Shields then-6 started again

In August–September, shield mining was resumed with two machines on the Rubtsovskaya–Stromynka section. The construction of tunnels is being carried out by Vasily Kostromenkov’s section from TO-6. Our correspondent observed how work is progressing at site No. 18.

The excavation was suspended at the beginning of summer, when both shields passed not only under the Yauza River, but also under the already begun pit of the installation chamber. By that time, they were separated by more than one kilometer of finished tunnels from site 5.2, where it was time to begin the construction of permanent structures - the exit chamber and the checkpoint.

At the same time, the mining complex serving the shield tunneling should have been moved forward, beyond the Yauza. To resume work there, it was first necessary to complete the installation chamber. Then it was necessary to carry out a series of operations related to both tunnels and tunneling complexes.

The site mechanic, Yuri Slutsky, spoke about the problems solved during the two-month shutdown period:

– Interacting with the machine operators, we ensured the fastening of the deepening pit, dismantled and removed both sections of the open distillation tunnels that fell within its boundaries, then concreted the tray, manufactured and laid metal ramps for entering it from the tunnels and for the exit. Also, ventilation and drainage were installed in both tunnels up to the shields, and lighting was restored. In general, a lot has been done on the electrical side. After all, it was necessary to supply power to the equipment along a new, shorter route.

The cutting tools on the shields themselves were changed. Drilling through hard limestone took a noticeable toll on the cutters. They were about halfway updated and both cars are running fine now. In case of an encounter with quicksand, we prepared a system for supplying a thickening polymer to the face, the rotor chamber and to the auger. Without this, the liquid mulya will not stay on the conveyor belt.

Listing the types of work done, the mechanic did not even mention the multi-flight metal staircase for descending into the pit almost 40 meters. Apparently, because it increased gradually, as successive fastening belts appeared, up to the eighth.

The Natalya tunneling complex, which is constructing the left tunnel, is controlled by TBM operator Alexander Smirnov. Mining foreman Kirill Valnyukov also works here. For the young engineer, the tunnel aimed at Stromynka was the second. On the underground path from site 5.2, much was new to him. For example, overcoming a zone of viscous clay, where the speed was slowed down by a lack of water.

In the second half of September, the route prepared another test for the left tunnel diggers: they had to pass a shield through the base of the trench. This is what is called in geology a trough-shaped bend in the layers of the main rock, filled with something else. In our case, it was water-saturated pulverized sand. Perhaps such a trace was left by the ancient Yauza oxbow.

In the first days of October, the head of the section, Kostromenkov, reported that the shield of the left tunnel safely passed the trench, which nevertheless made itself felt. The right TBM still needs to undergo such a check. The leading shield has less than one kilometer left to the Stromynka shallow station. Gradually rising towards it, the miners will cross layers of limestone, marl, and clay.