At the "Rzhevskaya" station inclinations are ready

At the end of November, the forces of section No. 7 of SMU-6 constructed a large slope with a length of 114 meters. The excavation started on March 11, 2019 and, despite periodic difficulties, was completed on time. Mining work was carried out by teams of Alexander Kurbatov, Vadim Kholod, Nikolay Marchenko and Sergey Malchenko.

According to the head of the site, Denis Gusarov, it was not possible to completely eliminate heavy manual labor when developing the face.

– The block layer TNU-4 is designed for a tunnel with a diameter of 9.5 meters. Colleagues from UMM modernized it, expanding it to 10.5. But this was not enough. The loader bucket did not reach 40 cm from below to reach the tray. The upper vault was finished by hand from scaffolding,” he added.

Approach corridor to the Rizhskaya interchange from a slight inclination

Not without ingenuity. Denis Gusarov, together with mechanic Albert Enikeev, speeded up the excavation by improving the skip hoist. They came up with a special mechanism. It made it possible to use two tubs simultaneously with one tap. While the first one is being cleared of rock, the second one is already being loaded.

“In the process, all layers went through: limestone, black, red and even blue clay. Until the 70th ring there was water-saturated sand, then hard rocks began. From the 125th ring, water appeared again, the influx of which reached 80 cubic meters per hour,” says the site manager, pointing to the working pumps.

After shipment, all soil is transported to a military training ground near Balashikha. It is used to make dumps for firing training.

Waterproofing work is currently underway on the slope; control injection has been carried out along the 98th ring. The site employees smoothly move to the tension chamber construction. The upper half-vault is being developed and two slotted half-rings with a diameter of 11.5 meters have already been installed. It is planned to install in just four months

37 rings. At the same time, Gusarov’s site is developing the excavation soil for the further construction of the main structures of the vestibule.

In parallel, section No. 4 of SMU-6, under the leadership of Sergei Sleptsov, completed the excavation of a small inclined passage. In the future, this slope will become the main transition between the Rzhevskaya station under construction on the Big Circle Line and the existing Rizhskaya station on the Kaluzhsko-Rizhskaya metro line.

The slope was completed in six months, 42 full rings and three fan rings were installed. They will connect the tunnel with the tension chamber.

– There were difficulties at the beginning with pumping out water. Since the slope cuts the aquifer, water arriving at a speed of 50 cubic meters per hour accumulates in the face. We managed it, installed the pumps,” Sleptsov shared.

According to the project, it was assumed that the incoming water would be discharged into the forward furnel. But by the time the decision to excavate was made, this connecting adit was not ready, nor was the station hall itself. The builders had to get creative.

– The construction of a tunnel with a diameter of 9.5 meters was carried out using drilling and blasting operations (D&B). To reach the upper arch, they came up with mobile scaffolding, which was constantly in the face and was removed only during the blasting operation. For convenience, we had to come up with something like a mini-paver; the lining was installed with winches.

While the rock was being loaded, a mini-excavator was lowered underground. He collected the soil into buckets, and they were lifted to the surface. Now the Sleptsov site has moved on to the construction of a tension chamber with a diameter of 10.5 meters.

Mechanic Albert Enikeev and site manager Denis Gusarov against the backdrop of a skip lift