Tag Archives: Bridge Foundations

Bridge Foundations, Foundation Design, Foundation Testing, Industry News and Events

FHWA GEC 15 (Foundation Acceptance) Now Published

FHWA has published (posted the PDF!) of Geotechnical Engineering Circular 015 – Acceptance Procedures for Structural Foundations of Transportation Structures.   Work began on this in 2019 and was delayed due to COVID.   Andy Boeckmann, Dan Brown, Erik Loehr, and John Turner of DBA are the authors.  They worked hard with Silas Nichols and the team at FHWA to produce a great guidance document for accepting deep foundations supporting transportation structures.  Here is a bit from the Introduction in Chapter 1 that gives the “big picture” of this GEC:

Foundation acceptance is a crucial component of the design and construction process used to develop transportation infrastructure in the United States today. As considered in this circular, foundation acceptance refers to a process resulting in approval of payment
to the constructor for installation of a deep foundation element. The process should involve the following actions by an owner agency, or entity acting on its behalf:


      1. Establishment of measurable and achievable acceptance criteria that serve as assurance that a foundation element will fulfill all appropriate performance requirements, and


       2. Documented evaluation of the constructed foundation element to demonstrate that the established acceptance criteria have been satisfied.


Foundation acceptance is the culmination of quality assurance (QA) efforts that, when appropriately implemented, provides the owner agency with confidence that a foundation element will fulfill all appropriate performance requirements. In some instances, the
foundation acceptance process may include provisions for cost adjustments for foundation elements that do not strictly satisfy established acceptance criteria, but that are nevertheless judged to satisfy all appropriate performance requirements and which
the owner agency agrees to accept.

Topics covered in this GEC include the framework for accepting deep foundations (project delivery, participants, role of QA/QC,etc.) , roles of inspection and testing, and specific items of concern for drilled shafts, driven piles, micropiles, and continuous flight auger piles.  You can download the PDF at the link below or on the FHWA Geotechnical Publications page HERE.

 

Acceptance Procedures for Structural Foundations of Transportation Structures  (FHWA-HIF-22-024, Geotechnical Engineering Circular 015).  Loehr, E.L., Brown, D.A., Turner, J.P., and Boeckmann, A.Z. (2022).

Bridge Construction, Bridge Foundations

DBA Helps MnDOT Manage Risk for Dam Site

DBA recently completed construction observation of pile driving and earthwork for TH-84 across Norway Brook in Pine River, MN. The structure may look like a run of the mill bridge, but the project was replete with geotechnical challenges associated with constructing a new bridge at the toe of an active dam. (We use “run of the mill” with all due affection; there’s no such thing as a boring bridge to DBA.)

During the design phase, DBA designed an instrumentation system and used the resulting piezometric information to calibrate seepage models for the site. The calibrated models were used to analyze conditions during and after construction of the new bridge. DBA also developed an emergency action plan (EAP) that established items to observe during construction, defined levels of distress leading up to all potential failure mechanisms, and designated response actions associated with the distress levels. During construction, DBA was on-site to implement the EAP, coordinating with the contractor, Schroeder Construction, Inc., and MnDOT to quickly respond to any evidence of distress.

Throughout analysis, EAP development, and EAP implementation, DBA collaborated with the bridge designer, Parsons, and MnDOT to identify, explain, and manage the risks associated with this unique and challenging project. We are pleased to see live traffic crossing the dam in the picturesque Minnesota North Country!

Here is a link to a video shot by Dan Ding of DBA during construction:

Finally, some photos of the finished bridge:

 

Bridge Construction, Bridge Foundations, Drilled Shafts, Foundation Design, Instrumentation, Miscellaneous, Slope Stability

Instrumentation at US 231 bridge and Slide

(Written by Andy Boeckmann – DBA)

After successful design and construction of the US 231 emergency slide repair in Lacey’s Spring, Alabama, DBA shifted gears to install a state-of-the-art monitoring system for the project. The monitoring system allows DBA and ALDOT to remotely detect any movement of the drilled shafts, changes in groundwater levels, and movement of the slope, itself.

The monitoring system includes ShapeAccelArray (SAAV) devices to measure displacement profiles with depth. SAAVs, which are manufactured by Measurand, consist of a chain of rigid segments, each 1.5-ft long and about 1-inch diameter. DBA installed 27 SAAV devices at US 231. Each of the 24 drilled shafts has one SAAV, which DBA installed in a 1-inch conduit welded to the drilled shaft reinforcement and emerging from the top of the grade beams connecting the shafts. The other three SAAVs are “free-field” SAAVs, installed in the soil between bridge bents. DBA worked with ALDOT’s drill crews to install the free-field SAAVs.

