Answer Happy

The 7 m high retaining wall is shown in Figure Q2 (b). Determine; (i) Rankine active and passive force per unit length of the wall together with the location of the resultant force. (8 marks) (ii) Rankine active force per unit length of the wall and the location of the resultant force if the groundwater level was found at 2 m from the ground surface. Given saturated unit weight is 19kN/m3 with a friction angle of 35∘. (13 marks)
Figure Q2(b): Retaining wall
Conventional retaining walls Rankine active and passive pressure Pa​=21​Ka​γ1​H2Pv​=Pa​sinα∘Pp​=21​Kp​γ2​D2+2c2′​Kp​​DKa​=tan2(45∘−21​ϕ1′​)​Pa​=21​Ka​γ1​H2+qKa​HPh​=Pa​cosα∘Kp​=tan2(45∘+21​ϕ2′​)​ Factor of safety against overturning FS=∑Pai​​zai​​∑Wi​Xi​​=∑Pai​​zai​​∑(Ai​×γi​)Xi​​FS=Pa​cosα(H′/3)γn+i​An+i​xn+i​+K+γn​An​xn​​​ Factor of safety against sliding FS=n∼.∑Vtan(32​ϕ2′​)+32​Bc2′​+Pp​​zo​=v2cu​​