Geological hazards when justifying the regulations of urban development

Relevance. Territorial planning of cities determines the reduction or prevention of possible or existing losses of the population, economic facilities and the environment from technoprirodnye hazards of different genesis. The effectiveness of planning regulations for urban development depends on the degree of validity of identification and forecasts of the occurrence and evolution of hazardous natural and technogenic processes in time and space. This, in its turn, is determined by the reliability of our ideas about the patterns of their formation and regional distribution. Aim. To identify geological hazards and propose the main engineering and geological constraints in urban planning on the example of Gomel. Objects. Natural and technical system "geological environment – technogenic impacts – hazardous natural and technoprirodnye processes". Methods. Systematic approach to the analysis of patterns of formation of hazardous natural and technoprirodic processes in the city; numerical modeling of geofiltration and geomigration processes based on the geofiltration model "GOMEL". Results. The most characteristic dangerous natural and technoprirodnye processes have been established on the example of the city of Gomel. Priority areas for the introduction of planning restrictions: tectonic situation; man-made flooding, were identified. Soil conditions are considered separately as one of the factors effecting the precipitation of natural and artificial bases under the influence of loads from civil and industrial buildings and structures. The authors have revealed the presence of disjunctive, as well as plicative in the form of flexures, age-varying and multi-scale dislocations forming the block structure of the upper part of the earth's crust of the city. It is shown that from the point of view of the stability of engineering structures, the absolute values of the velocities of long-period unidirectional block displacements are dangerous during long-term operation of structures located in interblock active zones. At the same time, short-period multidirectional movements in the active geodynamic zones of the articulation of blocks cause a change in the slope and bending of the foundations of structures. The paper introduces the engineering-geological features of the most common surface deposits: the terrigenous gray-colored formation of the Paleogene; glacial, periglacial and extraglacial formations of anthropogenic origin and their facies-genetic complexes. The authors identified the potential natural and technological hazards associated with the marked deposits. The paper demonstrates the causes and mechanisms of the formation of technogenic flooding of the city, as well as the genesis of the decrease in the deformation properties of moraine sandy loam with a technogenic increase in humidity. It is concluded that when establishing land use regulations for a city, as a rule, general measures cannot be taken, both for its entire territory and for certain stages of construction activity. The paper introduces the corresponding restrictions on the use of subsoil.