Question

1 Calculate the factor of safety against overturning and sliding for the concrete retaining wall shown in the figure below, without taking into consideration the passive earth pressure. (50 Points) Assume that 115 lbs/cf unit weight of soil: unit weight of concrete: 150 lbs/cf angle of internal friction: 30 coefficient of friction: 0.350 0° B: 14 5' 2" Ha 14 2.5 Compaction (Soils engineering uses the symbol ys for dry density and uses the term dry unit weight. In the compaction laboratory test we use the symbol pa for dry density. In other words, Ys and pa mean the same thing. The symbol p on the other hand is the density of the soil and in the english system whether you use the weight of the soil or the mass of the soil, the error will be minimal). Dry Density, pa: γ.-pa-Ms/V-ws/Vay/(1-w) Zero-air Voids Unit Wt, γη γ.-(Gs7-)(1 + Gsa) . . where: w is the water content Retaining Walls Rankine Earth Pressure k cos r, =1.trk, cosb+- cos' β-cos KA PA-Active Earth Pressure Pr Passive Earth Pressure Unit Weight of Backfill Soil KA Active Earth Pressure Coefficient Kr= Passive Earth Pressure Coefficient B-Backfill Angle φ-Backfill Angle of Internal Friction If β=0, then: 1-sin 1+sin and 1-sin ф Effects of Surcharge P'-Additional Active Earth Pressure Due to Surcharge w Uniform Load H-Height of Wall ka Active Earth Pressure Coefficient Soil/Rock Consistency/Quality Soil Consistency Very Soft Soft Medium Stif Stiff Very Stiff Hard SPT No. 0-2 2-5 5-10 10-20 20-30 30 Rock Quality Excellent Good Fair RQD 90-100 75-90 50-75

Answer 1

中: 30° 3.6 2.5' S 2" 3 overtumon moment, ma- Pix

MR 3ysDXG+ S2 x+ps3.sx/o S Mo Fs 882 pain 2 ph 2 37%, 67 lis Resisng borte, At bottom ob boong

Ph 31S6 63 Ps= 081