Water and Waves Attack the Supports

Maxim Alekseevich Smagin, Director of the Directorate for Perm Territory Projects Implementation

At the height of the Perestroika years, large-scale construction began in Perm – in 1988, construction of a bridge across the Chusovaya River was started. Many Perm residents were waiting for its completion, which is not surprising: before that, to get to the city they had to use ferry crossing, and in winter they crossed the Chusovaya River overice. The bridge made it possible to get from Perm to cities in the north of the Kama River area (Prikamye) by car in just a few hours. In 2013, people actively started talking about the second phase of bridge construction, and in 2019, construction of a twin bridge began 18 meters west of the existing bridge. Maxim Smagin, Head of Directorate for Perm Territory Projects Implementation at JSC Stroytransgaz talks about unique features of this structure, the difficulties faced by the team of specialists in the course of design and construction, and the way these difficulties were overcome.

Prologue

— The new Chusovsky bridge is one of the largest and most expensive infrastructure projects being implemented in Prikamye. However, its high price is far less than the significance for economy of the Perm Territory and its population – summer residents, residents of Verkhnekamye (the upper Kama River area), residents of the region northern area – they are all waiting for elimination of traffic jams at this section of entrance to Perm. Therefore, we can declare of having a responsible mission – to make the life of our fellow countrymen more convenient and comfortable.

Bridge over the Chusovaya River in Perm Territory

Outstanding Facility

— The Chusovaya River bridge is unique in its length (1,506 meters), the length of spans to be covered (up to 147 meters), and the variety of superstructures from the left and right banks. In general, from the design perspective, the bridge cannot be called anything other than a unique structure. It simultaneously performs a number of important functions: provides secure traffic capacity with the prospect of traffic intensity for decades to come, meets the navigation requirements, ensures protection from floods and ice drift, and provides carrying capacity for the passage of certain types of moving loads. In addition, it must be taken into account that the bridge must be a durable, reliable and stable structure, as well as economical – its total cost of construction, maintenance, repair and possible reconstruction will be optimal. All these functions were ensured at the design stage, while choosing the optimal parameters of the structure. With all this, an important role is played by laying deep foundations in hard engineering and geological conditions (for example, in the presence of rock inclusions, karst rocks), where the pile depth reaches 50 meters. Therefore, equipment of increased carrying capacity was used during the bridge construction and special drilling units were involved for supports installation: in particular, barges and tugs, auxiliary bridges were built for performance of great amounts of construction and installation work associated with supports arrangement. The new bridge is a copy of the existing one, and for a harmonious architectural ensemble of similar artificial structures, their close location to each other was taken into account in the project design. Such location also considers the safety margin of vehicle approaches to bridges, and from an economic point of view, this is the optimal scope of work in the reconstruction of the road part of the facility. We also took into account the navigational restrictions under which the position of the new bridge piers relative to the existing bridge should not create obstacles for the movement of river vessels. The close location of bridges is aimed both at reducing the negative impact of wind loads and preventing aeroelastic vibrations of span structures. 

Overcome Everything

In the course of the bridge foundation laying we started to face some difficulties: rock inclusions of large fractions came across the soil mass, which made it difficult to carry out drilling works for installing pile foundation of supports to the design marks and immersing sheet piles for pit enclosures. In course of channel supports installation during the flood period, we provided for additional measures to reduce ice loads on pit enclosures.

In general, all construction and installation processes were based on standard methods, while the innovative component was represented by unified and new special auxiliary structures and devices applied by us. These structures and devices simplify construction processes by reducing the labor intensity and construction time. Thus, to erect the superstructure carriageway slab from the left bank of the Chusovaya River, we used fixed formwork made of fiber-reinforced concrete slabs, and to assemble the superstructures, we applied such methods as pre-assembly, transverse and longitudinal launching of pre-assembled units.

It is planned to start traffic on the new bridge this year already. It is assumed that after the new bridge is constructed, all traffic will be routed to it for one season to perform reconstruction of the existing bridge.