Narrow Trench Pavement Replacement

[Dredger01]

I've got a project that requires installing about 160-ft of 3/4" gas line across a heavy vehicle maintenance yard (thick section 8" PCC, #4 12" OCEW).

The gas line will be a 2-ft bury, and I am considering the minimum width of trench for saw cutting and replacement of the paving.

Many details I've found recommend a 4-ft minimum width, with 1-ft overlap each side of the trench. I think this increased width is to have the replacement concrete act as a panel.

As a value engineering, would anyone recommend a 2-ft wide trench cut. I wonder if practically they could drill in dowels to the adjacent concrete (#4@12" O.C.) with such a narrow trench? I think compacted 3/4" gravel as trench backfill and subgrade would be appropriate rather than flowable fill.

Any thoughts?

 

[oldestguy]

I'd go wider, maybe 4 feet and limit trench bottom width, depending on excavator available. I'd want sloping sides of the trench so there is less chance of losing support for adjacent slabs. Of course it depends on subgrade material. In running sand, maybe go even wider. If a narrow trencher is used, there still is a good chance the sides will be loose, so sloping sides would be better.

 

[MotorCity]

I would look into directional drilling/boring and avoid open cut completely.

 

[cvg]

this is typically a "T" type trench. your trench can be any width that is constructable with your soil conditions and your equipment, preferably as narrow as possible, but pavement repair is usually wider.