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| Experimental study of flocculation combined with vacuum #br#
preloading to reinforce silt foundation |
| ZHAO Sen1，ZENG Fangjin1，WANG Jun2，3，4，FU Hongtao2，3，4，WANG Yadong1 |
| (1. School of Architectural and Surveying and Mapping Engineering，Jiangxi University of Science and Technology，Ganzhou，Jiangxi 341000，China；2. College of Architecture and Civil Engineering，Wenzhou University，Wenzhou，Zhejiang 325035，China；3. Key Laboratory of Engineering and Technology for Soft Soil Foundation and Tideland Reclamation，Wenzhou University，Wenzhou，Zhejiang 325035，China；4. The Innovation Center of Tideland Reclamation and Ecological Protection，Wenzhou University，Wenzhou，Zhejiang 325035，China) |
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Abstract The present method of vacuum preloading has low efficiency of vacuum transfer and the drainage plates are easily clogged，so the deep soil is poorly consolidated and the hydraulically filled mud needs a long construction period. A new kind of vacuum preloading combined with flocculant method was proposed. A type of inorganic flocculant was added into the dredged slurry before the vacuum preloading. The effective chemical flocculation led to the aggregation of small particles into lager clusters. Meanwhile，the viscosity was decreased and the permeability was increased，leading to the improved drainage of the soil after the flocculation. A series of model tests of vacuum preloading combined with different dosages of flocculants were carried out. The test results showed that the degree of vacuum in the deep soil was increased significantly. Both the pore water pressure dissipation and the process of soil consolidation were accelerated. The overall vane strength was improved obviously and with low decrement along the depth. The test proved that vacuum preloading combined with flocculant method achieved better effect of reinforcement. An optimal value of the percentage of the added flocculant exists. The best dosage of the flocculant was 1.5% for the slurry in Wenzhou(water content is 300%).
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2016, Vol. 35 
