The engineering-geological conditions of Ukraine’s territory depend on the geological structure, physical-mechanical properties of rocks (soils) that can serve as the foundation and environment of engineering constructions (installations), the character of geological processes, tectonic regime, relief, hydrogeological and hydrological conditions, and seismicity. Locally they are influenced by regular seasonal and temporal changes owing to different external actions, as well as influences of economical activity (technogenesis). Especially considerable changes of physical and mechanical properties of soils result in the change of groundwater regime and development of underflooding. The complexity, peculiarity, favourableness, insufficient favourableness, and unfavourableness of engineering-geological conditions depend on the complex of factors that determine these conditions on particular terrains and are assessed in relation to kinds and methods of these sites’ usage for definite kinds of construction.

The geological structure of Ukraine’s territory is determined by its location in the southwestern part of the East European platform and partially in the mountainous regions of the Carpathians and the Crimea.

The tectonic regime is characterized by slow differential vertical ascending and descending movements in the earth’s crust.

The relief, accordingly, is also determined by these conditions, as well as by the action of denudation – weathering, gravitational ablation, abrasion, and erosion. Relief elements undergo considerable changes through economical activities. Such relief elements as slopes have also great influence on construction. The distribution of areas over the geostructural regions of the Ukrainian territory by the surface inclination is defined by the indices of vertical and horizontal stratification of the territory and the character of the drainage network development. According to the State Construction Regulations (SCR 360 – 92 Town-Planning. Planning and Building Up of Urban and Rural Settlements), favourable for construction are considered sections of the surface with the inclination from 0.5 to 8% (0°18'–4°36'), insufficiently favourable – with the inclination of 8 to 15% (4°36'–8°36'). The areas with the surface inclination of more than 15% (8°36') are considered unfavourable for construction.

The tectonics and neotectonics are determinant factors for the formation of landforms and the development of geological processes, which radically influence the engineering objects, life, and activities of human society. Thus, the endogenous geological processes contribute to the increasing of the contrast of the relief and create its most significant forms, hence the conditions for the development of exogenous processes. The different directions of tectonic movements facilitate the vertical relief stratification and activation of certain groups of exogenous processes: for the elevation regions these are erosion, landslides, and downstoping; for the regional subsidence – underflooding, salinization, and loess settling. Hence, neotectonic and recent tectonic movements greatly influence the formation of landforms and hydrological network, determining the tendency of the development of exogenous geological processes.

The recent crustal movements in Ukraine’s territory are mainly of block character. The spatial differentiation of velocities of recent crustal movements is associated with the intensity of recent geological processes, especially erosional, which are major exogenous processes determining main geomorphological features of a territory.

All recent geological processes are closely connected with the dynamics of tectonic structures of different orders that is testified by their intensive manifestations in the zones of active tectonic dislocations and deep faults.

Hydrogeological conditions also belong to important factors of the development of exogenous geological processes. They determine the depth of the opening and drainabiity of karsting strata, the intensity of underflooding and waterlogging, and are most susceptible among other factors to the human intervention. In a short space of time the change of the underground water regime caused by the economical activities can trigger the change of engineering-geological conditions on a large area, which in its turn results in activation of geological processes.

The engineering-geological conditions are influenced mainly by the regime of the nearest to the surface aquifers in the zones of active water exchange, their depth, seasonal and age changes of these depths, as well as the mineralization of underground water and filtration rate. Conditions that allow construction without taking measures for groundwater level lowering are considered favourable; under the necessity of taking simple measures for groundwater level lowering, the conditions are considered insufficiently favourable. Unfavourable conditions require complex measures for lowering of the groundwater level.

The hydrological regime of water reservoirs and streams influences the engineering-geological conditions through flooding and underflooding of territories. The inundations of a territory over 0.5 m under the flood of 1% frequency and under 4% frequency are considered unfavourable for construction.

Seismicity is a major factor influencing local geological processes. It is the most intensive in the southwestern part of Ukraine within the narrow zones of seismogenerating tear faults. The local earthquakes are also a possibility in different parts of the country.

