Abstract:

Aimed at the land-subsidence cased by groundwater exploitation in Quaternary loose sediments, based on Biot’s consolidation theory, took the shallow groundwater exploitation in Wujiang as the case study, a three dimensional full coupling numerical model between the hydraulic action of the seepage field and the stress field was established, in which Duncan-Chang non-linear model and the dynamic models of permeability were introduced with considering the non-linear characteristics and the dynamic variation of hydraulic conductivity of soils with stress. Based on identification and verification of the model, with the constraint condition that the groundwater level would not be lower than half of the roof depth of the first confined aquifer and the land-subsidence wound not exceed 50 mm, the allowable exploitable quantity of groundwater in every town was predicted, the exploitable quantity of groundwater is 1 203.59×10⁴m³/a in the whole area.

Key words: Biot consolidation theory, land-subsidence, three dimensional full coupling model, non-linear, groundwater, exploitation