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 work is devoted to the study of the processes of displacement and deformation of the surface during the escalator tunnels construction of the subway by the method of artificial freezing of soils. The features of the construction and freezing technology, the rocks characteristics in which the escalator tunnels made are considered. The data of specially organized, full-scale surveying observations of deformations on the earth surface are presented. The main factors influencing deformation processes in the frozen strata of a layered inhomogeneous rock mass with inclined tunneling are determined, the complexity of the predictive task and the need to simplify the design scheme are shown. The work is focused on the assessment of the least studied geomechanical processes of soil heaving-uplifts and deformations during the periods of active and passive freezing stages. When studying the displacements processes of the earth surface and rock mass, the finite element method and analysis of the obtained data using field observations of displacements were used. A simplified calculation scheme is proposed for modeling, which allows taking into account the uneven influence of frozen rocks of an inhomogeneous layered rock mass with a large inclined tunneling. The satisfactory convergence of the data of field surveying observations on the earth surface and the results of modeling geomechanical processes for the period of active and passive freezing stages is shown. The proposed calculation scheme is recommended for the prediction of deformation at the stages of underground construction, characterized by the development of the most dangerous tensile deformations of buildings and structures on the surface.
In article the information on the modern systems of monitoring intended for control of a deformation condition of rocks and buildings, being in a zone of influence of mountain works is stated. Principles and features of work of some types of gages and systems are stated. Problems with introduction of such systems in Russia are specified. The urgency of carry- ing out special scientific and applied researches for maintenance of introduction of such systems at realization of actions for protection of buildings and constructions is shown.
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.
Account method of laser-scanning survey of hydraulic engineering tunnels of 2,7 km is stated in the general extent. The visual way of inspection of the tunnels, carried out in parallel with their leveling is resulted. The way of a deformation estimation of a condition of tunnels by the geometrical analysis of 3D-models received according to laser-scanning survey is considered.
In work problems application of theoretical methods mechanics continuous environment for calculation of displacement and deformations rocks are considered at a construction of tunnels. The basic attention is given the account in calculations of vertical asymmetry in distribution of displacement in a pedigree file round a tunnel. The short analysis of the reasons display such asymmetry is presented. The way of the account in calculations vertical asymmetry in distribution displacement over and under a tunnel on the basis phenomenological approach taking into account features of functions of distribution of deformations and the given natural supervision is offered.
In work the basic features geomechanical processes of rocks occurring in a file are stated at tunneling and developments of underground constructions. Principles of the organisation mathematical modelling of processes displacement and deformations of rocks for an estimation of harmful influence of underground building on buildings and constructions are resulted. The basic lacks of known approaches to modelling of geomechanical processes are stated, recommendations about the decision of key problems of calculation displacement in a pedigree file are made. The basic results of application of the complex approach to a look-ahead estimation displacement and deformations at maintenance of building of city underground constructions in St.-Petersburg are presented.
Now questions of the metrological control in маркшейдерских works have the uncertain status. The law in force about maintenance is uniform-stva measurements does not include in control sphere маркшейдерские work. Predlaga-etsja to return to practice of independent performance калибровочных works on the certificated ranges.
In the given work the way of an estimation geomechanical effect of additional activization of deformation process in a file of rocks and on a terrestrial surface is stated at a construction of two and more parallel tunnels on the basis theoretical decisions of mechanics the continuous environment. Similar quantitative and quality standard of this effect at calculations stress has received a wide circulation in mechanics of underground constructions and other applied areas. In mine surveying calculations displacement and deformations mainly empirical approaches are traditionally used. The resulted decisions allow to carry out such estimations and to take into account similar geomechanical effects in calculations of displacement and deformations.
In the given work one of ways the account vertical asymmetry of fields displacement in a file of rocks surrounding a passable tunnel is offered on the basis of classical analytical decisions from mechanics of the continuous environment. For the account of such asymmetry it is used functions of displacement and the deformations, received for symmetric settlement circuits, and their transformation in view of the revealed surface of zero displacement and deformations under a tunnel.
This paper presents a method for determining the boundary criterion for the rock deformation zone in the rock mass above a tunnel under construction when using two-layer calculation schemes in forecasts of earth surface deformations. The method is applied to the conditions of construction of tunnels of the St. Petersburg subway system.
The traditional photoplanerometric survey of the main excavation sections using digital photo and video cameras acquires a new meaning. The article considers the method of remote imaging of vertical technical boreholes. The scheme of equipment installation on surfaces and video camera placement in the borehole is given.
The effects of the construction of two column stations of the St. Petersburg subway are considered. Based on the comparison of these effects, as well as on the mathematical modeling of the stages of tunneling works, the analysis of the probable causes of additional subsidence of the ground surface above the stations under construction is given. The possible causes of some specific manifestations of geomechanical processes associated with the application of the new technology of sinking the middle hall of the station column with an advance support are outlined.
In the article the methods of an estimation of technogenic effect of mining minings on geologic medium, statistical and probabilistic models of distribution of quality for the geographical demarcation of fields are adduced. Are set up to fundamentals of the theory of operation GPS of instrumentation and electronic techeometers at overseeing ground movement of rocks, ergonomics of realisation of these supervision (observations).
In the article the feasibility of idealized methods to calculation of deformations of a surface is considered at facility of tunnels in simple geological conditions. Among such methods the special attension is given to methods of a mathematical theory of elastic strength, which one will widely be used in mechanics of underground structures (close in the essence to a considered problematics). The applicability (feasibility) of the analytical approach is detected within the framework of the registration of the separate mining-and-geological factors.