Load Settlement Behaviour of Sandy Soil Blended with Coarse Aggregate

The structures of every kind rest on the soil under laying them. The stability of these structures depends upon the load carrying capacity of the soil. The bearing capacity of soil also depends upon the quantum of coarser particles presents in it. The plate load test is used for the design of footing. Therefore, in the present investigation, the plate load tests were conducted to study the sand blended with coarse aggregate of various sizes and proportions. To strengthen the sub soil strata, coarse aggregates of 10mm and 20mm sizes were mixed in the sand in various proportions. The soil samples were prepared and tested first without mixing coarse aggregates, then by mixing coarse aggregates in varying percentages by weight starting from 5% to 30%. The plate load tests were conducted on 100mm, 150mm and 200mm diameters mild steel plates which indicates that with the increase in the size of the bearing plate, the bearing capacity of soil decreases (for plate settlement of 25 mm )and there is reduction in the footing settlement with the percentage increase of coarse aggregate. The improvement in the bearing capacity is represented by bearing capacity improvement factor (BCIF).The BCIF of 328 & 247; 307 & 293 and 174 & 185 were achieved with the inclusion of 10mm and 20mm coarse aggregates respectively for the said plate sizes.