Trinity 620005, Assembly Manual

Page: 17 / 42

TrinityHighway.com 16 Revision F November 2021
Important:
A flare rate of 30:1 or flatter is required if the barrier must be flared,
transverse across the median, or if CASS
®
S3 must change in
direction (See Appendix A).
Assembly on a Curve
Horizontal Curve
Complete the following steps to place the posts or post foundations along a curve.
1. When the cable is placed on a curve, post spacing may need to be reduced based on
the radius.
2. Weak soil conditions may necessitate a larger/deeper footing for the line posts, based on
the radius of the curve.
3. When placing posts on a curve, use the table below to adjust the spacing as required:
Curve Radius Post Spacing (NCHRP Report 350) Post Spacing (MASH)
0 to 650’ [0 to 198 m] CASS
®
S3 is not recommended
CASS
®
S3 is not recommended
651’ to 1,300’
[198 m to 396 m]
10’-6” [3.2 m] post spacing or less (as
specified by state/specifying agency)
10’-6” [3.2 m] post spacing or less
(as specified by state/specifying
agency)
Greater than 1,301’
[396 m]
21’ [6.4 m] post spacing or less (as
specified by state/specifying agency)
10’-6” [3.2 m] post spacing or less
(as specified by state/specifying
agency)
Note:
If any of the post spacing for a particular radii grouping is larger than the contract
specifications, use the contract specification post spacing.
Vertical Curve
For a sag vertical curve, the recommended minimum K value is 100’ [30 m]. There is no K
value limit for crest vertical curves.
K= L / (g
1
-g
2
)
L = length of vertical curve in feet [meters) between the two tangents
g
1
= grade of tangent in
g
2
= grade of tangent out
When the minimum sag vertical curve value is not met, the use of intermediate terminals at the
low point of the sag curve is recommended to minimize the cables from rising beyond the
allowable height tolerance relative to grade.
Line Post Foundation Placement
Warning: If the post cannot be placed, pursuant to these assembly
instructions, because of soil conditions, or any other environmental factor,
please contact the appropriate state/specifying agency immediately! NEVER
attempt to place posts if these assembly instructions cannot be complied with.