View of failed Baltimore retaining wall before soldier pile wall construction
Project Related

Hayward Baker Constructs Temporary Emergency Earth Retention for Landslide Repairs Near Train Tracks in Baltimore

Hayward Baker was among the contractors called in for emergency repairs to a failed retaining wall in Baltimore that destabilized a slope, causing a landslide that enveloped cars and threatened a railroad track below. The […]

Devil's slide repair of PCH 1 using
Geologic Hazards

Devil’s Slide Repair and Tunnel Bypass Presentation

Devil's slide repair of PCH 1 using [Updated Thursday May 29, 2009 – 1:00 PM PDT] Added a photo of the AIS Kaiser S2 excavator (spider excavator), and added photos of the Devil’s Slide debris dump where they have put the landslide material removed and the material from the tunnel excavation. [/Update]

Grant Wilcox, Geology Branch Chief with CALTRANS Office of Geotechnical Design West gave a presentation on the Devil’s Slide repair along PCH Highway 1 at the Southwest Geotechnical Engineer’s Conference on May 12 in Phoenix. I’ve posted about the project here before. When I saw Mr. Wilcox, I knew he looked familiar but I couldn’t figure out why. At the beginning of his presentation he made light of his being on You-Tube…then it clicked! He gave a nice overview of the history of the failures, the geology, and the tunnel project. What follows are a few quick tidbits from his talk based on my notes. (Photo via Caltrans site).


Anchored landslide in Japan
Geologic Hazards

Landslide Mitigation Examples in Japan

A couple of weeks ago the Landslides Under a Microscope blog had two nice posts about Landslide Mitigation examples in Japan. The author references the book “Landslides in Japan” (1996), but I’m not sure if […]


Cologne Tunnel Collapse: Investigations Focus on Tiebacks and Groundwater

image The latest information to come out of the collapse of a subway tunnel excavation in Cologne, Germany is that investigators are evaluating the ground anchors or tiebacks that were holding open the subway tunnel excavation. There doesn’t appear to be much information available to the public yet, and the New Civil Engineer article mostly quoted academics saying an anchor failure “could” have caused the collapse. Apparently at the time of the collapse, the excavation had reached the bottom depth after the slurry walls had been constructed along with the ground anchor system. Crews were supposedly working on the base slab which would have undoubtedly stiffened up the whole system. For what its worth, an anonymous comment left at the bottom of that article indicated that after half of the debris had been excavated, the diaphragm walls were still intact and without apparent displacement. So what other theories have been floated? Read on for more info.  (Image Credit: New Civil Engineer)