KOCHI: Passing by the Palarivattom Pipeline Junction, you will now see the remains of a flyover that made headlines for many months. However, it is barely sticks and stones now. With support from Uralungal Labour Contract Cooperative Society (ULCCS), the contracting firm, Delhi Metro Rail Corporation (DMRC) started dismantling the deck slabs, girders, and pier caps of the flyover on September 28.
The reconstruction of the majority of pier caps of the structure is in progress. “We have demolished 15 spans so far. Of the total 19 spans, we will be demolishing 17, including girders, pier caps and decks. The obligatory span (central span) will be removed later,” said a senior DMRC official.
The new structure is being built with a brand new design. “The new parameters are sharply different from the old one. We are not at all bothered about the details of the old structure,” said the official. The old flyover, commissioned by Roads and Bridges Development Corporation of Kerala Limited (RBDCK) in 2016, was closed in May 2019 after over 2,000 cracks were detected on its girders and pier caps.
Considering the severity of the issue, the state government entrusted DMRC with the reconstruction in September 2019. The work was supposed to begin from October 1, 2019. However, contractors and allied organisations approached the High Court with a demand to conduct a load test to determine the structural strength, delaying the construction by almost a year.
New and improved
According to officials, the reconstruction will give the structure a 100-year life, as compared to the 20 years the old one would have lived if strengthened using carbon-fibre wrapping. The existing piers (pillars) will be strengthened with a concrete jacketing. The flyover is expected to be opened for traffic in eight months, by June 2021. So far, the construction of over 30 precast girders has been completed at Muttom yard. “The demolition and reconstruction will progress simultaneously. Prestressed girders are being brought from Muttom yard in trailers, while pier caps are being reconstructed on the site. We have eight months and are hopeful of finishing it well within the schedule. So far, everything is going by plan,” said the DMRC official.
Seawall suggestion dropped
The suggestion to use debris from the dismantled structure to build a seawall in Chellanam which faces severe sea erosion was dropped due to practical difficulties in transportation. “Extracted rubble, bitumen and steel have already been disposed of and shifted to Muttom yard. We have decided not to reuse them,” said the official.
What went wrong?
To avoid jumping of vehicles between two spans, the old flyover design followed the deck continuity method instead of traditional expansion joints. Combined concreting of girders and deck slabs of multiple spans was incorporated for this. One span comprises six girders existing between two pillars.
Private agencies assigned by NHAI found cracks in pier caps 1, 2, 3, 7, 10 and 12 during studies conducted in 2017 and ‘18. Instead of repairing, RBDCK approached IIT Madras for further studies and their report has also pointed out severe defects in the structure. Metroman E Sreedharan’s visit in June along with structural expert Prof Mahesh Tandon and IIT professor P Alagusundaramoorthy found deep cracks in 97 girders and 16 pier caps.
As per regulations, cracks shouldn’t be more than 0.2 mm deep and the flyover had cracks over 0.3 mm deep. The team recommended reconstruction of the 17 spans and directed to change the low-quality iron-bearing used between pillars and spans. Following these reports, the Ministry of Road Transport Highways (MoRTH) suggested reconstruction to the state government.
Poor-quality materials were used in construction. M22 grade cement which usually opted for households and shops was used instead of M35 grade cement
Deficiencies in the placement of girders and height differences were evident throughout the structure.
Old flyover in a nutshell
Land acquired 52 cents
Project cost 42 crore
The total length of flyover: 750 metres
Total width: 17 m
Total number of spans: 19
Number of lanes: 4
Project Consultant: KITCO
Nodal agency: RBDCK
Contractor: RDS Projects Ltd
Design: Nagesh Consultants, Bengaluru
Expense of repair Rs 3 crore
Expense of IIT study: Rs 56.50 L
Estimated cost for restoration: Rs 18.71 crore
Timeline
Administrative sanction for flyover construction: October 2013
Contract agreement signed: March 2014
Foundation stone laid: June 2014
Commencement of construction:
September 2014
Inauguration: October 12, 2016
Detecting 20 potholes on the surface: July 2017
Assessment of RBDCK which found deficiencies: November 21, 2017
First study by pvt agency assigned by NHAI which detected cracks: March 13, 2018
Second study by pvt agency assigned by NHAI: September 21, 2018
Closed for repair work after IIT report: May 1, 2019
State govt assigns E Sreedharan for
detailed study: June 13, 2019
Sreedharan submits report with recommendation of reconstruction: July 3 2019
State govt decides reconstruction:
September 16, 2019
HC halts reconstruction plan on the petition filed by the contractor: September 24, 2019
HC directs govt not to reconstruct without its permission: October 10, 2019
HC verdict to conduct load test: November 21, 2019
Govt challenges HC verdict in SC:
February 7, 2020
Govt demands immediate hearing: August 22
SC verdict on reconstruction: September 22
Dismantling and reconstruction commenced: Sept 28
Expected launch: Before June 2021
The Palarivattom flyover was one of the most-discussed administrative failures in recent times. While the arrests and stories of corruption have been making headlines, the reconstruction is progressing fast, with almost 90 % of the old bridge being demolished so far. The new structure is likely to be opened for public by June 2021