The numerical simulation methods are widely used for the solution of geotechnical problems. However, it is necessary to use reliable soil parameters in order to obtain effective results. In nonlinear problems these parameters might differ from traditional values, for example, deformation modulus should be increased. It is shown that in order to determine horizontal load on a structure one needs to determine the internal friction angle in the stripe of deformation localization or in the zone of potential sliding surface (both of which correspond to the friction of soil particles during sliding or rotation). During seismic calculations the interaction between elements of the “base – foundation – overhead structures” system should be considered. Disregard to the base flexibility or the inertial mass forces of soil can lead to the distortion of the dynamic influence. The designed accelerograms built for construction site should be used as seismic loads. It is shown that the analysis of structures which include anti-seismic arrangements or seismic isolation is limited when the synthetic accelerograms of the normative documents are used exclusively. The mechanism of landslide-prone territory collapse is discovered, which gives an opportunity to provide apropos engineering safety measures and to ensure their efficient application. The development of landslide processes on the coast caused by the speed of abrasion, changes of sediment volume affected by sea currents and erosion phenomena on the slope is shown. The intensification of weak soil deformation as a result of technological factors is also influenced to these processes.