(a) Three within triangular ties
(b) Four within rectangular or circular ties
(a) For tied columns, where ties throughout the lap splice length have an effective area not less than 0.0015hs in both directions, lap splice length shall be permitted to be multiplied by 0.83. Tie legs perpendicular to dimension h shall be considered in calculating effective area.
Table 10.7.5.2.2—Tension lap splice class
|Tensile bar stress||Splice details||Splice type|
|≤ 0.5fy||≤ 50% bars spliced at any section and lap splices on adjacent bars staggered by at least ℓd||Class A|
|> 0.5fy||All cases||Class B|
|Framing at column end||Extension requirements|
|Beams or brackets frame into all sides of the column||Extend to the level of the lowest horizontal reinforcement in members supported above.|
|Beams or brackets do not frame into all sides of the column||Extend to the level of the lowest horizontal reinforcement in members supported above. |
Additional column ties shall extend above termination of spiral to bottom of slab, drop panel, or shear cap.
|Columns with capitals||Extend to the level at which the diameter or width of capital is twice that of the column.|