© 2016 Eastern Macedonia and Thrace Institute of Technology.Permeability variations in sandstone make the Three Gorges Reservoir Region (TGRR) vulnerable to frequent landslide disasters in the sandstone slope. In order to characterize the effects of water level variation and excavation unloading on permeability of sandstone in the TGRR, weathered sandstone samples were selected for permeability characteristics tests in three different ways under loading and unloading. The permeability variation of sandstone under different confining and pore water pressures was studied. A concept called unloading quantity of the effective confining pressure (UQECP), was proposed, and its effect on permeability characteristics of sandstone was studied. Results show that the permeability greatly changes at the loading-unloading cycle with the confining pressure of 110 kPa-300 kPa, whereas it tends to be smaller under the confining pressure of 300 kPa-800 kPa. When the UQECP is 60%-85%, the permeability is approximately twice the initial permeability. The permeability ratio rapidly increases and the mutability of the permeability manifests when the UQECP is larger than 85%. When is larger than 85%, special attention should be given to supporting the sandstone slope to prevent future landslides. In addition, the cyclic loading and unloading pore water pressure test reveals a preferable linear relation between the permeability and the pore water pressure. This research provides references for studies on the permeability characteristics of sandstone in the TGRR.
|Number of pages||8|
|Journal||Journal of Engineering Science and Technology Review|
|Publication status||Published - 2016|