When a sinkhole opened up in Pennsylvania State Route 422 in 2019, Gannett Fleming partnered with PennDOT to accelerate investigation and design and ensure the roadway was fixed and reopened to the public as quickly as possible. The solution was a rather involved micropile supported reinforced concrete slab. The depth of the micropiles extended as deep as 180 feet to tag into competent bedrock. Gannett Fleming’s newsletter, Forces of Change, describes more about the project. One cool thing is that you can watch a time lapse video of virtually the entire construction process. Check it out.
On June 11, 2002, a 150-foot wide and 60-foot deep sinkhole opened up in Pine Hills, Florida and came within a few feet of two 3-story appartment buildings. Geotechnical and Environmental Consultants (GEC) was contacted by the owner of the site to design emergency temporary and permanent stabilization measures to protect the buildings. The sinkhole mitigation began with a chemical stabilization of the soil using an injected sodium silicate chemical grout (incidentally, that work was performed by John N. Puder, Inc., recently acquired by Moretrench) to stabilize the sands underneath the buildings and adjacent to the sinkhole. After some GPR surveys, borings and other investigations, final sinkhole repair consisted of a 200-foot long wall omprised of interlocked 36-inch diameter steel tubular piles that extended to a depth of 50 feet. They were driven by Giken America Corp. using the press-in method which helped to avoid damage to the adjacent buildings. The entire stabilization was completed within 1-month of the initial sinkhole collapse! Click through for this fascinating video. (Photo credit Giken America Corp. by way of GEC)
A colleague of mine (thanks Jamie!) sent me an email with this intriguing title. I have no idea where it originated, but it is an interesting compilation of some amazing photos and short descriptions of various natural and man-made "holes". A few sinkholes, glory holes, and of course open pit mines. By the way I didn’t write (or edit) this, just some minor formatting updates. Check it out.
My colleague at DBA, Robert has posted some new photos for this interesting project involving micropiles supported piers, rock bearing footings at the abutments augmented with rock anchors, and rock bolted slopes. Scroll down for […]