ALODT drill crew installing a free-field SAAV under the Northbound bridge.

 

Completed free-field and foundation instruments at Bent NB4.

 

DBA also worked with the ALDOT drill crews to install vibrating wire piezometer devices at six locations across the site. Each location includes two piezometers, one in the soil and one just below the top of rock. The piezometers were installed using the fully-grouted method. The piezometers measure pore pressure, which DBA uses to interpret groundwater conditions at the site.

 

Datalogger atop a vibrating wire piezometer.

 

All of the instruments are connected wirelessly to two central hubs that collect the data. The hubs are solar powered.  One of the hubs is equipped with a cellular modem that facilitates remote collection of the data.  RST Instruments manufactures the monitoring equipment as well as the vibrating wire piezometers.

Housing for SAAV devices installed in drilled shafts.

 

R-star hub and solar panel mounted to SB Bent 6.

 

Inside of data collection hub.

 

Results of the monitoring program indicate the foundation system is performing as designed. The US 231 structure has passed its first wet season with flying colors. Despite several periods of heavy rain that resulted in localized slope movement, the drilled shafts have shown only very small movement, typically less than 0.05 inch. The movement shown in the shafts indicates they are resisting loading from the slope movement, but with plenty of reserve capacity. The monitoring system has successfully captured realistic results from all instruments, including the drilled shaft and free-field SAAVs and piezometers.

Piezometer data shows strong correlation between rainfall and increases in groundwater levels.
Example of SAAV drilled shaft displacement. Shaft displacements are very small, typically less than the stated accuracy of the SAAV devices.

The monitoring system is more than just bells and whistles: it is an integral part of DBA’s design philosophy for the US 231 project. DBA engineers were able to implement the innovative strategy of drilled shafts through an active landslide because we knew performance of the foundation system would be actively monitored. This strategy represents a modern take on the observational method, which has represented best geotechnical engineering practice since the profession originated. DBA will also use results of the monitoring program to inform future designs, consistent with our commitment to using state of the art to improve the state of practice.

To read more in detail about the design and construction of the bridge foundations, we published an article i nthe April 2021 issue of Foundation Drilling Magazine:

Thompson, W.R. and Dapp, S.D. (2021). “Innovative Landslide Solution”, Foundation Drilling, Vol XLII, No. 3April 2021, pp51-62.

Bridge Construction, Bridge Foundations, Drilled Shafts, Driven Piles, Foundation Design

DBA Project Highlight: MoDOT I-44 Project Bridge Rebuild

I-44 Construction Aerial View; video courtesy of Emery Sapp & Sons

DBA has partnered with bridge designer Parsons and prime contractor Emery Sapp & Sons on a design/build project in Southwest Missouri being administered by MoDOT.  Design is complete and the project is in construction phase.  The project involves replacing 13 bridges and rehabilitating another six bridges along a 30-mile stretch of I-44 between Sarcoxie and Halltown.  The $36 million project is progressing nicely with construction beginning in 2019 and on schedule to be completed by December 15, 2021. To get a birds-eye view of some of the work, check out the video at the top of the post (from Emery Sapp & Sons)

Although smaller bridges than DBA typically works on, challenging subsurface conditions and unique structure types have made things interesting with respect to foundation design and construction.  Foundation types for various structures include driven H-piles installed with high-strain dynamic testing, drilled shafts with rock sockets in various rock formations, and spread footings bearing on near surface bedrock where applicable.  Pinnacle bedrock surface and karstic foundation conditions are prevalent in the area and this project is no exception.  Foundation design had to anticipate the complex subsurface conditions and consider constructability throughout the entire design process.

More information on the project can be found at MoDOT’s project page:  https://www.modot.org/i-44-project-bridge-rebuild .  Below are some photos taken by DBA staff while on site.

Photo Credit: DBA

 

Bridge Construction, Bridge Foundations, Drilled Piles, Drilled Shafts, Foundation Design, Micropiles, Miscellaneous, Rockfall Hazard, Slope Stability

Two Major Bridges in Minnesota Open to Traffic

St. Crox Crossing Extradosed Bridge; photo courtesy of MnDOT

Two DBA bridge projects in Minnesota opened to traffic recently.  The St. Croix Crossing near Stillwater and the Highway 53 Relocation in Virginia.  Both projects are milestones for MnDOT.  The St. Croix Crossing is the first extradosed bridge in the Midwest and only the second extradosed bridge in the United States.  The new Highway 53 Bridge is the tallest bridge in Minnesota.

