Based on these considerations, it is necessary to critically consider the existing methods for determining the bearing capacity of the piles (to identify possible hidden reserves) and, first of all, the dynamic and static testing methods (probing method), as well as the calculated method of determining the bearing capacity of the piles recommended by SNiP. B.5-67.
This is all the more necessary, since the calculated formulas for determining the bearing capacity includes the so -called homogeneity coefficient, the value of which is constantly prescribed 0.7 for all occasions. This is not entirely true, since a priori can argue that the values of this coefficient should be different depending on the numerical indicators of the properties of soils, which different soils have different.
Design and calculation of pile foundations, as you know, is carried out after a thorough engineering and geological survey of development sites. Geological cuts, the results of static and dynamic sounding, the strength characteristics of the soils obtained in the laboratory, as well as other data that are at the disposal of the designer, allow it to assign the main parameters of immersed piles, based on the theoretical value of the bearing capacity of the single pile, calculated in accordance with applicable norms SNiP p-b.5-67.
However, the main criterion for the correct determination of the bearing capacity of piles is the data of static and dynamic tests of experienced (trial) piles immersed at the construction site. The volume and number of such tests, as a rule, are established in each case, taking into account the features of the design of the constructed structure, its work regime and other conditions.
Numerous experimental definitions of piles bearing capacity, made by various methods, indicate that data on calculated resistances obtained during static tests are the most reliable, while the results of a dynamic test and probing, as shown in the literature, so far can only approach them with one degree of accuracy.