Project of Earth Retaining Structure

1. EARTH PRESSURE DUE TO VIBRATORY COMPACTION IN RETAINING WALL EFFECTS ON HORIZONTAL EARTH PRESSURE AND VERTICLE OVERBURDEN PRESSURE

4. MODEL RETAINING WALL 1.5 m long 1.5 m wide 1.6 m high 45 mm thick •Model wall is actually the front side of the reinforced steel box •24, 20 mm thick steel columns were welded to reduce lateral displacement during loading Backfill Characteristics:- Air Dry Ottawa Sand Gs=2.65 , D 60 =0.39 mm; D 10 =0.26 e max=0.76, e min=0.50

8. Stresses in compacted sand Due to compaction of soil overburden pressure( σ v )in compacted sand is slightly greater because it has higher unit weight (γ) of soil. σ v =γ z = 16.6 *1.5=24.25 KN/m^2 It is concluded that there is no much impact on vertical earth pressure due to soil compaction The lateral earth pressure measured near the top of the backfill was almost same to the passive earth pressure estimated with Rankine theory Pp=1/2 γKpH^2 where Kp=tan^2(45+φ/2) Kp=tan^2(45+40.8/2) Kp=4.77 Pp=0.5*16.6*4.77*1.5^2 Pp=89.07 KN/m

9. Soil behavior in compacted backfill When compaction is applied on the surface of the first layer(0.3 m thick), passive zone is compressed laterally and after compacting three layer, passive zone goes to a higher level so the compaction influenced zone rises with rising compaction surface. There is no horizontal stress in soil element (zone III) next to the wall because of the relatively rigid model wall so horizontal stress below the passive Rankine zone is almost same to the horizontal earth pressure at rest by Jaky’s equation.