Compacting method for e.g. unconsolidated rocks uses one or more rotating spirals, with shape, length, pitch, direction, speed, all dependent upon edge conditions

Compacting is achieved by rotating one or more spirals in the loose ground. Shape, length, pitch, direction of pitch left or right, direction of rotation, RPM, and torque, are variable dependent upon edge conditions. Gas, liquid, or a liquid-solid mixture, is ejected from the spiral via nozzles or openings, to accelerate, support, improve the lowering and compression process dependent upon requirements. To reduce wear, the spiral consists of a wear-proof material and/or has a wear-proof jacket.