The Himalayan Times, 12 Dec 2017
Melamchi Water Supply Project is struggling to meet the tunnel breakthrough deadline of January 2018 due to continuous presence of weak rock.
Earlier on September, Melamchi contractor CMC Cooperativa Muratori e Cementisti di Ravenna had promised to break through the tunnel by December 2017 but due to hurdles and disturbance due to the festival season, the deadline was later shifted to the January 2018.
According to Melamchi Water Supply Development Board, so far, 743 metres of tunnel remains to be excavated in the 177 metres of the Ambathan-Gyalthum and 566 metres of the Gyalthum-Sindhu stretches.
Deputy Director General at the Board Ramakanta Duwadi said the 177 metres of the Ambathan-Gyalthum stretch of tunnel that remains to be excavated is likely to complete by this December but it is unlikely that the Gyalthum-Sindhu stretch will be completed by January 2018 due to appearance of weak rock structure.
“With an average daily excavation of 16 metres there won’t be any problem completing the Ambathan-Gyalthum stretch within this month, but continuous appearance of weak rock is making the breakthrough in the Gyalthum-Sindhu stretch difficult to complete by January 2018 where still 566 metres remains to be excavated.” Duwadi told The Himalayan Times.
He claimed it was likely that the time frame for breakthrough in the Gyalthum-Sindhu stretch would be shifted slightly, but it wouldn’t affect the water delivery schedule given by the contractor for March 26, 2018.
The Board said that normally 3 to 4 metres would be excavated from one blast, but due to the presence of weak rocks just 1.5 metres was being excavated by one blast.
In September this year, the contractor had promised to begin water supply from 26 March 2018. The contractor had also promised to complete the tunnel by December this month.
The tunnel comprises a total of 27.5 km tunnel comprising three stretches — Sundarijal-Sindhu – 9.5 km, Sindhu-Gyalthum – 8 km and Gyalthum-Ambathan 9 km. Of the three audit tunnels, the longest stretch tunnel Sundarijal-Sindhu was completed on December 28 last year.
Due to weak rock structure, the pace of tunnel construction has decelerated. The Melamchi Project’s first deadline was 2007. The second deadline expired in 2016. On April 3 this year, the deadline was extended to October 2017.The tunnel construction deadline was fixed for July 2017 but due to problems arising from weak rock structure, the project has missed the deadline again.
Meanwhile, MWSDB said four transit mixers out of eight are on the way to Kathmandu after customs clearance in Birgunj. The remaining mixers will be arrive in Kathmandu after customs clearance is completed this week.
It is said that after the mixers arrive laying concrete in the tunnel will proceed at a rate of 200 metres per day. Melamchi contractor CMC Cooperativa Muratori e Cementisti di Ravenna has promised to complete work within 100 days after the equipment arrives.