Question

(a) Determine and draw the lateral pressure distribution (active hydrostatic) acting on the smooth wall shown in Figure 2. The water table is at the interface of the soil layers. (8 marks) Soil 1: c'0 kPa, ' 32 y 16 kN/m 2 m 4 m Soil 2: c'-5 kPa, 30° Yet20 kN/m3 Figure 2 (b) In Figure 3 below, the L-shaped area carries a 200 kN/m2 uniform load. Determine the vertical stress increase due to the loading at a depth of 2 m below corner E (8 marks) 3 m 2 m 4 m E 2 m Figure 3 (c) The soil profile at a site consists of 4m of clay overlying rigid impermeable rock, and the water table is at ground level. A highway embankment to be built at this site will apply a pressure of 100 kPa to a point at mid-depth of the clay layer below the centre of the embankment. Calculate the expected settlement of the centre of the embankment using the one-dimensional method and a single clay layer. The soil properties are shown in Table 4 below: Table 4: Soil properties of clay layer Void ratio at centre of layer 0.7 Specific Gravity, G, 2.6 Over Consolidation Ratio, OCR 3 0.2 Compression Index, C Re-compression Index, C 0.04

Answer 1

C' o 163 utos 9:832 c'S Kpa 4.9 KGst elag d30 =20 31-305 Layes (Totaleve Lateral earth piezine pistakubion -xH O stiess (Poreoute u uxh = 0 pressure effectue Strese Jest above Layes DUIS- +Sing xH= 16 x2 = 32 N -6n32 Sin32 P Ka 0-31x22 ': -U = 3R KN 0-3072 Ka O-3 9.832 KN Laye Just below 32 -SIn30 0-3333 k -Sind DUIS+ Sn30 32 Ka O. 3333 Pa O.3333 x 32 - Qx5x 0-3333 i0-67-5.7732 i 4.9 KN m2

Layes 3 16*x 20x2 32+ 0 unit wt of = 9-8 KN ates M m2 = 9-81 xa KN U .62 m2 5Q-38 KN Ka = 0.3333

+Q.81x2) Pa - 2x5xO 3333 O-3333 x5a 38 5-773 3t 1q.62 1구-45825- KN 31-305 Pa

-3m intamlų gfstributed lcað =R00 KN Q 2x A (Load) qxA A = Avea of L-shapecd + - - 3 x4)4x) A = 20 4-000 KN Bawsinevg's Theary According O Jelo 4000 (2)* KN 4-77.46

Ar'00Kpa (favement) (Wates Take LevEL) instal Peyanete Cloy 4m Tmpermentle Rock intial effee Stsees ? Bw Unit acight of unte =9.81 KN m3 G G e O-7 9-81 2.6+0.7) +O7 Asat 19- 04-3 KN O 19-043 X2(9-81 x2' 18.465 KN OverConsatdahon rttn Preconsolickrtuonre OCR inihal effechve, stregs CR

3x6 55.398 KN final ponsolidateo f streps) = Compreson inclee 18-465+ ICO - Yecempiessio inde O.04 KN 18.465 - clay laye Settlement of clay (H) CR Ho -+e -E) jo910 Ho og10 Ie Layer 18. 45 55.398 4 x O.0< 55-398 8-465 +0.7 O.7 O.155339 28 O.04490 77 AH 200-247 mM OCDM im