Directional Drill Under Narrow Building

[majbacker]

Hi All,

I am the civil engineer on a project where we are installing below grade chilled water distribution pipe for a VA campus. A part of the pipe run needs to be routed below the foundation of an existing enclosed walkway (block walls concrete foundation and roof)the walkway is about 12' wide. I am considering using a directional drill method. Anyone out there spec a HDD under a building? There will be two pipes about 14" in diameter. My main concern is the casing pipe size and the depth below the foundation we would have to go.

Thanks!

Mike Major
Major Engineering

 

[LittleInch]

Its not usual, but the issue is settlement.

You can do settlement calculations for railways who have very exacting requirements and road authorities do the same.

The question then is what is an acceptable settlement? I've no idea.

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