{"id":8258,"date":"2020-07-20T10:41:47","date_gmt":"2020-07-20T00:41:47","guid":{"rendered":"https:\/\/sigra.com.au\/?page_id=8258"},"modified":"2023-04-04T15:08:04","modified_gmt":"2023-04-04T05:08:04","slug":"stress-change-monitoring","status":"publish","type":"page","link":"https:\/\/sigra.com.au\/sigra-services\/geotechnical-engineering-geomechanics\/rock\/stress-measurement-in-rock\/stress-change-monitoring\/","title":{"rendered":"Stress Change Monitoring"},"content":{"rendered":"
[vc_row][vc_column width=”4\/5″][vc_column_text]Sigra has the capability to measure stress change. This can be by installing and monitoring surface or near-surface strain gauges, or by cementing stress change cells in boreholes. The cementing process can be accomplished at great depth. Sigra has supplied and installed equipment to measure stress changes associated with dewatering and degassing of coal seams, and to monitor the changing stresses around a fault in a longwall.<\/p>\n
Both these installations used a stress change cell cemented at several hundred metres depth in a vertical borehole. The cementitious grout used in the installation expands following its initial set so as to pre-load the stress change cells and permits it to measure stress relaxation.<\/p>\n
Normally stress change devices would be installed in a hole where the initial state of stress has been determined by a stress measurement such as that through the Sigra IST system.<\/p>\n
The stress change installations take three forms: uniaxial, biaxial+axial, and fully triaxial.<\/p>\n