Portable penetrometer for investigating road surfaces - has separate tripod carrying pile driver and guide for element driven into surface of road

摘要

The portable penetrometer for investigating road surfaces comprises two parts: a tripod (10) carries a pair of collars (17) and (20) which receive a graduated cylinder (24) for guided vertical movement; and a quick member (34) which guides a rod (12) as it is driven vertically into the ground along with an irretrievable member. The cylinder is closed at the bottom and contains a freely vertically movable mass connected to a handle (28) to act as a pile driver. Level adjustors (30) and a bubble gauge (23) are employed to ensure the axis of the tripod is vertical. Similarly level adjustors (35) and bubble gauge (48) are employed to ensure the guide passage afforded by the guide member is also vertical. In use the mass is raised to a reference height in tube (24) and allowed to drop under gravitational force to drive the rod into the ground by increments measured on scale.