GEOSYNTHETIC REINFORCED POND ASH SUBGRADE FOR RURAL ROADS

摘要

Pulverised fuel ash, produced in huge quantities by thermal power plants of India, require large land area for disposal and causes environmental hazards. The bearing capacity of a weak pond ash subgrade can be increased by placing a granular course of required thickness on top of the pond ash fill. The load bearing capacity can be increased further and the thickness of the granular course can be reduced by providing a layer of geosynthetics at the interface of the two layers. In the present study, the bearing capacity behaviour of a rectangular load under static compression on the surface of the granular wet mix macadam (WMM) layer underlain by pond ash with a layer of geosynthetic at the interface are presented. Two types of pond ashes and different types of both polymeric geogrids and coir woven geotextiles have been used the study. The results obtained from the load tests at different thicknesses of the WMM layer with and without different types of geosynthetic reinforcement have been presented. The results show that lower thickness of WMM layer with geosynthetics at the interface perform better than that with thicker WMM layer without reinforcement. The effectiveness of coir woven geotextiles for rural road use is highlighted.