| 摘要 |
PURPOSE:To drive piles so that pile heads are located in a specified level, by a method wherein the discharge pressure of a ground improving material, being applied on the inside of a casing during lifting of the casing, is set to a value about proportioning the volume of the improving material poured in the casing. CONSTITUTION:When, with a casing 2 rotated, the casing is lowered down to a given depth, after rotation of the casing 2 is stopped, a ground improving material, such as quicklime is poured through a hopper 5, and through measurement of the weight by means of a load cell 41, a given amount of the improving material is poured in the casing 2. A shoe 3 is opened, and the casing 2 is lifted up as it is reversed to form a quicklime pile in a ground. In which case, a pipe length L0-L1, being a depth L0 of the casing less a pile head level L1, is computed by a processor 20 to determine a discharge pressure P1, and thereafter, ON and OFF of first and second electromagnetic valves 36 and 38 is controlled so that a discharge pressure is controlled to P1. |
