ALL CASING TYPE EXCAVATING METHOD AND DEVICE

PURPOSE: To enhance the easiness in works by grounding a middle excavating device unloading the tension of a hand-down wire rope, extending a gripper in the radial direction, and fixing the middle excavating device to the inner surface of the bottom of a casing tube. CONSTITUTION: A middle excavating device 3 is hung down into a casing tube 4 using a crawler crane etc. When the device 3 reaches the bottom of the tube 4 and the tension of a wire rope 13 is unloaded, a gripper 5 is expanded so that the inner surface of the tube 4 is pressed. Then the excavating device 3 is consolidated with the tube 4 and the ground is excavated by the torque and thrust force of a full-revolutional boring machine. The earth and sand are taken into a bucket in the device 3. and when it is filled, the gripper 5 is slackened, and the device 3 is separated from the tube 4 and carried to outside the pit by crane. Thus the discharge of the earth and sand is conducted. Thereby the middle excavation can be executed with no generation of noise or vibration, and handling can be made very easily only by the use of wire rope, and the execution of the works can be done without being significantly influenced by water present in the pit or the depth thereof.