IN-PLACE REINFORCED CONCRETE EXPANDED BOTTOM FOUNDATION PILE AND ITS CONSTRUCTION AND BIT THEREFORE

摘要

PURPOSE:To permit the construction of an expanded bottom foundation pile free of the lowering of strength in a good yield by forming the shape of the foundation pile into a staged shape in which the diameter of the pile is made smaller toward its lower part. CONSTITUTION:During the construction work, a horizontal force-acting pit P1 is excavated down to a depth where a horizontal force acts by using a drilling bucket with a given diameter, and then the pit is further excavated down to a design depth by using a small-diameter drilling bucket for excavating a shaft part P2. Then, the expanded bottom P3 is cleaned and subjected to a slime- removing treatment, and then a custom-made iron bar cage 10 is erected and also an air lift slime treatment is made. Afterwards, fresh concrete 12 is continuously placed and hardened, and the pit is embedded with excavated good quality soil and sand to construct a foundation pile.