In arch roof construction, where is the secondary safe place located?

In arch roof construction, the secondary safe place is located in the side walls of the building. This choice is correct because the curved shape of an arch roof distributes loads differently compared to flat or pitched roofs. The side walls typically provide structural support for the arch and maintain stability. In the event of a collapse or failure of the roof, the side walls can serve as a safer location for individuals who may be inside the building, as they are less likely to be directly impacted by falling debris from above.

The other locations, such as the top of the roof or the center of the building, present risks due to their proximity to potential falling materials or structural failures. Being near the entrance may offer a quick escape route, but it is not inherently safer due to the risks associated with the roof's structure. Therefore, the side walls are identified as a strategic point of safety in the context of arch roof construction.