We go through the mountains

On the Shkotovo-Smolyaninovo section of the Far Eastern Railway (FER) in the Primorsky Territory, two tunnels are being built as part of a program to modernize the infrastructure of the Baikal-Amur and Trans-Siberian railways. More than 1,200 meters of mining excavations have been made at the Eastern and Western portals. The site must be built by 2025. The work is being carried out by MMC International.

– Six months have passed since our last visit to the construction site. During this time, serious changes have occurred at the site - all four faces are in operation. And most importantly, the pace of penetration corresponds to the schedule. This is the only object on the entire Eastern training ground for which Russian Railways has no comments. From a production technology point of view, everything is going as it should be. I'm proud of our builders! – noted Sergei Zhukov, General Director of Mosmetrostroy JSC, who visited the Far East at the end of May.

IN HARD SCHEDULE

Currently, construction, production and household sites have been developed. Auxiliary buildings and structures were built, including RBU, RMC, warehouses, repair area for machines and mechanisms, and dormitories. Utilities have been removed from the construction area, including a 220 kV overhead line and a main water supply.

The tunnels, each 1.45 km long, are constructed using the mountain method, the total length of the section, including approaches, is 7.5 km. Portal excavations of the Western and Eastern portals were completed, where 480 thousand cubic meters of soil were excavated using open pit mining. Tunneling is carried out from two sides - more than 100 thousand “cubes” of rock have been developed. Work is underway to construct an embankment on the approach to the Eastern Portal. A deep drainage system is being installed and the slopes of the Western Portal excavation are being strengthened. The reconstruction of the Smolyaninovo TP is nearing completion.

– Today we have launched work at all project sites, and these are tunnels and approaches to it, bridge crossings, a complex of buildings and ITSO structures. Cycles have been completed on all four faces. We understand how to work in this geology and have learned to deal with water-saturated soils. The facility is fully provided with labor and equipment,” commented Mikhail Belenky, Deputy General Director of Mosmetrostroy JSC. – What is our main task? We are on a tight tunnel construction schedule. As of mid-June, a total of 1,240 of the 2,870 meters of rock had been covered. The target figure that we try to adhere to is 35–45 meters of penetration per month. The deadlines are known, the tasks are clear, we will fulfill them.

TURKISH FORMWORK DID NOT FAIL

Simultaneously with excavation, permanent lining of the tunnels is carried out. At the first stage, waterproofing is created from a polyvinyl chloride membrane 2 mm thick, at the second and third stages - a reinforcement frame and concreting.

– First, the lining of the base (reverse vault) is constructed. Then, using self-propelled mechanized formwork, specially designed and manufactured for this facility, the lining of the vault and walls is erected, explained Andrey Kuzmin, deputy chief engineer of MMC International. – 490 linear meters of permanent lining of the base and 310 meters have already been completed on the vault and walls.

REFERENCE

In geomorphological terms, the tunnel route cuts through the watershed area separating the valleys of the Shkotovka and Smolyaninovka rivers. The main mass of soils during tunneling is represented by interlayering of various soils: rocky soils in the form of fractured sandstones of varying degrees of strength, low-strength coals, as well as loams and clays of predominantly solid and semi-solid consistency. To suppress water inflows into the faces, the project provides for the injection of the soil mass with polyurethane resins.

As Sergey Zhukov, who personally inspected the progress of the work, noted, the quality of the permanent lining is good, the formwork made in Turkey is one of the best.

Two single-track bridges will be built on the approach to the Eastern Portal. At the moment, piles are being driven under the bank and riverbed supports. In addition, the construction of two supply canals is underway to collect water flows and concentrate them at the bridge crossings.

The project also includes buildings and engineering security facilities (ITSO). They are necessary for transport safety and tunnel management during operation. At the West Portal, local contractors began construction of a two-story guardhouse and garage.

PEOPLE AND EQUIPMENT

In general, about 1,000 people are employed in the Shkotovsky Pass area - mostly workers from various Russian regions who work on a rotational basis. Good living conditions have been created for them - there is a comfortable dormitory, as well as a canteen with three meals a day. For the construction of tunnels, more than 100 pieces of equipment are used, including specialized underground machines and mechanisms - mining excavators and combines, drilling rigs, shotcrete machines, loading and delivery vehicles.

According to MMC International specialists, the issue of purchasing specialized Chinese-made equipment - drilling rigs and shotcrete installations - is being considered. They must replace European analogues that have left the Russian market.

The commissioning of the bypass will make it possible to eliminate the “barrier” place on the path to the ports of Nakhodka by optimizing the path profile. Nowadays, on difficult terrain with ups and downs, pushing locomotives are used for freight trains, which reduces the efficiency of hauling. Thanks to the new tunnels, capacity will increase to 72 pairs of trains per day without additional traction.