A MULTIPOINT ANCHORING SYSTEM FOR GROUTED TYPE BOREHOLE EXTENSOMETER FOR STRATA MOVEMENT MEASUREMENTS IN UNDERGROUND EXCAVATION

摘要

A multi-point anchoring system has been disclosed which provides point-anchorage to a multi-point borehole extensometer using grouting technique. It essentially consists of an anchor carrying a cement capsule along with it and a device to rupture the capsule at the position of the anchorage. This rupturing of the capsule is done by a pivoted knife and thread pulling system.