The science implemented underground

Considering the rapid development of the transport industry, including metro systems, we decided to ask about scientific contributions into the transport infrastructure the Emperor Alexander I St. Petersburg State Transport University professor, Alexander Petrovich Ledyaev. 

Здание РАН в Санкт-Петербурге

The Russian Academy of Sciences building
Source: denvistorii.ru

On an annual basis the local scientific society celebrates the professional holiday on the 8th of February — the day of Russian Science, established by the order of the Russian president in 1999. Science has been always at the society service, being the driving force of the development in different human activities areas.

 - Alexander Petrovich, we congratulate you on the professional holiday. Can you estimate how intensive the scientific work looks towards the development of the transport systems. What work specifically does your university perform?  

Thank you for your greeting. Indeed, the day of the Russian Science is a nice occasion to celebrate those whose work is not very evident but essential for the development of such important urban activity as transport, railways included. Scientific staff members: professors, postgraduates, students annually receive about 70-80 documents protecting intellectual property (patents for inventions and useful models) in more than 10 areas of practice.

I am the Head of the department Tunnels and bridges, we are training specialists for the industry and as well we perform quite a volume of the scientific research for the different organizations involved into the underground construction. Based on the laboratory for the tunnel modelling efforts, existing for decades, the research work takes place, which makes the basis of the metro construction. I would like to emphasize the matter of the metro construction, because this field develops rapidly at present and makes the results of the scientific and production activities evident.  

Кафедра Тоннели и метрополитены

Tunnels and bridges department, Emperor Alexander I St. Petersburg State Transport University

From year to year in every interview I repeat that Saint Petersburg is a unique city. Going underground with such geological conditions is a very difficult task. The construction pit usually is quickly filled with the ground waters. Those who tried to dig the wells for personal needs in the country near the city got to know the problem quite well.

Metro construction uses the deeper and wider wells- the shafts. The shaft usually is located in the urban area with the buildings surrounding it. For the implementation of the inclined tunnel with the diameter more than 10 m at the angle of 30 degrees, it should meet all the requirements of the strength characteristics to guarantee, that the water-bearing grounds will not destroy the tunnel or misshape it. 

Строительная площадка второго выхода станции Спортивной

The construction of the second exit for the metro station Sportivnaya
Source: skyscrapercity.com

Today the tunnel construction volume in Saint Petersburg is one of the biggest, in my opinion. Thanks to the close cooperation of science and practice the unmatched projects are implemented.  It is a big accomplishment of Saint Petersburg designers and metro builders. Up until now the two-leveled underground metro station Sportivnaya has been the only one of its type. And recently completed second exit on Basil Island is something worth the State Award.

Believe me the construction of the underground hall of the station with the total square of 3,500 sqm below the river level, only 10 m deeper than the river’s bed, requires special professional approach, scientifically validated calculations and courage, especially if there are the historical buildings right near the construction site and the historical embankment. Also the hall is connected by the tunnel with the operating metro station.

Строительство станции метро Новокрестовская

The stadium and the metro station construction site in Saint Petersburg
Source: russoslivejournal.com

One more innovative object is the newest metro station Novokrestovskaya. This is one of the great accomplishments of the Saint Petersburg metro constructors. It took only one year to create 20 m deep multileveled underground object, where was The Gulf of Finland water previously.

The structure is held by 124 bearing piles 1 m diameter. Imagine such a column, which should go as deep as 35 m (9-storeyed house), being placed strictly vertical. The fluctuations cannot be more than 2 cm. The floor slabs lay on these columns, the top-down method was used for their construction. Water-proofing performed with the jet-grouting method and secured by  the diaphragm wall. Thanks to the above mentioned the structure is firmly stands on the raised beach. 

Двухпутный тоннель в Санкт-Петербурге

Double-track tunnel, the Mezhdunarodnaya station – the Prospekt Slavy station, Saint Petersburg 

Scientifically, also the tunneling of the double-track tunnel is quite interesting. It was implemented with the TBM weighted 10,000 ton. The satellite navigation was used for the tracking of the TBM position, with all the processes being computer-controlled and automatic. Nevertheless no mechanization is possible with manual labor.

I consider the work that was performed by metro builders when they had to extract big boulders in the water-bearing ground from under the TBM a hero act. One more engineering accomplishment is the simultaneous tunneling itself and the construction of the tunnel facilities:  the construction of the stiff base and closing of the vent shaft. This experience without any doubt should be described for the students.The science and the engineering achievements are implemented in the recent objects of metro construction. Very soon citizens of Saint Petersburg will be able to use the results of this work.And this is how science should perform – alongside the production, making plans the reality.

In conclusion I would like to congratulate all the citizens of Saint Petersburg on living in the capital of the Russian science. Peter the Great founded here the Russian Academy of Sciences in 1724. And Saint Petersburg stays the leading scientifically-educational center of the country. We implement unique projects, the underground construction area included, proving it. 

Background: 

Ledyaev Aleksandr Petrovich – Doctor of engineering, Emperor Alexander I St. Petersburg State Transport University professor, honored figure in higher education of the Russian Federation, Laureate of the Prize of the Russian Federation Government.  He is the Head of the scientific and analytical group for the development of the urban transport and the member of the Scientific Advisory Board for Transport of the Russian Academy of Sciences. 

Additional materials on the topic:

The architectural form and signature features of the Russian metro systems read more

St Petersburg lacks money, but has resources and capacity read more