Cracks develop on three Metro corridors

New Delhi, Jul 27 (PTI) Minor cracks have developed on
18 piers on three corridors of the Delhi Metro and the Delhi
Metro Rail Corporation (DMRC) has asked a consultant firm to
examine the locations to take "corrective measures", taking no
chance after the July 12 mishap that killed six persons.

Describing the cracks as "hairline" ones, the DMRC
said these were noticed by DMRC engineers and Shirish Patel
and Associates, who conducted a structural audit on all the
Metro corridors which are under-construction now.

"They found hairline cracks on eight piers of the
Central Secretariat–Gurgaon corridor, two piers of the NOIDA
corridor and eight piers of the Central Secretariat–Badarpur
corridor. All appear to be minor in nature," DMRC Chief Public
Relations Officer Anuj Dayal said.

"DMRC will carry out further corrective action if
required and take necessary remedial measures after Shirish
Patel and Associates have examined these locations," Dayal
said.

Meanwhile, DMRC chief Sreedharan visited several of
the sites where the piers have developed cracks and inspected
it personally. He has been visiting the sites from Saturday.

The developments came on a day when a meeting of the
Board of Directors discussed the report submitted by Prof A K
Nagpal panel that went into the Zamrudpur incident.

There were reports that some officials have faced
action after the Board meeting, but there was no official
word.

The group of directors gave their views on the report
based on which action will be taken against persons concerned,
sources said.

The DMRC will make the report of the panel public
Tuesday during a press conference to be addressed by
Sreedharan.

The panel consists of Prof A K Nagpal of IIT, Prof B R
Bose from Delhi College of Engineering and Steven Lowry.
Sreedharan had on Wednesday said that they have dropped its
design head Rajan Kataria from the panel.

The panel went into the aspects of material and design
deficiency.

After the Zamrudpur incident that killed six people
when an under-construction bridge collapsed, DMRC began a
special drive to re-check all cantilever piers of Phase-II and
as part of this exercise Shirish Patel and Associates were
engaged to conduct a structural audit.

The consultants were also asked to re-check the design
of all these 18 points in detail, apart from overall checking
of Phase-II structures.

Dayal said surface cracks in concrete are not uncommon
and there is no need for panic in the matter. "In fact, Indian
standard codes for design of reinforced concrete structures
allows and permits tension cracks within limits," he said.

The spokesman said ultrasonic testing and rebound
hammer testing will be done to check the integrity and quality
of the concrete. In addition, DMRC will get load testing done
wherever considered necessary.

Dayal said similar testing was done during Phase-I of
the construction also as a precautionary measure whenever
required.

The cracks on the Noida line have been noticed at a
time when the DMRC had begun trial runs on the much-awaited
Yamuna Bank-Noida line, which is set to be opened for public
by the end of August.

The cracks were spotted on piers 10 and 14, located
near the Indian Oil building in Sector 14 of Noida, and
Sreedharan said the crack on pillar 14 was superficial,
while he ordered a thorough inspection into pier 10 crack.

The Noida stretch was constructed by Gammon India,
which is also contractor of the Central Secretariat-Badarpur
line where the mishap occurred.

The trial runs on the 13.1-km-long Noida line have
only been started on the Yamuna Bank-New Ashok Nagar stretch
for now and will be extended to Noida City Centre Sector 32
after 10 days. PTI ETB
anu
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