The group of deformed structures includes buildings that have received unacceptable subsidence and deformation during the period of their construction and especially operation, which, however, do not interfere with the performance of their main functions, but may eventually collapse. Their causes are errors in engineering and geological surveys and design; violation of the rules for performing construction work and operation of buildings and structures. Long-term geodetic observations of the precipitation of the foundations of buildings on pile foundations have shown that both absolute and relative stabilized values of subsidence in the vast majority of cases are less than them and the normative limit values are calculated. Therefore, the group of deformed buildings on pile foundations includes somewhat less often similar objects with shallow foundations. The reasons for excessive subsidence of the foundations of pile foundations of buildings (and as a result, the occurrence and development of cracks and other deformations in load – bearing structures), in addition to these, are most often: unjustified use of increasing correction coefficients for the results of compression tests of highly acidic soils; the lower ends of the piles falling into layers of weak soil; the tip of the piles sinking from the design mark; overestimation of the bearing capacity of the piles due to non-compliance with the optimal time of their "rest" after immersion or erroneous interpretation of the graphs "load-pile sediment"; excessively close placement of neighboring piles in the plan, which when they are immersed, especially in the sand, leads to "pushing" up previously submerged; uneven loading of piles as part of the grillage; deformation of existing buildings and structures when driving piles near and tongue-and-groove, the development of pits, etc.