A Method for Bridging Two Types of Partial Drainage Boundary Parameters in Soil Consolidation

ABSTRACT The time‐dependent partial drainage boundary condition expressed in exponential form (named TDB model) has attracted the attention of many researchers due to its simply form and the ease of obtaining analytical solutions. The drainage parameter in this model is pivotal, but many previous studies have not adequately scrutinized its definition. This study proposed an algorithm that yields explicit formulas to describe this parameter for the consolidation in both saturated and unsaturated soils. More importantly, this approach establishes a clear relationship with the well‐recognized partial drainage boundary derived from the impeded‐layer hypothesis (the ILB model), which has an explicit physical interpretation. The results of ILB model are employed to calibrate the time‐dependent boundary (TDB) drainage parameter in the entire consolidation period. To facilitate the practical application of the calibrated TDB drainage parameter, a genetic programing approach was adopted to derive explicit formulas that describe its behavior. In contrast to the conventional definition of the TDB drainage parameter, the calculated results using the proposed model agree well with that of the ILB model and with measurements from real cases. The results indicate that assigning a constant value to the TDB drainage parameter is not reasonable. This parameter also varies with consolidation time.