This section of the Journal will now be permanent. It will contain material about large-scale and particular failures, the causes of which will be systematized. Analysis of the causes of failures makes it possible to establish more precisely and verify the analytical schemes of structures in the normative documents, the current practice of design of bases and foundations under different soil conditions, the procedures recommended in the normative documents for carrying out engineering-geologic explorations intended to determine the analytical characteristics of soil bases, and the values of the allowable deformations for different construction solutions under which normal operation of the structures is possible. The following article, written by the director of this section, Doctor of Technical Sciences, Professor M. Yu. Abelev, is devoted to large-scale errors that have been committed in engineering-geologic explorations and as a result of which failures and deformations have occurred in industrial, civil, hydraulic, and trasport structures.