GATE Civil Engineering (CE) 2016 Shift 2 Solved Paper

A 4 m wide strip footing is founded at a depth of 1.5 m below the ground surface in a c-φ soil as shown in the figure. The water table is at a depth of 5.5 m below the ground surface. The soil properties are: c' = 35 kN/m², φ' = 28.63°, γ_sat = 19 kN/m³, γ_bulk = 17 kN/m³ and γ_w = 9.81 kN/m³. The values of bearing capacity factors for different φ' are given below:
Using Terzaghi's bearing capacity equation and a factor of safety F_s = 2.5, the net safe bearing capacity (expressed in kN/m²) for local shear failure of the soil is __________