Equipment: Astec® DD3238 and a StraightLine® 4″ Air Hammer System.
Ground conditions: First 90 feet consisted of dirt and rocks smaller than 3-feet, the last 100-feet was solid granite.
Project: Water service requiring a minimum 3-foot of cover that totaled 190′ in length. Over the course of the bore the elevation rose 40-feet. Entered the granite at a minus 3% slope, in and out of rock for the first 90-feet, then encountered solid granite for the last 100′, engaged the hammer and powdered the rock, exited the bore at a plus 27% slope.
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