{"id":31578,"date":"2025-07-29T19:15:40","date_gmt":"2025-07-30T02:15:40","guid":{"rendered":"https:\/\/essential.construction\/news\/la-tunnel-work-remains-halted-after-partial-collapse\/"},"modified":"2025-07-29T19:15:40","modified_gmt":"2025-07-30T02:15:40","slug":"la-tunnel-work-remains-halted-after-partial-collapse","status":"publish","type":"post","link":"https:\/\/essential.construction\/news\/la-tunnel-work-remains-halted-after-partial-collapse\/","title":{"rendered":"LA tunnel work remains halted after partial collapse"},"content":{"rendered":"<p> [ad_1]<br \/>\n<\/p>\n<div>\n<div class=\"text-to-speech\">\n    <button class=\"text-to-speech__button button\"><br \/>\n        <img decoding=\"async\" class=\"text-to-speech__button__icon\" src=\"https:\/\/www.constructiondive.com\/static\/img\/play.svg?500116090725\" alt=\"-\"><br \/>\n        Listen to the article<br \/>\n        <span class=\"text-to-speech__button__audio-length\">3 min<\/span><br \/>\n    <\/button><\/p>\n<div class=\"text-to-speech__controls\">\n        <audio controls=\"\" class=\"js-text-to-speech\" preload=\"none\"><source src=\"https:\/\/res.cloudinary.com\/dmgi9movl\/video\/upload\/q_1\/v1753813082\/news\/text_to_speech\/la-tunnel-collapse-investigation_niyfat.wav\" type=\"audio\/mp3\"><\/source><\/audio><\/p>\n<div class=\"text-to-speech__controls__text\">\n            This audio is auto-generated. Please let us know if you have <a rel=\"nofollow noopener\" href=\"https:\/\/www.constructiondive.com\/contact\/\" target=\"_blank\">feedback<\/a>.\n        <\/div>\n<\/p><\/div>\n<\/div>\n<h3 class=\"standard-heading\"><span><span><span><span><span><span>Dive Brief:<\/span><\/span><\/span><\/span><\/span><\/span><\/h3>\n<ul>\n<li><span><span><span><span><span><span>A <\/span><\/span><\/span><\/span><\/span><\/span><a rel=\"nofollow noopener\" href=\"https:\/\/www.clearwater.lacsd.org\/pdf\/Letter_Response_Hahn_and_McOsker.pdf\" target=\"_blank\"><span><span><span><span><span><span><span><span>Los Angeles area wastewater tunnel partially collapsed<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/a><span><span><span><span><span><span> July 9 in a section \u201cwhere the ground exerted high pressure on the area,\u201d according to a letter from Robert Ferrante, chief engineer and general manager of the Los Angeles County Sanitation Districts. <\/span><\/span><\/span><\/span><\/span><\/span><\/li>\n<li><span><span><span><span><span><span>No one has yet been able to enter the tunnel or assess the breach location, Los Angeles County Sanitation Districts spokesperson Michael Chee said in an email on July 28, and the tunnel boring machine remains in place where it stopped mining. \u201cWork on the tunnel remains at full stop,\u201d Chee said. \u201cRed tag placed by CalOSHA remains in force.\u201d<\/span><\/span><\/span><\/span><\/span><\/span><\/li>\n<li><span><span><span><span><span><span>The pressure issue first surfaced in February, per the letter dated July 17, \u201cresulting in the \u2018squeezing\u2019 of the segment rings creating ovalization of those rings and some cracking.\u201d At the time, a tunnel liner engineer reviewed the problem and Broomfield, Colorado-based GC Flatiron\/Dragados adopted the suggested measures to mitigate it.<\/span><\/span><\/span><\/span><\/span><\/span><\/li>\n<\/ul>\n<h3 class=\"standard-heading\"><span><span><span><span><span><span>Dive Insight:<\/span><\/span><\/span><\/span><\/span><\/span><\/h3>\n<p><span><span><span><span><span><span>The investigation into the breach of the Los Angeles Effluent Outfall Tunnel is ongoing. The tunnel boring machine had advanced 4,100 feet away from this initial squeezing area when the partial breach occurred 370 feet below ground, according to the letter. Flatiron\/Dragados is currently working on an access plan for the tunnel, and more answers will become available once crews can reenter.<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p><span><span><span><span><span><span>Twenty-seven <\/span><\/span><\/span><\/span><\/span><\/span><a rel=\"nofollow noopener\" href=\"https:\/\/www.nytimes.com\/2025\/07\/10\/us\/tunnel-collapse-los-angeles-trapped.html\" target=\"_blank\"><span><span><span><span><span><span><span><span>workers escaped without major injury<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/a><span><span><span><span><span><span> from the tunnel in Carson, California, by climbing over a large mound of loose soil and emerging at the only entrance 5 miles away, The New York Times reported. Four others who went in to help with rescue efforts also emerged unharmed. The tunnel is designed to carry treated effluent, not sewage, and the partial collapse does not pose a risk to the environment, the agency said.