(2) From Table A-2, the section properties for

the post are:

Figure A-4 has 10 spans and has a change of direc-

tion at both ends. Both the toprail and posts are

38-mm, schedule 40 pipe, from 6061 T6 Aluminum.

The posts are spaced at 1.2 m on center and are

welded to a round aluminum plate with a 15 cm

diameter (*d *= 11.4 cm). The plate is attached to a

(3) Determine the load proportion factor *P*f

concrete surface via four symmetrically spaced

based on the relative stiffness *R*:

10-mm-diam wedge-type concrete anchors. The

manufacturer-specified pullout strength for the

anchors is 18.2 kN per anchor (including the safety

factor). Determine whether the guardrail system

can safely withstand the USACE-specified 890-N

(200-lb) horizontal concentrated loading.

(69 103 MPa)(129,000 mm 4)(1,040 mm)

(69 103 MPa)(129,000 mm 4)(1,220 m)

0.85

From curve "L" of Figure A-1, *P*f = 0.53

(4) Calculate the applied moment:

(890 N) (1,040 mm) (0.53)

491,000 N

mm

(5) Compare applied stress to allowable stress:

491,000 N mm

5,340 mm 3

97 MPa) ⇒ *Good*

92 MPa < (*f*allow

the guardrail system should be carefully inspected

for deterioration as described in paragraph A-2*b*.

(1) Calculate the applied moment:

For this example, it will be assumed that the guard-

rail system is in good condition and thus no reduc-

tions will be made to the allowable stresses or

(890 N)(1,220 mm)

section properties.

5

5

217,000 N

mm

(1) From Table A-1, the allowable stress for

Aluminum 6061 T6 pipe within 25 mm (1 in.) of a

weld (Refer to footnote in Table A-1) is:

A-8