Comparative Evaluation of Stress Distribution and Permeability Characteristics in Bentonite Cutoff Walls Using CPTU and ABAQUS Methods.

Bentonite materials are extensively used in cutoff walls at landfill sites. This study calculates the stress and permeability characteristics of bentonite materials using the piezocone penetration test (CPTU) and ABAQUS simulations. The lateral effective stress of bentonite materials is evaluated using arching models, lateral squeezing models, and a modified lateral squeezing model. Pore pressure dissipation types are categorized into standard and non-standard, with the coefficient of consolidation obtained using the half dissipation time of excess pore pressure () method. In the standard dissipation type, the excess pore pressure gradually dissipates over time after the cone stops penetrating. In contrast, the non-standard dissipation type is characterized by an initial increase in pore pressure until it reaches a maximum value, followed by a decrease to hydrostatic pressure. Additionally, the pore pressure dissipation process in bentonite cutoff walls is recorded and analyzed over various time intervals. Finally, the relationship between hydraulic conductivity and at landfill sites is established based on standard and non-standard dissipation types using CPTU and ABAQUS methods. The method is used for the standard dissipation type, while a modified method is used for the non-standard dissipation type from CPTU and a method is used in the non-standard dissipation type from CPTU. The is the modified value derived from . Cutoff walls made from bentonite materials offer the advantage of enhancing the isolation effects and meeting the design requirement of permeability (1.0 × 10 cm/s).