The Pianturino Viaduct is located along the N02 road, near the Cadenazzo Municipality. It was built between 1978 and 1980. It is a reinforced concrete structure with 3 spans (55-70-55 m) crossing the valley of the same name at about 70 m above the valley bottom. The project provided for the use of permanent pre-stressed anchors to ensure the stability of the protection walls of the pier foundations and the retaining structures of the abutment on the Chiasso side. In 1992, the anchored structures were subjected to extraordinary maintenance consisting in the integration of new anchors. Following the general inspection in 2019, FEDRO commissioned Lombardi SA to conduct a study with the aim of quantifying to what extent the stability of the slopes and anchored structures depend on the current state of preservation of the anchors. The methodological approach adopted was based on the logical sequence foreseen by SIA 269 and on the procedural approach of FEDRO Directive 12005. The updating information phase included the general examination of the structures, definition of the conservation state of the anchors and updating the geological-geotechnical reference model. The updated geotechnical and structural verifications of the anchoring elements showed that, with reference to the safety levels required by the regulations in force and the residual service life of the viaduct, the stability of the slopes and the structural safety of the works depend on the contribution of the prestressed anchors. Given the impossibility of establishing the ultimate anchor strength, linked to the evolution of the degradation processes of the system (reinforcement and header), retrofitting of the anchored structures was proposed in relation to two types of approaches: preservation of the existing and replacement of the anchors, respectively. Different investment scenarios related to the remaining service life were provided to the client.

The Bodio Portal at the southern end of the 57 km long Gotthard Base Railway Tunnel consists of a cut and cover section with two tubes of approx. 380 m length. Both cut and cover tunnels connect the actual portal with the underground section, advancing through a section with heterogeneous blocky soil. Based on the local geology and geological history, no time depending settlements were expected at the beginning of construction. However, after initial settlements a continuation at a constant low rate, showing almost no changes for years, was observed. As consequence, further ground investigations with deep core drillings up to a depth of approx. 200 m were carried out. Lombardi Ltd. was charged with the interpretation of the results of these additional ground investigations as well as the analysis of possible mechanism including the prediction of the future development of these settlements. Two mechanisms or the combination of both of them could be identified as possible cause for the still ongoing ground deformation. One possibility is that the settlements are caused by an ongoing consolidation of the deep lacustrine deposits (between 100 m and 160 m beneath the tunnel. The ongoing deformation could, however, also be referred to creep phenomena within the cohesive formations.

The Tunnel Vedeggio-Cassarate (L=ca.2'630 m) links the Valley of the Vedeggio River to the Valley of the Cassarate River northern of the city of Lugano in Switzerland. The project is a single bidirectional tunnel. The cross section has an intermediate slab, which separates the traffic space from the exhaust air aspiration channel. A parallel safety tunnel (Ø 4.5 m) was excavated on the south side of the main tunnel (30 m). Every 300 m, there are bypasses alternately for pedestrians and vehicles linking both tunnels. The first 2’350 m from the portal Vedeggio were excavated by D&B through the crystalline rock of the south alpine formations. The following ca. 200 m up to the portal Cassarate were excavated in loose material composed of quaternary heterogeneous glacial-river deposits in different consolidation states, with several independent artesian water tables characterized by pressures up to 2 bars.In the loose ground stretch the ground had to be previously consolidated with jet grouting. Where this was not possible from the surface the ground was consolidated in advance of the tunnel face with jet grouting and fore polling. In the middle of the tunnel is located a cavern equipped with two ventilators for the aspiration of the fume in case of fire and electromechanical devices serving the whole tunnel. The exhausted air is then expelled through a 60 m long tunnel and a 100 m high vertical shaft to the surface. The tunnel crosses twice the new Ceneri Base tunnel of the Gotthard main railway line with only few meters overburden (5 m and nearly 2 m).

The A2 motorway around Lucerne on the Basle–Chiasso axis is one of the busiest road stretches in Switzerland. The Emmen-Lucerne-Kriens section is characterized by a number of 1970's-era engineering structures: the Lehnen viaduct along the Reuss in the north, the roughly 600-metre-long Reussport tunnel, the Senti bridges over the Reuss linking to the city as well as the 1.5-kilometre-long Sonnenberg tunnel to the south. After almost 40 years of operation, steadily increasing traffic has left its marks. Between 2009 and 2013 the total renovation project of the Lucerne Cityring includes the upgrade of the roads and tunnels to a technology and safety level according to today’s standard. To maintain the flow of commuter traffic during the day and at the peak travel periods, the total renovation was done during night and on selected weekends. The construction demanded a lot from contractors, planners and builders, authorities, commercial enterprises as well as the residential population around Lucerne. Joining forces allowed to meet the challenges of this highly ambitious project. Thanks to the tremendous efforts of the building professionals, the extensive transport and structural measures as well as intensive outreach, the job was completed in time and at tolerable impact for the Lucerne region.