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# 2305.3.7.2 Perforated Shear Walls

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Where

The provisions of Section 2305.3.7.2 shall be permitted to be used for the design of perforated shear walls.

The following limitations shall apply to the use of Section 2305.3.7.2:

1. A perforated shear wall segment shall be located at each end of a perforated shear wall. Openings shall be permitted to occur beyond the ends of the perforated shear wall; however, the width of such openings shall not be included in the width of the perforated shear wall.

2. The allowable shear set forth in Table 2306.4.1 shall not exceed 490 plf (7150 N/m).

3. Where out-of-plane offsets occur, portions of the wall on each side of the offset shall be considered as separate perforated shear walls.

4. Collectors for shear transfer shall be provided through the full length of the perforated shear wall.

5. A perforated shear wall shall have uniform top of wall and bottom of wall elevations. Perforated shear walls not having uniform elevations shall be designed by other methods.

6. Perforated shear wall height,

*h*, shall not exceed 20 feet (6096 mm). The resistance of a perforated shear wall shall be calculated in accordance with the following:

1. The percent of full-height sheathing shall be calculated as the sum of the widths of perforated shear wall segments divided by the total width of the perforated shear wall including openings.

2. The maximum opening height shall be taken as the maximum opening clear height. Where areas above and below an opening remain unsheathed, the height of opening shall be defined as the height of the wall.

3. The adjusted shear resistance shall be calculated by multiplying the unadjusted shear resistance by the shear resistance adjustment factors of Table 2305.3.7.2. For intermediate percentages of full-height sheathing, the values in Table 2305.3.7.2 are permitted to be interpolated.

4. The perforated shear wall resistance shall be equal to the adjusted shear resistance times the sum of the widths of the perforated shear wall segments.

Design of perforated shear wall anchorage and load path shall conform to the requirements of Sections 2305.3.7.2.4 through 2305.3.7.2.8, or shall be calculated using principles of mechanics. Except as modified by these sections, wall framing, sheathing, sheathing attachment and fastener schedules shall conform to the requirements of Section 2305.2.4 and Table 2306.4.1.

Anchorage for uplift forces due to overturning shall be provided at each end of the perforated shear wall. The uplift anchorage shall conform to the requirements of Section 2305.3.6 except that for each story the minimum tension chord uplift force, T, shall be calculated in accordance with the following:

**(Equation 23-3)**

T |
= | Tension chord uplift force, pounds (N). |

V |
= | Shear force in perforated shear wall, pounds (N). |

h |
= | Shear wall height, feet (mm). |

C_{o} |
= | Shear resistance adjustment factor from Table 2305.3.7.2. |

ΣL_{i} |
= |
Sum of widths of perforated shear wall segments, feet (mm). |

The unit shear force,

*v*, transmitted into the top of a perforated shear wall, out of the base of the perforated shear wall at full-height sheathing and into collectors (drag struts) connecting shear wall segments, shall be calculated in accordance with the following:**(Equation 23-3)**

Where | ||
---|---|---|

ν |
= | Unit shear force, pounds per lineal feet (N/m). |

V |
= | Shear force in perforated shear wall, pounds(N). |

C_{o} |
= | Shear resistance adjustment factor from Table 2305.3.7.2. |

ΣL_{i} |
= | Sum of widths of perforated shear wall segments, feet (mm). |

In addition to the requirements of Section 2305.3.7.2.4, perforated shear wall bottom plates at full-height sheathing shall be anchored for a uniform uplift force,

*t*, equal to the unit shear force,*v*, determined in Section 2305.3.7.2.5.Each end of each perforated shear wall segment shall be designed for a compression chord force,

*C*, equal to the tension chord uplift force,*T*, calculated in Section 2305.3.7.2.4.A load path to the foundation shall be provided for each uplift force,

*T*and*t*, for each shear force,*V*and*v*, and for each compression chord force,*C*. Elements resisting shear wall forces contributed by multiple stories shall be designed for the sum of forces contributed by each story.The controlling deflection of a blocked shear wall with openings uniformly nailed throughout shall be taken as the maximum individual deflection of the shear wall segments calculated in accordance with Section 2305.3.2, divided by the appropriate shear resistance adjustment factors of Table 2305.3.7.2.