| 摘要 |
PURPOSE:To enable to take a direct reading of an insertion distance of a rod, by a method wherein, in a dynamic earth insertion tester which drives a rod into a ground by dropping a hammer from a given drop height, an insertion rod and division of a fixed rule are separately located. CONSTITUTION:If a hammer 10 is dropped under its own weight from a position of a pin 11 and is brought into a collision with a knocking head 9, an insertion rod 7 is inserted into a ground, and a ring 19 is lowered by the insertion distance. Then, a slide rule 20 is temporarily fastened to a guide pole 12 on the upper surface of the ring 19 at each strike, and thereby, the slide rule 20 stays in a position where it is located before the ring 19 is lowered. Thus, an equal division on the left side of the slide rule 20 indicates the insertion distance of the rod 7 inserted by an one-time strike or the degree of softness. A reciprocal division 27 on the right side of the slide rule 20 indicates an Nx value which is obtained by multiplying the reciprocal value of the division 26 which a reference value X, and this permits to take a direct reading of the number of strike times, or the degree of hardness, required to drive it by the distance of the reference value X. |
