TABLE 9. COMPUTATION OF e- AND FINAL STRESS FOR DETERMINATION OF e 



Depth 

 (cm) 



1/ 



e (from Fig. 27) 



Average Stress 

 (from Fig. 25, Curve 

 (g/cm2) 



13 

 18 

 23 

 28 

 32 



2.72 

 2,53 

 2.41 

 2.33 

 2.26 

 2.21 



14.46 



53.4 

 38.2 

 25.3 

 19.5 

 18.9 

 18.9 



174.2 



, 14.46 _, ,. 

 average e: ; z .4 I 



overage final stress = — — ^ — = 29.0 g/cm 



The amount of time for this consolidation to occur can be computed from the 

 formula 



'"(years) 



N H' 



1.3 X 10° c 



(15) 



where the drainage takes place In one direction only (up), t Is the time In years, N 

 is a factor corresponding to the percentage completion of consolidation In any given 

 problem, H Is the thickness In cm of the stratum undergoing consolidation, and c Is 

 the coefficient of consolidation In cm /minute obtained from a laboratory time consol 

 Idation relationship. This relationship is 



0.2 H 



50 



4t 



(17) 



50 



where Hen is the thickness in cm at the time {^^q) In minutes of completion of 50 

 percent of primary consolidation. 



1/ 



Depths selected at 5 cm intervals. 



6n-l . 



This formula usually Is given as t/ \ 



' ° (years) 



N H- 

 1400 c 



where H Is in feet , 



(16) 



57 



