The Baikal tunnel — new opportunities for the Baikal-Amur mainline (BAM)
The construction of the road tunnels and rail tunnels is a matter of necessity in the countries like Italy and Switzerland. While in the vast lands of Russia, largely lowlands, the challenge is not so persistent. Still sometimes it becomes the most rational decision for the route. One of a case in point is the tunnel at the Baikal-Amur mainline. This is the second Baikal tunnel.
Planning of the modernisation of the BAM and Trans-Siberian Railway
To enhance the capacity of the Baikal -Amur railroad is the important strategic challenge for the transportation industry in Russia. The modernisation of the two largest rail roads in Russia – Baikal-Amur and Trans-Siberian were initiated for that purpose. In August 2017, the President assigned 150 billion rubles from the National Wellfare Fund for it. The existing Baikal tunnel crosses the Baikal mountain range at the border of the Irkutsk area and the Buryat republic and it is one of the narrowest places along the route. For this reason the reconstruction of the railroad comprises the construction of the second section of the road.
The largest and most comprehensive object is the new line of the Baikal tunnel constructed by the specialists of AO Bamtonnelstroy. The main contractor is the AO Stroytrest. Both organisations belong to the SK Most Group. Vladimir Garting, general director of the Bamtonnelstroy talks about the construction work and its specifics:
— It is not our first tunnel at the Baikal-Amur line. Previously we constructed the Severoamursky (North-Amur) tunnel in the Republic of Buryatia, the longest in the country. Then we did six tunnels for the Dalnevostochnaya Rail Road (Far-East Railroad) and 2 for the Krasnoyarsk Railroad. The second Baikal tunnel is our current task.
The work started there in October, 2014. But the construction was stopped due to the funding issues. In March 2016, the work was renewed. The tunneling started from the Western tunnel face and went in parallel to the older Baikal tunnel. The total length of the structure is 6,682 metres and the diameter is 10 metres. The TBM Lovat 394 is used for the construction.
— Vladimir, as we are aware, the TBM was bought for the construction of the tunnel, which was among the Olympic Games objects in Sochi, right?
— Yes, we did the large tunnel for the Olympic road, which included three entries: railroad tunnel, road tunnel and the escape gallery. One of those objects was constructed using this TBM. So, one may say, Lovat is our battle-tested TBM. Now it was transferred to this new construction site and successfully was launched into work after some maintenance work. The average pace of construction is about 250 meters per month. At the moment of our conversation, 5.5 km long section has been already constructed.
— You work here with the rock soils, while in Sochi you had experience with the soft soils also the length of the tunnel here exceeds the one there. How much more difficult is it now?
— The main challenge for this tunnel is the difficult geological conditions, right. But we have the great equipment, albeit not new, but suitable for such work at our disposal. The soil is not too hard at the route of the tunnel. Our specialists are experienced in much harder conditions, like the geological conditions at the construction of the Manksy tunnel in Krasnoyarsk. .
However, we should not forget abrasive granitoids in the soil and they significant escalate the tool deterioration and often call for the work’s stops. Here we use some trick, the project suggests the escape galleries between the tunnel and the shaft tunnel each 300 meters. We build them ahead and when the TBM reaches stops we have access to the cutting head for the maintenance. On an average the stops take from 3 up to 5 days per month.
The construction of the second Baikal tunnel
— What are the others parts of the work plan?
— In conjunction with the tunneling we construct two drainage tunnels. One, with the length of 1,500 metres, runs from the Western tunnel face and another, 1,747 metres long, from the Eastern. These tunnels are not through, but so-called blind shafts, constructed in the soil and connected to the tunnel under construction.
We have to make some repairs to the ventilation shaft of the existing tunnel. The project comprises the unique decision, allowing using this shaft for the new tunnel as well. There are two cross passages – each 232 meters long, both completed. All the work plan comprises the tunneling of the new route, construction of the cross passages, more than 20 escape galleries. About 1,600 workers are currently engaged at the construction site. The work will be completed in the first half of 2019.
— Which works are outsourced to the subcontract?
— Usually at closing phases of the construction we invite specialists for the mantling of the overhead system, centralized alarm system, train signalling system and other special measures for the safety functioning of the trains. Also the passages to the tunnels usually are performed by our colleagues, while we only prepare the subgrade.
— What are the most interesting features of the project?
— It is remarkable, that we use both methods while constructing the tunnel – with the use of the TBM and blast and drilling, the last we use for the service tunnels. Our company usually does the large diameter road tunnels. This is our specialty.
— Are there any special modern requirements for the tunnel construction from the railway personnel?
— Their requirements for this project are quite within the standard range. I only would like to note we deliver almost ready tunnel after we leave the site. We do the mantling of the precision guided tunnel lining of reinforced concrete made by the plant in Krasnoyarsk.
Right after the tunneling we concrete the track superstructure, implement the mantling of the carriers for the cables, etc. Thanks to the experience, we manage to work at several tasks simultaneous with tunneling. And by the way, previously we worked sometimes at several different tunnels in all parts of the country, while now the times changed in Russia for the tunneling.
— Many tunneling companies turn to the diversification. How does this strategy match your approach?
— With the experience and professional skills of our specialists being at the high level, we may participate in the construction of very wide range of objects. For example, we worked at the construction of the spillway storage of the Sayano-Shushenskaya Hydro Power Plant. Our workers constructed the airstrip in the airport of Ulan Ude. We participated in the construction of the metro system of Novosibirsk. When we had the funding we made 3 km of rock excavation for the metro of Krasnoyarsk*. We did and do the works for the Moscow metro. From the experience, it is better to work in the field you are highly professional, as foreign specialists do. We are good at the tunnel construction – and we do them.
*The metro system of Krasnoyarsk was never finished. It could become the 9th metro system in Russia. The construction was stopped recently due to the lack of funding. Still the City spends about 70 million rubles each year to preserve it in its current state.
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