Concrete breakers breaking through strong rock

“Aviamotornaya” of the Big Circle Line (BKL) and the station of the same name on the Kalinin Line are connected so far only on the ground. The underground approaches are still under construction. A Metrostroevets correspondent found out when the connection of two lines in the east of Moscow will be ready.

Construction of an interchange from the “Aviamotornaya” BCL to the station of the same name on the Kalininskaya metro line

TRANSFER TO KALININSKAYA LINE

“Aviamotornaya” of the Big Circle Line (BKL) has been operating since the end of March. They plan to connect it with the yellow metro line next year. Construction of the transfer has already begun. The work is being carried out by SMU-1. Their arsenal includes a block laying machine with a special bucket. The mechanical arm of the machine takes the tubes and assembles them into rings.

– The inclined transfer course has now been completed on 137 rings out of 142, and we have begun excavation and installation of the fan part. Of the seven fan rings, two have been installed so far. By the end of the month we will finish excavating the inclined passage and begin installing the tension chamber,” said Evgeniy Mamonov, deputy chief engineer of SMU-1.

Before the start of excavation, freezing was used to strengthen the slope soils. However, the main difficulty was the strength of the rocks encountered along the way. The project indicated the fourth and fifth categories of fortress. In fact, the builders were faced with harder rocks - sixth, seventh and even eighth. They had to be broken up not with jackhammers, but with heavy concrete breakers.

“People seemed to be cutting into rocks.” This created additional difficulties, including time costs,” Mamonov shared. – To meet the deadline, the builders began waterproofing the inclined passage in parallel.

The work is being carried out simultaneously on two sides: on one of them, an inclined passage with a diameter of 10.5 meters is being built, on the other, a transfer unit is being built on the side of the shaft of mine No. 607. This old trunk, through which the Aviamotornaya Line of the Kalinin Line was built, had to be revived for the current project. The reinforcement in the trunk was replaced, protection was provided and the cables were re-arranged. The work was carried out together with SMU-24. Currently, construction of approach corridors for future transfers is underway.

“The drainage installation and approach to the existing transfer have been completed,” Evgeniy Mamonov told the details. – Work is underway to open the approach corridor, which is classified as permanent workings, to a diameter of 9.5 meters.

The main difficulty is the cramped conditions of the site, which do not allow for the full placement of the mountain complex. Therefore, at the first stage we had to use a truck crane. The project was adjusted and an opportunity was found to place a mountain complex, which will soon become a help for builders.

PEDESTRIAN CROSSING

In the future, lobby No. 2 of Aviamotornaya will be connected to a pedestrian crossing. Excavation work is also underway here. The main difficulty is the location of existing tracks nearby. Even minimal drawdowns must be eliminated; millimeters count.

Builders mainly encounter water-saturated sands and quicksand. They are pre-fixed using jet grouting. To do this, a protective screen was first made: 26 pipes were connected with a special lock, and the water-saturated sand was replaced with cement mortar.

“The drilling rigs cut the piles in an overlapping pattern, creating a cement mass. 36 meters of fortifications have already been completed,” said SMU-1 chief engineer Alexey Nosov. – To date, out of 73 meters of crossing, 22 have been built.

The shields in SMU-1 were abandoned in this area. The main equipment in use is an ITC-312 combine with a hydraulic cutter, purchased specifically for this tunneling. It allows you to take into account all the features when developing the face, loading rock and installing the ring itself. The “company” of the underground combine consists of 20 people involved in the excavation.

At the end of July, SMU-12 will carry out the next part of the work on consolidating the soil, and the second stage of excavation with its own characteristics will begin. Very close is the 40-meter technical zone of the Moscow Metro.

HELP

The Aviamotor BKL opened on March 27, 2020. Until the new ring is fully commissioned, it will function as part of the Nekrasovskaya metro line. The station is located along Entuziastov Passage at the intersection with Entuziastov Highway and the Ryazan direction of the Moscow Railway.