Search of the reason of failure of the pipeline

     If the tectonic with a fault is crossed, may arise only one component funnel-shaped object on the SSP-section. The ground has the reduced load-carrying ability and it decreases during a time within this component.
     Along the Uchitelskaya street (St. Petersburg) lays a sewer pipe. The SSP-profiling was made along street, is direct above a sewer pipe in April, 1997.
     On available data, the sewer pipe was whole at that moment. However presence on the SSP-section of one component funnel-shaped object (it is shown by red color), and near-surface structure (it is shown by turquoise color) unequivocally specifies activity of processes of destruction of buildings (pipes) taking place in this zone.
     As a result of check of a condition of a pipe with the help of a videocamera it was seen the destruction of a pipe in a zone of the structure found out by us with help of SSP method.
     It is considered, that the break of a pipe is initial, and the liquid flowing out from it erodes a ground, and result of that is such destruction. Therefore at repair of a pipe the strengthening of a ground first of all was made. In a new pipe the plastic pipe was stacked.
     However the break of already repaired pipe began directly after repair, and in the same place. It may be seen with the help of videoshooting. Unfortunately, this fact hide, and under documents a sewer under street is in a normal condition.
     It is strange, that builders perceive the break of pipelines as the reason of development of an emergency. Actually, that the pipe has lost the hermiticity, it is the result of a sag and bend effort. This effort arises on any site of a line of the pipeline where the load-carrying ability of a ground has reducing.