<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p><span><span><span><span><span><span>The $630 million tunnel, which broke ground in 2019, is part of the Sanitation Districts\u2019 <\/span><\/span><\/span><\/span><\/span><\/span><a rel=\"nofollow noopener\" href=\"https:\/\/www.clearwater.lacsd.org\/\" target=\"_blank\"><span><span><span><span><span><span><span><span>Clearwater Project<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/a><span><span><span><span><span><span> to protect local waterways, according to the project website. The new 7-mile tunnel will transport treated wastewater to the ocean and will replace two aging tubes. It will be built to current earthquake standards and with enough capacity to protect against overflows from major storms.<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p><span><span><span><span><span><span>The tunnel alignment is primarily within the public right-of-way and not under any homes, and \u201cthere is no information to suggest that any local streets or surface areas above tunnel construction have been compromised,\u201d per the letter. Nonetheless, survey crews will monitor the area daily.<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p><span><span><span><span><span><span>\u201cWe are committed to prioritizing worker safety and will pursue any and all corrective measures necessary to complete construction of this vital infrastructure project once all safety concerns <\/span><\/span><\/span><\/span><\/span><\/span><span><span><span><span><span><span>have been thoroughly addressed,\u201d the letter reads.<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p><span><span><span><span><span><span>A 2022 Mining Engineering magazine article noted that the <\/span><\/span><\/span><\/span><\/span><\/span><a rel=\"nofollow noopener\" href=\"https:\/\/me.smenet.org\/los-angeles-county-sanitation-districts-constructing-11-km-7-mile-tunnel\/#:~:text=Numerous%20geotechnical%20challenges%20will%20be,(1%2C100%20ft)%20to%20date.\" target=\"_blank\"><span><span><span><span><span><span><span><span>tunnel route passes through two active fault zones<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/a><span><span><span><span><span><span> \u2014 the Palos Verdes Fault zone and the Cabrillo Fault zone \u2014 and numerous geotechnical challenges would be encountered in its path.<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p><span><span><span><span><span><span>The project is being constructed by Flatiron West and Dragados USA, operating as a joint venture. The two parent firms <\/span><\/span><\/span><\/span><\/span><\/span><a rel=\"nofollow noopener\" href=\"https:\/\/www.constructiondive.com\/news\/flatiron-dragados-merge-us-infrastructure-giant\/722744\/\" target=\"_blank\"><span><span><span><span><span><span><span><span>merged last July to form FlatironDragados<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/a><span><span><span><span><span><span>.<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p><span><span><span><span><span><span>Work was expected to be completed in 2027 but it is not yet clear how much the breach will delay the project, according to the letter. Construction prep work at the tunnel boring machine arrival location at Royal Palms Beach in San Pedro continues as scheduled, according to Chee.<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p><span><span><span><span><span><span>A town hall meeting to give updates on the investigation and timeline is scheduled for Aug. 9, according to the project website.<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<\/p><\/div>\n<p>[ad_2]<br \/>\n<br \/><a href=\"https:\/\/www.constructiondive.com\/news\/la-tunnel-collapse-investigation\/756146\/\" rel=\"nofollow noopener\" target=\"_blank\">This article was originally posted at Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>[ad_1] Listen to the article 3 min This audio is auto-generated. Please let us know if you have feedback. Dive &#8230; <a title=\"LA tunnel work remains halted after partial collapse\" class=\"read-more\" href=\"https:\/\/essential.construction\/news\/la-tunnel-work-remains-halted-after-partial-collapse\/\" aria-label=\"Read more about LA tunnel work remains halted after partial collapse\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[457],"tags":[],"class_list":["post-31578","post","type-post","status-publish","format-standard","hentry","category-construction-dive","generate-columns","tablet-grid-50","mobile-grid-100","grid-parent","grid-33"],"_links":{"self":[{"href":"https:\/\/essential.construction\/news\/wp-json\/wp\/v2\/posts\/31578","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/essential.construction\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/essential.construction\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/essential.construction\/news\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/essential.construction\/news\/wp-json\/wp\/v2\/comments?post=31578"}],"version-history":[{"count":0,"href":"https:\/\/essential.construction\/news\/wp-json\/wp\/v2\/posts\/31578\/revisions"}],"wp:attachment":[{"href":"https:\/\/essential.construction\/news\/wp-json\/wp\/v2\/media?parent=31578"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/essential.construction\/news\/wp-json\/wp\/v2\/categories?post=31578"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/essential.construction\/news\/wp-json\/wp\/v2\/tags?post=31578"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}