Table 3-5 Recommended Tornado Missile Barriers for Performance Category 4

DOE-STD-1020-2002

the plank and pipe are uncoupled and should not be combined. The third missile is a 3000-lb

automobile that is assumed to roll and tumble along the ground at speeds up to 25 mph. Table

3-5 lists wall barrier configurations that have been tested and successfully resisted the timber

and pipe missile. Impact of the automobile can cause excessive structural response to SSCs.

Impact analyses should be performed to determine specific effects. In structures, collapse of

columns, walls or frames may lead to further progressive collapse. Procedures for structural

response calculations for automobile impacts is given in References 3-9, 3-10 and 3-11.

Although wind pressure, APC, and missile impact loads can occur simultaneously, the missile

impact loads can be treated independently for design and evaluation purposes. These are

minimum missile design criteria and should be reviewed for upgrading with the concurrent use

of new tornado hazard assessment methodology (Reference 3-14).

Table 3-5 Recommended Tornado Missile Barriers

for Performance Category 4

Missile Criteria

Recommended Missile Barrier

Horizontal Component:

2x4 timber plank

6 in. concrete slab with #4 rebar @ 6 in. on center each way in middle of

15 lb @ 150 mph

slab

max. height 200 ft.

8-in. CMU wall with one #4 rebar grouted in each vertical cell and horizontal

above ground

trussed joint reinforced @ 16 in. on center

Vertical Component:

2x4 timber plank

4 in. concrete slab with #3 rebar @ 6 in. on center each way in middle of

15 lb @ 100 mph

slab

Horizontal Component:

10-in. concrete slab with #4 rebar @ 12 in. on center each way placed 1.5

3-in. diameter

in. from each face

steel pipe 75 lb

@ 75 mph

max. height 100 ft.

above ground

Vertical Component:

3-in. diameter steel pipe 75 lb

8-in. concrete slab with #4 rebar @ 8 in. on center each way placed 1.5

@ 50 mph

in. from inside face

3-12