In Seismic Design Category C, what is the maximum spacing for vertical reinforcement in masonry shear walls?

In Seismic Design Category C, what is the maximum spacing for vertical reinforcement in masonry shear walls?

• A. 6 feet
• B. 8 feet
• C. 10 feet
• D. 12 feet

Answer: (C)

In seismic design of masonry shear walls, vertical reinforcement spacing is controlled to ensure the wall can develop adequate strength and ductility under lateral loads. Vertical bars help carry tension and keep the wall from cracking into uncontrolled modes, so keeping them reasonably close ensures cracks are intercepted and the wall acts as a coordinated system rather than a series of independent blocks. For Seismic Design Category C, the maximum spacing for vertical reinforcement is ten feet. This limit keeps segments between vertical bars short enough to effectively transfer shear and bending demands, maintaining stiffness and preventing large, uncontrolled cracks during an earthquake. If the spacing were larger, portions of the wall could lack sufficient reinforcement to engage properly, reducing shear strength and ductility. Smaller spacings, like six or eight feet, are more conservative and would still meet the requirement, while a twelve-foot spacing would exceed the category C limit and could compromise performance. The ten-foot limit reflects the level of seismic risk in Category C and the need for a practical, constructible reinforcement layout that still provides reliable seismic resistance.

In seismic design of masonry shear walls, vertical reinforcement spacing is controlled to ensure the wall can develop adequate strength and ductility under lateral loads. Vertical bars help carry tension and keep the wall from cracking into uncontrolled modes, so keeping them reasonably close ensures cracks are intercepted and the wall acts as a coordinated system rather than a series of independent blocks.

For Seismic Design Category C, the maximum spacing for vertical reinforcement is ten feet. This limit keeps segments between vertical bars short enough to effectively transfer shear and bending demands, maintaining stiffness and preventing large, uncontrolled cracks during an earthquake. If the spacing were larger, portions of the wall could lack sufficient reinforcement to engage properly, reducing shear strength and ductility.

Smaller spacings, like six or eight feet, are more conservative and would still meet the requirement, while a twelve-foot spacing would exceed the category C limit and could compromise performance. The ten-foot limit reflects the level of seismic risk in Category C and the need for a practical, constructible reinforcement layout that still provides reliable seismic resistance.