On different types, conditions, and factors of landslide risks in the city of Dnipro

The paper represents the research results as for the factors of such dangerous geological phenomenon as landslides in terms of geological medium of the city of Dnipro. It is emphasized that there are certain geological, geomorphological, and hydrogeological conditions favouring the development of a medium for landslide formation. Irrespective of long-term study of that phenomenon, spatiotemporal prognosis is a complex scientific problem requiring application of innovative ideas and scientific statements concerning both separate components of a geological medium and rather complex natural and technogenic system. The paper analyzes conditions of the development of deep landslides within the territory of the city of Dnipro connected with a geological structure in a scope going beyond traditional scope of engineering and geological studies. Despite wide occurrence of landslide developments within the territory of the region, landslide of the Dnipro region are not singled out as a separate regional type. According to different estimations, general number of landslides is more than 144 within the city of Dnipro. The studies are based on numerous calculations of slope stability indicating the importance of the occurrence of Pre-Quaternary deposits as the factor favour- ing deep landslide formations. Basing upon the processing of the geological studies, cartographic modeling of the surfaces of certain levels, their thickness, and analysis of landslides grouping within the areas of singled-out territories have been performed. Maps of the surfaces of reddish-brown (N2-Q1) and grey-green (N1-S2) clays as well as deposits of Obukhivska (P2ob) and Mezhyhirska (P3 mž) suites, representing together the rock thickness corresponding to Kharkiv Stage (P2-3hr), have been developed. It has been proved that occurrence mode of clays at the base of loessial soils creates certain conditions for the development of landslides being different in their mechanisms (i.e. cutting, slipping, and squeezing). An example of certain calculations of slope stability is given confirming the important role of argillaceous rocks in the formation of the zone of changed soil condition and property. It has been proved that occur- rence mode of the rocks occurring lower than the depth of water erosion development should be studied thoroughly while designing landslide protection structures to obtain accurate model of the geological medium.

The Movement Characteristics of Coal Granular Body in Excavating Rescue Channel in the Collapsed Body

The collapsed body formed after the underground power disaster is broken into loose body. The mechanical characteristics of the collapsed body are quite different from those of the homogeneous rock mass, and the rescue tunnel is affected by its moving characteristics. In this study, the lateral pressure coefficient of the collapsed body and the angle of the slip surface were deduced. The numerical experiment based on CDEM slump excavation was performed. The accumulation state of the collapsed body and the active lateral pressure coefficient and the angle of the slip surface are obtained. The characteristics of the force of the accumulation body which naturally collapsed were studied. Particle size, excavation position, excavation shape, volume, and the influence of natural repose angle on the occurrence mode and particle movement were obtained; the velocity field and slip surface of the lower left and middle lower parts during excavation and the variation of the natural repose angle were analyzed.

Process Mineralogy Study of a Refractory Mixed Copper Ore

Process mineralogy research of a mixed copper ore is studied to identify the occurrence mode of copper and to analyze the mineralogical factors influencing the floatation results. The results show that the ore has features of "high-sulfur, high copper", "various copper mineral types", "fine copper mineral granularity" "disorderly copper mineral distribution", which belongs to the more difficult processing high sulfur mixed copper ore. Therefore, in order to effectively utilize the copper mine resource, floatation process or combination of floatation-hydrometallurgy process should be adopt.

The Resource Characteristics of Marine Gas Hydrates and the Assessment of its Exploitation Technology

Gas hydrate is a new energy in the 21st century with the characteristics of high energy density, huge amount of resources and cleaning. It has important significances for resources development, environmental protection and global climate changing. Due to the limitations of the occurrence mode and the technical level of marine gas hydrates, at present, the development and utilization of the resources are still tentative. This article analyzed and evaluated several key technologies to develop marine gas hydrates, that is depressurization, thermal methods, chemical injection method, CO2 replacement method, and fluorine gas+microwave method.