An important part of a flexible net rockfall catchment fence system is the foundation. Catchment systems have been growing in capacity, able to stop larger and higher energy rockfall events. The trend for foundations has been for them to become larger and more rigid, according to the Association of Geohazard Professionals (AGHP). Members of the AGHP are interested in feedback from owners and engineers experienced in foundation design and their performance in order to synthesize an empirical study of catchment fence foundations and their design. More details can be found at the link below.
The Devil’s Slide Tunnel project is on schedule and on budget according to a news story at ABC7News.com from earlier in June. The video (shown after the break) has a few nice shots showing rock bolting, soil nailing at the portals, and the geologic mapping and laser scanning that happens at the tunnel face.
I also came across a very neat article about how the Ocean Shore Railroad Company was the first to try to cut into the slope along what is now PCH 1 at the Devil’s Slide back in the early 1900s. They were trying to connect the then rural farming community of Half-Moon Bay with San Francisco. The railroad fought the reoccurring landslide and serious rockfalls. Ocean Shore Railroad went bankrupt in 1922 and pulled up its rails, making room for the current highway. (Photo at left from halfmoonbaymemories.com)