Bollards 2

[ajk1]

I recently came across a case of 4 bollards placed around a light standard in a parking lot, where a car had driven too close to one of the bollards and the bollard became embedded behind the fender. This happened because the fender flexed when the car brushed against it, allowing the bollard to become trapped behind the fender (just in front of the front wheel) and not allowing the car then to move forward or backward. The bollards were short and glavanized (silver in colour). The incident happened at night. Thousands of dollars damage was done (to the vehicle's wheel mechanism, and the body too of course).

The original architectural design of the protection to the lamp standard when the bulding was built in the 1960's was with wood posts and horizontal wood bumpers spanning between the posts, at the top of the posts. This seems like a much better design than what was done by a contractor in a repaving project about 10 years ago, and would have prevented the recent incident.

I have searched the provincial building code and it does not turn up the word "bollard". None of the references to "guards" are for a bollard type of guard.

Question:

Is there any guide to good bollard design anywhere?

- If the bollard had been higher, it would not have been able to get behind the fender; it would have caused body damage but not the extensive mechanical damage that it did to the wheel linkage etc.

- If it has been painted yellow, it would have been more visible.

- If it had horizontal wood bumpers between the bollards at their top (like the original design by an architect), the bollard could not have become embedded behind the fender.

 

[SlideRuleEra]

See this thread:

http://www.eng-tips.com/viewthread.cfm?qid=131273

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[JedClampett]

I think the people asking for bollard designs are not too worried about damaging the vehicle. Their concern is the protection of the stuff behind the bollard. In their mind, if you hit the bollard, you should have been more careful. Now they don't want to make bollards so unforgiving that if you hit one, you're dead, but beyond that it's your problem.
As far as wood, there's preservatives or paint, or both. The wood posts rot and have to be replaced. It's a maintenance issue.

 

[BAretired]

Don't know if there is a code requirement, but I believe a bollard should be at least one meter high.

http://ezisecurity.com.au/products/security-gates/bollards/

BA

 

[EEJaime]

ajk1,

I don't know of any specific code requirements. I do know that our electrical utility companies have published standard designs for their minimum requirements to protect their above ground structures and equipment. This is in the US, so I don't know that it would necessarily apply to your situation. Their standard design is for a 30" embedment in an 18"diameter footing with the same 30" extension above finished surface. This would be for incidental traffic and not for heavier equipment. The bollards we used at a recent airport project to protect our equipment against aircraft tugs, baggage tugs and maintenance and fueling vehicles were rigid steel pipes of 12" diameter in a 30" diameter base embedded 48" below grade and extending up 42" above finished paving. So as stated by others, the parameters will change depending on the expected loads, vehicle speeds, etc.... And if a vehicle impacts one, and is severely damaged, but the protected item is safe, we would consider that a "win" for the system.

You are correct that they are more effective in a yellow or yellow/black stripe configuration for added visability. We've even used reflective paint or tape systems in some cases.

Good luck and regards,
EEJaime

 

[Ron]

ajk1...Bollards are guards...subject to the same requirements as guardrails...42 inches high or at least as BAretired noted...1m

 

[dhengr]

Ajk1:
And, who’s side are you on? If you hadn’t been seeing how close you could come to the light pole, there wouldn’t have been a problem either. I assume this happened while backing out and they swung the wheel well right over the bollard top and got it stuck btwn. the tire, the sheet metal and the head light. And, if the bollards were not there, you might be paying to replace their entire light pole. Now we should design for max. world wide wheel well opening height, plus 6". Alternatively, we could install flashing neon lights on the bollards. Or, put a 6' high fence outside the bollards.

 

[XR250]

IMHO, they should be tall enough to be easily seen - which is about 6 ft. in todays visibility challenged vehicles.
I have hit a low bollard in my truck because it was invisible from my driving position

 

[ajk1]

Thanks everyone for the mostly helpful comments. Much appreciated.

ExcelEngineering - I think you expressed it very well when you described "today's visibly challenged vehicles". That is certainly part of the problem, as Consumer Reports notes in their auto ratings.

dhengr - You ask whcih side I am on. I am on no side, except the side of good thoughtful design which anticipates and adresses problems(as did the original architectural design). Isn't that what engineering/architecture is to a large extent about? Sounds like you have never made an error while driving and damaged your car. Bless you. But if you ever do, I think you will appreciate that whatever you impacted was designed with at least some care to minimze the damage to your vehicle. I guess that you are not in favour of energy absorbing bumpers either, as their only purpose is to minimize damage when a mistake is made.

Good design was the original guard protection designed by the architect for this site in the mid-1960's, but discarded by a paving contractor when he repaved the lot about 10 years ago and put in the current bollards. I would have thought that if it is possible to design a bollard that protects the light pole AND also prevents the type of mechanical damage to the vehicle that I described, then that is a superior engineering/architectural design.


As for the issue of wood rotting, if cedar is used it will last a good long time (in this case the original wood lasted 40 years and was still serviceable). In our corrosive chloride environment in Toronto, galvanized steel will eventually corrode through and needs to be replaced and I am very doubtful that it would last 40 years.

I will have to check the bollard height when the snow melts, and let you know.

Thanks for the good suggestions and comments about bollard design and visibility, particularly BA Retired, EEJaime, SlideRuleera and ExcelEngineering.

