Wall collapse renders Hamilton’s Claremont Access inaccessible

Downnbound lanes of the Claremont Access, which connects the Hamilton mountain and the city’s downtown core, were closed in November after the failure of a portion of an upper retaining wall was noticed during a tree removal project.

"This failure involved the localized collapse of 25 metres of bin (retaining) wall, but did not involve a collapse onto the roadway. The location was investigated and to protect adjacent vehicular traffic, the downbound lanes of the Claremont Access were closed. The upbound lanes were not affected," said Brian Hughes, manager of capital rehabilitation and technical operations for the City of Hamilton.

This most recent incident prompted the city to bring in a team of experts to look at ways to avoid a future landslide such as the one that occurred in 2012. That wipeout of the 40-year-old wall closed parts of the busy access for days.

Comparing the 2012 situation to this most recent one, Hughes said, "The initial work following the road closure involved removing the 25 metres of bin wall that had failed. There is now a section of bin wall, approximately 55 metres long, with 19 panels, located between the failure that occurred in 2012 and the recently noticed failure (in) 2016 that now needs to be removed. The removal will proceed in a controlled manner."

The estimated cost to ensure the access is safe to traffic is $1.1 million, which is more than double the $450,000 budgeted for rock face maintenance for 2017.

The public works department has proposed that the balance of the $450,000 set aside for this work come out of a roads reserve fund, which could potentially be dipped into for other planned scaling and fencing work projects planned for 2017.

"If the funding for the emergency work is covered through a reserve fund, then the annual escarpment maintenance program will proceed as normal in 2017," said Hughes.

Since the 2012 wall collapse and ensuing landslide, to prevent a similar failure to that degree, a number of trees that were identified as causing problems for the walls due to their weight and increased root structure have been removed.

Also, several bin wall columns have been strengthened and the exposed area of rock slope in the location of the 2012 failure was scaled.

"Immediately following the bin wall failure, a concrete barrier was installed along the length of the bin walls, which reduced the number of downbound lanes, but provided protection to the adjacent traffic," said Hughes.

He also deemed this latest effort that involves the removal of 80 metres of bin walls as a "short-term solution.

"We need to have this work done as soon as possible in order to re-open the downbound lanes for traffic. A study is underway on the entire Claremont Access escarpment face which will identify short, medium and long-term options. It is anticipated that this study will be completed this spring," he said.