New territories for our cities

The growing population of the planet makes us look for ways to expand functional urban spaces. One of the ways is the reclamation of territories. Scientists of the SPbGASU Department of Construction Technology are also engaged in the research in this area. On April 19, the Scopus-indexed Soil Mechanics and Foundation Engineering journal published an article entitled “Improving Efficiency of Devices in the Fences of Excavations and Artificial Islands”. The authors of the article are Professor Vladimir Verstov, Dr. of Engineering, Professor Antonina Yudina, Dr. of Engineering, and Associate Professor Anton Gaido. Cand. of Engineering.

– “In St. Petersburg,” says Anton Gaido, “beach nourishment has been going on since Peter the Great. This is conditioned by the location of the Northern Capital. Beach nourishment was used to create the Summer Garden, the island of New Holland, the park of the 300th Anniversary of St. Petersburg, the port of Bronka, and other objects. On the warplands, the Lakhta Center and the Baltic Pearl area were built. It’s been for several decades that work has been carried out on Vasilievsky Island; similar works are scheduled in Sestroretsk. My colleague, professor Vladimir V. Verstov, Dr. of Engineering, from the Department of Construction Technology, has been engaged in research in this area for many years.”

– Anton, please tell us about the most significant stages of your joint research.

– On September 15, 2014, our university received a patent for invention No. 2549789 on the “Method for immersing thin-walled steel shells with deepening into a dense waterproof soil”. The inventors were Professor V.V. Verstov and I. The invention relates to the construction and can be used in the construction of watertight enclosing cellular lintels in the waters during the erection of artificial islands, mooring and enclosing structures.

With our article in the Soil Mechanics and Foundation Engineering, we expect to draw the attention of the scientific community to our national technologies and expand the range of their application. Beach nourishment is an extremely relevant, up to date topic.

– How are warpland territories formed?

– First, a fence is erected. To do this, the steel sheet pile is immersed in a dense waterproof soil. But during the immersion process, distortions can occur, due to which the waterproofness of the joints and the stability of the structure as a whole may be infringed. The elimination of this particular problem was the subject of our work. Then the circuit is filled in layers with imported soil, which is fed through pipelines. After the formation of such a site, in order to make it possible to erect buildings and structures, soil compaction is carried out either by micro explosions, or by crash rammers, or using vibration methods (vibro flotation) crushed stone piles are arranged.

– What did you and your colleagues suggest to solve the problem?

– We proposed that to create fences a different technology can be applied: it is successfully used in the assembly of tanks of oil-loading complexes. Steel shells of large diameter, previously assembled at the stands, are immersed in the target of the structure, which are subsequently filled with soil. The shells are pre-assembled on bench stands located close to the place of their deepening, and then transported by watercraft to the installation site and immersed in the section of the future fence. The mass of such shell is 50 tons, diameter - 16 meters, height - 15–16 meters, thickness - 10 millimeters. If the immersion is performed by vibration-shock way, the shell will evenly deepen under its own weight. In the traditional method, the sheet pile in these conditions is difficult to load without blockages of walls, breaks of locks.
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– Please share with us your future plans.

– The plans are to conduct field experiments.

Text: Tatyana Petrova
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