Nguyen, Ba-Phu
Consolidation and load transfer characteristics of soft ground improved by combined PVD-SC column method considering finite discharge capacity of PVDs - Vol.53(1), Feb - USA Springer 2023 - 127-138p.
Prefabricated vertical drains (PVDs) can be installed with soil cement (SC) columns to enhance the efficiency of soft soil improvement. In this combined method, PVDs are first installed and then SC columns are established between the PVDs; this enables a larger spacing between SC columns resulting in a lower construction cost. As an embankment load is applied on composite foundation, time-dependent behavior occurs in the soft soil due to consolidation according to the radial flow toward PVDs, while the corresponding stress transfer takes place between the SC columns and the soft soil. This paper develops an axisymmetric finite element model to analyze the consolidation and stress transfer behaviors of composite foundation, in which an equivalent permeability of subsoil is proposed considering the effects of finite discharge capacity of PVDs. The developed model is applied to an embankment located in China to estimate the settlement of soft ground improved by the combined method. Subsequently, the current numerical model is applied to investigate consolidation characteristics and the stress transfer mechanism of composite foundation. The results show that the consolidation of soils can cause significant effects on the stress transfer process and the stress concentration ratio of the composite ground. The stress concentration mobilizes with the depth over time and stabilizes around the middle of the treated soil when the consolidation time exceeds 50 days. The magnitude of drain discharge capacity also contributes significantly to mobilizing stress concentration in the composite foundation.
Civil Engineering
Consolidation and load transfer characteristics of soft ground improved by combined PVD-SC column method considering finite discharge capacity of PVDs - Vol.53(1), Feb - USA Springer 2023 - 127-138p.
Prefabricated vertical drains (PVDs) can be installed with soil cement (SC) columns to enhance the efficiency of soft soil improvement. In this combined method, PVDs are first installed and then SC columns are established between the PVDs; this enables a larger spacing between SC columns resulting in a lower construction cost. As an embankment load is applied on composite foundation, time-dependent behavior occurs in the soft soil due to consolidation according to the radial flow toward PVDs, while the corresponding stress transfer takes place between the SC columns and the soft soil. This paper develops an axisymmetric finite element model to analyze the consolidation and stress transfer behaviors of composite foundation, in which an equivalent permeability of subsoil is proposed considering the effects of finite discharge capacity of PVDs. The developed model is applied to an embankment located in China to estimate the settlement of soft ground improved by the combined method. Subsequently, the current numerical model is applied to investigate consolidation characteristics and the stress transfer mechanism of composite foundation. The results show that the consolidation of soils can cause significant effects on the stress transfer process and the stress concentration ratio of the composite ground. The stress concentration mobilizes with the depth over time and stabilizes around the middle of the treated soil when the consolidation time exceeds 50 days. The magnitude of drain discharge capacity also contributes significantly to mobilizing stress concentration in the composite foundation.
Civil Engineering