Bison weigh-in-motion system at the service of Anas Spa for monitoring the viaduct Molise

Bison weigh-in-motion system at the service of Anas Spa for monitoring the viaduct Molise

During March 2022, a installation of the BISON weigh-in-motion system was completed along the State Road 647 “Fondo Valle del Biferno” that connects the city of Termoli to Campobasso. The BISON system is part of the planned maintenance project on the Molise I viaduct, one of the most important infrastructures of the Molise region road network, carried out by AMEC S.r.l. on behalf of the road operator ANAS S.p.A.

The S.S. 647 has a strategic importance in the context of the road network of the center-south of Italy as it is the only link between the A14 Adriatica and the capital of Molise. The viaduct Molise I, inserted in the splendid frame of the Biferno Valley, is affected by the passage of a large number of heavy vehicles destined to carry goods on behalf of the different industries present in the surroundings of Campobasso and Isernia. The structure is characterized by a total length of 4856 m, and most of the bays are supported by pylons that rest on the bottom of Lake Guardialfiera, an artificial body of water overlooking the nearby Liscione Dam.

The viaduct is therefore subject to heavy traffic of trucks and of articulated vehicles that limits its useful life and this context consequently requires periodic maintenance operations and a constant monitoring of the behavior of the structure and of the loads passing on it.

Transient load monitoring: the BISON weigh-in-motion solution

Among the advantages and applications of the Bison weigh-in-motion system is the possibility of measuring the transiting loads on viaducts h24; in this way, the infrastructure manager will have in real time the weight data of the means and consequently the control of traffic flows affecting that stretch of Bifernina State Road.

Installation of the iWIM solution: timing and logistics

The operations of laying the scale were carried out over a working day while ensuring the vehicular flow, organizing a single direction alternating to ensure the viability of the stretch to the users.

On the same day, in addition to the weighing bending plates, the road cabinet was laid: it contains the technological components of the system such as the industrial pc and the signal collector; the ANPR camera with its support pole was also installed. At the same time, connections to the electricity distribution network were made, and to the devices for the network connection and the related wiring and connections. At the end of the installation, our iWiM technicians were able to carry out the first tests and verifications necessary to deliver to the customer a wim system operational and complete with everything. In the days following the installation, the system calibration operations were also carried out, organizing, without interfering with the vehicular traffic, a series of passages with known weight over the plates with different heavy vehicles.

BISON and transmitted data for real-time monitoring, future processing and statistical analysis

The data collected by BISON are transmitted online, they can be viewed in real time by the monitoring staff and can be stored for future statistical analysis and processing. The data package made available to the Infrastructure Manager includes a set of specific information in addition to the total weight of the vehicle, such as the associated plate, the speed of the vehicle, direction (the system is bidirectional), number of axles of the vehicle, width and length of the vehicle on the ground and classification of the vehicle (lorry, articulated vehicle, etc.). The package is completed with information regarding, for each individual vehicle, the composition of the axles on the ground, the distance between them, the weight of single axle and semi-axle and the differentiation of single or twin wheel.

For the case in question, ANAS will therefore have access to an important and significant amount of information, which will be also available in a simple and clear way through the statistical report ANAS PLUS, a very useful service for the systematic monitoring and total control of heavy vehicles traffic on the Molise I viaduct.