capaeby 292 4 KPa unit ukight ot So м famrd lbada: - 10o KN D. L Self weight af footing Q lo7. = 20o t900 t300 Total lsad 330ok load otng SBC 3300 =I.29ml 292.4 2: LB Rato «В хВ : 1.29 *.375 m chuk (i) еf dhue uned Cs Scanned with CamScanner

Critical arta (a«d) btd) (500 t 55) O 843m - (а12. чхо 43) Shor tonu pumchang 3 300 along? cnticl nehor Perim Punchry ha mommal Shu strs : primilu x d 3035S a1483 "pо 3-7o XOSS .483 N/mm A llowabl tu uayshuor Sote againnt Cs Scanned with CamScanner