Microtunneling and Pipeline Installation across Soan River crossing at Ch 73.9 km of 18 inch Khanna Nangal Pipeline

PIPELINE INSTALLATION BY MICROTUNNELING METHOD

Complete work of the crossing (between the limits as defined in approved drawing) by Micro-tunneling Technique (as defined in scope of work) including all additional tunnelled/drilled lengths necessitated by Contractor's design of water crossing including "Receiving and taking over" owner supplied 3LPE coated line pipes from owner's designated places of issue/ dump site(s) and transportation to Contractor's stock yard/ work shop/ worksite including all handling, loading, unloading etc., supply of all materials as per the 'scope of supply' to worksite(s) including design & supply of Jacking pipe of suitable size (minimum 1200 mm ID) to accommodate 1 no. 18" NB carrier pipe and 2 nos. 40 mm HDPE ducts in the same tunnel, design, fabrication, supply and installation of roller supports for carrier pipes & ducts inside tunnel, supply of all consumables, manpower, equipment, other resources and acquiring the required land for storage, fabrication, string preparation, construction of temporary approach road (as required), development of construction site on both sides etc. and execution of, but not limited to, following works in accordance with specifications and instructions of Engineer-in-charge and as per all provisions of Contract Document.

Locating existing pipelines (if any) in the existing ROU corridor using pipeline locator, marking the pipeline location, taking necessary safety precautions including providing warning signs, barricading, scaffolding, etc. as per instruction of EIC for safeguarding the existing pipelines (if any).

Geotechnical and Hydrological survey data is enclosed in bid document to the extent available. Contractor, if desired, may verify the geotechnical survey data without any additional cost to Owner. However, MECON/OWNER shall not be held responsible for the change of strata if found to be variable. Contractor/ bidder shall carry out all other additional surveys for collecting data relevant to design & construction of crossing, engineering, preparation of all necessary construction drawings, procedures etc. duly approved by owner/ concerned authority.

Pre-construction survey, obtaining scour depth from concerned authority (as required), necessary cover required over the carrier pipeline from lowest bed level of the stipulated water crossing to be obtained from concerned authority, bed strata data including design & detail engineering and making of crossing drawing for obtaining approval from concerned Authority/ Engineer-in-charge, getting permission/ work permit/ NOC for river crossing as well as utility crossings (if any) encountered during water crossing from respective concerned authority (Local/State/Central Govt. Departments like NHAI, PWD, Irrigation, etc.) including other stake-holders, if any, as applicable prior to start of the execution of work. Required authority permissions and opening of ROU shall be arranged by GAIL, however, liasioning with authorities, land owners etc. shall be in Contractor's scope which shall be payable through separate SOR item.

Following data shall be obtained from concerned authority/ local sources to finalise/ re-verify scour depth (if deemed necessary):-

(i) Past Historical flood level data indicating HFL to determine highest flood level.

(ii) River flow data including velocity of water flow.

(iii) Necessary information regarding type of soil and strata underneath the river bed.

String preparation including taking over of 3LPE coated carrier pipes from CLIENT's designated yard, handling, loading, transportation to site, unloading, stringing, welding, 100 % radiography by X-ray, welding repair and re-radiography, pre-installation hydrotesting (as required) as per approved procedure, cutting pipes to accomodate in shaft (as required; Note - single carrier pipe of 6m (Minimum) length is permissible in the Micro Tunnel section.), rebevelling (if required), UT testing to check for lamination (as required by specification), re-welding, joint coating and repair of pipeline coating with repair patch or equivalent material (including supply of repair patch) as per specifications/approved drawings.