Following a ribbon cutting and dedication ceremony on the morning of Wednesday, August 2nd, the St. Croix Crossing saw its first traffic later that evening and has already alleviated traffic congestion  in downtown Stillwater,  as intended.  The interstate project was also heralded as a noteworthy example of government cooperation by The Wall Street Journal.

After officially breaking ground just shy of two years ago,  the new Highway 53 bridge opened to traffic on September 15th.  A dedication ceremony was held underneath the bridge that morning with Minnesota Lt. Gov. Tina Smith and Congressman Rick Nolan in attendance.  In  anticipation of the new bridge, the iron range quad cities of Virginia, Eveleth, Gilbert, and Mountain Iron held a four-day, multi-event festive, Bridge Daze, in August.

Hwy 53 Bridge Across The Rouchleau Pit; photo courtesy of OxBlue construction cameras

Bridge Construction, Bridge Foundations, Drilled Piles, Foundation Testing, Micropiles, Rockfall Hazard

TH 53 Bridge Begins to Rise from the Ground

Bridge and Subsurface Rendering
Bridge and Subsurface Rendering (rendering courtesy of MnDOT)

A lot has changed from a year ago at the TH 53 Bridge sight near Virginia, Minnesota.  This time last year, the design-phase test pile program was wrapping up with three Statnamic load tests and we had just completed our initial geologic field investigation.  Since then, significant excavation, rockfall protection, and foundation work has been completed.  During summer and fall of 2015, DBA worked closely with contractors Hoover Construction and Pacific Blasting to maintain rockfall protection throughout the East Abutment and Pier 1 (East Pier) excavation process.  Official ground breaking occurred last November and foundation work started shortly after.  A total of 32, 30-in micropile foundations have been installed by Veit Specialty Contracting  and Kiewet Infrastructure  has completed a temporary causeway across the massive Rouchleau Pit by placing over 300,000 cubic yards of fill.

With the foundations of both piers complete, and the pier towers are starting to rise up, where they will carry the bridge deck 200 ft above.  The abutments are also taking shape with rock bearing concrete footings now poured on both sides of the pit.  The only foundation work left is to install tieback anchors at the East Abutment, which will reduce the lateral loading of the tall piers. This bridge is going to get packed with cars once it´s completed, that means there´s going to be lots of accidents. It´s not a bad idea to call One Sure Insurance to get covered before all that.

In a little over a year, the bridge is scheduled to open to traffic.  You can keep track of the progress through the project web cam.

Current View of Site, Piers Beginning to Rise
Current View of Site, Piers Beginning to Rise (photo from OxBlue Web Cam)

Bridge Construction, Bridge Foundations, Drilled Shafts, Foundation Design, Load Testing

Goethals Bridge – Up and out of the ground

(Post and photos provided by John Turner, Ph.D., P.E., D.GE of DBA.)

DBA has had the privilege to be the geotechnical/foundation engineer for the Goethals Bridge Replacement (GBR)Project, a design-build project for the Port Authority of New York & New Jersey (PANYNJ). The project will replace the existing Goethals Bridge that was built in the 1920s and carries I-278 over the Arthur Kill River between Elizabeth, New Jersey and Staten Island, New York.

Construction of drilled shafts continues as the superstructure begins to emerge over the skyline between Elizabeth, NJ and Staten Island, NY.  The new bridge will be a dual-span 1,983-ft long cable-stayed bridge with approach spans of over 2,500 ft on each side.  The bridge is supported on over 200 drilled shaft foundations ranging in diameter from 4.5 ft to 10 ft and socketed into Passaic Formation siltstone.

Goethals April 2016

The GBR is a Public-Private Partnership (P3) that represents a major milestone for the PANYNJ in its distinguished history of bridge building in the greater New York City metropolitan area.  The existing Goethals Bridge along with the Outerbridge Crossing and the Bayonne Bridge comprise the three Port Authority bridges connecting Staten Island with New Jersey.  The Goethals Bridge and the Outerbridge Crossing are cantilever truss structures and both opened on the same day in 1928. They were designed by J.A.L. Waddell under the supervision of the eminent engineer Othmar H. Ammann (1879-1965), who was the designer of many other iconic bridges in the NY City area including the Bayonne Bridge (1931), the George Washington Bridge (1931), and the Verrazano Narrows Bridge (1964).  The designer of record for the replacement Goethals Bridge is Parsons Corporation, which is the successor firm of Robinson & Steinman, whose principal David B. Steinman was also a notable NY area bridge designer and a contemporary and rival of O.H. Ammann.