The richter magnitude scale assigns a single number to quantify the amount of seismic energy released by an earthquake. To determine the intensity of an earthquake the behaviour of structures and soils under the earthquake is estimated as well as human sensations. The engineering-geological conditions in the regions of seismic activity are defined more exactly with micpinkismic zoning that takes into account the character of the landforms and soils, the level of their moisture, and possibilities of manifestations of exogenous geological processes.

The technogenic (induced) seismicity is a special factor decreasing the seismic stability of the upper zone rocks of geological profile (increase in shaking or conventional increase in magnitude). The technogenic increase in seismicity occurs in the zones of underflooding, subsidence, and surface displacement over the excavations (in Donbas during a coal mines closure and high-powered blasting operations, in Peredkarpattia (Forecarpathians) in the areas of oil fields and salt mines), and on the areas of surface overload after filling of reservoir storage.

The dynamic load on geological bodies in the wave fields during earthquakes and vibration induced by working mechanisms and transport change the physical-mechanical properties of soils and character of geological processes determining alterations of geotechnical conditions. These changes can take place either momentarily during propagation of seismic waves (syndynamic) and some time after wave attenuation (postdynamic). Frequently on impact of seismic waves the bearing resistance declines and buildings become critically endangered. The gravitational deformations and dislocations of soils occur on slopes and scarps. The disastrous 6-grade earthquakes after MSK scale often provoke landslides on slopes under proper conditions–availability of mobile material, sufficient height and steepness of slope, excessive moistening and overload of soils, surface and area relaxation, rifts and fissures.

The postdynamic deformations of slopes result from passing of seismic waves in the massif adjoining the slope; the follow-up changes form zones of relaxation, rocks accumulation which can lead to landslides. The changed geohydrology of slope-draining aquifers and disruption of groundwater filtration push up the water table and, as a result, the hydrostatical and hydrodynamic pressures go up.

The territories prone to earthquakes, i.e. abrupt sudden underground shakes that threaten human life and activities and change engineering-geological conditions, belong to seismic ones.

The periods and frequency of seismic wave vibrations vary with the character of geological environment. Thus, the frequency of vibrations in magmatic rocks (granites, diorites, syenites, basalts) is 200–3 000 c^-1, while in water-saturated sands, loamy sands, and loams – 10–100 c^-1.

Accelerations appearing in the basement rocks are dangerous for structures. Seismic accelerations depend on the amplitude and period of vibrations.

The structures in the territory of Ukraine are founded mainly on quaternary deposits represented on 63% of its area by soils of loess formations. These soils are water-sensitive: they are prone to water erosion, soaking, gullies evolve here and there, the banks of rivers, lakes and water reservoirs tend to erode, there are many basal, slipping, toe, and solifluction slopes.

The loess soils have special characteristics: in the case of extra sludging their bearing strength deteriorates and subsidence sets in. Loess soils whose subsidence properties become manifest in the foundations of constructions under wetting and additional load from structures belong to the 1st type and terrains with such soils are considered insufficiently favourable for construction works. Wetted loesses subsiding under their own weight belong to the 2nd type and sites with such soils are considered unfavourable for construction works. Loess soils as special deposits formed under certain climatic conditions mantle relief elements of plain territories. Their thickness varies from several metres to tens of metres. In the territory of Ukraine, the thickest loesses are found in the lower reaches of the Dnipro. When assessing sites with loess cover, it is necessary also to take into consideration the conditions of the cover attitude, in particular the character of underlying rocks in the view of their strength and filtration behaviour.

Boggy deposits are most unfavourable soils for the foundations of structures, and among them the most typical and determining is peat. It is a layer of organic genesis formed in bogs and waterlogged soils because of accumulation and decomposition of organic residues, mainly vegetable, and has sandy-argillaceous additives. According to regulatory documents, peat is a material that has more than 60% of vegetable remains. Deposits that have from 10 to 60% of vegetable remains are called peaty.

