化学絮凝结合真空预压处理的渤海湾海洋疏浚泥固结特性

Consolidation characteristics of marine dredged slurry in Bohai Bay treated by chemical flocculation combined with vacuum preloading

为了改善渤海湾海洋疏浚泥渗透性差和排水固结时间长的不足,引入化学絮凝结合真空预压的地基处理方法.首先分析了山东东营地区疏浚泥的矿物成分与物理性质,然后采用两种不同的絮凝剂进行了沉降柱试验与真空预压模型试验.结果表明:絮凝剂APAM添加量越大,混液面沉降速度越快,在添加量为15%时速度最快,约5 min内沉降基本稳定;絮凝剂CaO添加量越大,混液面沉降速度越慢,当添加量越过某一值(10%)时,最终混液面基本保持不变;真空预压排水速率并非絮凝剂添加量越大越快,絮凝剂CaO添加量为0.6%时速率最快,絮凝剂APAM添加量为15%时速率最快.研究成果对于东营疏浚泥地基处理工程实践具有一定的指导意义.

Chemical flocculation combined with vacuum preloading is introduced for foundation treatment to improve the poor permeability and long consolidation time of marine dredged slurry in Bohai Bay. Firstly, the mineral composition and physical properties of dredged slurry in Dongying, Shandong area are analyzed. Then settlement column test and vacuum preloading model test are carried out with two different flocculants. The higher the adding amount of APAM flocculant, the more quickly the sedimentation rate of the mixing liquid level. The sedimentation is stable in about five minutes at the maximum sedimentation rate when the adding amount is 15%. The higher the adding amount of CaO flocculant, the slower the sedimentation rate of the mixing liquid level. When the adding amount exceeds a particular value(10%), the final mixing liquid level remains unchanged. The rate of vacuum preloading drainage is not faster with the increase of the adding amount of flocculant. The rate is the fastest when the adding amount of CaO is 0.6%, and the rate is the fastest when the adding amount of APAM is 15%. The research results have a particular guiding significance for the practice of dredged slurry foundation treatment in Dongying.