BEARING CAPACITY IMPROVEMENT OF SOIL USING GEOSYNTHETIC REINFORCED GRANULAR COLUMNS

Stone column technique of ground improvement is an effective method to strengthen poorly graded soil. The study deals with bearing capacity improvement of soil installed with coir geosynthetic reinforced crushed coconut shell column using experimental and numerical analysis. A number of plate load test were used to examine the behaviour of vertically and horizontally reinforced columns in soil.  Study focus on using crushed coconut shell (CCS) a biomass waste product, used as infill material and coir geosynthetics used as reinforcement. Column of various diameter and length in-filled with crushed coconut shell was erected into soil were used for test. Geotextile wrapped around the column is used to provide vertical reinforcement and geogrid placed in the column at intervals of D, D/2 and D/4 to provide horizontal reinforcement. Finite element analysis using PLAXIS 2D was also carried out for the study to compare the laboratory results. Bearing capacity of effective sized CCS column increased by 130.8%, bearing capacity of vertically encased CCS column increased by 161% whereas bearing capacity of horizontally reinforced CCS column at S=D/4 increased by 238% compared with unreinforced sand. A variety of potential site applications were made possible by this range of performance for the geosynthetic reinforced crushed coconut shell column technique in soil.