CAST-IN-PLACE LARGE DIAMETER PILING METHOD BY CASING ROTATOR IN UNDERWATER ROCK CONDITIONS

摘要

A method for installing a pile having a large diameter on an underwater rock by using a casing rotator is provided to reduce construction costs by mounting various kinds of equipment and reverse circulation drill(RCD) equipment on the upper end of a casing, so that a pile with a large diameter is able to be installed even in the deep sea. A rotator bracket or a file jacket is installed on a barge, and a casing rotator is installed on the rotator bracket or the file jacket. A rotator casing is installed on the casing rotator, and a rock is cut by using the rotator casing. The rock under the rotator casing is crushed by dropping a chisel into the rotator casing after the rotator casing(30) is drawn. The crushed rock is removed by using a hammer grab. A concrete trim pipe is installed into a permanent casing formed with a space bar. Concrete is casted into the permanent casing through the concrete trim pipe, so that the concrete fills an excavation hole to bury a lower end portion of the permanent casing into the concrete. RCD equipment is mounted on the upper portion of the permanent casing so that the RCD equipment passes through the concrete to excavate the rock by a required depth. The casing rotator and the rotator casing are released from the rotator bracket or the file jacket of the barge, and a wire net is inserted into the permanent casing, so that file concrete is casted into the permanent casing. The rotator bracket or the file jacket is released from the barge if the file concrete is grown.