Theoretical analysis of vacuum preloading combined with short and long PVDs

A new analytical model is proposed to analyze the vacuum consolidation combined with the short PVDs installed within the dredged marine clay layer among the long PVDs installed within the entire clay layer. The predictions from the proposed model align well with both field test results and literature data. Parametric studies were carried out to examine key factors affecting the Degree of Consolidation (DoC). It is found that the insertion of short PVDs among the long PVDs can effectively enhance the consolidation efficiency of the entire stratum. The DoC of the vacuum consolidation decreases when the value of R_e/r_w increases from 12 to 24. With the decrease in the value of load increment ratio P_u/σ′₀, the disparities in curves of DoC become progressively more pronounced. However, this effect is not obvious in the DoC versus consolidation time curves of the soil with a lower compression index. The severity of clogging intensifying in the clogging zone or the higher the magnitudes of τ and a lower value of β induce a lower permeability coefficient of the clogging zone and thus a gradual reduction of the DoC curves.