Potential of Rock Flour for Use As Fill Material in Reinforced Soil Structures

摘要

The flyover constructions have seen a revolutionary change ever since reinforced earth walls have emerged and replaced the conventional retaining walls. The approaches sections of flyovers are now being connected with reinforce earth retaining walls due to fast constructions, low cost and better seismic resistance. The major component of the reinforced earth retaining wall in frictional fill and so cost of the fill influences cost of the wall. The construction cost of reinforced earth walls can be significantly reduced if alternate cost effective materials are used in place of conventional fill material, i.e. sand and gravelly soils. The process of assessing any alternate cost effective material such as a waste, it is essential to have knowledge on requirements of fill for use in reinforced soil structures and methods of evaluation of frictional characteristics of the fill with reinforcing materials. So in the present work besides explaining concept of reinforced earth, requirements of fill material to satisfactory for using in reinforced soil constructions and tests for evaluate of interfacial frictional parameters of fill and reinforcement have been reviewed. In the present study rock flour, waste material produced from granite rock crushing plant is assessed for its suitability as fill material in reinforced soil constructions. The study is extended to study the interfacial friction characteristics of rock flour with synthetic geotextiles from modified direct shear tests. The results have been compared with respect to river sand and rock flour of Leptynite origin. The results of study indicated better interaction in comparison to river sand and rock flour of Leptynite origin. Rock flour of granite origin mobilized friction coefficients of 0.84 & 0.79 in OMC & MDD condition and 0.79 & 0.75 in wet condition with woven and non woven geotextiles respectively.