Purpose. To carry out comparative analysis of results concerning determination of stressstrain state (SSS) of shal low mine workings using calculation models for problems in elastic approach. Methodology. Rock mechanics methods; methods of analysis of the results of theoretical calculations and nu merical experiments using FEM. findings. Algorithm to calculate SSS of rock mass, involving extended mine working, has been substantiated. Nu merical experiment has demonstrated that to determine displacements within a mine working boundary it is required to consider plane strain state. It has been identified that the use of a plane stress state results in misinterpreted values of mine working boundary displacements to compare with accurate ones. The following basic conclusion has been made: it is possible to use adequate threedimensional (i.e. spatial) problem while arranging relations according to certain rules to solve the considered problem with a calculation model of limited length as for the research subject. originality. Divergence has been determined between extended mine working boundary displacements calculated using calculation models of a plane stress state (approximate analytical model), and those of a plane strain (accurate calculation model). It has been demonstrated that calculation of extended mine workings should involve analytical model of a plane deformation reflecting SSS of rock mass-mine working system adequately; otherwise, calculation er rors may be more than 100 % for horizontal displacements, and 25 % for vertical ones. Practical value. The obtained results make it possible to select reasonably calculation models for extended mine workings where support stiffness properties vary periodically. For instance, such mine workings are meant whose stability and deformability are provided by frame, anchor, combined frameanchor, complete reinforcedconcrete, reinforced equally distanced sequences of anchors, and similar support structures.

The strength criteria substantiation of water-saturated soils and mine rocks, which make it possible to obtain the analytical solutions necessary for determining the stability of water-flooded soil slopes and side-hills. Methods. The methods are applied of analysis and generalization of the theoretical and numerical experimental studies results. The rocks and soils characteristics are taken into account: specific cohesion c, internal friction angle φ, compressive strength R c and tensile strength R p of the rock, as well as the bulk density. The load q was imposed to the water-saturated seam roof from the overlying mine rock or soil seams, the weight of equipment or structures located on the surface. It was accepted that the seam is saturated with water (gas) with the excess pressure Р. A point on the mine working surface (or vertical slope surface), located at a depth z is considered. It is determined at which ratio of q, P and z parameters the soil or rock seam will be destroyed. The problem solution is based on the Mohr-Coulomb strength criterion. Findings. The strengths of water-saturated rock and water-free rock are compared. The ratios have been obtained that make possible to determine the critical load on the daylight surface of water-saturated and water-free vertical slopes, side-hills, trenches and foundation pits, as well as various mine workings in soil bases and mine rocks. The analytical solution has been obtained, which makes it possible to determine a value of the critical pressure on the water-flooded vertical surfaces and soil slopes. The generalization has been made of a certain one-dimensional Mohr-Coulomb strength condition for a water-saturated base characterized by the strength characteristics с and φ for the dimensional case. Originality. It has been theoretically proved that for any pore pressure value in the water-saturated mine rock (or soil) their strength will be less than in their water-free state. New solutions have been formulated for determining the critical height of a water-saturated vertical soil slope or the wall in the vertical mine working. Practical implications. The obtained results make it possible to solve the practical engineering problems on determining the stability of water-saturated slopes and side-hills with a load-free daylight surface, therewith, taking into account the weight of the equipment, stored material and the stability of vertical walls of water-saturated seams of open-cut mine workings.

Objective of the studies is the substantiation of energy efficient technologies to support permanent mine workings under complicated conditions of mines in Western Donbass. The results of analysis of geomechanical processes within rock mass neighbouring extended mine working have been demonstrated. The possibility to fill up underpropped area at different stages of a mine working construction has been shown. Efficient technology to improve the stability of mine workings by means of underpropped area filling up with hardening mixtures pneumatically has been considered. The results of the new technology to fill up underpropped area while constructing the main crosscut in Samarskaia mine (“DTEK Pavlogradugol” Company) have been demonstrated.

