{"id":527273,"date":"2018-08-24T11:29:46","date_gmt":"2018-08-24T11:29:46","guid":{"rendered":"http:\/\/www.webuildvalue.com\/?p=527273"},"modified":"2025-07-16T14:16:13","modified_gmt":"2025-07-16T14:16:13","slug":"the-bay-bridge-ready-for-the-next-challenge","status":"publish","type":"post","link":"https:\/\/www.webuildvalue.com\/en\/reportage\/the-bay-bridge-ready-for-the-next-challenge.html","title":{"rendered":"The Bay Bridge: ready for the next challenge"},"content":{"rendered":"\n
\"bay-bridge-sanfrancisco-earthquake.jpg\"<\/figure>\n\n\n\n

I<\/strong>t might take up to a thousand years for the next earthquake to hit, but when it does, the new and retrofitted bridge across the San Francisco Bay<\/strong> will be ready<\/strong> for<\/strong> it<\/strong>.<\/p>\n\n\n\n

The San<\/strong> Francisco<\/strong>–Oakland<\/strong> Bridge, <\/strong>better known as the Bay<\/strong> Bridge, was one of the longest and most expensive undertakings in recent memory in California. <\/strong>Stretching 13.5 kilometres (8.4 miles) to unite<\/strong> the cities<\/strong> of San<\/strong> Francisco<\/strong> and Oakland<\/strong>, it underwent major improvements after being damaged by the Loma<\/strong> Prieta<\/strong> earthquake<\/strong> in 1989<\/strong>. It took nearly a decade of work at a cost of $6.4 billion before the<\/strong> self-anchored suspension bridge reopened to traffic in 2013. Of all the work done to make it resistant to the next earthquake, the most extensive was the replacement<\/strong> of the East<\/strong> Span<\/strong>, which stretches from Oakland<\/strong> to Yerba<\/strong> Buena<\/strong> Island<\/strong>, the mid<\/strong>–point<\/strong> of the bridge<\/strong>.<\/p>\n\n\n\n

\u201cDespite the journey’s length, it has been completed before the arrival<\/strong> of our next<\/strong> big<\/strong> earthquake<\/strong>,\u201d Steve Heminger, executive director of the Metropolitan Transportation Commission, which is responsible for transportation planning in the San<\/strong> Francisco<\/strong> Bay<\/strong> area<\/strong>, was quoted as saying by the Associated<\/strong> Press<\/strong> (AP<\/strong>) news agency at the opening ceremony. \u201cAnd thank goodness for that.\u201d Californian state Lieutenant Governor Gavin Newsom said he hoped it would inspire young engineers to pursue similarly ambitious projects. \u201cThis is more than just connecting two land masses,\u201d he was quoted as saying by AP. \u201cI hope that the progress that’s being represented at this moment is for a generation to dream big dreams and to do big things.’<\/p>\n\n\n\n

Although the original<\/strong> bridge<\/strong> had<\/strong> stood<\/strong> proud<\/strong> since<\/strong> it<\/strong> was<\/strong> erected<\/strong> during the darkest years of the Great Depression, it was laid<\/strong> low<\/strong> by the 1989<\/strong> earthquake<\/strong> that registered high on the Richter scale at about 7.0. The tremor was so strong that a 250-ton (226.7 tonne) section of the East Span\u2019s upper deck collapsed. The scale of the damage was such that officials<\/strong> eventually decided<\/strong> to replace<\/strong> the entire<\/strong> span<\/strong>.<\/p>\n\n\n\n

\"bay-bridge-sanfrancisco-earthquake-4\"<\/figure>\n\n\n\n

Construction of the new Bay Bridge<\/h4>\n\n\n\n

According to the California Department of Transportation, engineers<\/strong> made sure its replacement<\/strong> would resist<\/strong> the next<\/strong> earthquake<\/strong> by using so-called \u201crock<\/strong> motions<\/strong>\u201d to calculate the maximum seismic forces it would experience. Rock motions are the vibrations<\/strong> that travel through the bedrock when a fault deep under the Earth\u2019s surface slips. \u201cThe new East Span has been designed to withstand<\/strong> rare seismic<\/strong> events<\/strong>,\u201d reads a department website dedicated to the bridge. \u201cSpecifically, the span has a 1,500-year return period<\/strong>. This is defined as the largest rock motions expected to occur at the bridge site once every 1,500 years.\u201d<\/p>\n\n\n\n

