Tunnels of the northeast of the big ring completed

The output of the Herrenknecht S-772 “Tatyana” TBM put a confident point in the construction of one of the most difficult sections in the history of the capital’s metro construction. With the completion of this excavation, the construction of tunnels on the northeastern section of the Big Ring, entrusted to Mosmetrostroy, is completed.

Round pit on site No. 17, located next to the Riga overpass

The Herrenknecht S-772 TBM passed the last meters underground at the end of September. Over the course of three years, the shield successfully connected the Lefortovo and Rizhskaya stations of the Big Circle Line (BCL). Moscow Mayor Sergei Sobyanin came to the release ceremony for “Tatyana”. According to him, the metro construction workers coped with one of the most difficult tasks on the site. He emphasized that this was the last deep tunnel built for the Moscow Metro in the coming years.

– This is a landmark day in the implementation of the Moscow Metro development program. The excavation of the distillation tunnel, which lasted three years, has been completed. The shield traveled more than 4.6 kilometers at a depth of 25 to 45 meters, the mayor said. – The depth of the excavation was determined by the need to create convenient transfer hubs at the Elektrozavodskaya and Rizhskaya BKL.

“Tatyana” began its journey from site No. 5.2 on Semenovskaya embankment behind the Lefortovo station, the shield transited the pits of two future stations of the Big Circle Line - Elektrozavodskaya and Sokolniki. At Sokolniki, a chamber was built in which the TBM made a stop for sanitation and routine repairs.

“The geology did not cause us any great difficulties,” noted Ilya Zvyagin, head of section No. 1 of SMU-1. “However, there was more control on the surface than underground.

In particular, “Tatyana” took place under the existing Sokolniki metro station on the Sokolnicheskaya metro line and the park of the same name. Here we had to coordinate underground work. The shield went under the attractions, the operation of which was stopped during the excavation. The main task was to prevent subsidence of structures on the ground. To achieve this, additional measures were taken: geodetic surveillance was carried out in the park around the clock, and in the tunnel they tried to withstand the load of soil in accordance with the drilling schedule diagram, and also to prevent a lag in the injection of cement mortar. “Tatyana” also walked under the railway tracks of the Moscow Railway.

“The section where the TPMK passed in the area of the Rizhskaya metro station was under special control,” Zvyagin continued. “Not only our representatives, but also specialists from the railway were already on duty here. Geodesy services and emergency crews were constantly in touch with us. We reported how far the shield traveled, they answered what objects it passed on the surface. At this time, the level of cement slurry and pressure in the bottomhole chamber were monitored.

During the excavation, “Tatyana” was serviced by eight drifters, six specialists from UMM, two surveyors, a shift foreman, seven people from the unloading team, a metalworking group, electricians, a mechanic and a site manager. The cutting tool was changed along the way. To do this, three times during excavation the advance of the shield was stopped, and our miners went into the downhole chamber to inspect the cutting tool. If necessary, it was changed.

The final point of Tatyana’s route, 4661 meters long, was a unique dismantling chamber with a circular cross-section, 30 meters in diameter and 45 meters deep, at site No. 17, not far from the future Rizhskaya station. The TBM is currently being dismantled; the work is being carried out by UMM specialists. The shield will have to undergo refurbishment and replacement of some parts. After this, the mechanized complex will be sent for a new excavation.

– Currently, SMU-1 is dismantling communications after tunneling the shield. We are removing ventilation, water supply and drainage pipes, a fire pipeline, a high-voltage cable, a running compartment, sleeper rails along which the soil was hauled away,” the site manager continued. – Then the tunnel will be cleared and handed over to the general contractor – SMU-12. The goal is to complete the entire scope of work by November 1.

The Herrenknecht S-772 TBM with the name “Tatyana” traveled more than 4.6 kilometers at a depth of 25 to 45 meters

BTW

The opening of the north-eastern section of the Big Circle Line from the Nizhegorodskaya station to the Savelovskaya station will improve transport services for residents and working areas of Maryina Roshcha, Meshchansky, Sokolniki, Basmanny, Sokolinaya Gora, Lefortovo, Kosino-Ukhtomsky and Nekrasovka with a population of more than 750 thousand people. The commissioning of this section will reduce the load on the central sections of radial metro lines.