1* Кафедра будівництва, геотехніки і геомеханіки, НТУ «Дніпровська політехніка», пр. Дмитра Яворницького 19, Дніпро, Україна, 49005, тел. +38 (095) 706 91 66, ел. пошта miasnykov.i.v@nmu.one, ORCID 0000-0002-7525-6196 2 Кафедра будівництва, геотехніки і геомеханіки, НТУ «Дніпровська політехніка», пр. Дмитра Яворницького 19, Дніпро, Україна, 49005, тел. +38 (050) 362 04 47, ел. пошта hapieiev.s.m@nmu.one, ORCID 0000-0003-0203-7424 3 Кафедра будівництва, геотехніки і геомеханіки, НТУ «Дніпровська політехніка», пр. Дмитра Яворницького 19, Дніпро, Україна, 49005, тел.+38 (050) 361 07 19, ел. пошта referent@mlad.com.ua, ORCID 0000-0001-9069-543X 4 Кафедра будівництва, геотехніки і геомеханіки, НТУ «Дніпровська політехніка», пр. Дмитра Яворницького 19, Дніпро, Україна, 49005, тел. +38 (066) 438 13 95 , ел. пошта sanya-prokudin@rambler.ru, ORCID 0000-0003-4132-8662 НОВІ ТИПИ МІЖРАМНОГО ОГОРОДЖЕННЯ ДЛЯ ПІДВИЩЕННЯ НЕСУЧОЇ ЗДАТНОСТІ КРІПЛЕННЯ КАПІТАЛЬНИХ ВИРОБОКМета. Метою досліджень є знаходження методів зниження витрат на ремонт і підтримку капітальних виробок шахт задля зменшення собівартості добутого вугілля. Методика. Для одержання поставленої мети, у ході виконання досліджень були досліджені капітальні гірничі виробки, частина з яких не відповідає вимогам правил безпеки (ПБ), та причини виходу кріплення таких виробок з ладу на прикладі шахт Західного Донбасу, що входять до структури ПрАТ «ДТЕК Павлоградвугілля». Результати. На базі отриманих експериментальних даних були розроблені способи підвищення несучої здатності капітальних гірничих виробок, такі як застосування нових типів міжрамного огородження з підвищеної несучою здатністю та способи його застосування у комбінованому кріпленні з тампонажем закріпного простору. Оцінений їх вплив на загальну несучу здатність гірничого кріплення та економічний ефект від їх застосування. Наукова новизна. Запроваджені новітні методи по підсиленню та удосконаленню сучасних типів комбінованого кріплення капітальних гірничих виробок. Запропоновані технологічні параметри такого кріплення та технологічні аспекти його застосування. Практична значимість. Запропоновані конструкції міжрамного огородження підвищеної стосовно залізобетонного огородження несучої здатності дозволяють підвищити міжремонтний період експлуатації гірничого кріплення капітальних виробок, а, отже, знизити експлуатаційні витрати. Застосування запропонованих конструкцій підвищує безпеку праці гірників. Конструкції, розглянуті в статті, є економічно доцільними та дозволяють отримати під час застосування економічний ефект за рахунок зменшення капітальних затрат на ремонт та підтримку капітальних виробок, закріплених таким видом комбінованого кріплення.Ключові слова: міжрамна огорожа; гірниче кріплення; несуча здатність; капітальні виробки; комбіноване кріплення ISSN 2413-6212 (Online), ISSN 2227-1252 (Print) Мости та тунелі: теорія, дослідження, практика, 2018, № 13

Purpose. To solve the problem of the allocation of contact vertical normal tensions along the sole of a rigid round stamp, located in an elastic isotropic half-space at a certain depth h  0. To compare the obtained solution with the well-known classical result for h = 0, to check the obtained results for adequacy. Methodology. Based on the analysis of the decision on the stress-strain state of the base, inside which there is a vertical arbitrary load distributed over the area of the circle, the necessary formulas are obtained to solve the problem. An algorithm for constructing an approximate solution has been developed, the essence of which is to use a combination of the boundary element method and the iteration process by S.N.Klepikov. For a number of depths, approximate solutions of the considered problem are obtained. Findings. The proposed algorithm for the approximate solution of the problem of indenting a round rigid stamp into the upper boundary of an elastic isotropic half-space has good agreement with the exact solution and can be used to solve contact problems. The outlines of the contact stress diagrams depend on the depth at which they are determined – the greater the depth, the flatter the outlines of the diagrams are, while starting from a certain depth, the diagrams of contact stresses practically coincide. The greater the depth is at which the stamp is located, the more force must be applied to obtain equal displacements of the stamp. Originality. The obtained research results significantly expand the possibilities of solving various problems of soil mechanics and foundation engineering, make it possible to obtain absolutely new results. In particular, a clear dependence of the contact stresses along the sole of a rigid round stamp on the depth at which it is located was identified. In addition, the presented data allow us to designate an absolutely new direction in the calculation of the foundations of ground anchors, namely, the calculation of their deformations. Practical value. For engineering practice, it is important that the greater the value of Poisson’s ratio of the base is, the greater the contact stresses are, other things being equal.