The GAP rail-trail is 150 miles of hiking and biking between Cumberland, Md, and Pittsburgh, Pa. created along the former railway line. In Cumberland, the GAP joins the C&O Canal Towpath, creating a continuous 335-mile long trail experience all the way to Washington, DC. It’s become a favorite biking destination for people from around the Mid-Atlantic states. One of its main tunnels, the Pinkerton Tunnel, an 849-foot former Western Maryland Railway tunnel, has been closed since 1975 due to erosion and unstable conditions. The Allegheny Trail Alliance, the organization that built and now maintains the 150-mile GAP, and the Somerset County Rails-to-Trails Association (SCRTA), wanted the tunnel reopened and helped fund the project.
[Editor] Click through for the rest of the press release from GeoPrac sponsor, NCFI Polyurethanes (makers of TerraThane). [/Editor]
The New York MTA's East Side Access Tunnel Project is what I would refer to as a 'Mega Project'. Any time you're in the Billions of dollars range, I'd say that qualifies, and this one sits at $10.2 Billion! When completed, this project will at long last bring Long Island Rail Road trains to Grand Central Terminal. The photos by The Gothamist are worth spending a few minutes looking at. [Source: Check out the Photos at The Gothamist via @GannettFleming. Image: Jake Dobkin / Gothamist]
The Bertha TBM creating the Alaska Way Viaduct Replacement Tunnel and the Seattle Tunnel Partners JV just can't seem to catch a break. After being stopped for nearly 2 years to replace the entire cutterhead and make other repairs, Bertha finally began tunneling again just before Christmas on December 23. The machine had tunneled about 100 feet as of January 13 when there was a problem with a barge that was transporting excavated material from the tunneling. It began listing from an uneven load, was released from it's moorings to avoid damaging the conveyor system, and spilled (supposedly uncontaminated) soil in Elliot Bay. The barge then impacted two piers, it didn't sound like the damage was significant.
Just a few hours after the barge incident, a sinkhole opened up in between the repair pit and the TBM location. On January 14, WSDOT notified Seattle Tunnel Partners that the tunneling was suspended "for cause" pending a safety review. Even the governor of Washington weighed in on the issue. The sinkhole has been filled with concrete now. The concern by critics is the obvious question of what will happen if there is ground loss like this under the viaduct, or underneath downtown Seattle. If you recall, the project included jet grouting beneath the viaduct, so that should help reduce the risk there, and STP has said that once Bertha dives deeper, the risk of sinkholes will reduce. It sounds like the long hiatus had cause them to be a little complacent about the monitoring of the material coming from tunneling. Normally there is a very careful accounting of all the material that is excavated to predict when there is a ground loss risk. I don't think that will happen again! [Source: Read or watch the Washington Governor rail on the tunneling safety. Image: Seattle PI]
The Geoprofessional Business Association has released a new guide document on the In-House Review of Geoprofessional Reports. The document has information for report writers and reviewers with a 'focus on a reportâ€™s ability to satisfy the contractual obligations it was intended to fulfill; the quality of its technical and risk-management content; and the clarity of presentation.' Read more at the link below. As with most GBA documents, it is free for GBA member firms. [Source: Geoprofessional Business Association. Image: GBA]
There are two notable geotechnical engineers among the recipients of the 2016 ASCE Opal Outstanding Projects and Leaders awards. Rudolph Bonaparte, Ph.D., P.E., D.GE, F.ASCE, NAE, the president and CEO of Geosyntec, will receive the award for design. Jerry A. DiMaggio, P.E., D.GE, M.ASCE, will receive the award for government for his many years of service as the FHWA's lead geotechnical engineer. [Source: Read more about the award and bios for the recipients at the ASCE Roundup Blog. Image: ASCE Roundup]
This is an awesome limited access foundation project from Crux Subsurface! They designed and installed micropile foundations for new steel tubular towers to replace old steel latice structures. The high altitude (about 10,000 feet) meant limited construction season window, and challenges with the size of helicopter needed for loads. They also provided an innovative steel cap design to the micropiles, thereby avoiding the need to bring in additional concrete and rebar for a traditional micropile cap. Check out the excellent video below. [Source: Read more about the project at Crux Subsurface. Image: Crux]
I gave a presentation recently on a monthly webinar for URETEK Holdings, one of the licensed affiliates (installers) of products by GeoPrac sponsor, URETEK ICR. The topic was Geotechnial Aspects of Polyurethane Grouting. I gave my perspective on some of the benefits of polyurethane grouting, the challenges in geotechnical characterization of the improvements to the soil after grouting, and some unique applications of the technology people are currently using and could potentially use in the future. If you have time to check it out, let me know your thoughts!
GeoPrac sponsor Moretrench is a specialty geotechnical contractor known for their expertise with a variety of geotechnical construction methods. But they are probably best known for their niche work with ground freezing technology. Popular Mechanics Magazine recently did a story on Moretrench's ground freezing work at the Washington D.C. First Street Tunnels project. The ground freezing allowed three vertical access shafts and four deep adits to be excavated in the dry using the frozen ground support. [Source: Read more abot this interesting technology and project from Moretrench. Image: Moretrench]
The 2015 Karl Terzaghi award was presented by Donald A. Bruce, Ph.D., D.GE, C.Eng., L.G., L.E.G., President, Geosystems, L.P. at the Geo-Institute's 2015 Geo-Congress Conference. The Geo-Institute has generously made his lecture available to all of us on their YouTube Channel, so be sure and subscribe. From his abstract:
In historic literature, there is the "Great Man" theory, whereby history is reflected in the biographies of preeminent characters. In the more theoretical and academic branches of specialty geotechnical engineering, the theory holds true, with, of course, Professor Terzaghi one of the heroic great men â€“ a researcher, problem solver, and inspiration sans pareil. In contrast, in the branch of specialty geotechnical construction, technological advances occur principally through "Great Leaps" as opposed to steady and progressive evolution.
Six criteria must be satisfied in support of awarding "Great Leap" status, beginning with a project-specific challenge of unprecedented scope or complexity, and ending with a legacy document detailing and codifying the leap. These steps are illustrated by reference to developments in drilling and grouting; cutoffs for dams; deep mixing; and micropiles, all techniques in which the author has been intimately involved throughout his professional career as a researcher, contractor, educator, and consultant.
Here are the top 50 GeoPrac content items of the year based on your clicks. They are sorted by hits/day to not bias the items published towards the beginning of the year. Thanks to all of my visitors for spending some of your valuable time getting your news from GeoPrac. I know everyone is busy, so I appreciate it very much!
You know how it feels good to clean off your desk and have a fresh start? I've collected a number of articles over the past 6 months that I didn't get a chance to blog about. As we move rapidly towards 2016, I wanted to start with a clean slate. There are certainly some gems in here! Hopefully you have some time off over the holidays, and maybe you check this list twice with a drink in hand!