These are the problems that substandard drainage structures cause. These problems pose imminent danger to the public, and are less expensively fixed before they surface. Depending on the depth of the pipe and the soils around it, these voids may have existed underground for decades before surfacing, or for just a few hours.
Sinkhole-like depression in sidewalk
Sinkhole barely noticeable under sidewalk
Cracking in sidewalk due to void in substrate caused by infiltration into pipe
Sinkhole we fixed (along with the problem that caused it) for NCDOT @ I-40 in Raleigh
Sinkhole in Mount Pleasant, SC at Rivertowne Golf Club grew to this size because the golf course kept covering up the problem with dirt, while the cause of the problem worsened until the sinkholes weren't small
Cracking in asphalt in line with pipe
Sinkhole we repaired for SCDOT @ I-26 outside Columbia
Seemingly bottomless sinkhole in Asheville with pipe buried 40'
A series of sinkholes like this appeared beside the green
One of the greenside sinkholes that alerted everyone involved to the problem.
Infiltration at joints causing sinkholes on surface.
Sinkhole caused by infiltration at joints.
Patch in asphalt above pipes where infiltration had created depressions