The study of stress state and nechanism of rock massif deformation upon the formation of technonatural karst collapses

Author(s):  
Yu. A. Mamaev ◽  
A. N. Vlasov ◽  
M. G. Mnushkin ◽  
A. A. Yastrebov

The paper deals with the assessment of stress-strain state variation in rock massifs upon the formation of displacement moulds and surface sinkholes in the undermined areas of Verkhnekamskoe potassium salt deposit in Perm krai, Russia. Engineering geological conditions, as well as natural and technogenic factors influencing the development of hazardous geological processes are described by the example of one typical site of the deposit. Methodical issues of the development of geomechanical model for this site and compilation of finite-element calculation scheme with selecting calculation parameters of rock properties and boundary conditions of the calculation area are considered. Regularities in the variation of stress fields and rock massif deformations upon cutting mines at one depth are considered. The possible mechanisms of deformation and destruction of karstified rock massifs upon the formation of technonatural sinkholes on the earth surface are described. The results of the study are significant for predicting hazardous processes and undertaking protective measures.

2020 ◽  
Vol 7 (7) ◽  
pp. 83-91
Author(s):  
Irina V. Abaturova ◽  
◽  
Ivan A. Savintsev ◽  
Liubov A. Storozhenko ◽  
Elvina D. Nugmanova ◽  
...  

geological environment. Actively change all the components of engineering-geological conditions (EGC), formed during the long geological time: the topography, structure of rocks, hydrogeological and permafrost conditions, are formed by geological processes and, at the same time on the surface of the Earth formed a new strata of man-made structures, and often man-made deposits. The scale of technogenesis in mining today is comparable to the results of geological activity that took place over many millions of years. Therefore, even at the early stages of studying the EGC MD, it is necessary to understand the dynamics of changes in the EGC in order to provide preliminary protective measures. Purpose of work. Consideration of striking examples of the dynamics of the EGC MD (from exploration to development), in order to provide methods for managing these changes. Methodology. The article considers the stages of obtaining engineering and geological information for the period of MD operation, which will solve the problems of rational use of the subsoil and protection of the geological environment. Results. For example, the number of objects marked all the stages of learning to yoke the dynamics of their changes, which led to the formation of engineering-geological processes that adversely affect the further testing of MD. Summary. The reaction of the geological environment in the development of MD is not long in coming and is expressed in the development of large-scale engineering and geological processes, which often do not allow further development of MD and threaten people's lives. Therefore, even at the early stages of studying the EGC MD, it is necessary to understand the dynamics of changes in the EGC in order to provide preliminary protective measures.


On the basis of engineering and design surveys of the building, engineering-geological and geophysical studies of the soils of the territory conducted by the article authors, as well as with due regard for the results of studies conducted on this territory by other authors, the features of the foundations, soils of their foundation and engineering-geological conditions of the territory of the Melnikov House are established. It is shown that the Melnikov house is located under complex engineering-geological conditions on the territory of high geological risk, in the zone of influence of tectonic disturbance. To the North of the area there is a zone of intersection of the observed disturbance with a larger disturbance that can have an impact on geological processes. To the North-East of the site of the Melnikov House, a sharp immersion of the roof of carbon deposits was revealed. It promotes groundwater seepage into limestone of the carbonate strata from overlying water-bearing sands and activation of processes of suffusion removal and sinkhole phenomena of the soil. The surveyed area is assessed as potentially karst-hazardous and adjacent to it from the North-East territory as karst-dangerous. In this regard any construction on the adjacent territory can provoke activation of sinkhole phenomena on the surface. The foundations of the building are basically in working condition. Existing defects can be eliminated during repair. The foundation soils mainly have sufficient bearing capacity. Areas of the base with bulk soil can be reinforced. However, when developing a project for the reconstruction of the building and its territory, it should be taken into account that the design of the Melnikov House does not provide for its operation on the loads at the formation of sinkholes.


2020 ◽  
Vol 12 (1) ◽  
pp. 1094-1104
Author(s):  
Nima Dastanboo ◽  
Xiao-Qing Li ◽  
Hamed Gharibdoost

AbstractIn deep tunnels with hydro-geological conditions, it is paramount to investigate the geological structure of the region before excavating a tunnel; otherwise, unanticipated accidents may cause serious damage and delay the project. The purpose of this study is to investigate the geological properties ahead of a tunnel face using electrical resistivity tomography (ERT) and tunnel seismic prediction (TSP) methods. During construction of the Nosoud Tunnel located in western Iran, ERT and TSP 303 methods were employed to predict geological conditions ahead of the tunnel face. In this article, the results of applying these methods are discussed. In this case, we have compared the results of the ERT method with those of the TSP 303 method. This work utilizes seismic methods and electrical tomography as two geophysical techniques are able to detect rock properties ahead of a tunnel face. This study shows that although the results of these two methods are in good agreement with each other, the results of TSP 303 are more accurate and higher quality. Also, we believe that using another geophysical method, in addition to TSP 303, could be helpful in making decisions in support of excavation, especially in complicated geological conditions.


2018 ◽  
Vol 56 ◽  
pp. 02014
Author(s):  
Maksim Rasskazov ◽  
Marina Potapchuk ◽  
Gennady Kursakin ◽  
Denis Tsoy

The paper presents the results of geomechanical studies on the assessment of the potential rockburst hazard of the rock massif of the South Khingan deposit of manganese ore at the stage of development. Geodynamic zoning has been performed, mining and technical, mining and geological conditions of field development have been studied, and parameters of physical and mechanical properties of enclosing rocks and ores have been determined. Numerical simulation methods have been used to estimate the stress state of a rock massif at various stages of the deposit development. The tendency of the lower part of the South Khingan deposit to rockburst has been established. The complex of effective organizational and technical security measures has been substantiated in the development of this field.


Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Vilde Dimmen ◽  
Atle Rotevatn ◽  
Casey W. Nixon

Fluid flow in the subsurface is fundamental in a variety of geological processes including volcanism, metamorphism, and mineral dissolution and precipitation. It is also of economic and societal significance given its relevance, for example, within groundwater and contaminant transport, hydrocarbon migration, and precipitation of ore-forming minerals. In this example-based overview, we use the distribution of iron oxide precipitates as a proxy for palaeofluid flow to investigate the relationship between fluid flow, geological structures, and depositional architecture in sedimentary rocks. We analyse and discuss a number of outcrop examples from sandstones and carbonate rocks in New Zealand, Malta, and Utah (USA), showing controls on fluid flow ranging from simple geological heterogeneities to more complex networks of structures. Based on our observations and review of a wide range of the published literature, we conclude that flow within structures and networks is primarily controlled by structure type (e.g., joint and deformation band), geometry (e.g., length and orientation), connectivity (i.e., number of connections in a network), kinematics (e.g., dilation and compaction), and interactions (e.g., relays and intersections) within the network. Additionally, host rock properties and depositional architecture represent important controls on flow and may interfere to create hybrid networks, which are networks of combined structural and stratal conduits for flow.


2021 ◽  
Vol 27 (1) ◽  
pp. 24-33
Author(s):  
D. Shesternev ◽  
◽  
A. Verkhoturov ◽  

he study of flooding of engineering structures as a dangerous engineering and geological process and the prevention of emergencies and environmentally adverse consequences is an important task of national economic importance. The purpose of this work was to study the natural conditions of the area of the Kadala airport in Chita to identify the main causes of flooding of the artificial runway (IVPP). The object of research was the near-surface part of the geological environment, the subject-the factors of formation of hydrogeological, engineering-geological and geocryological conditions. In the course of the research, the following tasks were solved: 1) identification of factors that affect flooding; 2) assessment and proposal of acceptable protective measures. The research methodology included: collection and analysis of materials from previous engineering and geological studies; interpretation of satellite images; field survey of the artificial runway and adjacent territory; analysis of hydrometeorological conditions. As a result of the research, the factors that lead to flooding of the south-eastern section of the airport, and in winter to the formation of ice and deformations on this section of the airport’s artificial surfaces are determined. The identified factors are divided into regional and local. The hydrogeological and engineering-geological conditions of the territory and their dynamics over time are considered. It is determined that the main factors of flooding are the creation of barrages in the path of the movement of underground water and the intensive freezing of the soil on the section of the artificial runway. Recommendations for the stabilization of the ground base on this site and measures for the engineering protection of the airport territory are given. The implementation of the recommendations will ensure the accident-free operation of the artificial runway and improve the environmental condition of the settlement adjacent to the airport from the south-east


Author(s):  
А. Bakalov

Difficult engineering and geological conditions of the Imeretinskaya lowland: the presence of specific soils with a thickness of more than 30 meters, several aquifers, including pressure, the development of dangerous geological processes (flooding, abrasion, suffusion, etc.) and, finally, increased seismicity was put before prospectors, designers and builders a very difficult task of erecting a whole series of unique Olympic facilities on this territory.


2018 ◽  
Vol 55 (1) ◽  
pp. 133-140
Author(s):  
Olga Eremina ◽  
Irina Kozliakova ◽  
Nadezhda Anisimova ◽  
Irina Kozhevnikova

Exogenous geological processes are exerting a significant impact on urban geo environment in Moscow endangering both surface and subsurface constructions. For surface construction, the principle geohazards in Moscow are karst-suffosion sinkholes, land subsidence, landslides, and waterlogging. The subsurface construction is endangered by karstification and fracturing of limestone, decompaction and swelling of clay, quicksand phenomena, and groundwater breakthrough to tunnels. Different methods are applied to study geohazards depending on the purpose and the scale of study. At the preliminary investigation stage, small-scale mapping and zoning of city surface or subsurface appears to be the most appropriate for the qualitative assessment of the risk of economic losses caused by exogenous geohazards. Assessment of the geological risk in Moscow was carried out separately for already existing urban infrastructure and for future planned construction. For existing surface urban infrastructure, geological risk is considered to be an integral parameter of probable damage caused by geohazards and the anthropogenic load on the specific territories. The main aim of risk mapping in this case is outlining the territories, for which restrictions and prohibitions should be imposed for further urban engineering development. For future subsurface urban construction, the risk-analysis consists in assessing the impact of geohazards on the engineering structure by comparing the future expenditures for the construction and operation under different engineering geological conditions. The risk maps in this case will help planners to compare and make alternative project decisions in order to minimize the cost in future economic expenditures. Both approaches are successfully approved in this investigation in Moscow.


Author(s):  
G. E. Blight

AbstractGeological conditions and processes in the tropics may differ considerably from those in temperate climates. After briefly considering the nature of tropical soils, the paper describes some of the geological processes, occurring in the tropics, that may result in rapid geological change. These processes may act sufficiently quickly to produce significant change in a lifetime or at the very least, in a few centuries.


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