The Pacific Earthquake Engineering Research Center and the California Department of Transportation have recently developed design guidelines for computing foundation demands during lateral spreading using equivalent static analysis (ESA) procedures. In this study, ESA procedures are applied to two parallel bridges that were damaged during the 2010 M 7.2 El Mayor-Cucapah earthquake in Baja California, Mexico. The bridges are both located approximately 15 km from the surface rupture of the fault on soft alluvial soil site conditions. Estimated median ground motions in the area in the absence of liquefaction triggering are peak ground accelerations = 0.27g and peak ground velocity = 38 cm/sec (RotD50 components). The bridges are structurally similar and both are supported on deep foundations, yet they performed differently during the earthquake. … Continue Reading ››
The replacement bridge will be located directly south of the existing bridge and will provide:
The project also includes the demolition of the existing … Continue Reading ››
- Three 12-foot-wide lanes in each direction replacing the current two narrow 10-foot-wide lanes
- A 12-foot-wide outer shoulder and a 5-foot-wide inner shoulder in each direction
- A 10-foot-wide sidewalk/bikeway along the northern edge of the New Jersey-bound roadway
- Improved safety conditions and performance reliability by meeting current geometric design, structural integrity, security and seismic standards, and reduces life-cycle cost
- A central corridor between the eastbound and westbound roadway decks, sufficient to accommodate potential transit service
- State-of-the-art smart bridge technology
NCHRP Report 697: Design Guidelines for Increasing the Lateral Resistance of Highway- Bridge Pile Foundations by Improving Weak Soils presents design guidance for strengthening of soils to resist lateral forces on bridge pile foundations. Lateral loads may be produced by wave action, wind, seismic events, ship impact, or traffic. Strengthening of soil surrounding the upper portions of piles and pile groups—for example by compaction, replacement of native soil with granular material, or mixing of cement with soil—may be more cost-effective than driving additional piles and extending pile caps as ways to increase the bridge foundation’s capacity to resist lateral forces associated with these loads. This report presents computational methods for assessing soil-strengthening options using finite-element analysis of single piles and pile groups and a … Continue Reading ››
Rob is a graduate of the University of Tennessee (BSCE and MSCE) with 11 years of experience. He began his career at S&ME working with our own Tim Siegel and for the last 8 years has been with GEOServices, LLC in Knoxville. He has a broad design background, specializing in analysis and design of earth retention systems and deep foundations. His experience with earth retention systems includes design and construction of soil nail walls, soldier pile walls, anchored systems, temporary shoring, and mechanically stabilized earth walls. His experience with deep foundation design includes lateral response analysis of deep foundations and design of deep foundation in karst geology. Rob has been involved with several major projects for private companies and public agencies including Foothills Parkway in Blount co., Tennessee, Interstate 240 expansion in Memphis, Tennessee, and Bridgeforth Stadium at James Madison University.
Rob will be located in Knoxville, Tennessee with Tim Siegel.
Ben is … Continue Reading ››
February 24, 2014, Hawthorne NJ: Maney Publishing and the Deep Foundations Institute (DFI) are pleased to announce the appointment of Anne Lemnitzer and Timothy C. Siegel as the new co-editors of DFI Journal: The Journal of the Deep Foundations Institute. They will succeed lead editors Ali Porbaha and Dan Brown, who are stepping down after being editors since the Journal’s inception, and Zia Zafir, who will remain on the editorial board. Timothy Siegel is a principal engineer with Dan Brown and Associates PC and member of the adjunct faculty at the University of Tennessee. He holds a B.S. and M.S. in Civil Engineering from Georgia Institute of Technology and has spent over 20 years working in industry. He is a member of the DFI’s Ground Improvement and Seismic and Lateral Loads Committees and has authored or co-authored over 45 technical papers and has presented at conferences … Continue Reading ››
Dr. Dan Brown has joined the DFI Educational Trust Board and the DFI Board of Trustees as treasurer, effective January 1, 2014. Dr. Brown is recognized as one of America's leading authorities on the construction and design of deep foundations for transportation structures. After 22 years on the faculty at Auburn University, Dr. Brown remains active in deep foundation practice through his consulting firm, Dan Brown and Associates. He has been recognized with the DFI Distinguished Service Award, ASCE Martin Kapp Foundation Engineering Award and the ADSC Outstanding Service Award.
David Coleman of Underpinning & Foundation Skanska, has been elected to a second five-year term as Trustee (2014-2019), and Roger Healey of Goettle, was elected to second two-year term as At-Large Trustee (2014-2016).
The elected officers for the Board of Trustees in 2014 are:
Chair: David Coleman
Vice Chair: M. Byrl Williams… Continue Reading ››
DBA has had the pleasure of working with T.Y. Lin and Slayden-Sundt JV in their effort to replace the Sellwood Bridge over the Willamette River in Multnomah County, Oregon, near Portland. Designed by Gustav Lindenthal, the existing Sellwood Bridge was constructed in 1925 to replace the Spokane Street Ferry, connecting the communities of Sellwood and West Portland. In response to budget issues at the time, the Sellwood Bridge design was scaled back to minimize costs. Fast forward to 2014 and the existing Sellwood Bridge is now the only four-span continuous truss highway bridge in Oregon and possibly the nation. The bridge is extremely narrow, two lanes, no shoulder or median, and one small 4-ft sidewalk. In addition to these shortcomings in design with respect to the modern age, the west end of the bridge was constructed on fill, and the hillside above the bridge is now slowly sliding toward the river. Ground movements have caused some of the girders to crack. Furthermore, the existing bridge was not designed to any seismic standards which present a major concern given the bridge’s location in the seismically active Pacific Northwest.
The new Sellwood Bridge will be a … Continue Reading ››
The blogosphere, as the world of blogging is sometimes called, is always changing as blogs come and go. A new one focusing on geology education is geologydegree.org. This is a new blog intended to promote the study of geology. A recent post called Geology Online: 105 Websites That Rock included our very own blog as well as that of one of our good friends, GeoPrac.net by RockMan (aka Randy Post). While DBA (and others listed, including GeoPrac.net) are not strictly geological blogs or websites, what we do includes a lot of geology as we design foundations to bear in or on rock. Understanding the geology of a site is also important to understand the soils that are present above the bedrock. Take a look, especially if you have a young’un (that’s Southern for young one, or child) at home that may find geology or geotechnical engineering interesting.