Experimental Study on Performance of Prefabricated Vertical Drain on Kaolinite with Various Drain Material

The improvement of soft clay by primitive method of sand drain is extended to PVD (pre-fabricated vertical geodrain). In this context, the present investigation provides economical materials for fabrication of vertical geo-drain, comfortable operational procedure, and effective results of improving the bearing capacity and relative cost effective solutions. Theme of the research work comprises of consolidation of soft clay by radial drainage through radial seepage using PVD considering the effect of drain materials. Modern modified Rowe type hydraulically pressurized oedometer is employed for measurement of settlement and pore pressure. An empirical co-relation between strength of soil and n-value is developed. It has been found that the success of improvement of soft soil using PVD is dependent on ideal short- and long-term properties of drain, rate of loading, pattern of drain installation, and uniform distribution of pore pressure at any time (isochrones) and rate of pore pressure distribution. Among various drains of different material considered in investigation, Jute wrapped with polyamide polyester geosynthetics seems to be efficient among various other drains viz. Sand, SD, and SDW seems to be efficient showing higher rate of dissipation of pore water pressure, i.e., higher rate of settlement and magnitude of settlement along with best fitting with Barron’s theoretical results. Further, it is efficient and appropriate to use the same drain in prototype model because of having good hydraulic conductivity and discharge capacity which has induced good compressibility and higher gain in strength at all radial distances from the drain.