Withstand Earthquakes! — Steel Plate Shear Walls

Steel plate shear walls (SPSW) (a.k.a special plate steel wall) have been used mainly in Japan and North America since the 1970s to reinforce buildings. The SPSW have been used in high-risk seismic region and been considered as a promising alternative to conventional earthquake resisting systems. The SPSW is designed to reduce the lateral force in buildings.

This article is a brief introduction to the Steel Plate Shear Wall systems.

There have been numerous research programs in Japan, USA, and Canada to more understand the SPSW behaviour during earthquakes. However, there are many buildings that have the SPSW as their primary lateral force resisting system. According to Seilie & Hooper, 2005 “Steel Plate Shear Walls: Practical Design and Construction”, some of these buildings are the following:

• United States Federal Courthouse, Seattle, WA — 23-story building (350 ft ≈ 107 m)
• Sylmar Hospital, Los Angeles, CA — six-story building
• Canam-Manac Headquarters Expansion, St. George, Quebec — six-story building
• Hyatt Regency Hotel at Reunion, Dallas, TX — 50-story building (562 ft ≈ 171 m)
• The Century, San Francisco, CA — 46-story building (465 ft ≈ 142 m; the project was cancelled after the completion of design and permit)
• Nippon Steel Building, Tokyo, Japan — 20-story building
• Shinjuku Nomura Building, Tokyo, Japan — 51-story building (693 ft ≈ 211 m)
• Kobe Office Building, Kobe, Japan — 35-story building (425 ft ≈ 130 m)

These walls absorb stress and bend but do not entirely buckle under pressure. In addition, they are significantly thinner than concrete shear walls offering similar levels of resistance and stability, reducing construction costs and lowering total building weight without compromising public safety.

However, there are three different SPSW systems: [1] un-stiffened, thin SPSW, [2] stiffened SPSW, [3] composite concrete SPSW.

For example, the most common research and application in North America is the un-stiffened, thin SPSW. In Japan, the stiffened SPSW system is more common.

Many researchers, since the 1980’s, according to Bruneau et al., “Steel Plate Shear Wall Buildings: Design Requirements and Research”, performed studies of the SPSW considering the design limit state of the system to be out-of-plane buckling of the infill panel. However, several experimental analytical studies using quasi-static and dynamic loading were performed. In addition, many researches on un-stiffened steel plate shear walls has investigated the effect of simple versus rigid beam-to-column connection on the overall behaviour.

Like every system, the SPSW have advantages and disadvantages.

Advantages of the SPSW system:

• Wall Thickness: It allows less structural wall thickness compared to the thickness of concrete shear walls.
• Building Weight: SPSW results in lesser building weight compared to buildings with concrete shear walls.
• Fast Construction: The use of SPSW reduces the construction time.
• Ductility: A relatively thin steel plate has excellent post-buckling capacity (Astaneh & Zhaw, 2002)

Disadvantages of the SPSW system:

• Stiffness: The SPSW systems are usually more flexible compared to the concrete shear walls.
• Construction Sequence: Excessive initial compressive force in the steel plate panel may delay the development of the tension-field action.
• New System: The SPSW system is unfamiliar to contractors, thus they will estimate a relatively high construction cost. This may be solved by engaging the contractor early in the design phase.

In addition, the SPSW systems have two distinct configurations:

• SPSW core systems are best suited for medium- to high-rise buildings.
• Multiple planar SPSW are most suitable for low-rise buildings and also for rehabilitating existing buildings.

Finally, after the usage of SPSW systems as a primary lateral force resisting system in buildings, their good performance in major earthquakes, and the robust performance in laboratories concludes that the SPSW systems are here to stay.