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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 StructuresEarthquake Design and Evaluation of Concrete Hydraulic StructuresEarthquake Design and Evaluation for CW ProjectsSafety 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.


Division of Safety of Dams.

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


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.”

Remaining Portions of Dam After Failure.

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.


The Los Angeles Dam Story.


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.