{"id":50,"date":"2015-02-03T15:00:31","date_gmt":"2015-02-03T23:00:31","guid":{"rendered":"http:\/\/research.engineering.ucdavis.edu\/gpa\/?page_id=50"},"modified":"2015-05-11T08:59:01","modified_gmt":"2015-05-11T16:59:01","slug":"liquefaction-lower-san-fernando-dam","status":"publish","type":"page","link":"https:\/\/research.engineering.ucdavis.edu\/gpa\/earthquake-hazards\/liquefaction-lower-san-fernando-dam\/","title":{"rendered":"Liquefaction &amp; Lower San Fernando Dam"},"content":{"rendered":"<hr \/>\n<h2>Liquefaction-Induced Failure of the Upstream Slope<\/h2>\n<p>The upstream slope of the Lower San Fernando Dam, in California, failed due to liquefaction during the 1971 San Fernando earthquake. The dam was constructed by &#8220;hydraulic filling,&#8221; which involves mixing the fill soil with a large amount of water, transporting it to the dam site by pipeline, depositing the soil and water on the embankment in stages, and allowing the excess water to drain away. The fill that remains is loose, and is subject to liquefaction as the result of earthquake shaking. Another famous failure of a hydraulic fill, at Fort Peck Dam, is believed to have been triggered by movement in the foundation, leading to &#8220;static liquefaction&#8221; of the hydraulic fill.<\/p>\n<div id=\"attachment_896\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Aerial-of-LSF-dam.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-896\" class=\"size-medium wp-image-896\" src=\"http:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Aerial-of-LSF-dam-300x197.jpg\" alt=\"The dam is located in the lower left corner of this areal view. About 80,000 people living in the area downstream were threatened by the failure of the embankment and the very real possibility that the dam would fail completely, inundating the area by a catastrophic flood wave. Disaster was narrowly averted by drawing down the reservoir before the remaining remnant of the crest gave way.\" width=\"300\" height=\"197\" srcset=\"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Aerial-of-LSF-dam-300x197.jpg 300w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Aerial-of-LSF-dam-1024x674.jpg 1024w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Aerial-of-LSF-dam-228x150.jpg 228w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Aerial-of-LSF-dam-150x99.jpg 150w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Aerial-of-LSF-dam.jpg 1097w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><p id=\"caption-attachment-896\" class=\"wp-caption-text\">The dam is located in the lower left corner of this areal view. About 80,000 people living in the area downstream were threatened by the failure of the embankment and the very real possibility that the dam would fail completely, inundating the area by a catastrophic flood wave. Disaster was narrowly averted by drawing down the reservoir before the remaining remnant of the crest gave way.<\/p><\/div>\n<div id=\"attachment_899\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-aerial.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-899\" class=\"size-medium wp-image-899\" src=\"http:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-aerial-300x204.jpg\" alt=\"This aerial view shows how the crest of the dam disappeared under the reservoir as a result of the slide in the upstream shell. The slide occurred shortly after earthquake shaking ended, and was attributed to loss of strength in the hydraulic fill due to liquefaction.\" width=\"300\" height=\"204\" srcset=\"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-aerial-300x204.jpg 300w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-aerial-220x150.jpg 220w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-aerial-150x102.jpg 150w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-aerial.jpg 725w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><p id=\"caption-attachment-899\" class=\"wp-caption-text\">This aerial view shows how the crest of the dam disappeared under the reservoir as a result of the slide in the upstream shell. The slide occurred shortly after earthquake shaking ended, and was attributed to loss of strength in the hydraulic fill due to liquefaction.<\/p><\/div>\n<hr \/>\n<p>&nbsp;<\/p>\n<div id=\"attachment_898\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-898\" class=\"size-medium wp-image-898\" src=\"http:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-300x196.jpg\" alt=\"About 1 m of freeboard remained after the upstream shell slid into the reservoir. The paved crest of the dam can be seen descending into the water at the top of this photo.\" width=\"300\" height=\"196\" srcset=\"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-300x196.jpg 300w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-1024x670.jpg 1024w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-229x150.jpg 229w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide-150x98.jpg 150w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Crest-after-slide.jpg 1101w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><p id=\"caption-attachment-898\" class=\"wp-caption-text\">About 1 m of freeboard remained after the upstream shell slid into the reservoir. The paved crest of the dam can be seen descending into the water at the top of this photo.<\/p><\/div>\n<div id=\"attachment_897\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Slide-after-drawdown.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-897\" class=\"size-medium wp-image-897\" src=\"http:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Slide-after-drawdown-300x196.jpg\" alt=\"The slide in the upstream shell is shown here with the reservoir emptied. The paved road surface identifies the former crest of the dam.\" width=\"300\" height=\"196\" srcset=\"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Slide-after-drawdown-300x196.jpg 300w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Slide-after-drawdown-1024x669.jpg 1024w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Slide-after-drawdown-230x150.jpg 230w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Slide-after-drawdown-150x98.jpg 150w, https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-content\/uploads\/sites\/43\/2015\/02\/Slide-after-drawdown.jpg 1645w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><p id=\"caption-attachment-897\" class=\"wp-caption-text\">The slide in the upstream shell is shown here with the reservoir emptied. The paved road surface identifies the former crest of the dam.<\/p><\/div>\n<hr \/>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<h2>Liquefaction-Induced Failure of the Upstream Slope<\/h2>\n<p>The upstream slope of the Lower San Fernando Dam, in California, failed due to liquefaction during the 1971 San Fernando earthquake. The dam was constructed by &#8220;hydraulic filling,&#8221; which involves mixing the fill soil with a large amount of water, transporting it to the  \u2026 <a href=\"https:\/\/research.engineering.ucdavis.edu\/gpa\/earthquake-hazards\/liquefaction-lower-san-fernando-dam\/\"> Continue reading <span class=\"meta-nav\">&rarr; <\/span><\/a><\/p>\n","protected":false},"author":69,"featured_media":0,"parent":30,"menu_order":4,"comment_status":"closed","ping_status":"closed","template":"","meta":{"ngg_post_thumbnail":0,"footnotes":""},"class_list":["post-50","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-json\/wp\/v2\/pages\/50","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-json\/wp\/v2\/users\/69"}],"replies":[{"embeddable":true,"href":"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-json\/wp\/v2\/comments?post=50"}],"version-history":[{"count":1,"href":"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-json\/wp\/v2\/pages\/50\/revisions"}],"predecessor-version":[{"id":1029,"href":"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-json\/wp\/v2\/pages\/50\/revisions\/1029"}],"up":[{"embeddable":true,"href":"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-json\/wp\/v2\/pages\/30"}],"wp:attachment":[{"href":"https:\/\/research.engineering.ucdavis.edu\/gpa\/wp-json\/wp\/v2\/media?parent=50"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}