 

[racookpe1978]

If you have snow problems, you HAVE to make them higher enough, and in enough of a contrasting color to be visible THROUGH the haze, dirt, snow, ice, windshield muck and ice and condensation to be visible.

Visible to the car driver backing up AND going forward AND to the snow truck driver! The snow truck will be working from higher above, but will be "packing" snow around the bollard location, so "fender high" in summer is going to be "invisible high" in mid-winter.

 

[ajk1]

racookpe1978 (Nuclear) - I would agree with you completely, seems a sensible approach, but it is interesting from at least one response here that not all engineers agree. I am going to see how high the bollard is, and from how far away the driver of a car has to be from the it to be able to see it. What happened was that the driver made a last moment decision to proceed to another parking spot closer to the building entrance due to the extreme cold (minus 20 deg. C), and could not see the bollard at that point because he was so near to it.

 

[CANPRO]

ajk1, I think dhengr's comment was just a little Friday afternoon humor...seemed like your were asking this question for a "friend" of yours.

Regarding the bollards....I guess it depends on the mindset of the owner. If the owner of the light post wants to protect his property and doesn't give a sh!t about the cars hitting the bollard, well then I guess this incident was mission accomplished...1 less car to threaten the light post.

I do agree with you though, the bollard should provide protection while causing minimal damage to the car.

 

[SteelPE]

I always thought that bollards were there to help protect the structure....but not of sufficient design to stop a vehicle from actually hitting the structure. I always tell my clients that bollards are there to let people know they hit something w/o hitting the actual thing you are trying to protect (usually from someone backing up etc). I've been in a car where someone actually hit a light pole in a parking lot during a snow storm. He just wasn't pay attention to what he was doing, threw his car in reverse and smashed into the light pole. Luckily, nothing happened but a bollard there would have been nice to protect the pole and let him know he was doing something he shouldn't have.

 

[Archie264]

There are such things as anti-ram bollards for security purposes but they are of specific things.

 

[FEM4Structures]

Some of the answers can be found in following references. Not sure abt your jurisdiction but I am sure your state of practice will have following similar stipulations.

Reference: 2010 Fire Code of NYS
Section 2703.9.3 – Protection from Vehicles >>describes the importance of providing bollards to protect storage tanks, pipings, fittings and such apprentices.


Section 312 – Vehicle Impact Protection
312.1 General
312.2 Posts: Guard posts shall comply with all of the following requirements.
1. Constructed of steel not less than 4 inches (102 mm) in diameter and concrete filled.
2. Spaced not more than 4 feet (1219 mm) between posts on center.
3. Set not less than 3 feet (914 mm) deep in concrete footing of not less than 15 in (381 mm) diameter.
4. Set with the top of the posts not less than 3 feet (914 mm) above round.
5. Located not less than 3 feet (914 mm) from the protected object.

312.3 Other barriers. Physical barriers shall be minimum of 36 inches (914mm) in height and shall resist a force of 12,000 pounds (53,375N) applied 36 inches (914 mm) above the adjacent ground surface.


Let me know if this helps?


Thanks,

FEM4Structures

 

[ajk1]

CANEIT (Structural)- Thanks for your comments. Since the parking lot is at a place of worship, I would have hoped that the owner cared about causing needless damage and heartache...but the truth is there was no formal design or spec for the repaving project and the contractor lacked knowledge of bollards. It is annoying that the original design in 1966 by an old-time architect (he graduated in the 1920's when engineering and architecture were in the same faculty) was near perfect. Why did they change the design when repaving 10 years ago? My rule is don't fix what aint broke, and don't change a design that has had no problems with it, unless there is a compelling reason to do so. Shows that architects do (or did) fulfill a usful role.

SteelPE (Structural)- interesting. I think people backing at high speed into something is not all that uncommon, given the dreadful visiblity in today's cars, and the need for back-up cameras nowadays. But that was not the case in the situation that I am describing, which was very low speed, and driving forward.

Archie264 (Structural)- I am not quite sure what you are referring to. Are you referring to anti-terrorist barriers?

FEM4Structures (Structural) - this is really good information. I live in Ontario. I am not sure our fire Code covers these sort of items but I will check. Thanks again for this very useful information. Much appreciated.

 

[Archie264]

ajk1,

Yes, my reference was to anti-terrorists barriers. They come in various configurations, including bollards. But, these bollards aren't just posts in the ground placed with a bag of sac-crete; there are specific designs for them which have been tested for their capacity to resist impact. If that's what you're looking for a quick google search should point you in the right direction. Suffice it to say that they tend to be more robustly constructed than simple loading dock bollards and the like.

 

[ajk1]

Archie264 (Structural)- yes I know something about them. About 10 years ago I was involved with specifying them and worked closely with a least one manufacturer of them...but then the issue died out and they were nevwe installed!

 

[JLNJ]

Highway guardrail is just 31" high (32" posts, 31" @ the rail). Maybe that's all the higher it should be. Any more is just to aid visibility if so desired.

 

[ajk1]

JLNJ (Structural) - yes, and similarly with vehicle guards around the perimeter of parking garages. BUT in these cases there is a continuos horizontal member between the posts, so there is no possibility of a single post (or bollard) becoming lodged behind the car fender, as happened with single bollard.