Influence of a quicksand on engineering constructions

     At expansion of river-front of the Obvodny channel (St. Petersburg) after the beginning of the rabbet ramming into a bottom of the channel , there was a quick immersing in a ground of lines of communication (a high-voltage cable of underground, a telephone cable and a sewer ). These objects are taking place from water on distance approximately in 30 m. Approximately there, where were made SSP lines 1 and 2.

     The tectonic disturbance revealed by these profiles (it is shown by ellipses) is in accuracy there where immersing communications took place. To find out the mechanism of influence this work on communications on distance 30 m the profile N 3 on the edge of water was made. This profile also has opened a tectonic disturbance. Profiles NN 4 and 5 also have opened the same tectonic disturbance the line of which is shown by a dot lines.
     The mechanism of influence of works to a line of profiles NN 1 and 2 managed to be found out only after realization of a profile N 5. The situation is that simultaneously with a tectonic disturbance the SSP method on the profile N 5 found out a quicksand.
     Owing to the rabbet ramming into a bottom of the channel near to a tectonic disturbance (near the profile N 3), was broken a hermeticness of quicksand, and in result of it the quicksand through the ground having in a zone of a tectonic disturbance where is increased filtration, has moved to the channel. As a result of it on all line of a tectonic disturbance the hydro-geological conditions was broken.
     In result, and the ground should lose the bearing capacity not only in area of 1-st and 2-nd profiles, but also and under house N 48. Inspection of a house has completely confirmed this logic line. Really, the house, takes place from the channel more than on 50 m, after began the rabbet ramming was began to be immersed in a ground, and now is in an wreck condition.
     Thus, when the building is made, it is necessary to have the information on presence of zones of tectonic disturbances around the building site.