Homogenization of spatially variable hydraulic conductivity in the presence of a geotechnical structure
Journal
Computers and Geotechnics
Journal Volume
156
Start Page
105255
ISSN
0266352X
Date Issued
2023-04
Author(s)
Abstract
This paper proposes a novel homogenization method for spatially variable hydraulic conductivity (k). The main novelty is that it can characterize the effective hydraulic conductivity “felt” by a geotechnical structure for steady state flow problems, whereas the prevailing homogenization method does not address the existence of a geotechnical structure or complex boundary conditions. An engineer can apply this relatively simple method to determine a characteristic value that is consistent with both physics and spatial variability. The proposed method is based on a weighted geometric average (GA) with weight proportional to the degree of mobilization, which can be approximately determined at a modest cost using a single deterministic finite element analysis. Monte Carlo simulation of a flow problem in a spatially variable medium requires costly repeated runs of a random finite element analysis. Based on the results from numerical examples, it is shown that the proposed method is superior to the prevailing homogenization method based on uniform GA when a geotechnical structure or complex flow boundaries are present. The proposed method reduces to the prevailing method for an example where there is no geotechnical structure. The applicability of the proposed method is verified by a real pumping test case study.
Subjects
Effective hydraulic conductivity
Homogenization
Spatial variability
Steady state seepage
Weighted geometric average
Publisher
Elsevier Ltd
Type
journal article