Numerical model of natural compaction in isothermal sedimentary basins
G. Gambolati, G. Giunta, P. Teatini
Dept. Mathematical Methods and Models for Scientific
Applications, University of Padova, Padova, Italy
ABSTRACT
We develop a mathematical model to analyze the compaction driven by
unsteady groundwater flow in an isothermal sedimentary basin.
We assume a process of continuous vertical sedimentation and derive a
1-D model of flow where water flow obeys relative Darcy's law in a
porous medium which undergoes a continuous compaction under the effect
of an increasing load of the overburden.
The time interval spanned by the model can be million of years and soil
porosity, permeability and compressibility may vary with the effective intergranular
stress according to empirically based constitutive relationships.
The model takes into account the non-linearity which arises from the
consideration of solid grain movement and is solved using both the Eulerian
and the Lagrangian approach.
Preliminary results from the 1-D non-linear compaction model are
provided and compared with the results from the linear model
of Bredehoeft and Hanshaw (1968) which neglects the medium compaction.
