Kochi: A geotechnical study has unearthed that there exists a gap between the piles and the rock beneath the problematic 347th pillar of the Koch Metro at Pathadipalam near Edapally. This is understood to be the reason for the fragility of the pillar that caused a slight slanting of the railway track atop the pillar.

However, Kochi Metro Rail Limited (KMRL) has not officially confirmed the news.

It was found during the study at the spot that the rock is situated 10 meter below marshy water and the bottom part of the piles is not reaching up to the rock. The piles are not touching the rock inside the earth. It was also found that there is a gap of one meter between the rock and the pile.

The metro pillars are supposed to be built by way of carrying out continuous piling till the rocks are found. Even after the piles get in contact with the rock, the procedure is that the bottom part of the piles has to be fixed inside the rock by piercing it through the rock at a distance which is two times the diameter of the pile.

REPAIR PLANS
The present repair plan is to strengthen the pillar by fixing new piles. The repair work is planned in such a way that four piles will be erected with one meter diameter at a place half meter away from the existing piles of the 347th pillar. The new four piles to be erected will be unified with the existing pile caps. Above the pile caps, a new pile cap with a large plate having a thickness of 50 cm will be built.

The KMRL is yet to ascertain whether other pillars are suffering from such piling issues.

After finishing the repair work, the KMRL has to get the permission of the Railway Safety Commissioner to resume the service.

The KMRL is planning to entrust the L&T company with the rectification work. The civil work was carried out by L&T. Though the period for free undertaking of repair work was over, the L&T would be entrusted with the work with the condition that it is responsible to undertake the repair work as it did the original civil work.

The flaw came to limelight one month ago when a marginal slant of the Metro tracks was detected. At present, the traffic through the Kochi Metro was regulated for carrying out repair work, without affecting the services.

The geotechnical study was carried out by engineers from Delhi Metro Rail Corporation (DMRC), KMRL, L&T and Egis India.