Influence of fibre morphology on the integrity of geofibre-reinforced soil barriers
Landfill cover barriers are susceptible to flexural distress due to the differential settlements caused by biodegradation and heterogeneous composition of the underlying waste. The effect of discrete fibre inclusions on the flexural distress of landfill cover barriers was studied using centrifuge model tests. Three types of fibres were used: polyester (PET), polypropylene-tape (PP-T) and polypropylene-fibrillated (PP-F). For unreinforced barriers (UB), the crack initiation and water breakthrough were observed at low distortion levels compared to identical fibre-reinforced barriers (FB). The strain at crack initiation and strain at water breakthrough for FB was 2.36 times and 2.76 times higher than identical UB, respectively. Also, suppression of the cracks and improved water tightness was observed due to the overburden pressure in both UB and FB. PET fibre-reinforced barriers were found to be superior in maintaining the water tightness of the barrier compared to PP-T and PP-F fibres used in the present study. Propagation of cracks penetrating through the thickness of the soil barrier was significantly restrained by the fibres irrespective of the fibre type. Scanning electron micrographs of exhumed fibres indicated that the fibres in the present study were distorted and participated in taking tension due to differential settlements.
- Source: Geosynthetics International, Volume 16, Issue 2, 1 Apr 2009 (109–115)