Parametric studies on two-tiered model fly ash wall

Abstract

ABSTRACT The multi-tiered wall is earth-retaining structure, similar to a reinforced wall, constructed by providing offsets between the tiers at a certain height of the reinforced wall. The current study makes an effort to employ fly ash as a backfill material for the multi-tiered reinforced wall. The behaviour of laboratory models has been studied. Single and two-tiered models were prepared for the study. The effect of the reinforcement length, reinforcement spacing and the offset distance between the tiers on the failure pattern, horizontal displacement and normalized surcharge pressure was determined. From the experimental investigation, it was observed that the critical offsets between the tiers of the wall increase due to the introduction of reinforcement, as offsets between the tiers, D was observed 0.4L and 0.6L for the wall model without any reinforcement and the wall model with reinforcement, respectively, where L is the lower tier height. The failure patterns were found to agree with the Federal Highway Administration (FHWA) guidelines for tiered wall except for the unreinforced wall model at the 0.4L offset distance. There was an increase in normalized surcharge pressure due to the introduction of jute geotextile reinforcement up to 68.75% at the 0.7H length of reinforcement, where H = total wall height. As the jute geotextile reinforcement length increases, the horizontal displacement of the wall facing reduces up to 98% as compared to unreinforced model whereas, the increase in spacing between the reinforcing layers increased the horizontal displacement of the wall facing.