Borehole extension measurement with continuous indication - using cable attached to extensometer tube and driving chart recorder pen

摘要

An arrangement for continuous recording and display of the axial expansion of boreholes (1) and sections of boreholes is partic. applicable for mountain safety e.g in prediction of landslides. It uses some conventional components and has extensometer rods (3), tubes etc. arranged inside the boreholes. A cable (5) is attached at one end to the measurement rod (3) at a point inside the borehole and away from its mouth where the cable passes over a roller (4). The other end of the cable passes to a measurement arrangement (8) contg. a strip recorder (13). The strip recorder pen (12) is a worm shaft on a transfer shaft (10) forming part of a roller (11) carrying the cable (5) and tensioned by a spring motor. The measurement arrangement (8) is detachably mounted on a frame fixed to a solid base (22).