Donor: French Society for Soil Mechanics and Geotechnical Engineering (CFMS)
The removable extensometer is a test apparatus design for in-situ pile testing. It was mostly developed by LCPC former French public works institute. The extensometer is composed of several metallic strips (such as the one presented) assembled in a measuring chain with inflatable a blocking device at each strip extremity. During a test, the chain is placed in a sonic inspection tube. Blocking devices are inflated to solidarize the chain to the tube. Therefore during the test, pile deformation can be measured by measuring average strip strain with strain gauge.