2013
Left hand canyon flood
The Challenge
In September 2013 Left Hand Creek experience a major flash flood event which created massive debris flows down Left Hand Canyon and caused rapid and extensive realignment of the creek channel north of Boulder. In some locations, the channel relocated thousands of feet to one side or the other – carving away the earth, structures, machinery, and livestock, in between. DRS was immediately called in to help shore structures which had been precariously undermined. Little time was available to gather geotechnical information and design specific repairs – time was of the essence.
DRS mobilized crews to the area with a variety of geotechnical support systems and an open mind. Debris of all sorts obstructed the work area so we worked in tandem with several fantastic excavators who provided rapid access to the work areas with our limited access geotechnical equipment proving to be the ideal solution to get into final position for underpinning.
Our Solution
Upon initial survey of the work areas it became obvious that buried cobbles would be our biggest challenge. Helicals would have been nice for rapid shoring but they weren’t the right solution to this cobble laden challenge – although the objective was rapid shoring, we wanted our shoring to become the permanent solution if possible.
We new bedrock was rather shallow, and we wanted any system employed to bear in the bedrock. We elected to get our limited access drills out and got to work installing Micropiles where we had confidence the structure was stable enough to allow grout curing time and Atlas Resistance Piles in the most precarious situations which required immediate support. These systems provided a rapid and permanent solution to saving the lifetime investment of these owners.