The new East Span<\/strong> includes 1.2-mile<\/strong> (1.9-kilometre) Skyway<\/strong>; a Self-Anchored Suspension span consisting of a 525-foot (160-metre) tower supporting a bridge deck connecting the Skyway to the Yerba Buena Island Transition Structure; and the Oakland Touchdown, the east end of the bridge connecting to the toll plaza.<\/p>\n\n\n\n

Meanwhile, the West Span<\/strong>, the part of the bridge that links the island to San Francisco, escaped the wrecking ball but underwent significant repair and retrofitting. A one-mile (1.6-kilometre) stretch of Interstate 80 and three on- and three off-ramps were replaced. The double-deck feature of the West Span was heavily reinforced, and a column was added to support each deck on the West Approach, according to the website.<\/p>\n\n\n\n

Although the West Span still features double decks, the East Span no longer does. T<\/strong>he two decks are side by side to give drivers more expansive views.<\/p>\n\n\n\n

When the original<\/strong> bridge<\/strong> opened<\/strong> in 1936<\/strong>, it was the longest<\/strong> in the world<\/strong>. Its builders, American Bridge Company for Columbia Steel Company – both subsidiaries of United States Steel – defied critics who thought it was impossible to build the bridge due to the turbulent waters and strong winds, among other factors.<\/p>\n\n\n\n

Cars drove in both directions on the upper deck, while trucks and trains travelled in both directions on the lower deck. This double-deck feature allowed the bridge to support a large flow of traffic. In its first year, it saw the passage of nine million vehicles. Traffic would inevitably increase in subsequent decades, rising to more than 100 million a year.<\/p>\n\n\n\n

The structure was the\u00a0most dangerous and expensive project<\/strong>\u00a0in the\u00a0country<\/strong>\u00a0at the\u00a0time<\/strong>. On the western side were two\u00a0suspension<\/strong>\u00a0bridges<\/strong><\/a>\u00a0joined in the middle by a massive central anchorage 30-storeys high with more concrete than the volume used to build the Empire State Building<\/a> in Manhattan.<\/p>\n\n\n\n

Speaking in a documentary film commemorating the bridge\u2019s 75th<\/sup> anniversary, Bob McKee said he was awestruck<\/strong> when he joined his parents for a drive across the structure on the opening day. \u201cIt was very exciting<\/strong> for (an) almost five year (old),\u201d he said, remarking that the excitement of so many other drivers had gotten the better of them. \u201cThere were a lot of cars and a lot of accidents.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

It might take up to a thousand years for the next earthquake to hit, but when it does, the new and retrofitted bridge across the San Francisco Bay will be ready for it. The San Francisco–Oakland Bridge, better known as the Bay Bridge, was one of the longest and most expensive undertakings in recent memory in California. Stretching 13.5 kilometres (8.4 miles) to unite the cities of San Francisco and Oakland, it underwent major improvements […]<\/p>\n","protected":false},"author":10,"featured_media":116370,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[32],"tags":[41164,19002,19013,18999],"yst_prominent_words":[3895,2267,14718,14721,17706,16673,3900,14708,14711,14722,14719,14709,1266,6287,14712,3904,14720,14710,3898,14707],"class_list":["post-527273","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-reportage","tag-bridges","tag-new-challenges","tag-north-and-south-america","tag-roads"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/posts\/527273","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/comments?post=527273"}],"version-history":[{"count":10,"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/posts\/527273\/revisions"}],"predecessor-version":[{"id":570897,"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/posts\/527273\/revisions\/570897"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/media\/116370"}],"wp:attachment":[{"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/media?parent=527273"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/categories?post=527273"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/tags?post=527273"},{"taxonomy":"yst_prominent_words","embeddable":true,"href":"https:\/\/www.webuildvalue.com\/en\/wp-json\/wp\/v2\/yst_prominent_words?post=527273"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}