3.16. Regarding geogrid reinforced unpaved roads:
(a) What is the required aggregate thickness for an unpaved road carrying 10,000 vehicle
passes of 80 kN with rut depths of 0.15 m on a soil subgrade whose undrained shear
strength is 20 kN/m2? (Use Figure 3.10.)
(b) Using BX 1200 geogrid reinforcement, channelized traffic, and a high likelihood of
aggregate contamination, how much aggregate can be saved?
(c) What increase in load-spreading angle does this represent (assuming that the nonreinforced
case is ao = 26.6°)?