Behavior of Reinforced Fly Ash Slopes with Cellular Mattress and Strips under Strip Loading

Abstract

This paper directs its aim to present a new approach to convert fly ash from becoming a hazardous waste for the environment into an artificial resource as effective construction material. The fly ash slopes analyzed were made at a 60° inclination from horizontal, having wrapped facia made of steel grid–jute geotextile composite reinforcement. Postconsumer plastic water bottles, another unwanted waste material usually disposed to the geoenvironment in bulk quantity, were used to form the cellular mattress reinforcements in slope backfill. The three-dimensional reinforcement layers were positioned keeping an even vertical spacing of 0.2H, while reinforcements were in strip forms with coverage ratios of 0.5 and 0.6 and in continuous form, i.e., coverage ratio (Cr) of 1. The influence of the height, length, coverage ratio, and varying edge distances (1.0B, 1.5B, and 2.0B, where B = footing width) of cellular reinforcement on the bearing capacity of the slopes subjected to strain-controlled static strip loading over the top slope surface through a rigid steel plate as footing was studied systematically. Test results indicated that improved footing capacity for a continuous mattress is 1.93 times greater and for a coverage ratio of 0.6 improved footing capacity is 1.58 times greater at 10-mm settlement for L=0.6H (where L = length of cellular reinforcement and H = height of slope) when De/B=1.5 (De = edge distance) and CR5020 (CR5020 = cellular reinforcement of diameter 50 mm and geocell height 20 mm) over reinforced fly ash slopes as compared with that over unreinforced slopes for both mattress and strips. Substantial improvement was observed on the settlement of the backfill with the alteration in edge distances and length of the cellular reinforcement.