Influence of pore pressure variation on sandstone behaviour and its contribution to subsidence and strata behaviour interpretation in the Collie Basin

Summary

This project investigated the variation in the mechanical characteristics of saturated, included sandstone aquifers in the Collie Coal Basin as they were dewatered.

The methodology adopted consisted of simulating the assumed in-situ conditions on triaxially confined, saturated laboratory specimens that had been prepared from in-situ core samples.

Dewatering was simulated by pore pressure release followed by vertical water flow induction through the specimen.

The tests required the design and commissioning of modified triaxial test equipment and the development of a modified triaxial test technique.

The report describes the equipment and test techniques, and gives an analysis and interpretation of the results.

Keywords: sandstone, aquifer, pore pressure, dewatering, triaxial, subsidence