Jersey Barrier Anchoring Advantage 1

[Claudia_C]

Good Morning All,

I am working on a project to place jersey barriers around our above ground pipeline sites to mitigate any risk of impact due to traffic. Most of our sites are located on the side of roads in easements.
I have been doing some research and it appears that to anchor a barrier you have to anchor it to asphalt or concrete.
Has anyone ever anchored a jersey barrier to soil? How was this done and is there any advantages to doing so?

Thank you

 

[BridgeSmith]

Jersey barrier section are typically anchored by steel pins (1" diameter, I think). Embedding the pins in soil would decrease the movement of the barrier very little if it gets impacted. If the expected movement of the barrier under impact is too large, you can pour a concrete footer to pin it to, or create an earth berm behind it to absorb the force and limit the movement. That's assuming you are allowed to make the barrier stiffer; that's not always allowed, as it increases the hazard to the occupants of a vehicle that may impact it.

 

[Claudia_C]

If making the barrier stiffer would increase the hazard to the vehicle occupants, why are some of these barries anchored to the ground?
At the moment i dont know what that movemwnt would be if a car was to strike one of these barriers.

 

[swazimatt]

a lot of the barriers just use their own weight to "fix" them in place. Possibly look at a larger one, there are now those "zipper" ones they use to add/decrease lanes based on peak flow, those are not pinned. I have only ever seen them pinned on bridges

Moveable barrier for improving traffic capacity | Lindsay Infrastructure

Learn why road authorities and contractors have used the flexible, cost-effective Road Zipper system to improve safety and traffic management.

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[Claudia_C]

Thank you. The zipper barrier is very interesting!
We have one valve site where we placed 4-10ft barriers and each barrier is anchored into the soil with 2-4" sch40 pipes roughly 8ft into the ground.

I'm wondering now, if we need to even take this extra step of placing this "anchoring system".

I will need to check for barrier displacement next based on various impact energy i guess.

 

[IRstuff]

You've not said, but much depends on whether the collisions are intentional or accidental

 

[BridgeSmith]

I have only ever seen them pinned on bridges

Generally, they are pinned on bridges because they have to be. There's usually not enough space behind the barrier without creating a hazardous condition for the construction workers or allowing the barrier and vehicle to go over the edge. It's the same reason why guardrails are flexible, but bridge rails are very stiff. the barriers/guardrails are allowed to flex and absorb impact over a larger distance when it's feasible to do so.

Barriers within the clear recovery zone adjacent to public roadways are subject to the requirements established by the owner of the roadway, be it the state, county, or city. If this barrier is going in next to a public roadway, before you get too far into the process, you should check with the owner to verify that you're outside the clear zone, and if you're not, what they will allow you to do within it.

 

[LittleInch]

There's a lot that remains unsaid here.

I suspect each location will need a separate assessment to work out whether it is realistic / risk assessed to see if there could be a head on collision at speed froma car / truck or more likely a glancing blow.

Most pipeline and piping type protection from moving vehicles I've ever seen are the "Armco" type barriers which tend to deflect and absorb some energy whislt then pushing the vehicle back ot the road.

I've also see many pipe type barriers installed, becasue there is a load of spare pipe lying around, so maybe a 6" or 8" pipe buried 3-4ft down encased in and filled in with concrete. They work pretty well.

The jersey barriers are really designed to be temporary and rely more on gravity and surface friction than pinning them down into something.

A lt depends ont he space available so e.g. an earth berm on the station side would help a lot or provide some distance for any collision which did occur.

But in the end there are limits. So e.g. that car that ran into the valve station in Houston and caused a huge fire a few months back - I don't think anyone would have seen this as a risk or that any barriers would have stopped a direct hit from a 2 ton SUV travelling at 50 -60 mph.

but if you've considered other types of barriers and decided these large concrete blocks are the way to go then just dig a small footing and "pin" them to that.

 

[HTURKAK]

Has anyone ever anchored a jersey barrier to soil?

I did not see ..But if this is the final decision , an anchorage system can be developed using helical screw anchor etc. Just curious , can it be an option to use protective berm ? Berming is typical method for protection of above ground pipelines if buried can not be .

Can you post a sketch showing the cross-section of road and relative position of pipelines ?

 

[LittleWheels]

How much space do you have available between the barrier location and the pipeline?

Concrete traffic barriers can be individually pinned to a bridge deck or highway but some can also be linked longitudinally but allowed to slide laterally. By linking them longitudinally, the barriers behave like a heavy chain with longitudinal tension progressively slowing the impacting vehicle without much lateral movement. You have to have a flat enough surface to allow the barrier to slide.

https://jjhooks.com/applications/traffic is one example of a linked concrete barrier system.
I was involved with crash test certification of https://www.ferrostrada-uk.com/steelgard but that system is intended as a retrofit bridge parapet system that needs to be fastened down to a concrete slab or bridge deck.

 

[BridgeSmith]

the barriers behave like a heavy chain with longitudinal tension progressively slowing the impacting vehicle without much lateral movement.

It depends on the impact they have to absorb. For linked, unpinned barriers on highway work, we have to allow space for 9 feet of deflection/movement. For pinned, the expected movement is 9 inches. Alot depends on the expected/allowed vehicles and the design speed of the roadway.

 

[LittleWheels]

Generally, they are pinned on bridges because they have to be. There's usually not enough space behind the barrier without creating a hazardous condition for the construction workers or allowing the barrier and vehicle to go over the edge. It's the same reason why guardrails are flexible, but bridge rails are very stiff. the barriers/guardrails are allowed to flex and absorb impact over a larger distance when it's feasible to do so.

