For state bridges, a nontoll seismic retrofit program is used. Sfobb east span seismic safety project limits and existing span. The detailed design of the izmit bay suspension bridge is used as an example, and descriptions are given of the local models prepared during design as well as the used analysis software. After the loma prieta quake, the bay bridge was deemed a ticking time bomb. Designing a bridge for earthquake country scientists estimate a more than 60 percent chance of a major earthquake hitting the san francisco bay area within 30 years.
The new eastern span of the bay bridge in san francisco is designed to go with the flow if a major earthquake strikes. The bay bridge is located between the hayward fault and the san andreas fault which are capable of producing magnitude 7. Bay area bridges bay bridge overview san franciscooakland bay bridge richmondsan rafael bridge san mateo bridge dumbarton bridge carquinez bridge. The san franciscooakland bay bridge, known locally as the bay bridge, is a complex of bridges spanning san francisco bay in california. Seismic conceptual design of buildings basic principles.
Behaviour and seismic design of stiffeners for steel bridge tower legs and piers. Mahan1 abstract the newly approved aashto guide specification for lrfd seismic bridge design referred to as lrfd seismic guide spec, july 2007, is greatly influenced by caltrans seismic design criteria. The east spans of the san francisco oakland bay bridge were closed in 1989 when a 50ft portion collapsed due to the 7. The companys software is making a green impact on san francisco alone, from the new energyefficient california academy of sciences to the bay bridge seismic retrofit and presidios doyle. Bay bridge design task force, engineering and design. Seismic assessment and strengthening of reinforced concrete structures. The gallery bay bridge east span seismic safety project autodesk. The division of engineering services des is the lead project delivery organization for the design, construction, and oversight of bridge and other transportation structures. San franciscos huge new quakeproof bridge new scientist. It has one of the longest spans in the united states. The program requires as input a gis point dataset of earthquake locations containing strike, dip, and rake values for a nodal plane of each earthquake. Behaviour and seismic design of stiffeners for steel.
San franciscooakland bay bridge seismic safety projects. Bay bridge design task force engineering and design advisory panel process outline the objective of this process is provide a structure for the engineering and design advisory panel to develop its recommendations for the bay bridge design task force. The new bridge across san francisco bay, the largest of its kind ever built, must be able to sway to withstand a big earthquake and one is expected. San franciscooakland bay bridge seismic retrofit strategy 12. Dismantling of the san franciscooakland bay bridge east main span. The bay bridge lies between the hayward and the san andreas faults which can generate magnitude 7. Lusas bridge is used by engineers worldwide for all types of bridge analysis, design and load rating from simple slab deck bridges, steel trusses, integral bridges and bowstring arch bridges, through to box girder, movable, cable stayed and suspension bridges. The bridge configuration was taken from massachusetts avenue overcrossing of. Portal is a software to be used for the design of steel structures. The seismic retrofit of the san franciscooakland bay bridge is more than an upgrade to one of the countrys busiest bridges. Rendering of the san franciscooakland bay bridge east span. Seismic analysis of san francisco oakland bay bridge.
The san franciscooakland bridge, better known as the bay bridge, was one of the longest and most expensive undertakings in recent memory in california. The project is located in a zone of very difficult environmental conditions characterized by deep soil strata of essentially normally consolidated silty clays to depths in excess of 80 m, a high water depth 60 m and a very strong seismic design motion with a peak ground acceleration of 0. The quake caused the oakland side of the bridge to shift 7 in 18 cm to the east, and caused the bolts of. Replacing the earthquakevulnerable east span of the bay bridge is the biggest engineering project in california history. The macarthur maze or simply the maze, also called the distribution structure is a large freeway interchange near the east end of the san franciscooakland bay bridge in oakland, california. Ucsd structural engineers honored for contributions to new bay. To survive a quake, new bay bridge span will offer least. Buckle the catastrophic collapse of the cypress street viaduct during the loma prieta earthquake of october 17, 1989 and the loss of spans in both the struve slough bridge and the san franciscooakland bay bridge has emphasized, very forcibly. To construct the worlds toughest bridgebuilt with seismic strength and staying powerengineers had to design it like a machines that moves. Worked on various alternatives for the replacement structure of the existing bay bridge east crossing 30% submittal. Seismic engineers who designed the span used a variety of innovative techniques some borrowed from offshore construction to help make the bridge strong, yet flexible enough to. San franciscooakland bay bridge seismic safety projects program overview. Advances in design software and construction materials. The jiaozhou bay bridge, which china claims to be the worlds longest, is now open.
Caltrans is the agency facing the challenge of making the bay bridge earthquake safe as quickly as possible. The design, engineering and construction teams have met the challenge of making the bay bridge seismically resilient with cuttingedge innovations and. The existing bay bridge east span was designed for 10%g earthquake acceleration which was consistent with the 1930 uniform building code recommendations. Software to download usgs earthquake hazard program.
