The Earthquake Engineering Online Archive

Performance of improved ground during the Loma Prieta earthquake

Mitchell, James Kenneth; Wentz, Frederick J.

UCB/EERC-91/12, Earthquake Engineering Research Center, University of California, Berkeley, 1991-10, 100 pages (480/M57/1991)

The 1989 earthquake provided one of the first opportunities to evaluate the behavior of treated ground that had actually been subjected to significant shaking. A comprehensive evaluation was made of 12 sites with improved ground: five on Treasure Island, two in Santa Cruz, and one each in Richmond, Emeryville, Bay Farm Island, Union City, and South San Francisco. The treatment methods used included vibro-replacement using stone columns, sand compaction piles, nonstructural timber displacement piles, deep dynamic compaction, compaction grout, and chemical penetration grouting. At all but one of the sites the treated soil was a manmade fill. This report details the study.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-91-12.pdf (4 MB)