Dear Editor,

I noticed that in the photos of the Gordon Town breakaway the exposed face of the hillside below the roadway has a layer of packed stones laid against the soil. This is the technique I have often seen used to retain steep hillsides below country roads. If the soil under the roadway becomes wet, as occurs in periods of sustained rainfall, it loses its strength and tends to slump sideways, causing the roadway to fail and slide downhill.

Failures of this type are inevitable in the type of rainfall event we just experienced, so why is everybody so surprised?

There has been weeping, wailing, and gnashing of teeth, especially from the politicians, who are supposed to have engineers advising them.

The long-term, cost-effective solution to prevent this type of failure from occurring year after year is to either support the soil with a proper retaining wall with a wide enough base capable of holding back that amount of slumping soil, or, where the soil or rock in the hillside is strong enough to be drilled into, and ground anchors placed deep into the hillside to hold the wall.

Howard Chin

Member

Jamaica Institution of Engineers

hmc14@cwjamaica.com