WEGH Group offers a wide range of specific superstructure solutions for subway lines, ranging from the “Arianna M Slab” ballastless slab track systems in both Standard and Plus versions to the Floating Slab system and the Top-Down and Bottom-Up solutions. These products are designed for installation in peculiar locations, such as subway lines, where space is limited, the need exists to minimise vibrations, and maintenance and cleaning operations have to be easy.
The floating slab system is the most efficient solution to maximise the reduction of vibration dispersing into the surrounding areas. It is the perfect choice for sections where the underground line runs underneath – i.e. tunnels – or along – i.e. above-ground sections or viaducts – historical monuments, densely inhabited centres, buildings with architectural and artistic significance, hospitals and historical centres in general. This type of superstructure is characterised by a large, cast-in-place reinforced concrete slab with prefab elements in it, e.g. sleepers, and a continuous elastomeric pad underneath the casting.
Arianna® M-Slab is a ballastless system consisting of prefab slab tracks made of prestressed reinforced concrete installed on a base foundation with the insertion of a special bedding layer that creates a regular and even resting surface, thus compensating foundation irregularities. This is the ideal solution when the investment is evaluated especially from the point of view of the life cycle, as the system requires little maintenance over time if compared to other superstructure systems. Arianna® M-Slab does not require traditional maintenance operations such as ballast tamping, levelling, cleaning and renewal (which is a significant factor especially in stations). It is suitable in cases when the line construction times are particularly short because it can be installed quickly, and the installation times can be calculated with a discrete level of certainty. The Arianna® M-Slab system is available in standard version, where the anti vibration features are comparable to those of the ballast system, and in Plus version, which is the ideal solution when high performances are required in terms of vibration damping, such as in sections going through urban centres in order to safeguard the historical and urban heritage, in tunnels or in stations.
The Top-Down system is a cast-in-place infrastructure for underground lines. It is adopted in cases when the available space is narrow – both in height and width -, which is quite frequent in tunnels or on viaducts. The insertion of an elastomeric pad underneath the in-place casting provides for medium to high vibration damping. The Top-Down laying solution begins with the anchoring of the fasteners and the tracks, while in-place casting is made at a later stage.
The Bottom-Up system is a cast-in-place superstructure for underground lines. It is adopted in cases when the available space is narrow – both in height and width -, which is quite frequent in tunnels or on viaducts. The insertion of an elastomeric pad underneath the in-place casting provides for medium to high vibration damping. The Bottom-Up laying solution is based on the casting of the foundation, first, followed by the installation of the fasteners and the tracks.