It isn't necessarily a problem if a flexible barrier allows a vehicle to go partially over a bridge edge.

CC, a large part of solving your problem is defining how large a vehicle you are intending to stop, how fast is the vehicle travelling and at what angle does the vehicle impact the barrier.

 

[LittleInch]

littlesmith: CC, a large part of solving your problem is defining how large a vehicle you are intending to stop, how fast is the vehicle travelling and at what angle does the vehicle impact the barrier.

This is the key for sure. So each location needs a different solution. There are quite a few threads on this site over the years on how to build a barrier to stop everything from cars at 10 mph glancing blows to trucks travelling at 50 mph in a head on collision.

I think its AACE or maybe the different DOTs who have good standards on road barriers so no need to reinvent the wheel here.

 

[Claudia_C]

You've not said, but much depends on whether the collisions are intentional or accidental

Accidental.

 

[Claudia_C]

Generally, they are pinned on bridges because they have to be. There's usually not enough space behind the barrier without creating a hazardous condition for the construction workers or allowing the barrier and vehicle to go over the edge. It's the same reason why guardrails are flexible, but bridge rails are very stiff. the barriers/guardrails are allowed to flex and absorb impact over a larger distance when it's feasible to do so.

Barriers within the clear recovery zone adjacent to public roadways are subject to the requirements established by the owner of the roadway, be it the state, county, or city. If this barrier is going in next to a public roadway, before you get too far into the process, you should check with the owner to verify that you're outside the clear zone, and if you're not, what they will allow you to do within it.

Ok good. Point i will check if any of our high risk sites are within any clear zones.

 

[Claudia_C]

There's a lot that remains unsaid here.

I suspect each location will need a separate assessment to work out whether it is realistic / risk assessed to see if there could be a head on collision at speed froma car / truck or more likely a glancing blow.

Most pipeline and piping type protection from moving vehicles I've ever seen are the "Armco" type barriers which tend to deflect and absorb some energy whislt then pushing the vehicle back ot the road.

I've also see many pipe type barriers installed, becasue there is a load of spare pipe lying around, so maybe a 6" or 8" pipe buried 3-4ft down encased in and filled in with concrete. They work pretty well.

The jersey barriers are really designed to be temporary and rely more on gravity and surface friction than pinning them down into something.

A lt depends ont he space available so e.g. an earth berm on the station side would help a lot or provide some distance for any collision which did occur.

But in the end there are limits. So e.g. that car that ran into the valve station in Houston and caused a huge fire a few months back - I don't think anyone would have seen this as a risk or that any barriers would have stopped a direct hit from a 2 ton SUV travelling at 50 -60 mph.

but if you've considered other types of barriers and decided these large concrete blocks are the way to go then just dig a small footing and "pin" them to that.

I'm still in the process of trying to decide what barriers would be the best option. Jersey barriers were considered because I assumed they would be cheaper than the Armco barrier, but I still have to do some comparisons.
We have used the armco barriers, jersey Barriers and bollards in other sites. I guess I still have work to do on which one is best.
I just was not sure if anchoring a jersey barrier with pvc pipe filled with concrete would a) serve any real purpose or b) if this would present any dangers to the people in the vehicles.

 

[Claudia_C]

I did not see ..But if this is the final decision , an anchorage system can be developed using helical screw anchor etc. Just curious , can it be an option to use protective berm ? Berming is typical method for protection of above ground pipelines if buried can not be .

Can you post a sketch showing the cross-section of road and relative position of pipelines ?

I had not thought of using a berm. I can try and get a sketch uploaded. I have about 20 sites at the moment we need to "protect".
I'll choose one out of those.

 

[Claudia_C]

How much space do you have available between the barrier location and the pipeline?

Concrete traffic barriers can be individually pinned to a bridge deck or highway but some can also be linked longitudinally but allowed to slide laterally. By linking them longitudinally, the barriers behave like a heavy chain with longitudinal tension progressively slowing the impacting vehicle without much lateral movement. You have to have a flat enough surface to allow the barrier to slide.

https://jjhooks.com/applications/traffic is one example of a linked concrete barrier system.
I was involved with crash test certification of https://www.ferrostrada-uk.com/steelgard but that system is intended as a retrofit bridge parapet system that needs to be fastened down to a concrete slab or bridge deck.

I want to say we have between 5ft and 7ft. In some cases. Thanks I will look into longitudinally linking them.

 

[Claudia_C]

It depends on the impact they have to absorb. For linked, unpinned barriers on highway work, we have to allow space for 9 feet of deflection/movement. For pinned, the expected movement is 9 inches. Alot depends on the expected/allowed vehicles and the design speed of the roadway.

I believe this is why we anchored the barriers on the valve pen where we deployed them. We anchored barriers with pvc and filled concrete to minimize the deflection. I'll post a sketch to allow for better visualization on the anchoring.

 

[Claudia_C]

It isn't necessarily a problem if a flexible barrier allows a vehicle to go partially over a bridge edge.

CC, a large part of solving your problem is defining how large a vehicle you are intending to stop, how fast is the vehicle travelling and at what angle does the vehicle impact the barrier.

Right. I was going to assume a mid to large size SUV so about 6000lbs, travelling at 60mph, and hitting the barrier at a 30 degree angle. Typically.