Last spring, DBA conducted a construction phase load test program for a U.S. Army Corps of Engineers floodwall improvement project along the Missouri River in Kansas City, Kansas. Located on property owned and maintained by the Kansas City Board of Public Utilities (BPU), the BPU floodwall was slated for structural improvements including a series of buttresses founded on 24-in drilled shafts. As part of the project contract a load test program performed under the direction of a qualified P.E. and D.GE was required. General contractor L.G. Barcus & Sons, Inc., secured our Paul Axtell, P.E., D.GE as the qualified load test expert. DBA teamed up with load testing subcontractor Applied Foundation Testing, Inc., to perform the static load tests.
The load test program requirements included three test shafts, a statically loaded axial test shaft, a statically loaded lateral test shaft, and a combined statically loaded axial and lateral test shaft. The required combined lateral and axial test shaft provided some unique challenges with respect to applying the loads and collecting data. As can be seen in the picture above, the axial load was applied using dead weights.
We have added selected pictures from this unique project to our web albums, which can be viewed here.
Our own Ben Turner (future Dr. Turner!) was lead author on a report by the Pacific Earthquake Engineering Research Center (PEER) on liquefaction and lateral spreading effects on bridges. The report is titled “Evaluation of Collapse and Non-Collapse of Parallel Bridges Affected by Liquefaction and Lateral Spreading”. Ben’s coauthors are Dr. Scott J. Brandenberg and Dr. Jonathan P. Stewart of the Department of Civil and Environmental Engineering at UCLA. From the abstract:
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. A span of the pile-supported railroad bridge collapsed, whereas the drilled-shaft-supported highway bridge suffered only moderate damage and remained in service following the earthquake. The ESA procedures applied to the structures using a consistent and repeatable framework for developing input parameters captured both the collapse of the railroad bridge and the performance of the highway bridge. Discussion is provided on selection of the geotechnical and structural modeling parameters as well as combining inertial demands with kinematic demands from lateral spreading.
This report is part of Ben’s work on his doctoral dissertation. You can download the report by clicking on the linked citation below.
DBA is on the design-build team that is replacing the Goethals Bridge for the Port Authority of New York and New Jersey (PANYNJ). We are not able to post much about the project or our involvement due to security agreements. However, the PANYNJ has a public website for the project (http://www.panynj.gov/bridges-tunnels/goethals-bridge-replacement.html) that has several webcams. As is the case with most big projects these days, the webcams are a common feature and show some great views of the project.
To give you an idea of what the project involves, here is a summary from the PANYNJ site:
The replacement bridge will be located directly south of the existing bridge and will provide:
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
The project also includes the demolition of the existing bridge upon completion of the replacement bridge.
In the forward of the report, Andrew Lemer of TRB writes:
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 simplified approach employing commercially available software. The analysis methodology and design guidelines will be helpful to designers responsible for bridge foundations likely to be exposed to significant lateral loads.
DBA is please to announce the addition of two new members: Robert M. Saunders, P.E. and Benjamin Turner, P.E.
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 currently pursuing a Ph.D. in geotechnical earthquake engineering at UCLA with an emphasis on the transfer of forces between the ground and foundation elements during seismic loading. Prior to starting at UCLA, he worked for two years for the Los Angeles office of Shannon & Wilson, Inc. Ben worked in both construction and geotechnical firms while attending school for his B.S. and M.S. degrees. His experience includes: design, construction, and load testing of deep foundations; geotechnical earthquake engineering including soil-structure interaction, seismic hazard analysis, site response, liquefaction triggering analysis and mitigation of liquefaction-induced ground failure; and, characterization of structural behavior of reinforced concrete foundations.
Ben will be working part-time as he can while completing his Ph. D. and will join DBA full time after completing his studies, staying in the Los Angeles, California area.
We’re almost done with an upgrade to our website. With more than 50% of our site traffic now coming from smartphones and tablets, we needed a responsive web design, i.e., one that provides “an optimal viewing experience—easy reading and navigation with a minimum of resizing, panning, and scrolling—across a wide range of devices (from mobile phones to desktop computer monitors).” So the site now detects the type and size of your device and reshapes its presentation of the content while keeping the visual design.
That visual design is new, too. We’re using the Twenty Fourteen theme by WordPress, in part because of its ‘magazine style’ presentation of blog content. At the top of the home page, we now feature six blog posts, each with a featured image or photo. Clicking on the title or the photo of any of those takes you to that blog post where a larger version of the photo and the complete content is displayed. Other blog posts that aren’t selected by us to be featured will appear in the usual reverse chronological order on the blog/home page.
