For a wind farm near Lawton, OK, many of the foundations consist of rock sockets 19 feet in diameter, 20 feet deep. The rock was blasted to presplit the holes and facilitate excavation. The bedrock in the area was so shallow that blasting was needed to construct the access roads, removing the high spots and providing material to fill in the low. In areas where the bedrock was deeper, spread footings were used. [Source: National Driller. Image: National Driller]
Recently, URETEK ICR was asked to review a project involving lifting and stabilization of 10 precast transformer pads at a wind farm located in South Dakota.
The pads had settled to varying degrees with 8 of the 10 having settled 1 (±0.5) inch and requiring only stabilization and the two remaining, with settlement in excess of 3.5 inches, requiring lift and stabilization.
[Editor] Click through for more on this interesting project by GeoPrac.net sponsor, URETEK ICR! [/Editor]
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"The blasting will be to excavate a platform for construction, about 40 feet wide and will look similar to a road cut through a hill," [Corps Project Manager Linda Adcock] said. "Just the nature of how we grout, and moving equipment back and forth on the current slopes, which are as much as 40 percent and greater, is just really difficult. So for these reasons, for safety, quality, the accuracy and the consistency of the drill holes are much better done from a platform, they proposed this road cut type of a platform."
The drilling is for grouting remediation of the dam foundation. Story from Herald-Citizen, Cookeville, Tennessee.
Urban miners have been busy constructing a new water supply tunnel underneath New York City to supply the megalopolis with the water it needs. The miners, or sandhogs as they are known, are about halfway complete with the new tunnel which is expected to be in service by the year 2020. Work on the 60-mile tunnel began in 1970 and the total projected cost is $6 billion and is widely regarded as one of the most complex public works projects in the western hemisphere. When complete, it will help deliver 1.2 billion gallons DAILY to 8 million New Yorkers. The city currently gets its drinking water from two water supply tunnels that were constructed in the early 20th century and have not been inspected or repaired since then. More after the break. (Image credit History.com)
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