Galurgia JSC, Perm, Russia:
V. A. Soloviev, Principal Researcher, Professor, Doctor of Engineering Sciences, e-mail: Solovyev@gallurgy.ru
V. N. Aptukov, Principal Researcher, Professor, Doctor of Engineering Sciences

Uralkali, Bereznyaki, Russia:
E. K. Kotlyar, Principal Engineer

It is a standard method to reinforce mine shafts in salt rocks using concrete lining or tubing support. From the experience of operating mine shafts, loads on the support grow with time under influence of rock pressure and rheological properties of salt rocks, and the support collapses. Rock pressure in salt rocks grows with the increase in mining depth, enlargement of mine shafts and exposure areas in rocks as well as at junctures of mine shafts and dosing chambers and inlet drivages. Miners know that one of the principles of stable mine support is that the support gives under rock pressure and deforms under critical load with no loss of the load-carrying capacity. This principle is particularly vital for mine workings driven in salt rocks that possess creep. The mentioned method is successfully used in tunneling. A pliable layer is made of cribbing, friction props or tubular members placed between rocks and rigid frame support. The authors suggest making pliable layer of compressible (nondestructive) material—foamed polystyrene—produced in the form of plates and widely used in civil underground construction. The article describes research findings on interaction between concrete lining, pliable layer and salt rock mass, the calculation method and flowchart for two-layer support with a pliable layer in mine shaft construction. The put forward method of mine shaft construction allows eliminating expensive cast iron liner. The method is now in operation at Upper Kama Potash Deposit, in projects of construction of mine shafts in Ust-Yaivinsky and Polovodovsky Mines, shaft no. 4 in Solikamsk Mine-3 and in construction of junctures of mine shafts and drivages at Usolsky Potash Mining-and-Processing Plant.

1. Solovyev V. A., Aptukov V. N., Konstantinova S. A., Sekuntsov A. I. Sposoby obespecheniya ustoychivosti sopryazheniy shakhtnykh stvolov s primykayushchimi vyrabotkami v solenosnykh massivakh gornykh porod (Stability of junctions of shafts and mine roadways in saliniferous rock masses). Gornyi Zhurnal = Mining Journal. 2013. No. 7. pp. 53–56.
2. Solovev V. A., Konstantinova S. A., Aptukov V. N. Okhrana gornykh vyrabotok v solyanykh porodakh. Teoriya i praktika (Protection of excavations in salt rocks. Theory and Practice). Saarbrücken : Palmarium Akademic Publishing, 2013. 412 p.
3. Tim van Xaiden. Modern freeze technology in action as five shafts are sunk at two project sitters. Mining Report. 2015. Vol. 151. No. 2.
4. Kunz J. Untertagige bauwerke unter Gebirgsbewegung — eine Herausfederung an die konstruktive Durcbilding. Bergbau, November 2014. pp. 486–490.
5. Kratz T. Optimization of mucking and hoisting operation in conventional shaft sinking. Mining Report. 2015. Vol. 151. No. 2.
6. Konstantinova S. A. Metodicheskie osnovy primeneniya ankernoy krepi (Methodic basis of application of roof bolting). Metodicheskoe rukovodstvo po vedeniyu gornykh rabot na rudnikakh Otkrytogo Aktsionernogo Obshchestva «Silvinit» (Instructional guidelines for mine excavations at the JSC «Silvinit» mines). Novosibirsk : Nauka, 2011. pp. 220–243.
7. SP 91.13330.2012. Podzemnye gornye vyrabotki (Sanitary rules 91.13330.2012. Underground excavations). Moscow : Minregion of Russia, 2012. 53 p. (in Russian)
8. Oellers T., Moniquet J.-P., Koshurnikov N. S. Proektirovanie stroitelstva stvolov kaliynykh i solyanykh rudnikov (Design of construction of potassium and salt mine shafts). Rudnik budushchego = The Mine of the Future. 2011. No. 3. pp. 44-52.
9. Pleshko M. S., Pashkova O. V., Nasonov A. A. Geometricheskie neodnorodnosti monolitnobetonnoy krepi shakhtnykh stvolov i ikh vliyanie na ustoychivost vyrabotki (Analysis of geometrical nonuniformity of lining in operating shafts and its influence on shaft stability). Gornyi Zhurnal = Mining Journal. 2015. No. 3. pp. 33–37.
10. Zhukov A. A., Tarasov V. V., Prigara A. M., Tsarev R. I. Kompleksnaya diagnostika sostoyaniya betonnoy krepi shakhtnykh stvolov kaliynykh rudnikov (Integrated diagnostic of concrete lining in potash mine shafts). Gornyi Zhurnal = Mining Journal. 2014. No. 4. pp. 39–45.
11. TU 5767-015-56925804-2011. Plity polistirolnye vspenennye ekstruzionnye (Technical requirements 5767-015-56925804-2011. Polystyrene foamed extrusion plates). Saint Petersburg : LLC «PENOPLEKS SPb», 2015. (in Russian)