Diaphragm wall may have failed: Experts

Kochi: Even as district Collector Muhammad Y Safirulla has constituted an expert committee to find out the reasons for the collapse of a massive under construction structure in Kaloor on Thursday night, structural engineering experts indicate chances for diaphragm wall failure which led to the collapse.

The Corporation has given permission for construction of three underground floors. Excavation of soil from more than 15 metre depth was underway.

“The collapse might be most likely due to the failure of the diaphragm wall which is constructed surrounding the excavation site,” said M.M Francis, consultant structural engineer from Thrissur, who has more than 30 years of experience in offshore sites in UAE.

“The shoring piles, the support used in building construction and excavation, have been caved in when the diaphragm wall collapsed due to external pressure.”

“There are three possible reasons for the failure of the diaphragm wall. It might be due to the pressure of water seeped from the Thevara – Perandoor Canal.

Though the canal is more than 10 metres away from the site, there might have leakage through underground cracks. Another possible reason is the heaving effect of the soil. Heaving is the upward movement of the soil when water pressure in the earth increases. When wet ground clay push upwards causing the soil to rise and affect the upper surface of an area. This can cause structural damage to diaphragm wall. The third possibility is structural failure of shoring pile due to insufficient steel, anchorage depth, and inadequate concrete strength.

There are possibilities for a land slide like situation caused by the gush of water from canal, jerking due to heavy traffic through the adjacent road,” remarked Mr. Francis.

Meanwhile, the expert committee constituted by the district collector will inspect the ill-fated project site and examine all possible causes before submitting a final report.

High level Committee to submit report in 1 week

The high level procedure committee constituted by district collector Muh-ammad Y Safirulla on Saturday will submit report on the collapse of an under construction building in Kaloor within a week.

The procedure committee has been constituted as per the Disaster Manage-ment Act and will probe the reasons for collapse of the structure and will check various permits accorded, possibilities for further construction works and the basic sketch of the building.

The collector has constituted the procedure committee based on the discussions held with the initial technical panel which conducted the initial probe.