DEM Study of Wave Propagation in Weak Sandstone

摘要

We are using DEM simulations in conjunction with experimental measurements of artificially cemented laboratory specimens to investigate the effects of small amounts of inter-granular cement on mechanical behavior. With current PC computing capabilities, it is possible to create DEM sample assemblies that faithfully replicate foll three-dimensional laboratory test specimens. The ultimate objective of these studies is to devise procedures to predict the degree of cementation and strength of granular material with applications to wellbore stability, sand production from wellbores and liquefaction. Preliminary work has focused on wave propagation in sands and weakly cemented sandstones using Itasca's PFC Discrete Element Method (DEM) code. We discuss results of our DEM simulations concerning: (1) relationships between micro-mechanical processes and bulk deformation behavior, and (2) stress-induced velocity anisotropy around wellbores.