H-20 Traffic Rated Vault Grate
H-20 Traffic Rated Vault Grate
(OP)
Everyone,
This may be a shot in the dark but here it goes. I have an existing 4 ft x 8 ft x 12 ft deep existing concrete vault (appears poured in place). At the top of the vault there is a steel frame supporting 4 ft long I-Beams (about 6" deep) at 13" on center. These beams support 4 solid plates (grates) serving as the cover to this vault. The plates are flushed with existing ground and are to be flushed with the proposed pavement for a new parking lot been proposed.
The proposed parking lot will have approximately 75 spaces and expected low traffic volume (don't know exaclty how many trips are generated by the faclity but for the moment is expected to be low). The existing vault will lie directly on one of the parking lot's travel lanes.
Now the contractor is been asked to replace the frame and grate for one that is traffic rated. However is there a way to show that something existing would be H-20 traffic rated? There are no logos or part numbers that appear on the existing frame and grate system.
Your thoughts/suggestions would be appreciated. Thanks.
This may be a shot in the dark but here it goes. I have an existing 4 ft x 8 ft x 12 ft deep existing concrete vault (appears poured in place). At the top of the vault there is a steel frame supporting 4 ft long I-Beams (about 6" deep) at 13" on center. These beams support 4 solid plates (grates) serving as the cover to this vault. The plates are flushed with existing ground and are to be flushed with the proposed pavement for a new parking lot been proposed.
The proposed parking lot will have approximately 75 spaces and expected low traffic volume (don't know exaclty how many trips are generated by the faclity but for the moment is expected to be low). The existing vault will lie directly on one of the parking lot's travel lanes.
Now the contractor is been asked to replace the frame and grate for one that is traffic rated. However is there a way to show that something existing would be H-20 traffic rated? There are no logos or part numbers that appear on the existing frame and grate system.
Your thoughts/suggestions would be appreciated. Thanks.





RE: H-20 Traffic Rated Vault Grate
RE: H-20 Traffic Rated Vault Grate
Without knowing the details of how the concrete was constructed, it would be difficult to have an engineer certify the design.
It would probably be easier to replace than have it certified.
RE: H-20 Traffic Rated Vault Grate
In doing some research I did notice some manufacturers to show that their products (lids, grates, etc) are H-20 rated and then they say for "...ocassional traffic impact...". Is there a limit to how much traffic is allowed on an H-20 rated product? Is there a higher rating than H-20?
RE: H-20 Traffic Rated Vault Grate
My work is primarily in NYC; we use HS-25 for bridge design but the sewer department accepts 16K gratings.
In your case, it doesn't seem that it would take very long to analyze a 6" beam.
RE: H-20 Traffic Rated Vault Grate
RE: H-20 Traffic Rated Vault Grate
RE: H-20 Traffic Rated Vault Grate
The first (link) is a design criteria for heavy duty bar grate from Ohio Gratings, Inc.
The second (PDF) is a standard detail sheet from the State of New York, DOT.
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