Widening the Grand-Pont Bridge
Designed by engineer Adrien Pichard, the Grand-Pont bridge is located in downtown Lausanne and provides the east-west link as part of the city’s small beltline. The 170 m (558 ft.) Grand-Pont bridge was built in 1844 with two superimposed arcades. The lower level, composed of 6 arches, was buried when the Flon Valley was backfilled. The upper level of 19 arches is still visible.
The enlargement project is part of the efforts to develop the main roads, and in particular high-level bus service operations, between Lausanne and Morges. Widening the deck will offer more space and comfort to the various users: buses, cyclists and pedestrians. Widening the deck from 15 m (49 ft.) to 17.10 m (56 ft.) will be achieved by installing a prestressed, monolithic concrete slab and removing the existing deck consisting of crossbeams and slabs for sidewalks.
Given the historical value of this bridge, the architectural office of the city of Lausanne and the office of monuments of the canton of Vaud were consulted during project development. These consultations helped integrate the support of the slab and the treatment of the parapet, railing and mast details. The final project is simple and calm—no element disturbs the rhythm of the 1844 arches.
The new deck is a prestressed concrete slab varying in thickness from 25 cm (10 in.) at the end of cantilever to 40 cm (16 in.) over the support. This 3.90 m (13 ft) slab accommodates sidewalks yet is nevertheless sized to withstand accidental loads of heavy traffic. The slab was designed to be entirely prestressed to manage the concrete’s long-term cracking. A bituminous waterproofing layer is placed over the entire slab. The installation of a new concrete deck and a waterproofing layer will stabilize the existing masonry structure, which suffers from numerous water infiltrations, and it will ensure the structure is more durable. It also will improve the operation of the commercial spaces under the arches.
The new guardrail was proposed in 2005 as part of a tendering process. It consists of vertical metal blades that have been designed to withstand the impact of vehicles.Share