Question

I want solution!

3. A laboratory consolidation test was conducted on a specimen collected form the middle of the overconsolidated clay layer and the field consolidation curve is given below. The effective overburden pressure was 40.95 kN/m²at the middle of the clay layer. Calculate a) the recompression index, b) the compression index, and c) the consolidation settlement when the average vertical stress increment at the middle of the clay layer is 50kN/m² due to a foundation load. The thickness of the clay layer is 10 m.

Answer 1

Solution - Effective stress, a' (log scale) CaNim?). e. Recompression cune. e, virgin compression curre. void ratio a) let the recompression index = cr. ." (y = - 4e lozim ) ( Recompression index is calculated by Recompression curve) . De = e, lo = 1.076- 1.10 se= -0.024. T = 70 kN/m2 oo=40195 kN/m2 Cra (-0.024) 0.10307 logio (uoias 70 Cys 0.10307 b) let the compression index = Cc cc is calculated by virgin compression Curre. CcE De logio

Here, De= 1:03 - 1:076 - -0.046.3 Pune, of = 100 kN/m² o'=70 kN/m² Cc = (-0.046) 0297 log lo ( 70 (-0.297 C) the Qverage vertical stress increment = so'z sokNime. So, total stess at middle q clay layers To'tool, (a) ire. a = Totor= 40.95t so = 90.95 KN/m². let the consolidation Settlement =H .. OH = Cy H Itlo logo l ) + CH logio Asio ( ootor 5 ) - Itlo V atta where, Holomi .: DH= 0.10307. X10 logio 70 0297x10 .) + + logioli 90.95 I+1110 40.95 I+):10 70 DH = 0.114282118 + 0.1608108 T =) OH 0.2751 m. HE 277 51 mm