Compliance Report of Adit-1A, Adit-II and Face-1,2,3 & 4
COMPLIANCE
REPORT
100/MHPA/HRT/General Correspondence/2019/ Date:
03.06.2019
REF:
1. Inspection Report of HRT of Mangdechhu Hydroelectric
Project on 23rd May 2019 submitted by HRT Inspection Team from DHPS,
DGPC & the internal HRT inspection team from MHPA. (After Emptying the WCS)
2. Letter from Consultant, NHPC No NH/DD-II/Mang/11/33
dated 01.05.2019 (Leakage of water from HRT Adits and Gates)
3. Tour Report of Design Team from NHPC vide
letter no NH/DD-II/Mang/11/2383 dated 20.05.2019.
The compliance has been done
as per discussion with Chief Engineer I/c
(HRT) and as directed. The compliance report is submitted for HRT Adit-IA,
Adit-II & Face 1-2-3&4.
ADIT- IA:
- ·
Face of Adit Plug was
treated with 3 layers of Penetron.
- ·
The unplugged Grout
hole in Gallery was re-grouted and plugged with Epoxy mortar.
- ·
Gallery treatment
with one layer of V-groove finished with Epoxy and 3 layers of Penetron was
done where some dampness was observed.
- ·
Daily monitoring of
seepage was carried out by installing V-notch (Readings attached as Annexure-1)
- ·
The other portion of
Adit Plug towards Portal was completely dry and no seepage was observed. No additional
consolidation grouting in the Adit beyond the concrete plug up to 10m from the
last leakage point towards Adit portal was done.
·
ADIT-II:
- ·
Daily monitoring of
seepage was carried out by installing V-notch (Readings attached as Annexure-2)
- · 3 Nos. Holes, 6 mtr length were drilled along the adit Plug one at centre and two nos above SPL on either side beyond the adit plug. Grouting was carried out at the pressure of 3-5 Kg/cm2 .
- · Additional 4.5 mtr long hole was drilled at location on the left crown behind adit plug where some seepage was observed earlier. Grouting was carried out at the pressure of 3-5 Kg/cm2.
- ·
Consolidation
grouting beyond concrete plug up to 10 mtr was carried out at three sections 3
m c/c .
- ·
For 7th
and 8th panel joints of inspection gallery, 4 Nos. of 500mm depth
grout holes was drilled and grouted. V-groove finished with 3 layers of
penetron was applied.
- ·
Face of Adit Plug
where dampness was observed, one layer of V-groove finished with Epoxy and 3
layers of Penetron was carried out.
FACE-IV:
- ·
As pointed out in the
Inspection Report, Cold joint at RD 15 m was rectified by providing V-groove
finished with Epoxy treatment.
- ·
Grout hole at RD 680
m (r/s) was plugged with a mixture of Bentonite and Epoxy.
- ·
Grout holes at RD
1400 m (r/s & l/s) was plugged with a mixture of Bentonite and Epoxy.
- ·
Fine debris deposited
on the Invert b/w RD 1440 – 1460 m was removed.
Submitted for kind
information and further instruction, if any please.
(ChengaPenjor) (HimanshuNagpal)
AEE.
Adit-II EE, Adit-I & II
Chief Engineer I/c (HRT)
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