A Model Study on Accelerated Consolidation of Coir Reinforced Lateritic Lithomarge Soil Blends with Vertical Sand Drains for Pavement Foundations

Abstract

Sub-grade soils of lateritic origin encountered in the construction of highway embankments in various regions of India, often comprise intrusions of soft lithomargic soils that result in large settlements during constructions, and differential settlements at later stages. This necessitates the use of appropriate soil improvement techniques to improve the load-carrying capacity of pavements. This work deals with accelerated consolidation of un-reinforced and coir-reinforced lateritic lithomargic soil blends, provided with three vertical sand drains. The load-settlement characteristics were studied for various preloads ranging from 50 kg (0.0013 N/mm 2 ) to 500 kg (0.013 N/mm 2 ) on soil specimens prepared in circular ferrocement moulds. It was observed that at lower preloads up to 200 kg, across the blends, the relative increase in consolidation (R ct ) for randomly reinforced soil with vertical drains was significantly higher than that of un-reinforced soil without vertical drains, with an average value of 124.8%. Also, the R ct for un-reinforced soil with vertical drains was quite higher than that of un-reinforced soil without vertical drains, with an average value of 103.9%. In the case of higher preloads, the R ct values for randomly reinforced soil with vertical drains were moderate with an average value of 30.88%, while the same for un-reinforced soil with vertical drains was about 20.4%. The aspect-ratio of coir fibers used was 1:275.

Mineralogical Analysis of Lithomargic Clay Deposits along the Coastal Belt of Uttara Kannada Region in South India

“…It is formed due to tropical or subtropical weathering, which contains hydrated alumina, kaolinite, and primary silicates. It also has an amorphous blend of Al2Si2O5(OH)4 [3]. The investigation into lithomargic clay along the Udupi region's coastal belt revealed abundant minerals, including quartz, feldspar (such as orthoclase), muscovite, kaolinite, dickite, gibbsite, halloysite and illite in substantial proportions [4].…”