Stochastic compressibility for land subsidence modeling
M. Ferronato, G. Gambolati, P. Teatini
Dept. Mathematical Methods and Models for Scientific
Applications, University of Padova, Padova, Italy
D. Bau'
Dept. Geological and Mining Engineering and Sciences, Michigan Technological
University, Houghton, Michigan, USA
ABSTRACT
Numerical models for predicting land subsidence due to fluid
withdrawal require the correct eval-uation of representative
mechanical properties of the deforming porous medium. One such
property is the vertical uniaxial compressibility cM
which is obtained through either lab oedometer tests or in situ
measurements, and typically exhibits a marked scattering.
The present communication addresses the influence of the
cM uncertainty for the predicted land
settlement using a stochastic approach where cM
is regarded as a random variable. A compressibility law,
characterized by a log-normal distribution with depth-dependent
mean and constant variance, is implemented into a Finite Element
poroelastic model and used in a preliminary study based on the
Monte Carlo method. The results show how the cM
variance affects the reliability of the expected land
subsidence and point out the impact of the cM
uncertainty on the quality of prediction.
