Method for calculating horizontal drain induced non-linear and large strain degree of consolidation

• Published in: Geotextiles and geomembranes Vol. 50; no. 2; pp. 231 - 237
• Main Authors: Chai, Jin-chun, Wang, Jun, Ding, Wenqi, Qiao, Yafei
• Format: Journal Article
• Language: English
• Published: Essex Elsevier Ltd 01.04.2022; Elsevier BV
• Subjects: Clay; Consolidation; Deformation; Dredging; Geosynthetics; Horizontal drains; Mathematical analysis; Mechanical properties; Non-linear consolidation; Nonlinearity; Prefabricated horizontal drain; Scale models; Slurries; Slurry; Strain; Strain rate; Vacuum consolidation; Vacuum consolidation; Geosynthetics; Non-linear consolidation; Slurry; Prefabricated horizontal drain
• ISSN: 0266-1144; 1879-3584
• DOI: 10.1016/j.geotexmem.2021.09.008

Consolidating dredged clay slurries using a combination of vacuum pressure and prefabricated horizontal drains (PHDs) is widely used in practice. This is a large strain problem, but there is no existing large strain theory for PHD induced consolidation. A method with explicit equations has been proposed to consider both mechanical and geometrical non-linearities in analyzing PHD induced consolidation. The method considers stepwise variation of properties using imaginary time concept. An imaginary time is determined by the condition of continuity of degree of consolidation before and after changing the properties. Then the method was applied to analyze a large scale model test of vacuum consolidation with PHD. Two analyses were conducted. One considered both the mechanical and geometrical non-linearity (large strain), and another only considered mechanical non-linearity (small strain). The results of large strain analysis agree with the measured settlement curve and excess pore pressures well. While the small strain analysis under-estimated the rate of consolidation significantly. The results from this study indicate that for analyzing PHD induced consolidation of clay slurries considering the effect of large strain is important, and the proposed method can be a useful design tool. •An explicit consolidation solution considering both mechanical and geometrical non-linearities.•A large scale model test of vacuum consolidation with PHD.•Demonstrating the importance of considering large strain phenomenon in consolidation analysis.