Salient Technical Features of HEAD RACE TUNNEL (BALANCE WORK) PACKAGE FOR TAPOVAN VISHNUGAD HYDRO ELECTRIC POWER PROJECT (4x130 MW)

“Salient Technical Features of the equipment/systems/services covered in NIT No. CS-5505-908(R2)-2 dated 06.05.2015 are mentioned below. These Salient Technical Features are mentioned only to facilitate the prospective bidders to prima-facie understand the requirements under the tender and shall not in any way limit or alter the scope of work and technical features/specification of equipment/ systems/ services covered in the Bidding Documents. Detailed provisions in regard of scope of work and technical features/ specification of equipment/ systems/ services, contained in the Bidding Documents shall be final and binding.”

SALIENT TECHNICAL FEATURES

LOCATION
a)

State

-

Uttarakhand
b)

District

-

Chamoli
c)

Tehsil

Joshimath
d)

Latitude & Longitude at barrage

-

Latitude : N 30° 29˘ 30˛

Longitude : E 79° 37˘ 30˛
e)

River

-

Dhauliganga (Tributary of Alaknanda)

HEAD RACE TUNNEL
a)

Length and shape

-

12.087 km, Horse shoe/ Circular
b)

Diameter

-

5.64 m
c)

Design discharge

-

122.18 cumecs
d)

Velocity

-

4.96 m/sec
e)

Number of intermediate adits

-

3

PRESENT STATUS OF HEAD RACE TUNNEL PACKAGE WORKS

Sl. No.

Description of work

Present Status

1

Excavation of Intake adit

Completed

2

Excavation of TBM Entry Adit

Completed

3

Excavation of Branch Adit

Completed

4

Excavation of TBM Exit Adit (Charmi adit)

193m left

5

Excavation of HRT by Drill and Blast Method

· HRT excavation from RD 14.5m to 1911.5m has been carried out from intake adit.

· HRT excavation from RD 2798m to 2939m has been carried out from Branch Adit

· HRT Excavation from RD 11914m to RD 12087 has been carried out from surge shaft adit.

6

Tunnel Concrete lining works in Drill and Blast Portion of HRT

· Overt lining works carried out from RD 23m to RD 207m and RD 218m to 230m in HRT U/s of Intake adit.

· About 72m overt lining has been carried out from surge shaft end

7

Excavation of HRT by TBM

Excavation of HRT by TBM has been carried out from RD 11914m to RD 6482m (5432m), Precast lining has also been erected in this reach.

8

Present status of TBM

Presently TBM is standing in an area having multiple weak zones. A top heading has been created above TBM from 9 O’clock to 3 O’clock.