| 摘要 |
PURPOSE:To increase the bearing force of a pile by a method in which a head provided with an excavating blade to be expanded slantly upwards against the resistance of soil to be excavated is attached to an auger, the auger is penetrated into a pile pit to form an expanded portion at the pile bottom, and cement mortar is injected. CONSTITUTION:An earth auger 2 is inserted into a pile 1, an excavating blade 4 attached through a pin 8 to the auger head 3 is expanded by normal rotation, and the pile 1 is settled to the supporting ground by excavation and oil moving. The auger 3, also, is turned reversely and the excavating blade 4 is closed. The auger 2 is pulled up to the ground surface and the auger head is exchanged with a large-diameter head 3. Under the condition that the excavating blade 4 is closed, the head 3 is expanded into the hole of the pile 1 and the auger 2 is normally turned, whereupon the excavating blade 4 is expanded to excavate expansively the ground to form an excavated portion 5'. Cement mortar 6 is injected through the shaft hole of the auger 2 from the tip port 7 and the auger 2 is pulled up while being turned reversely to form an expanded cement mortar foundation 6'. |
