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Safe work practices of mine workings are provided by fixation of working surface. The ability and technical requirements to frictional fixation rock bolts are determined by ‘Change N°1’ for GOST 31559-2012 along with traditional rock bolts. Analysis of its construction has shown that the main indicator which determines reliable operation is load-bearing capacity and it is determined as minimum value of three values of load capability: a rod of the rock bolt, a limit stop on a rock bolt and a support plate. It is stated that load-bearing capacity of frictional fixation rock bolt must match load capability of the limit stop on a rock bolt. Maintenance of the initial indexes of load capability for the whole period of service is being provided by application of protective coatings on all rock bolt surfaces. Practicability of the coating based on high-density polyethylene compositions 600-800 μm thick has been proved as a result of the performed research. Comparative analysis of resistibility to concentrated alkaline and saline environment has shown retention of tensile strength.

The load-bearing capacity of a rod of a tubular anchor of a friction type (friction-type anchor) is determined by the nature of its interaction with the walls of the hole. The preliminary (estimated) calculation of this indicator is difficult because of the lack of information about the deformed state of the rod. The proposed interaction scheme assumes coupling only over a part of the cross-sectional profile. Force factors are represented by concentrated and distributed loads. On the basis of accepted assumptions, a mathematical model which indicates rod-hole force interaction is formed. The determination of the parameters characterizing the adopted interaction scheme is based on the solution of the obtained nonlinear equations. The physical simulation of the process of installing the anchor in the borehole model was performed. The accepted scheme of interaction of a rod – borehole is experimentally confirmed. The results of numerical simulation have large convergence with experimental data.

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