BCA intervenes as residents complain of early morning works at collapse site

Updated 1pm with BCA comments

The Building and Construction Authority (BCA) has instructed a contractor undertaking remedial works at the site of a construction site collapse to carry out works "strictly" within normal hours, following resident complaints. 

The authority's statement follows complaints from neighbours about being woken up by vehicles carrying construction material to the Naxxar site as early as 4.30am. 

The contractor had been permitted to operate from 5am, but only with the Naxxar local council's permission — which the council said in a statement last night it had not provided.

Writing on Facebook on Thursday night, the council had said it never authorised or agreed to works beginning at 5am, and had communicated its position to the Building and Construction Authority (BCA) on the matter.

“The council wishes to make it clear that it is not opposed to exploring every possible means to expedite the required remedial works. However, this cannot be achieved at the expense of residents,” it said.

The BCA later responded that it had instructed the contractor to carry out the works "strictly" within the hours allowed by law.

A report into the construction site collapse recommended remedial works be undertaken as swiftly as possible.

Resident complaints

Naxxar residents living next to a precarious construction site say they are being woken up in the early hours of the morning by loud trucks carrying construction material to the site.

Videos sent to Times of Malta show a convoy of trucks passing through Triq Senesalk at the crack of dawn, their diesel engines revving, and entering the access road to the construction area.

Families living near the construction site were ordered to evacuate their homes for a night when the foundations of a multi-storey development suddenly gave way last week.

At the time, the developer insisted there was no danger on site. Since then, an independent architect’s report found that the site is “very precarious, at various levels” and recommended the foundations be backfilled again as quickly as possible.

The BCA said it allowed the remedial works to take place between 5am and 8pm because of the urgency of the matter. The works are limited to the remedial actions recommended in the architect’s report.

What went wrong

The construction site sits on an old hardstone quarry that had been exhausted and backfilled over the years. The site is being developed into a complex of apartment blocks sitting atop three levels of underground garages.

Last Thursday, part of the structure holding back the fill material beneath the garage levels gave way.

According to the independent architect’s report, the core problem was a dangerous pressure imbalance.

The construction method involved building stone masonry support walls inside the curved enclosure, then backfilling the spaces between them.

However, the area immediately to the east of the structure had been excavated, leaving an open void.

The fin walls within the structure contained backfill between them

The connection between the fin walls and the outer enclosure was only held together by shallow interlocking stonework (“mursalli”) with weak mortar, which the report said was insufficient to contain the internal pressure.

As a result, the material used to fill the space between the fin-walls was creating an outward pressure on the curved wall, which eventually led to the partial collapse.

The site is now considered precarious. The exposed fin-walls left standing after the collapse have a slenderness ratio over 40, meaning they’re tall and unsupported enough to buckle and fail without warning.

The area beyond the collapse, towards Triq is-Seneskalk, is built the same way and under the same pressure, so further collapse is a risk, especially if rainwater infiltrates the fill, the report warned.

The report's author recommended a controlled backfilling of the excavated void near the wall, in phased stages, to rebalance the pressure. As each backfill phase progresses, soil-cement and C15 concrete would be poured between the fin walls to create stiffening “belts” providing lateral support.

However, all the work must be done remotely; the report emphasised that no workers should be allowed under or near the precarious structure.

BCA intervenes

In a statement later on Friday, the BCA said that following the council's concerns, the contractor had been instructed to carry out remedial works "strictly within the hours permitted by law".

The authority said the proposed extended working hours at the site "were initially considered strictly in light of overriding safety considerations" with the aim of completing the works in the shortest time possible.

It added that the proposed working hours had been discussed in a meeting earlier this week with a "substantial number" of affected residents, to which the council was also invited.

"The BCA remains committed to ensuring that public safety is safeguarded while also taking into account the legitimate concerns of residents."