Box Jacking

The underpass construction technology for minimizing the traffic impact

Box Jacking is a trenchless method of underpass construction that consists in pushing one or more prefabricated concrete boxes into the soil using high capacity hydraulic jacks, while excavating the soil.

The Box Jacking method can be used under railways, roads and highways with active traffic flow and is designed to avoid any impact on traffic during processing. The Box Jacking methodology reduces, if not completely eliminates, the amount of time that the tracks, or carriageways, must be out of service.

For more than 40 years, Petrucco’s know-how has been entirely dedicated to minimizing traffic impact during the construction activities on grade separation.


Railway underpasses, road underpasses and highway underpasses
The different types of Box Jacking


We build underpasses under roads and railways without compromising traffic circulation. In total safety.

Petrucco uses the Box Jacking technology in different ways according to the needs of the client and the circumstances of the work, such as type of terrain, morphology of the territory, organization of the construction site, type of railway line or road to be crossed.
In addition, the company has patented a system that allows for the construction of underpasses without (or with only partial) traffic interruptions on roads or railways.
Although there is no universal solution and each project is customized by our engineers and designers, the types of underpass construction with the Box Jacking system can be divided into four subgroups.



The jacked box can be pushed under railway tracks without compromising in any way the movement of trains during processing. The technology of our patented Temporary Bridges (link) guarantees the continuity of railway traffic in total safety while driving under active tracks.



Thanks to the anti-drag technology developed by the Petrucco Group, it is possible to build an underpass under roads and highways, partially diverting traffic. This technology allows for the continuity of traffic during construction, minimizing the impact on traffic.



This solution entails jacking the box without removing the material cover between the upper slab of the box and the road or railway infrastructure above. This solution is only feasible under certain conditions of underpass geometry and geology of the site and, when possible, allows for the underpass to be buit while maintaining the traffic above it. In the railway case, however, it is necessary to install a temporary bridge (link), given the very limited geometric tolerances allowed on the tracks.



This method of underpass construction entails a full road closure while launching of the box with open cut excavation. Despite the temporary interruption of traffic, this method allows the work to be carried out very quickly and construction times to be reduced. Although the timing varies from case to case, this methodology allows you to complete the crossing implementation as well as the restoration and reopening of the crossed road in a period ranging from 12 to 56 hours, depending on the size of the box and the amount of excavation envisaged.


Thanks to the experience of specialized technicians and the pushing equipment owned by the company, the Box Jacking technology used by Petrucco can jack boxes of any weight and size. The Petrucco group has jacked boxes weighing up to 12,000 tons, measuring over 50 meters wide, and with a travel distance of over 120 meters, but there are no weight and size limits.

With over 40 years of experience and more than 1750 successful projects around the world, Petrucco has established itself as a leader in the Box Jacking methodology.

Although widely used and known in Europe, the Box Jacking method was introduced in Canada in 2013 and the United States in 2017 by the Petrucco Group, making our company the pioneer of the Box Jacking methodology in the American market. The Evergreen Line in Vancouver (2013) (link), the LIRR expansion project in New York (link) and the construction of underpasses for the BRIGHTLINE in Florida (link) are some examples of our most notable projects.

Underpasses and Safety Level
crossings removal for the prevention of intersection accidents.


The Petrucco know how is fully dedicated to the minimization of the traffic impact during the construction activities on grade separation


Nowadays, the rising demand for people and freight movement in a fast, safe and multi-modal way leads to a strong necessity to improve the existing infrastructural networks and to create new ones. As a result of this growth, it is necessary to manage conflicts at intersections in a way that has to be FAST, SIMPLE AND SAFE.
The construction of underpasses prevents and definitively eliminates accidents at intersections and level crossings. Across the world, the elimination of level crossings is becoming a priority for railway organizations.