一、前言下荆江(藕池口至城陵矶)自1860年藕池决口(1870年松滋决口)以来,已成为长江中游著名的蜿蜒性河段。该河段除南岸受山丘阶地约束变化较少外,其北岸为广阔的冲积性平原。岸坡中部以下以细砂层和中细砂层为主,抗冲能力极弱,且地面普遍低于南岸5～7 I. Introduction Jingjiang (Ouchi mouth to Chenglingji) Since 1860, Ouchi burst mouth (1870 Songzi burst mouth), has become the famous meandering river in the middle reaches of the Yangtze River. In addition to the southern bank by the Hill terraced changes less constrained, the north bank of the vast alluvial plain. Below the central part of the bank is a fine sand layer and a medium fine sand layer, with very weak impact resistance and a generally lower surface area of ​​5 to 7