Safety Assessment Program Evaluator Student Manual

CA Emergency Mgmt. Agency Safety Assessment Program Evaluator Manual April 2011As stated before in Chapter 2, older concrete tilt-up wall construction has a problem with failureof the roof-wall connection. The older designs allowed the ledger to which the roof was attachedto be split down their length at the through-bolt to the wall in response to lateral forces, resultingin a failed lateral load system. The simplest way to brace these walls temporarily is with steeltilt-up wall braces, similar to those used in the construction of tilt-up walls. If the stabilizationneeds to be done at once, and such braces are not readily available, wood braces can be usedtemporarily, provided that they have the capacity to support the walls.In Figure 3-14, the braces are too slender to support the wall. They were installed tight as well,indicated by the bowing in the braces. Even a moderate aftershock or wind would have thecapacity to load these braces to the failure point. If a SAP evaluator finds a situation like this inthe field, the collapse zone should be barricaded with barricade tape, tagged AREA UNSAFE,and the building department alerted about this hazard.Photo courtesy Global Emergency ManagementFigure 3-15 – Brick veneer failure, 1991 Sierra Madre EarthquakeFigure 3-15 shows a brick veneer that is no longer well attached to the exterior wall, and aneffort to brace it has been done. It would probably be better to simply remove the veneer andstore it for re-attachment later, since the anchorages failed and the brick veneer has to beremoved anyway. Removing the veneer instead of bracing the veneer accomplishes the samething – removal of the potential falling hazard.95