Rehabilitation and Improvements to Sholayar Dam of Water Resources Department in Valparai Taluk of Coimbatore District DRIP Phase II Civil Works Package I

Removing the loose/damaged/deteriorated mortar joints in submerged condition using divers by mechanical means using pneumatic breaker upto a minimum depth of 50 mm along the mortar joints and cleaning using high pressure water jet cleaner in under water condition and after carefully completing the work satisfactorily, scrubbing the joints by using pneumatic wire brush scruber by deploying divers by strictly following safety norms as per IS 10291 – 1982 and by following standard specifications and IS codes, safety aspects and rules and finally submitting the completed work by means of photos and videos by clearly marking the measurements of the completed work portions as directed by the departmental officers etc., complete.

Pointing the racked out old mortar joints with new epoxy pointing mortar in under water condition using screw conveyor gun upto a minimum depth of 50 mm and width of 50 mm as per requirement and site condition and by completely finishing the treatment satisfactorily using divers by strictly following safety norms as per IS 10291 – 1982 and the special epoxy mortar should be such that it offers, durability, high strength, moisture insensitive, under water curing, water proof, abrasion resistant with good bonding properties as per standard specification and IS codes and finally submitting the completed work by means of photos and videos by clearly marking the measurements of the completed work portions and as directed by the departmental officers etc., complete. The warranty period for the under water pointing work shall be of 5 years which should ensure maximum seepage reduction inside the gallery at corresponding levels after duly completing the work in all aspects as per standard specification. The warranty should also include non pealing of the epoxy mortar.

Removing the deposited debris on the upstream side using special debris removal equipments including labour charges, lead,lift etc., in under water condition using divers by strictly following safety norms as per IS 10291 – 1982 complete complying with standard specification and as directed by the departmental officers

Drilling with Diamond core drill machine using diamond bit of NX size (75 mm) diameter including cost of all materials and labour and preserving core in boxes of required dimensions as per standard specification and as directed by the departmental officers etc., complete.

Drilling with Diamond core drill machine using diamond bit of NX size (38 mm) diameter including cost of all materials and labour and preserving core in boxes of required dimensions as per standard specification and as directed by the departmental officers etc., complete.

Drilling with Diamond core drill machine using diamond bit of NX size (150 mm) diameter including cost of all materials and labour and preserving core in boxes of required dimensions as per standard specification and as directed by the departmental officers etc., complete.

Washing and cleaning the masonry grout holes of size of 38mm dia,75mm dia and150mm dia by means of sending water and air at different pressure until the return water turns out to be of the same character as the original water inserted without any foreign materials and as directed by the Engineer-in-charge of the work and complying with Technical specifications

Conducting water permeability test in 38mm dia,75mm dia and150mm dia holes in random rubble masonry portion in the drilled holes at different elevation in stage using packer method at required pressure in each elevation including cost of all assembly and other charges of Labour and machinery as directed by the Engineer-in-charge of the work and complying with technical specifications.

Grouting and sealing the construction joint with hydrophillic hydro structural four component resin (with mixing ratio 1:1, viscosity 40 mpa-sec, Elongation 150 %, swelling property 30 %, with application time from 14 sec to 40 minutes) using inflatable packer with pneumatically operated high pressure piston pump by reaching bottom most point of drilled hole by performing stage by stage grouting at 1.00 m difference in levels such that the grout penetrates to the maximum extent on the entire width of 0.05 m and breadth of 3.00 m of the expansion joint and carrying out and completing the work effectively in all aspects, following standard specification and as directed by the departmental officers. The warranty period for the joint sealing work should be of five years,such as drilling and grouting the joint with hydrophilic structural resin and ensuring that it attains the foundation level such that it considerably and effectively reduce the seepage from the masonry dam into the entire gallery system along the block joints.

Grouting 38 mm and 75mm dia, grout holes upto bottom level at different stages or as directed by the Engineer-in-charge of the work for grouting in random rubble masonry portion in the drilled holes of different elevation in stages using packer method of required pressure in each elevation using fine cement of Blains value of about 3500 mixed with 5% Bentonite, including cost of cement, grouting assembly and other charges of labour and machinery as directed by the Engineer-in-charge of the work and complying with technical specifications. During the process of grouting, the drainage holes in the vicinity of the grout hole being grouted have to be continuously jet washed by the agency during the grout work as per standard specification and as directed by the departmental officers.For grouting in NX 75 mm dia hole, Five bags or 250 kg / 1 RM cement.For grouting in NX 38 mm dia hole, Two bags or 100 kg / 1 RM cement.