A miser will pay twice
In a specific feeling, we had been fortunate to own St. Petersburg Mostotrest one of the primary consumers because they cope with an operation that is day-by-day of. Furthermore, Mr. Y. Petrov, whom was once the manager of Mostotrest at that moment and a fantastic expert and “patriot” of the Northern Capital bridges, demanded fr om us to make certain to start with a long-lasting solution dependability associated with bridges. Besides, he constantly emphasised we have no right to build unsightly bridges or to design just a common structure that we live and work in St. Petersburg, and therefore. The vector of development he has designated for Stroyproekt nearly fully complied with this very own perceptions and choices. But, the genuine situation with Russian road industry into the 90-es could not expedite the duty! Russian construction regulations and SNIP norms (which are being currently upd ated) are dated back into 60-es and 70-es once the engineering ideology had been primarily dedicated to materials saving. The efficiency that is economic the fundamental requirements for design assessment plus some Russian developers still follow through this approach. As opposed to this, we constantly strived to quickly attain a dependable framework while providing for logical usage of metal and concrete.
St. Petersburg bridges demonstrably illustrate the distinction of the two design approaches. One of the Neva River bridges which is why a reconstruction has been produced by us design, Troitsky and Dvortsovy Bridges withstood about a century without major repairs. Besides, their structural elements mostly remained in reasonable condition and needed just some fix not replacement. To the contrary, the Lieutenant Schmidt Bridge (or Blagoveshchensky Bridge), which includes been recently reconstructed based on our design, has quite an alternative fate. After it had been reconstructed in 1936 – 1939 according towards the design by Academician G. Peredery the connection could remain about sixty years just. The Volodarsky Bridge integrated 1936 in accordance with G. Peredery design could endure also less without having any repairs: it absolutely was reconstructed in 1986 – 1993.
Inside our time, we had been taught to adhere to within the instance of G. Peredery, whom as an apologist of constructivism believed the greater rational was the greater beautiful. Besides, this concept had been therefore jealously utilized in the belated Soviet duration that presently the Peredery’s arches in Volodarsky Bridge of 1936 appearance even more appealing as compared to present facade of this same connection. Nevertheless, the training shows that concepts associated with connection dependability and durability usually do not contradict the sweetness concept. In the– that is 60-es they relegated the visual element of the backdrop while pursuing the effectiveness and nearly ignored bridge architectural aspects. During party associated with the company’s twentieth anniversary this season we had been extremely pleased to learn fr om certainly one of our visitors that individuals had found a fresh bridge design approach since any connection created by our business had its specific “face”. In reality, it is not a fresh but as soon as generally speaking accepted and soon after forgotten approach. When making we have to always remember that the general public do value a artistic look of bridges along with other road works. If you don’t a professional, you would not manage to gauge the structural design efficiency you could always notice perhaps the structure is breathtaking or otherwise not. Consequently, we se t up a group that is architectural the organization at the very beginning of our expert tasks.
Dispute about composite strengthened concrete
So during our first separate tasks, partially consistent with Mostotrest demands and also latin bride horror stories to some degree in accordance with this individual opinions we already designed to replace the approaches that are prevailing. The first task where we were assigned to end up being the General Designer had been a tiny connection throughout the Slavyanka River at 676 kilometer of Moscow – St. Petersburg engine road (1995–1996). We now have proposed a brand new design concept of composite decks for little bridges that included a cast-in-situ slab and flexible studs manufactured from rebar metal. Regrettably, only a few the solutions with this bridge were realized, nevertheless afterwards in 1997–1998 our concept had been implemented for rehabilitation of this connection within the Saimaa Canal when you look at the city of Vyborg.
Bridge building in Soviet Russia had been commonly predicated on general utilization of precast beams for little spans. Carriage way slab joints had previously been a point of this type of structure week. Whenever into the last half associated with the 90-es Stroyproekt was included into connection assessment, design and direction for the Russian Bridges Rehabilitation Program of Overseas Bank for Reconstruction and Development, we’d to be able to see with this very very very own eyes the situation that is terrible bridges had been. Simply for some thirty many years of procedure the bridges made from precast beams got totally away from purchase! And they were probably the most bridge that is common. Consequently, we began to look for an alternate to precast beams that could make sure structural durability. At that right amount of time in Russia cast-in-situ concrete started to get some popularity which it currently had abroad. In specific, this technology ended up being utilized for Moscow Ring path construction. Nevertheless, Moscow national featuring its capabilities that are financial a very important factor, as well as the sleep of Russia was different things. For Russian contractors cast-in-situ reinforced concrete structures had been uncommon and inconvenient, they needed equipment that is new work training and as a consequence their construction had been higher priced as a whole. For many years our connection builders had used to precast structures that have been prefabricated at plant and erected at spot. We knew that cast-in-situ reinforced concrete would hardly ever become extensive in Russia and an alternative was found by us that has been really obvious because it had recently been mentioned in magazines of N. Streletsky, V. Bystrov, etc.
We began utilizing composite reinforced concrete for little spans
You could not dream from it throughout the Soviet times: metal had been a critical product needed for defense industry as well as its use ended up being strictly restricted. In connection building, steel had been utilized just for over 60m long spans. This limitation ceased to occur just in 90-es so we began trying: first during the Slavyanka River venture and in the future at Saimaa Canal.
Wanting to abandon precast slabs also to begin to use slabs that are cast-in-situ we’ve considered complete jobs as one example. An issue with studs must be fixed. Soviet rigid studs frequently broke slabs (and beams also) making them non-durable. Flexible Nelson studs are widely used today. And for the connection over Saimaa Canal we was able to implement an appealing innovation of o. Bakhurin, an expert of Scientific analysis Institute of Concrete and Reinforced Concrete. He proposed a unique welding device for ribbed club welding. Rebars might be welded using this device at place, that was less costly. Unfortunately, Bakhurin welding device (Gefest) had not been accepted for mass-production and after this contractors need certainly to buy foreign-made Nelson studs and welding that is foreign for them. a strength that is high ended up being utilized for the Saimaa Canal Bridge as well as versatile studs made from reinforcement steel in leave-in-place formwork. This project that is relatively small a starting place for further professional growth of the business including elaboration of y our very very very own design methods. Although we’d made our choice, ideological disputes whether composite reinforced concrete had been right for brief spans proceeded for the very long time.
Whenever back in 1999 Stroyproekt had been developing the style for St. Petersburg Ring path interchange with Primorsky roadway near Gorskaya railway place, we utilized composite structures not just for the primary overpass but also for curved ramps of 60 m radius. It absolutely was an innovation aswell since curved beams had been regarded as being hard to produce. Nonetheless, our solution had been effectively realised and soon after on we now have usually tried it when making the Ring path facilities. At that moment construction regarding the Ring path that were anticipated because of the town for so very long had just started, and now we attempted to result in the Gorskaya interchange architecturally simple recognisable. We had been not necessary to take action; it had been our personal initiative. White ?-shaped (or trapezoid) pylons imitating entrance gates made this big structure look light and stylistically complete. This interchange exposed in 2001 became an expression of the brand new phase associated with Northern Capital transportation development which had started utilizing the Ring path construction.