Application of Geosynthetics in coffer Dam: A case study

Application of Geosynthetics in cofferdam of Loharinag Pala Hydro project for diversion of river Bhagirathi is presented as a case study. Timely completion of diversion components is of utmost importance in hydro projects, as the major activities of Barrage construction commence after river diversion only. To overcome the time constraint, Geosynthetic material like geomembrane in place of clay core, non-oven geotextile in place of filter and Gabions in place of rip-rap were used in construction of coffer dam of this project. The design of cofferdam was finalized after detailed seepage analysis using SEEP/W software. A breaching section was also introduced for passage of monsoon flood as the diversion scheme was designed for passing non-monsoon river discharge only. The design of cofferdam, associated construction activities and its performance is presented in this case study.