Experimental and numerical modeling on vacuum consolidation behavior of staged-filled soil slurry with prefabricated horizontal drain and flocculant  

作　　者：Ding-Bao Song Yu Pan Wen-Bo Chen Zhen-Yu Yin Wei-Qiang Feng Jian-Hua Yin 

机构地区：[1]College of Civil and Transportation Engineering,Shenzhen University,Shenzhen,China [2]Department of Civil and Environmental Engineering,The Hong Kong Polytechnic University,Hung Hom,Kowloon,Hong Kong,China [3]Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第12期5231-5248,共18页岩石力学与岩土工程学报（英文）

基　　金：supported by the Research Grants Council of Hong Kong Special Administrative Region Government of China(Grant Nos.15210322 and R5037-18);the financial support(Grant No.86902-00000240)from Shenzhen University.

摘　　要：The vacuum-assisted prefabricated horizontal drain offers a promising method for strengthening soil slurry,allowing simultaneous filling and vacuum-dewatering via staged construction.However,there is limited research on the unique characteristics of staged filling.This study aims to investigate the vacuum consolidation process of staged-filled soil slurry through laboratory model tests and numerical simulations,also assessing the impact of anionic polyacrylamide.Comparative analyses are conducted between vacuum consolidation with and without anionic polyacrylamide,as well as self-weight consolidation without anionic polyacrylamide.Results reveal contour lines of excess pore pressure,water content,and soil strength forming an ellipse around the prefabricated horizontal drain board.During the consolidation process,a higher degree of consolidation,lower water content,and higher soil strength were observed closer to the prefabricated horizontal drain board.After treatment,the uppermost filling layer exhibits an average water content that was approximately 40%higher than the lower filling layer,and its average strength was about 60%lower.This discrepancy is primarily due to the absence of sealing on the top surface and the relatively short vacuum consolidation time caused by staged filling.The introduction of anionic polyacrylamide-induced flocculation significantly improves the initial consolidation rate but minimally affects the dewatering capacity of vacuum preloading.Using flocculant can enhance both the staged filling rate and soil strength(by 1e2 times).Additionally,employing a staggered arrangement between different prefabricated horizontal drain layers is advisable to prevent top-down penetration in areas with low soil strength.

关 键 词：FLOCCULATION Model test Numerical modeling Prefabricated horizontal drains Staged-filled slurry Vacuum consolidation 

分 类 号：TE377[石油与天然气工程—油气田开发工程]