Most barrier systems require at least 600mm from the back of the barrier to the batter hinge point (BHP) of a slope to perform as designed and tested. If a barrier had to be closer to this point usually the embedment depth of the post would be extended to compensate for the reduction in soil support on the post.
|Nu-Guard® 31 testing of post in relation to BHP|
|Nu-Guard® 31 post extracted after testing|
As the Nu-Guard® 31 post yields at ground level rather than rotating in the soil (as with traditional guardrail posts), CSP Pacific undertook testing at Opus Research analysing the performance of the post in varying locations away from the BHP to determine if the 600mm could be reduced.
As a result of this testing, CSP Pacific is pleased to announce that the Nu-Guard® 31 steel guardrail system can now be installed as little as 200mm from the BHP, therefore maximising the available road width when installing the barrier.
Please note that to install the Nu-Guard® 31 system up to 200mm from the BHP the soil conditions must be compliant to both of the following NZ Transport Agency specifications:
- TNZ B/2 - Construction of unbound granular pavement layers
- TNZ M/4 - Basecourse aggregate
Where the posts are installed in weak soil conditions a minimum of 600mm of soil between the post and the BHP still applies.