Devil’s Slide Tunnel Update and First Attempts to Tame the Landslide
Geologic Hazards
Soledad Mountain Road Landslide Update
Residents of approximately 75 of the 111 homes evacuated after the slide have been allowed back into their homes. The City of San Diego is not wasting any time in determining the cause of the slide. The first of three 100-ft deep exploration shafts was excavated on Friday, and a Forensic Geologist from a firm hired by the City was sent down the hole to observe geology conditions and to locate the actual slip surface. Also, claims of leaking City water and/or sewer pipes prior to the failure have begun to surface. More details in the full post. (Photo by NELVIN CEPEDA / San Diego Union-Tribune)
Geologic Hazards
Devil’s Slide Tunnel Construction Kicks Off
On September 17, CALTRANS and Kiewit Pacific held a "tunnel excavation celebration" to kick off the start of tunnel construction on The Devil’s Slide Tunnels project on California State Route 1 (the Pacific Coast Highway) in San Mateo County between the town of Montara to the south and the city of Pacifica to the north. The project involves the creation of a separated two-lane road, one lane in each direction. This road will pass through twin tunnels, over twin bridges and connect with an existing non-separated two-lane road at each end. The new road will be approximately 6,500 feet long, made up of the roughly 4,000-foot twin tunnels, the 1,500-foot north approach road (which includes the 1000-foot parallel bridges), and the 1,000-foot south approach road. Upon completion, the new road will bypass geologically unstable portions of existing Route 1, sections of roadway subject to lengthy closures, high maintenance costs over the years, and risk of permanent failure. Thanks Geology.com for the heads up. [Read on for more background, photos, maps, and movies!] (Images by CALTRANS)
Project Related
Foundations for California Highway 1 Pitkins Curve Bridge
On the Big Sur coatline, the Pitkins Curve area of California Highway 1 (the PCH) is undergoing some improvements to help alleviate landslides and roadway instability. National Driller magazine reports on the project in their […]