7.4 Light Industrial Buildings

Light industrial buildings are used through out the United States for offices, light manufacturing, laboratories, warehouses, and other commercial purposes. Typically, these buildings are low-rise buildings three to five stories high, often using tilt-up concrete construction. Typically, they are located in industrial or commercial complexes and may have significant setbacks from public streets. They are serviced by surface parking lots or parking structures outside the building. Security may vary widely depending on the use of the building. For a building used for laboratories or manufacturing, there may be already be significant security measures at the perimeter and inside the building. For office buildings, security may be light to negligible.

The main focus of this section is on light industrial buildings that house office space, because these are the buildings with potentially high populations, and therefore, life safety is a primary concern. For warehouses and manufacturing plants, the primary objective is more likely to be protection of the contents and processes. For laboratories, the primary objectives are to prevent release or deflagration of hazardous materials and to protect processes.

Office parks inherently have an open character with medium-to-large setbacks from the street and public parking. In this environment, the most effective way to protect the building from moving vehicle threats is to use landscaping methods between public streets and parking to prevent the intrusion of vehicles. Devices such as ponds, fountains, berms, and ditches can be very effective in reducing the accessibility of the building exterior to high-speed vehicles.

Parking should be placed as far as practical from the building. Driveways leading directly to the building entrance should have a meandering path from the public streets that does not permit high velocities to be achieved. Separation between the driveway and building may be achieved through a number of devices such as a pond with a bridge leading to the entrance, a knee wall with foliage in front, or other landscape features.

The design of parking structures servicing these buildings should fulfill two main objectives to prevent explosions in the parking structure from seriously damaging the main office building. The first is to control the lines of sight between the parking structure and the building to limit air-blast effects on the building. One solution is to use a solid wall that is bermed and landscaped on the side of the parking structure facing the building. Second, design the parking structure to withstand the designlevel explosion without structural failure in order to reduce the potential for debris from a parking structure failure damaging the office building. This second objective can be achieved while still allowing the parking structure to sustain significant levels of damage.

For the tilt-up walls, use continuous vertical reinforcement with staggered splices, preferably on both sides of the wall to resist large lateral loads. It may be advantageous to consider designs that permit the wall to bear against floor diaphragms to resist loads. Connections between the walls and structural frame should be able to accept large rebound forces to prevent the wall from being pulled off the exterior. Care should be taken to prevent the wall from bearing directly against exterior columns to limit the opportunity for progressive collapse. Using laminated glass on the exterior reduces the potential for laceration injuries. For the roof, a concrete slab with or without decking is preferred over a solution using metal decking only.