There are three types of bogs: 1st type – the thickness of boggy deposits is small (to 3 m), peat has the stable consistency with the load-bearing capacity of more than 0.025 MPa and can be partially or completely removed (de-peating), the topography of the mineral bottom is smooth; the 2nd type is characterized by a relatively small (5–6 m) thickness of  boggy deposits but peat in bogs of this type has an unstable consistency with the load-bearing capacity of 0.01 to 0.025 MPa. This is the so-called ooze or fen or quagmire. The mineral bottom topography of such bogs is relatively smooth. Bogs of the 3rd type have the thickness of boggy deposits more than 6 m of the unstable consistency, often with an overlying water layer; their load-bearing capacity does not exceed 0.01 MPa. These bogs form predominantly as a result of waterlogging of reservoirs. Their bottom relief is most often uneven, with the presence of buried slopes of considerable steepness. Within the boundaries of Ukraine, the greatest amount of bogs and waterlogged areas is found in Polissia, in the valleys of steppe rivers, and in the mountainous regions of the Carpathians. The total area of bogs is about 10000 km². A considerable part of them is reclaimed and used in agriculture and forestry. In some bogs peat is extracted. Also, measures are taken to protect bog massifs as important storages of moisture.

When designing foundations, considerable complications appear on terrains with the occurrence of karsted and karsting rocks. Estimating territories in respect to their suitability for construction, we distinguish: 1) territories stable and relatively stable, within which soluble rocks are weakly karsted and an annual average quantity of collapse events on the area of 1 km² does not exceed 0.01, as well as those where weakly karsted deposits lie at the depth of more than 10 m and are covered by dense and stable deposits. When planning construction on such territories, their karsting can be disregarded; 2) territories with reduced resistance where soluble deposits have increased karsticity, an annual average number of collapses on the area of 1 km² reaches 0.01–0.05; the thickness of overlying deposits is small or insufficient in comparison with the thickness of the active zone of structures. It is recommended to limit the height of buildings and the dwelling density to 20%; 3) territories insufficiently resistant are characterized by increased karsting of rocks where an annual average quantity of collapses and subsidences of the surface reaches 0.05–0.1 and they occur often. The construction of buildings to 5 storeys is possible only in exceptional cases with special argumentation. The dwelling density should be up to 10%; 4) unstable territories, where soluble deposits are hyperkarsted, collapses and subsidences of the surface occur often. Capital construction is prohibited. In the territory of Ukraine, karst prevails mainly in the Carpathians, the Crimean Mountains, Podillia, and Donbas.

In the conditions of a rugged terrain, on high and steep slopes gravitational processes develop: collapses, screes, and landslides, and the amplitude of upwarping of big tectonic blocks define the possibility of the development of slope processes. The activation of slope erosion-gravitational processes, especially in mountains, often occurs under the anomalous development of hydrometeorological processes – heavy showers, floods, and windfalls.

Mudflows are possible on mountainous rivers, basins of which accumulate much loose sandy-argillaceous, argillaceous-detrital and detrital material.

On plains there are underflooding, deflation, loess subsidence, and salinization, in river valleys lateral erosion prevail over the bottom one.

The inclusion of territories with the development of natural processes into the sphere of economic activity leads to inevitable changes in the environment, which entail their technogenic aggravation with destructive and sometimes even catastrophic manifestations. Under the influence of the technogenic factor a tendency to the expansion of areas included in the processes is observed, as well as an increase in the intensity of their manifestations.

Territories damaged by mining works have especially problematic engineering-geological conditions. In Ukraine, they take up considerable areas (the Donbas, Kryvyi Rih, the L’viv-Volyn’ coal basin, regions of brown coal mining and manganese ore extraction, places of building materials quarrying), whose engineering-geological conditions have suffered great changes.

Surface mining changes the landscape completely and it becomes unsuitable for use without carrying out reclamation works. Among the characteristic features of such a landscape are deep exhausted open-cast mines, often watersealed, waterlogged, with complicated water exchange, refuse heaps that take areas 3–4 times larger than the area of the quarry. To prevent negative consequences of the subsidence of refuse heaps it is necessary to envisage their multistage planning. Territories with excavations are used for construction after the termination of the surface deformation processes. Construction is not permitted on the underworked territories where are possible the formation of collapses and landslides or exceeding of permissible levels of expected deformations of surface. Territories with excavations on depths less secure can be used for construction after the termination of displacement processes or after taking measures that exclude the possibility of collapses formation.

In general, the engineering-geological conditions of Ukrainian territory are mostly of low, medium and high complexity. The high complexity is peculiar only to the mountainous regions of Carpathians and Crimea, as well as some areas of Volyn’–Podillia.