ANALYSIS OF THE SHEFFIELD DAM FAILURE

THE CIRCUMSTANCES LEADING TO THE FAILURE OF SHEFFIELD DAM, A 25-FT. HIGH EARTHFILL DAM, DURING THE 1925 SANTA BARBARA EARTHQUAKE ARE DESCRIBED. PHOTOGRAPHS AND DESCRIPTIONS OF THE DAM AFTER THE EARTHQUAKE INDICATED THAT FAILURE OCCURRED BY SLIDING ON A NEARLY HORIZONTAL PLANE NEAR THE BASE. PSEUDOSTATIC METHODS OF ANALYSIS USING SOIL STRENTHS DETERMINED BY STATIC LOADING TESTS INDICATED A THEORETICAL FACTOR OF SAFETY BETWEEN 1 AND 1.2. HOWEVER, THE POSITION OF THE MOST CRITICAL SLIDING SURFACE DID NOT CORRESPOND WITH THE OBSERVED MODE OF FAILURE. DYNAMIC RESPONSE ANALYSES ARE DESCRIBED INCLUDING TEST DATA OBTAINED BY CYCLIC LOADING TRIAXIAL AND SIMPLE SHEAR TESTS AND STRESS DISTRIBUTIONS DETERMINED BY FINITE ELEMENT METHODS; THESE LEAD TO IMPROVED PREDICTIONS OF BOTH THE FAILURE MECHANISM AND THE CALCULATED FACTOR OF SAFETY. THE STUDY SUGGESTS THAT FAILURE WAS INITIATED BY LIQUEFAC TION OF A ZONE OF SOIL BELOW THE CENTER AND AT THE BASE OF THE DAM; AS SHAKING CONTINUED THE ZONE OF LIQUEFIED SOIL SPREAD LATERALLY UNTIL AFTER 10 OR 15 SEC. THE BASE BECAME SO WEAKENED THAT THE DAM WAS PUSHED DOWNSTREAM BY THE FORCE OF THE RESERVOIR WATER. /AUTHOR/

• Authors:
  • Seed, H B
  • Lee, K L
  • Idriss, I M
• Conference:
  • Engineering Geology and Soils Engineering Symposium, Proceedings of the 6th Annual
  • Location: Boise ID, United States
  • Date: 1968-4-17 to 1968-4-19
• Publication Date: 1970-4

Media Info

• Pagination: 235 p.

Subject/Index Terms

• TRT Terms: Dams; Dynamic loads; Earthquakes; Failure; Liquefaction; Soils; Static loads
• Uncontrolled Terms: Dynamic response; Sliding
• Old TRIS Terms: Dam failures; Static loading
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00235827
• Record Type: Publication
• Source Agency: Eng Geol & Soils Eng Symp Proc, Boise
• Files: TRIS
• Created Date: Jan 26 1971 12:00AM