Erykov A.A. – Строительные материалы и изделия

FUNCTIONAL AND STRUCTURAL CONNECTIONS IN THE ARCHITECTURE OF MODERN INDUSTRIAL BUILDINGS

https://doi.org/10.34031/2618-7183-2022-5-1-15-37

15-37 p.

Abstract

Today, up to 80% of buildings and structures are built on deep foundations, the main elements of which are concrete and reinforced concrete piles (hammered, bored and piles made according to CFA technology). Since the beginning of the mass use of drilling piles (the 60s of the last century), there is still a problem of ensuring the reliability of foundations, due to the fact that the process of installing piles is hidden from observation, and unacceptable defects may form in the pile trunks, which reduce the bearing capacity of piles and can lead the structure to an emergency condition. Pile construction technologies are constantly being improved, however, it is still not possible to avoid the appearance of defects in pile trunks because there are quite a lot of reasons for the formation of defects that it is not always possible to foresee and take into account. That is why, during the construction of deep foundations, output monitoring of the technical condition of drill pile shafts should be provided, which cannot be performed without the use of non-destructive diagnostic methods. The use of these methods and means, which implements them, should be mandatory to ensure the reliability and safety of the operation of buildings and structures and today is already provided for by numerous standards and regulatory documents. Currently, acoustic methods are mainly used for diagnostics, namely: single- and multi-channel acoustic logging; pulse Echo method with shock excitation of elastic waves (hereinafter referred to as the method of vibration-shock diagnostics). It should be noted that in the case of using high deformation to excite elastic waves, at which the impact energy on the end of the pile reaches the limit of proportionality, an assessment of the bearing capacity of experimental piles is given, and the low technique is used exclusively for diagnosing pile trunks. For a long time, these methods could not be widely implemented in the field. Their capabilities have increased significantly after the development of digital signal processing methods.

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STABILIZATION OF SUBSIDENCE OF BUILDINGS OF MODERN MEDICAL CENTERS

https://doi.org/10.34031/2618-7183-2021-4-6-5-25

Erykov A.A.

5-25 p.

Abstract

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.

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