Question

4.17 A layer of clay deposit extends to a depth of 15.0 m below the ground surface. The groundwater table coincides with the ground surface. Given, for the clay: void ratio 1.0, specific gravity of soil solids 2.78 plasticity index 25%, over consolidation ratio Determine the shear modulus and damping ratio of this clay at a depth of 75 m for the fifth cycle at a strain level 0.1%, assuming that the frequency is about l Hz. (Note: Use Figure 4.64) Given: Ko(overconsol)Ko(nrm conso) (VOCR) Properties of Dynamically Loaded Soils 181 40 (a) OCR - 1(b) OCR-2 (c) OCR-3 10 1.5 1.5 1.3 1.3 0.9 0.7 0 0.3 0 0.9 0.7 0.5 0.3 0.3 0 25 50 750 25 50 750 25 50 75 Plasticity index 40 (d) OCR-4(e) OCR- 5(f) OCR- 6 10 e- 1.7 1.7 1.3 1.3 1.3 0.9 0.7 0.5 0.9 0.7 0.5 0.3 0.9 0.7 0.5 0.3 0.3 0 2550 750 25 50 75 0 25 50 75 Plasticity index Figure 4.64 Reference strain for geostatic stress condition (after Hardin and Drnevich, 1972)

Answer 1

iven data Void ratio , e= We Cnow at maxim umshaar whare Moollug casoidateel dlo

(k,he = o ko)o joc = 0.0132 t+2 max= 323

2 (6548) NOw eremc train γん 045 Now

: 0.06163% 1.15 8911625 1+1 85 31222 SS

Now Dam l 0: Now D a(= 1+0.2 бу 0.2