The effects of the construction of two column stations of the St. Petersburg subway are considered. Based on the comparison of these effects, as well as on the mathematical modeling of the stages of tunneling works, the analysis of the probable causes of additional subsidence of the ground surface above the stations under construction is given. The possible causes of some specific manifestations of geomechanical processes associated with the application of the new technology of sinking the middle hall of the station column with an advance support are outlined.
The history of an introduction of the laser of direction is described at building undergrount of city, and also the characteristic of a modern park of the laser of direction and problem of usage them for today is given.
