Question

A 2-m thick of compacted soil of unit weight 20 kN/m3 will be placed on the top of the ground surface. Δσ y 14.0 kN/m3 3.0 m Sand Y 17.5 kN/m3 2.0 m 3.0m A Soft clay y= 13.5 kN/m3 6.0 m Medium clay y=15.0 kN/m3 B 4.0 m Bedrock a) Before placing the compacted soil, what are the overconsolidation ratios (OCR) for point A and B? b) When placing the compacted soil, what external load Ag would be? c) How much primary consolidation settlement you would expect in the soft clay layer? d) How much primary consolidation settlement you would expect in the medium clay layer? e) After primary consolidation completes, what are the oversonsolidation ratios (OCR) for point A mlden bobeaa oonol doum wo y=14.0 kN/m2 3.0 m Sand 2.0 m Y 17.5 kN/m3 3.0m 6.0 m y=13.5 kN/m3 A Soft clay Y 15.0 kN/m Medium clay 4.0 m B Bedrock For the soil profile given above, determine the following a) Total stress, pore water pressure, and effective stress at point A b) Total stress, pore water pressure, and effective stress at point B c) If the total horizontal stress at point A was found to be 85 kPa, what is the coefficient of lateral earth pressure at rest, Ko? A 2-m thick of compacted soil of unit weight 20 kN/m3 will be placed on the top of the ground surface. Δσ y 14.0 kN/m3 3.0 m Sand Y 17.5 kN/m3 2.0 m 3.0m A Soft clay y= 13.5 kN/m3 6.0 m Medium clay y=15.0 kN/m3 B 4.0 m Bedrock a) Before placing the compacted soil, what are the overconsolidation ratios (OCR) for point A and B? b) When placing the compacted soil, what external load Ag would be? c) How much primary consolidation settlement you would expect in the soft clay layer? d) How much primary consolidation settlement you would expect in the medium clay layer? e) After primary consolidation completes, what are the oversonsolidation ratios (OCR) for point A

Answer 1

For the Sal pofile gien odctermine the folouwing 7 -5YW T14 KN/m Sand 2D Y=1 5 KN/M 3m Y=13 S KNIM3 Soft clay 6 m A 2m Y-15 KN/m Hedium clay 4m Bed Roch Totul strem, bore usater brenure d effechive stren at pont A 14X 3) + KN/n* +(3Sx3) to tal Strem at A= CA 117 pore usater prem we at A = UA =T hA = 9.81 X 8 78.48 KNIM l effechve stren at point A = 6A-UA 11 117-5-38-48 39 02 KN/m D Total Strem, pore usates brenure & effechie stren at pont B 14 X3) + (17-5X 2)+ 13 Sx6)+15x 2) tn tal strers atB=6a = pore usater pren re at 8Ug =To he 11 9.81 X 13 = 127. 53 KN/M A! 66-UB 68= effechive strem at B= 188-123S3 60.47 KN/n

(2 fhe total horigontal 85KPA, what is the coetticiet ot hest Ko ? Stres at point A U9as found to be lateral earth brewure NAS=85 KN/m effechve hoi3ontal stren to tal honsontal stren Ko= effechve vertical sten vestical Stren total 85 D.23 A 6xA is uen then we will we (Note: 'A

2m thick Compacted Soil unit weight et 9o KN/m3 wile be laced on the top the round Surtace P KN/m3 20 2m Y=14 3m Sa nd кVm 2m E 19.5 3m 6m r=13-5 KN/m2 Soft cloy 2m ro 15 kNpm3 Medium 4m day before placng the compacted soil, ishat are the over Consolidation ratios (OcR) fo point A& 82 a OcNaximum effedive stres applied in past Existing effechie sben

Shen fill Lsan not there 4 max etf stren applied in the past ct A = 39 02 KN m & existing at A = eff strers bA-UA (117St 20x2)- 38 43 39 02 KN/m 39 02 OCRA = E0.49 FI O2 Stmilaly max eff stren applied in past at B=60.49 KN/ existing 66- a 198+ 20x2) 127.53 - 100 49 KN/m 60.49 OCRE loo 47 (b) hen placing the compacted soil ushat external load be ? A6 50ald 46= 20KN/M3 40 KN/m X 2m Consolid ation settlemect you oould © Hoes much prmay expect in the Sott clay layer ? consolidation settiemet is given by Prinasy Oc Ho LoJto AH = Afeo initial layer thicknes ohere initial void Yatio effechive strer e=

Ao Change in eff stem 40 KN/m2 e-er C= Coeff o compresion logCa/a) As information to calculation void rodhio (eo) given, One settlem ext Cre not not calculae the primary consolidahon can Same amwer as for this settiemet need to determine the bnmaty Consolidation we Ainst & then comeponding effechve stren existing