Sheffield Dam, Liquefaction Failure, from 1925 Santa Barbara Earthquake
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Dam Failures in May (Any Year)
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Dam Failures in April (Any Year)
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The Los Frailes tailings dam (Aznalcóllar, Spain) was a tailings storage dam. The failure type has been categorized as a foundation sliding failure (or loss of bearing, which then initiated sliding). The weakest part of the foundation was comprised of blue marl (clay and approximately 25% carbonate – CaCO3).
Heavy Equipment Icons
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What are some iconic types of Heavy Equipment in the industry?
D10 Dozer – Operating Weight: 154,700 lbs (Caterpillar)
772 Off Highway Truck (Caterpillar)
Gross Operating Weight: 181,000 lbs, Payload: 50 tons, Heaped: 41 cu. yd.
992 Wheel Loader – Bucket Capacity: 14 to 16 cu. yd. (Caterpillar)
Construction Equipment | Construction Industry Product Information
Design Earthquakes – Definitions
For Concrete Structures: OBE (operational basis earthquake) = 144-yr Return Period (50 percent chance of being exceeded in 100 years).
Max. Design EQ: for Structures Defined As Critical use MCE, In general for other structures, MDE = 950-yr return period (10 percent chance of being exceeded in 100 years).
MCE is defined as the greatest earthquake that can reasonable be expected to be generated by a specific source (which comes from a deterministic site hazard analysis).
USACE references: Stability Analysis of Concrete Structures, Earthquake Design and Evaluation of Concrete Hydraulic Structures, Earthquake Design and Evaluation for CW Projects. Safety of Dams – Policies and Procedures.
Dams Under State Jurisdiction – CAL DSOD
Dams that fall under State jurisdiction are subject to: Statutes and Regulations Pertaining to Supervision of Dams and Reservoirsby the California Division of Safety of Dams (DSOD). Dam height (in feet) is measured from the downstream toe to the maximum storage elevation/spillway. Storage capacity is in the units of acre-feet.
1 foot (ft) = 0.3048 meters (m), 1 acre-foot (ac-ft) = 1233.5 cubic meters (m^3)
Dam Failures in March – St. Francis Dam Disaster
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St Francis Dam Failure, 12 March 1928. Failed catastrophically upon its first full filling, near midnight, killing at least 450 people. Seepage (dirty water) was observed the day of the failure. A massive landslide occurred in the dams left abutment, comprised of schist.
“Greatest American civil engineering failure in the 20th century.”
Historical Society of Southern California: St. Francis Dam Disaster.
Excellent Photo Display at: St. Francis Dam collapse – Framework – Photos and Video – Visual Storytelling from the Los Angeles Times.
Type: Concrete Gravity Thick Arch Dam, Maximum Height = 195 feet, Storage (at time of failure) = 38,000 acre-feet
Dam Failures in February
PLEASE Add to the Blog of Dam Disasters that Occurred in February (any year). Join the community of knowledge and contribute. Enter Your Own Personal Observations. Share pictures you might have of the site during the incident. It’s Valuable Information for Everyone. Thank You.
LOWER SAN FERNANDO DAM FAILURE, 9 FEBRUARY 1971, LOS ANGELES, CA. Due to Liquefaction and the Magnitude 6.7 San Fernando Earthquake of 1971.
New Dams In Construction – Calaveras Dam, San Francisco Bay Area
Construction began in 2011. A zoned earth and rock fill dam that is 220 feet high.
Two ancient landslides were discovered during excavation in 2012, but was not found in pre-construction geotechnical investigations. An additional 3.5 million cu yds of excavation was required to remove the landslide materials.
Workers (bottom right) place explosives deep into the ground to… Photo-4514415.60874 – SFGate.
New Dams – Don Sahong Hydropower Project
Still in Planning Stages, what is called a “prior consultation,”…”to discuss and evaluate benefits and associated risks of the project which may have significant impacts on the environment and people.”
Engineering Status Report Vol.1
Engineering Status Report Vol.2
via Don Sahong Hydropower Project » Mekong River Commission.