FIELD: underground construction engineering; compaction and strengthening of rocky soils, loose rocks or construction of buildings, tunnels and passages in oil and gas fields. SUBSTANCE: water means for compaction and strengthening of rocky soils, loose rocks and soils which are in contact with water containing ions Ca2+ includes 2 to 40 weight-% of SiO2 (dry substance in terms of aqueous means) in form of aqueous silicon sol. Water means contains additionally hardness stabilizers from group including aminotris- (methylene phosphonic acid),1-hydroxyethane-1,1-diphosphonic acid, phosphono-butane-tricarboxylic acid, polyacrylic acid or mixtures of these agents in concentrations of from 0.00001 to 0.04 weight-%. Method of compaction of strengthening of rocky soils or loose rocks consists in bringing material in contact with said aqueous means. Proposed method is performed in presence of water containing alkali- earth metals. EFFECT: avoidance of undesirable quick compaction. 6 cl, 2 tbl, 7 ex
