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Bollards can be an amenity.

By: Tom Davis Category: Sidewalk Features

Preface: This will be the first in a short series of posts about bollards used in a revitalized street scape.

BollardsMainCommerce.jpg

To state the obvious, bollards are meant to protect whatever is behind them; usually from cars. Therefore, one must assume they will be hit. Often designers put the “look” at a much higher priority than the ability to replace them when they are hit. That brings up the need to design them to be repaired or replaced.

For this first post on bollards we will look at those at Main St. and Commerce St. (map) That intersection was completely rebuilt when the light-rail train system was installed on Main. The photo here shows you the west side looking north across Commerce St. The LRT is in the center of Main St. and goes up the bridge over Buffalo Bayou adjacent to the car in the background of the photo. Across Main from the photographer’s position is a new educational building of the UH Downtown and many students cross Main and Commerce to go to the main building over the bridge.

This is a great design from a pedestrian and accessibility point of view as there are no curbs–hence, the reason for the bollards. As the bollards are to provide the same service as the curbs and keep cars in the street away from pedestrians they must be substantial. The bollards in the photo are the top ends of a 24″-diameter drill pier extending deep into the ground. So far they have stopped vehicles.

The vehicles that wandered did not leave the scene unscathed and the bollard was broken at the ground and/or the top shattered. But, the remains was nothing money could not fix. A contractor bid on the cost to remove the broken concrete, save as much rebar stubs as possible, drill in and epoxy-grout new dowels; place a sonotube form with the attractive large reveal and pour back the bollard. That process was just completed to three of them in the photo as a driver coming over the bridge hit them.

These bollards are attractive and substantial but not cheap. A future issue will be that once they have been hit and repaired several times we will have a concrete stub at the ground level with no places for new epoxied dowels to anchor the replacement top section. Then we will likely have to core in a larger section as the coring machine can cut into the epoxy and broken rebar from past repairs. It is only money but nice things cost.

Lesson Learned – Plan for many repairs, how they will be accomplished and the cost. Those issues can be mitigated if the columns are very visible like these–but they will still be hit.

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