PROPULSION CONSTRUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To facilitate surfacing of a propulsion guide body to a specified position by placing heavy material around a specific surfacing position of the ground surface in a surfacing process of a propulsion construction method. SOLUTION: A path shown by a broken line from an end point A2 of a horizontal crossing process reaching a spot A2 from a spot A1 is made a predetermined track of a surfacing process up to a specific spot X of the ground surface. When annular heavy material 40 with the flat bottom face is placed in the form of surrounding the spot X on the ground surface, downward pressure F is applied to the ground surface through the bottom face. This pressure F has an effect of controlling in the direction of heightening earth pressure around the spot X so as to make it easy for a guide body 2a to come out around the center of an opening part 44 provided at the center of the heavy material 40 avoiding an area of the pressure F applied from the heavy material 40. The guide body 2a is thereby guided to the vicinity of the ground surface spot X.