Sinking of railway embankment road for further study
By Oscar P. Clarke
Stabroek News
April 12, 2004
Nearly two years after sections of the railway embankment road sank and cracked, the Public Works Ministry is still deciding on what action should be taken and another probe of the failure is to be done.
As recent as last week the ministry was still mulling several options to be used to repair the defective section of the 12.8-mile roadway which was completed in 1998 by Dipcon.
Stretches between Coldin-gen and Buxton, East Coast Demerara have over the last year or two developed cracks, some of which have since widened.
This happened despite there being light traffic on this stretch because of the high levels of crime. This is worrying to the ministry as other sections of the roadway with heavier traffic have not developed the same problem.
It is for this reason in particular that the ministry intends to secure the services of an independent engineer to investigate what caused the cracks, Communication Consultant in the Ministry of Public Works, Ajay Baksh said.
According to Baksh the ministry agreed to a new investigation by someone outside of it in the interest of determining what had really gone wrong with this section.
Although engineers at the ministry had cited several possibilities including `benching' as possible causes for the faults they are yet to arrive at a definitive answer, Baksh said.
Two other possibilities were recently considered including the presence of an abandoned drainage canal and an old pipeline in the area of failure. These however require detailed investigation, Baksh said.
The embankment road constructed at a cost of $429M was initially designed as a bypass road to ease traffic congestion while work to rehabilitate the Mahaica to Rosignol main road was ongoing, Baksh noted.
He said the road was never designed to the specifications of a main public road and as such the asphalt concrete surface was not as thick as required for such roadways. It was only the stretch between the university access road and Sheriff Street which had a thicker surface, Baksh said.
It was for this reason that the ministry had instituted restrictions with respect to trucks traversing it as a means of maintaining its integrity, Baksh said. He however said that this policy was reversed when the administration of the embankment roadway, as is the case with other roads, was taken over by the police traffic department. He acknowledged that greater traffic than anticipated is currently being seen on the road as it is more convenient for many.
The ministry, he further said, is committed to undertaking repairs despite the defects liability period having expired. This period only covered one year after formal completion by Dipcon of the roadway in 1998.
Baksh however said that it would be improper to proceed with any remedial work costing millions of dollars when there was still some mystery surrounding the exact cause of the folding.
What was more perplexing for the ministry's engineers was that the faults occurred at a time when there was no traffic flowing on the roadway, Baksh said.
Baksh added that the ministry is to begin some patching on the Embankment road in the Buxton/Friendship area this week in an effort to correct defects due to pipe-laying and telephone cabling works.
A pothole on the Lusignan bridge highlighted in a photo in Wednesday's edition has since been fixed by the ministry, Baksh said.
Retired Civil Engineer Phillip Allsopp in an interview with this newspaper last year October had highlighted the incorrect use of material and a flawed design process as being among the reasons for the cracking of the embankment road.
Allsopp, a former head of the government's Hydraulic Division in the Ministry of Works and one who has considerable experience in infrastructure works had said that it was his belief that the plasticity of the sand/clay mix was probably not adequately controlled.
The benching technique achieved by cutting a bench shape into a portion of an existing structure and levelling that material over the area not previously covered by the surface, is one that is used when there is a need to widen the surface area as was the case with the Embankment Road.
During the road's construction, American Consulting Firm Wilber Smith and Associates in association with David Klautky and Associates had overseen the project.
However Klautky had told this newspaper that neither his firm nor the American firm had been responsible for designs but merely supervised to see that the designs were carefully followed.
Although having not supervised the entire stretch of the road as funding ran out, Klautky was adamant that the materials had been applied according to design specifications.
Trinidadian road construction firm Dipcon had also echoed similar sentiments.