Providing PVC Geomembrane water Proofing System on the Upstream Dam Face and Cleaning of Vertical Porous Drains / Foundation Drains under DRIP II.

Surface Preparation consisting of inspection of the entire section, hydrojetting the entire upstream masonry face with special pressure jet pumps operating between 100 to 200 Bar pressure to get rid of loose particles. Hammer test to identify the hollow section of the gunite layer and wherever required, removal of loose gunite layers needs to be filled up with special geosynthetic grid materials to fill up the cavities and including all tools, equipment, anchors, fixation materials using special platforms, labourers, technicians etc. The entire works to be done in dry conditions and as directed by the Engineer-in-charge, complete.

Design, Supply fixing and testing of waterproofing system with an impervious liner consisting of two layers of geo-synthetics mechanically heat coupled together during extrusion, one being a PVC geo membrane of 2.5 mm thick and the second one a non-woven geotextile needle punched polypropylene geotextile having mass per unit area not less than 500g/m2 to form a PVC “geo-composite” of width not less than 2m, laid over an anti-puncture geotextile of minimum 11mm thick having mass per unit area not less than 2000g/m2 wherever required.

Excavation of Deposited Overburden Silt and debris from the upstream face of the dam on the left and right flanks at the sloped section of the dam to make required working space to attend to Geomembrane Sealing System works using earth moving equipment, tippers or other equipment etc, as directed by the Engineer-in-Charge Complete.

Chipping, racking and re-pointing of masonry face to provide structural integrity of the dam using plain cement mortar and fill the cavities wherever required, as directed by the Engineer-in-Charge, Complete.

Drilling holes of 50 mm dia. on the Upstream Face of the dam with an inclination using NX Diamond Drill Bit to consolidate porous section of the dam body to a depth of 2 to 3 meter in stages, wherever the foundation could not be reached during excavation, as directed by the engineer in charge, complete.

Cement Grouting for the drilled holes in various stages, including cost of cement, grouting equipment, etc. Water Percolation Test to be conducted prior to check the flow path of the cement grout. Properly plugging the adjacent drilled holes before to grout the target hole, complete as directed by the Engineer-in-Charge.

Carrying out Vertically Upward Drilling from foundation gallery of dam for cleaning of Vertical Porous Drains (VPD) by specially designed High Powered Hydraulic Drilling Rigs remote control operated for dia upto 150mm.

Upto 15m depth