| 摘要 |
<p>An apparatus comprises a segment has two triangular projections on the center of its both upper and lower face, and four cutted edges of its each corner forming a V-shaped concave when a segment is connected with each other. So, the triangular projections are inserted in the V-shaped concave; PC steel wire or PC steel rod is inserted in both vertical sheath and horizontal sheath of each segment; and jack setting up one way of the connected segment gives a tensional force to PC steel wire or PC steel rod.</p> |
