深圳湾淤积泥沙自重沉积固结试验

摘要

With the main study object of the deposited sediment from Shenzhen River and Bay,deposited sediment settling and consolidation process was fully simulated with the laboratory settlement column experiment,and then studied the settlement consolidation characteristics of the riv-er and marine deposited sediment respectively. The main conclusions are as follows:a)sediment settlement can be divided into the initial free set-tlement,block settlement and the weight consolidation settlement,of which,the lasting time for the initial free settlement stage is 3~6 hours,30 days for the block settlement stage and 10~400 days for the final consolidation stage. Moreover,the settlement lasting time is mainly determined by the sediment suspension initial concentration and the clay particle content. b)Sediment initial concentration and the clay particle content mainly in-fluence the sediment particle volume fraction. Sediment particle volume fraction increases with the initial concentration,and the clay particle con-tent determines the flocculation effect. c)With the initial concentration of 60~70 g/L,sediment suspension settlement amount is relatively small which also will decrease the dredging amount perfectly.%以深圳河及深圳湾水底淤积泥沙为研究对象，通过室内沉降柱模拟淤积泥沙自重沉降固结过程，研究了河、海相淤积泥沙的沉降固结特性。结果表明：①泥沙沉降过程可分为自由沉降、阻滞沉降、自重固结沉降3个阶段，其中自由沉降历时3～6 h、阻滞沉降历时30 d左右、固结沉降历时10～400 d，沉降历时主要与泥沙初始浓度、黏粒含量相关；②泥沙初始浓度、黏粒含量均影响着泥沙的体积分数，初始浓度越大，体积分数越大，黏粒含量主要与黏粒絮凝效应的相对大小相关；③初始泥沙浓度为60～70 g/L时，能够得到较为优化的泥沙沉降结果，可以有效地减小疏浚清淤的工程量。