How its seismic issues are resolved will affect millions of people in san francisco and the east bay when a major quake hits and the outside world tries to rush in to help. Design criteria for the bay bridge require it to be operational within 24 hours after a major earthquake. This libguide is designed to help guide high school students when researching and building bridge structures. In april 1932, the preliminary final plan and design of the bridge was. Errors and defects in the conceptual design cannot be compensated for in the following calculations and detailed design of the engineer. A seismically correct conceptual design is furthermore necessary in order to achieve a good earthquake resistance without. Suspension bay bridge 1, where buckling of the stiffened tower leg plates were observed and faster strength degradation. Izmit bay bridge software free download izmit bay bridge. The seismic retrofit of the bay bridge includes numerous cuttingedge and stateoftheart features that makes the bridge more resilient during an earthquake. The skyway structures design of the new san francisco. For part 1 of this story, see the march 2011 story superstructure rising slated to open in late 20, the new eastern span of the san franciscooakland bay bridge is meant to do what the old one didnt. San francisco oakland bay bridge replacement structure phase i.
Caltrans entertained bids and selected two semifinalist designs from. New bay bridge design deemed quake safe local news. The bridge is a designated lifeline a road guaranteed to be accessible to emergency relief efforts soon after an earthquake. But it takes more than length to make a great bridge. Now, mounting revelations of construction problems are calling. San franciscooakland bay bridge east span seismic safety project overview.
Des is a comprehensive, multidisciplinary engineering organization committed to providing our clients with quality products and services in a timely manner. A modern seismology study indicated that the hayward and san andreas faults, which the bridge is situated in between, can generate magnitude 7. San francisco bay area toll bridge seismic retrofit and. The new structural system is not only capable of preventing from the structure failure so as to protect peoples. Izmit bay bridge geotechnical challenges and innovative. Marwan nader, lead design engineer for the new eastern span of the bay bridge, discusses features that give the bridge the flexibility to. The design, engineering and construction teams have met the challenge of making the bay bridge seismically resilient with cuttingedge innovations and enhancementssome never before used in bridge buildingthat are transforming the bridge into a stateoftheart engineering icon. Seismic design of buildings worked examples worked examples presented at the workshop ec 8. Bay bridge made to withstand major earthquake sfgate. Earthquake resilient structure is a new branch of the seismic structural design. The old bridge is at risk in large bay area earthquakes as was demonstrated during the 1989 loma prieta earthquake.
To construct the worlds toughest bridge built with seismic strength and staying powerengineers had to design it like a machines that moves. Seismobuild is an innovative finite elements package for the seismic assessment and strengthening of reinforced concrete framed structures that is targeted to the design office. Pretty interesting to see the engineering that allows the bridge to twist and flex. Under this bay bridge prooftest program, every type of structural element, designed to see. Dual screen high resolution backgrounds 2009 is designed to fit across two screens. The seismicallyvulnerable san franciscooakland bay bridge east spans, which connect oakland to yerba buena island ybi, will be replaced with a dual, 3. Lrfd seismic bridge design, california example mark s. Design of the new san francisco oakland bay bridge. San francisco bay area toll bridge seismic retrofit and regional measure 1 programs 2012 second quarter project progress. It splits bay bridge traffic into three freewaysthe eastshore i80i580, macarthur i580 and nimitz i880. Global inhouse ibdas3d fe software 7sets of earthquake time histories, at each of the 4foundations. To one side, traffic streams towards oakland across the existing bay bridge. The new eastern span of the san franciscooakland bay bridge was. Learn how autodesk 3d design products were used to help retrofit the bay bridge, the largest engineering project in california history.
During the 1989 loma prieta earthquake, a portion of the eastern sections upper. Chen3 abstract this paper presents the various geotechnical issues considered during the seismic design of. The san franciscooakland bay bridge crossing was the longest. Seismic engineers who designed the span used a variety of innovative techniques some borrowed from offshore construction to help make the bridge strong, yet flexible enough to withstand the. It is used routinely for all types of architectural bridges with slender or curved shapes, and especially where. Simulation of the newly opened bay bridge in san francisco in an earthquake. Looked into software modeling issues regarding pushover analysis. Each screen must be set to either 1280x1024 or 1440x900 with total image resolution 2560x1024 or 2880x900. San franciscooakland bay bridge east span seismic safety. One lesson learned from the collapse of the newhall overpass at the interchange of interstate 5 and state route 14 was that during a strong earthquake, short columns cannot displace as much seismic force as adjacent taller columns and can fail. The existing bridge was not designed for the most basic no rcollapse seismic safety criteria that is typically employed in modern bridge design. Lrfd design of california bridges sheet 11 of job title bent design originator bob matthews date 10192007 job no. The northridge earthquake brought another significant change in bridge design and retrofitting. The san franciscooakland bay bridge, known locally as the bay bridge, is a complex of.
San francisco a seismic safety examination of plans for a new eastern span of the san franciscooakland bay bridge has determined that the state department of transportation is on. Communicating how the worlds largest selfanchored suspension bridge would reshape the surrounding landscape, as well as individual lives, was crucial to the success of the project. The loma prieta earthquake, also known as the quake of 89 and the world. Modelling and pre design of steel and composite structures 19961999. As part of interstate 80 and the direct road between san francisco and oakland, it carries about 260,000 vehicles a day on its two decks. Performance criteria require that the bridge must be operational immediately following a 1500year return period earthquake from either of these two faults. In 1981, caltrans seismic design specifications were updated again following publication of the.
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