Using simulation and finite element method calculations of stress-strain state of monolithic concrete support for underground structures with non-circular outlines made of fast-hardening concrete are carried out in the paper. Based on the obtained results, the maximum stress zones and their magnitude in the reinforced concrete support are established. The stresses are compared with circular-form supports. The factors influencing the stress state of the support are determined.

Keywords: Underground structures; soils; concrete support; voltage; the experiment plan; modeling; finite element method

The results of researching the speed of increasing strength of modified concrete materials in early period of hardening used for mounting underground structures are given. As a result of researching the most effective supplements like D5 and RELAMIX T-2 are determined. The composition of supplement D5 with fillers of ordinary quality and a con drafting 15 sm, it will gain high strength of 6.5 MРa in 18 hours while with RELAMIX T-2 fillers it will be 2.8 MРa. The given results were used for modeling stress strained state of ground mass and concrete fastenings of non- circular shape.

Keywords: Рassage, fastening, composition of concrete, modifier, concrete strength, young modulus, stresses