Using the data of the remote inductive sensing method, a cluster analysis of the detailed variability of the electrophysical properties of the sandstones of South Yakutia, which form the foundations of engineering structures in Neryungri, was performed. It has been established that in the identified five clusters, sandstones at a depth of 0–14 m have a complex heterogeneous structure and a variable strength state. The first cluster characterizes low-strength sandstones with high background values of dielectric constant and low background values of electrical resistance. The second cluster has strong sandstones, whose electrophysical properties are opposite to the first cluster. The third and fifth clusters characterize medium-strength sandstones. In five clusters, the electrical resistance of sandstones increases at a depth of 5-14 m, and the dielectric constant decreases. The amount of clay weathering material in sandstones at a depth of 5–14 m decreases, and the massif itself is compacted and strengthened by an average of 2,08 times. This forecast estimate was obtained from the difference in the background values of the electrophysical properties of sandstones in the format of complex numbers and the results of calculations of the average strength of sandstones based on the attenuation of the harmonic field of a vertical magnetic dipole at a frequency of 1,125 MHz.

Leonid G. Neradovskii
Doctor of Technical Sciences
Senior Researcher at the Laboratory of Engineering Geocryology
Melnikov Permafrost Institute SB RAS
36, Merzlotnaya Str., Yakutsk, 677010, Russia
е-mail: leoner@mpi.ysn.ru

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