中文摘要：

单颗粒沉降、絮团发育沉降、絮网压缩沉降是粘性细颗粒泥沙悬浮体系絮凝发育的三种不同相态，其中关于从絮团发育沉降转变到絮网压缩沉降这一临界状态的研究比较少见。本文从特征絮团的角度出发，考虑形成絮网的临界状态分别得出了静水、动水不同条件下区分絮团发育与絮网发育的临界判据，其分析结果与试验观察定性的一致。

英文摘要：

There are three different phases during the flocculation of cohesive sediment in suspensions： single particle sedimentation, floc sedimentation, gel-like network compression and sedimentation. The investigation on the critical condition of formation of gel-like network is rarely seen. Based on the concept ＂characteristic floc＂, the critical criterions which can be used for distinguishing floc sedimentation and gel-like＇network sedimentation under static and shear flows are respectively put forward. The results are consistent with experiments＇ observations.