The paper will analyse non-rock, i.e. soil substrates. Soil properties critical for the application of HDD techniques will be mentioned. The problem of swelling, plastification and filtration deformations inclusive of local quicksand will be discussed. The issue of geotechnical layers secretion, selection of geotechnical investigation methods, and developing proposals related to HDD will also be mentioned.

dr inż. Jerzy Sobkowiak, GEOMENOS Jerzy Sobkowiak, Tomasz Sobkowiak sp.j.