Abstract: The invention pertains to a process for sealing off ground sites in particular a waste dump, abandoned dumping grounds, pipelines or the like, or also excavated construction sites, using sealants, wherein a fully course-controlled boring technique is used to drive at least one bore underneath the ground site from the surface outside the ground site and the sealant is injected into the soil surrounding the bore. To implement the process, jets for injecting the sealant into the soil are mounted on the steerable remote-controlled boring head.

Abstract: The invention relates to a method for decontaminating soil containing harmful substances, wherein a number of bore holes (11) are advanced to the areas at the edge of the area (21) of contaminated soil by means of a course controlled boring method, then under a continuation of the boring a directed injection of at least one appropriate injection medium (8) from the bore holes (11) is carried out such that the harmful substances are forced into a smaller soil area (21) and are finally removed. Furthermore, the invention relates to a boring head for carrying out the method according to the invention. The boring head includes a tubular boring head body with an inner flow passage and a boring head tip connected to the boring head body and having a convex tip surface the head tip has a plurality of openings connected to the inner passage.