Lastly, we’re now showing excerpts of all blog posts on the home page rather than the entire contents of each post as before. This allows you to more quickly scan the latest posts, while giving you enough of a glimpse of each one to help you decide whether it interests you enough to click on it.
If you notice any problems with the new site, we’d appreciate hearing from you via our Contact Us page.
As Robert recently posted, Dan is taking on new roles at the Deep Foundations Institute (DFI) as a member of the DFI Educational Trust Board and as treasurer of the DFI Board of Trustees. Tim Siegel is now stepping in to fill Dan’s former role as co-editor of the DFI Journal. From DFI:
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 throughout the USA.
Anne Lemnitzer is assistant professor at the University of California in Irvine. She holds a Ph.D. in structural engineering from UCLA as well as an M.S. in Geotechnical Engineering from California State University, Long Beach and B.S. from the University of Applied Science in Leipzig, Germany, where she was awarded a Fulbright Scholarship to continue her education. Her research interests lie at the interface of geotechnical and structural earthquake engineering.
Tim Siegel comments, “At no time in history has the practice of foundation engineering been as challenging as it is now. Ambitious projects, stringent design codes, the likelihood of litigation, and high expectations require engineers to effectively intertwine theory and experience. At a time when many technical journals are focused on the former, the DFI Journal plays a vital role by offering a balance between theory and experience. This is one reason that DFI Journal is a leading platform for technology transfer on design and construction of deep foundations and ground improvement.”
Anne Lemnitzer comments, “I am excited to work with my colleague Tim Siegel in serving as co-editor of the DFI Journal and hope to further enhance its reputation and circulation in the geotechnical community. We are determined to seek the best deep foundation research from across the world and combine it with the most innovative design projects currently built, hereby creating a unique stage for intellectual exchange, transfer of knowledge and professional development. The DFI Journal provides this alternative approach compared to traditional scientific journals and we are looking forward to widening the audience through hands-on, understandable publications that can make lasting impacts on our foundation industry.”
“DFI is excited to have members, Tim Siegel and Anne Lemnitzer taking the lead as Journal co-editors as we strive to increase the readership and frequency of the publication. The Journal is the perfect vehicle for achieving DFI’s mission to disseminate practical and useful content to the deep foundations construction industry and be the information resource for design and construction of foundations and excavations. We are confident the new editors will provide excellent insight, technical expertise and leadership in their new role,” says Theresa Rappaport, DFI executive director.
Tim, congratulations and thank you for your contributions to the industry!
Dan has taken on some new responsibilities with the Deep Foundations Institute (DFI). He has joined both the Board of Directors and the Educational Trust Board as treasurer. From DFI:
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:
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 deck arch structure with three arches supporting the deck of the main river spans and is designed to the latest seismic standards. It will feature two 12-ft travel lanes, two-12 ft shared use sidewalks, and two 6.5-ft bike lane/emergency shoulders. Multnomah County is using the existing bridge truss on temporary pile foundations as a detour to save time and money during construction with minimal impact to traffic. The original bridge truss was shifted on January 19, 2013. Complicating the move was the enormity of the bridge, an 1100-ft single truss weighing 3400 tons. In addition to the size and weight of the span, old age and its curved alignment added to the technical challenges. The impressive move took only 14 hours. The detour bridge is currently fully operational and will continue to carry traffic until the summer of 2015 when the new bridge is scheduled to open.
DBA played key roles in the design and construction of the main arch piers. As part of the VE Design, DBA assumed engineering responsibility for the 10-ft diameter drilled shafts supporting Piers 4, 5, and 6 (4 & 5 being in the river and 6 on the eastern shore). The lengths of these shafts ranged from 81 ft to 225 ft through a number of subsurface conditions which posed many challenges to construction. Subsurface conditions ranged from large loose cobbles/gravel (Catastrophic Flood Deposits) to cemented cobbles and gravel (Troutdale Formation), to very hard intact basalt bedrock. Due to the challenging geologic conditions and variability of these conditions across the site, DBA implemented an observational method in which the final shaft length determination was made on the basis of our on-site observations in relation to a set of predefined criteria. This approach provided the necessary flexibility to efficiently confront different subsurface conditions in a timely manner. Drilling subcontractor Malcolm Drilling successfully completed construction of the last of these shafts in mid-October 2013.
You can learn more about the bridge and the project at Multnomah County’s website, SellwoodBridge.org. The website has current field work updates, photo gallery, history of the project, and a live construction camera with daily, weekly, and monthly time-lapse videos. There is also a time-lapse of the moving of the old truss.
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.
Specialists in Deep Foundation Design, Construction, and Testing and Slope Stability Problems