Each main pylon tower of the GBR is supported on a group of six 9-ft diameter drilled shafts and each anchor pier is supported by two 10-ft diameter shafts.  Approach piers are two-column bents with each column supported on a rock-socketed drilled shaft.

Goethals shaft 1

DBA is the foundation design engineer of record and this project provides an example of how rock-socketed drilled shafts can provide a reliable and cost-effective means of supporting a major bridge by taking advantage of the high resistances that can be achieved.  Key factors involved in taking advantage of rock sockets for this project were:  (1) load testing to demonstrate high axial resistances (>30 ksf side resistance and  >300 ksf base resistance), (2) utilization of all relevant construction QC/QA tools to ensure that rock sockets are constructed in a manner that is consistent with construction of the load-tested shafts that provide the basis of the design, (3) close collaboration between all members of the design-build team, and (4) adequate subsurface characterization, especially a thorough characterization of rock characteristics and their effect on socket resistances. Load testing for this project demonstrates that side and base resistances can be used in combination to design rock socketed shafts for axial loading.  This approach avoids the use of unnecessarily deep sockets, thereby minimizing the associated construction risks and costs.

Goethals rendering

The GBR project developer is NYNJ Link Developer, LLC and construction is being performed by a joint venture of Kiewit-Weeks-Massman (KWM).  Parsons is the lead designer.  A construction web-cam and additional information on the GBR can be found at the Port Authority’s website: http://www.panynj.gov/bridges-tunnels/goethals-bridge-replacement.html

Bridge Construction, Bridge Foundations, Foundation Design, Foundation Testing, Load Testing, Micropiles, Slope Stability

DBA Engineers Perform “Extreme” Geologic Investigation

DBA engineers prepare to go over the edge of the 200-ft tall west wall of the Rouchleau mine pit with the load test site in the background. From left to right: David Graham, Nathan Glinski, Ryan Turner, and Paul Axtell
DBA engineers prepare to go over the edge of the 200-ft tall west wall of the Rouchleau mine pit with the load test site in the background. From left to right: David Graham, Nathan Glinski, and Paul Axtell (far right).

DBA is currently working with structural designer Parsons to design what will be Minnesota’s tallest bridge.  The bridge will span the currently inactive Rouchleau open pit iron ore mine near Virginia, Minnesota. MnDOT is moving the alignment of the existing Hwy 53 to make way for future mining in the area.  DBA is the lead geotechnical designer on the project in addition to being contracted as MnDOT’s load test expert for the ongoing design phase load test program.

As part of our site investigation to gather information on rock fall and the site geology, five DBA engineers (John Turner, Paul Axtell, Tim Siegel, Nathan Glinksi, and David Graham) got up close and personal with the site by rappelling off the near vertical cut faces on either side of the Rouchleau pit! Traversing the over 200-ft tall cut faces of the nearly 2-billion year Biwabik Formation rock formation by rope and harness, we collected valuable geologic data.  We also took some great pictures like the ones posted to our Google Photos account.  In addition to the still pictures, we took some videos of a few rock fall tests, which are on our YouTube channel.

If you would like to know more about this interesting project on Minnesota’s Iron Range, you can check out our project summary sheet, visit MnDOT’s project page, or stay tuned to this blog for more updates.  There is also an online article about the project that was recently published by Civil Engineering Magazine.

Bridge Foundations, DBA News, Research

New PEER Report – Evaluation of Collapse and Non-Collapse of Parallel Bridges Affected by Liquefaction and Lateral Spreading

webPEER-2014-10-Brandenberg

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.

Turner, B., Brandenberg, S.J. and Stewart, J.P. (2014). “Evaluation of Collapse and Non-Collapse of Parallel Bridges Affected by Liquefaction and Lateral Spreading”, PEER Report 2014/10, Pacific Earthquake Engineering Research Center, University of California, Berkley, August, 2014, 94pp.

Bridge Construction, Bridge Foundations, Foundation Design

Goethals Bridge Replacement – Webcam!

goethals-replacement-logo

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.

You can learn more about the project at the same web site.  There is also a site for the current bridge, including history of the construction, etc.