In the current mine surveying practice, when assessing the harmful impact of underground construction on the earth's surface and undermined objects, the geotechnical system underground structure – rock mass is traditionally considered, which does not include the surface infrastructure. Such an approach can lead to distorted estimates of load levels, impacts and potential deformations for both buildings and the earth's surface. In order to determine the influence of the building and assess the interaction of elements of the geotechnical system tunnel – rock mass – building, the study analyses the undermining of the historical stage building of the Mariinskii Theatre by a complex of workings in Saint Petersburg metro station Teatralnaya. Numerical simulation by the finite element method in the PLAXIS 3D software package is used, the geotechnical model is calibrated in accordance with data of the field mine surveying and geodetic measurements. The models show that during undermining of buildings, their heterogeneous structure, weight and spatial rigidity significantly affect the distribution of deformations in the base of the construction, which is confirmed by localization of cracks in load-carrying structures that appeared after the start of mining operations. When assessing and predicting deformations by numerical methods, it is not always sufficient to simulate the rock mass – tunnel system, since this can lead to overestimated predicted values of the earth’s surface deformations, underestimated values of subsidence, and an incorrect assessment of the harmful effect on the undermined object. It was concluded that only an integrated approach using simulation, field measurements and survey data can ensure a correct analysis of the interaction of the rock mass, underground structures and above-ground infrastructure facilities with complex spatial geometry and allow a reliable assessment of the harmful effect on the undermined object with reference to structural damage. This contributes to adoption of adequate and timely protection measures for buildings and structures.
The analyses of daily surface deformations and destructions as a result of coal seam «Baikaimski» mining into the mine «Krasnoyarskaya» area was executed. The unusual character of subsidence, were surface destructions are observed when the mining depth more than 50 times exceed the seam thickness, is marked. The hypothesis of mechanism of surface destructions is offered.
In article problems of methodical maintenance and standards of an estimation of adverse effect of underground construction for conditions of St.-Petersburg are considered. The characteristic of the basic operating standard documents in sphere of maintenance of protection of the buildings developed in the Russian Federation is given. The reasons defining illegitimacy of application of some norms of these documents are stated. The urgency of creation of documents regulating an estimation of adverse effect of mining works on buildings, and also a technique of supervision for deformations is shown. Variants of maintenance of working on the specified documents for conditions of Saint-Petersburg are offered.
The Article presents the results of long-term investigations of the problem concerning the protection of shafts with pillars of reduced sizes under conditions of the Talnakh and Oktiabrsky deposits. The principal potentiality of partial mining of shaft-bottom pillars VS-3 and GS has been proved at the Oktiabrsky ore mine. Certain recommendations are given on optimization of parameters of shaft-bottom protective pillars.
The paper considers the existing standards in the field of rock movement and protection of engineer constructions from harmful influence of mining operations. It is emphasized the necessity in revision of some standards in compliance with the real mining production.
A cost-effective method of mining a thick sloping deposit using compacted rock filling instead of solidifying is proposed. Calculations by the finite element method showed the acceptability of the proposed technology for mining of protected objects on the earth's surface.