cast in place top base was formed connection groove

摘要

After the rubble fill of this invention is to file a subsequent process connection Drilled top ring and the upper connecting the reinforcement process simplicity and reliability, and workability to be connected is provided a cast-in-place is formed the groove so as to ensure the economic top file. ; This connection site formed in accordance with the groove designed for achieving the above object top placing files with top portion formed at the same time as hollow and formed into a hollow image lights hahyeop; And the file body portion is formed with a predetermined length at the same time, the hollow shape and a hollow portion extending to said top sub; In the top file which is comprised of the files in the file body portion lower end cross-section of the distal end is reduced to form a predetermined angle, characterized by a top portion of the upper surface is connected to a predetermined concave groove formed at a predetermined depth is formed in the top position of the file.