Abstract

A quantitative description of the total and local channel scour in given (at Rechnoe in the Astrakhan Region); three pipelines (out of four) are laid within the zone of intensive river channel changes. Problems of such pipelines operation at the sites of underwater crossings drilled without any account of trends and rates of channel changes dangerous for a stability of such pipelines are discussed. It is noted that underwater drilling of pipelines across rivers above the line of the extreme channel scour may cause not only a more intensive retransformation of the channel but accidents due to pipelines denudation and deflection during the first years of their operation.

Recommendation has been made on the implementation of some protective measures to provide a reliable operation of the study pipelines at the sites of underwater crossings.

Keywords: Channel process, river channel changes, non-complete meandering, morphologically homogeneous reach, underwater crossing, line of extreme scour