Night demolition of A4 motorway overpass

The overpass of the Fauglis-Torviscosa municipal road, built in the 1960s, had restrictions on the transit of vehicles weighing more than 18 tons.

A company specialized in the construction of large-scale works had been awarded the contract for the construction of the third lane Palmanova-Gonars which, among other works, also included the demolition of the overpass. Since we had already collaborated with the aforementioned company in the past, they asked us to carry out, together with other companies, this particular intervention.

The peculiarities of this demolition project

In this project we had to deal with several critical elements:

• it was a night-time job and to be carried out in the winter season;
• the execution times were very tight;
• there were several companies involved that had to work in synergy;
• there were many men and vehicles in the field at the same time;
• the materials had to be completely removed and the underlying road surface preserved;
• the subsequent disposal and partial recovery of the removed materials was required.

Bureaucratic formalities and coordination

To be able to work on this project, it was essential to have the SOA certification for the OG 8 category (River, defense, hydraulic and reclamation works).

Up until then, we had not needed it, but in just 15 days from the start of the process we obtained it, following the entire process with great care and determination. A result that was not to be taken for granted in such a short time.

In addition to this certification, the project required several coordination meetings between managers and operators. There were many variables in play, including 5 large excavators in action at the same time, which had to operate without getting in each other's way.

It was also essential to take into account both the management of motorway and ordinary traffic, and the supervision of the methods of carrying out the works.

Intervening on an interconnection node, where the A4 and A23 cross, required a careful study of traffic flows and the preparation of alternative routes.

Spreading the sand

On December 1, 2017, the day before the intervention, we transported 90 cubic meters of sand taken from our Pradamano treatment plant and positioned it next to the reference area.

At 11:00 p.m. on December 2, the work began with the closure of access to the overpass and the stretch of highway below.

The first operation consisted of positioning 900 square meters of non-woven fabric on the highway road surface. On this, with our mechanical shovels, loaded by excavators, we spread 50 cm of sand whose function was to cushion the blows of the falling parts of the demolished overpass and therefore prevent the road surface from being damaged.

In the meantime, teams of workers removed the guardrails and horizontal signs.

Alternating demolition with excavators and grabs

When everything was ready, the work began alternating between the 5 excavators with pneumatic hammers, which made the holes, and the subsequent intervention of the demolition pliers, which crushed the parts just drilled.

The work was spectacular precisely because of the synergy between vehicles and men and the very precise timing.

The cold was making itself felt, but there was no time to waste because at dawn the highway had to be reopened.

The clearing of materials

Once the demolition operations were completed, the removal of the materials began.

First, the demolished bulky elements were removed, then the layer of sand was removed and finally the non-woven fabric. Finally, motor brushes carefully cleaned the road surface.

In addition to the demolition of the overpass, some signage portals and variable message panels were removed, the horizontal signage of the A4/A23 connection ramps at the Palmanova hub was adjusted, and the central guardrail near the demolished overpass was restored.

The reopening of the road network

At 6:00 am on Sunday 3 December, traffic on the A23 motorway was restored, 3 hours ahead of schedule.

The more than 150 people at work, including technicians, workers, assistants, maintenance workers and the Highway Police, were able to breathe a sigh of relief for the great work done. The 27 Gesteco technicians involved also joined in the general satisfaction of all parties involved.

We were able to optimally manage the various elements of complexity of this intervention.
In just 160 minutes we carried out the planned interventions. The road system of that stretch of highway was reopened the following morning without any damage to the road surface.

We also started the recovery of 135 cubic meters of demolition material.
Watch the video which summarizes the main phases of the demolition intervention.