n-20 
  
n-*l0 
  
T T ! 
0 !/a V2. 3/4 
a 
Fig. 7. Average curves of the standard errors of the elevations of both ways 
triangulated strips of varying lengths. b = d = 0.6h w= 1 
í 
dard errors in meters on the ground of the entire strips for u = 0.01 
mm, 1:s = 1:20000, b = d = 0.6h and for the different lengths of 
the strip.