Tag Archives: Deep Foundation Design

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:

 

FHWA GEC 10 Update for 2018 Released!

UPDATE!  Posting of the PDF to the FHWA Resource page has been delayed while the formatting issues noted below are worked out. 

CLICK HERE for a Final DRAFT for use until FINAL document is posted by FHWA.

The long anticipated update to FHWA GEC 10 Drilled Shafts: Construction Procedures and Design Methods has finally been released by FHWA, The same team that authored the major update in 2010 that shifted design from ASD to LRFD also completed this update: Dr. Dan Brown, P.E., D.GE, and Dr. John Turner, P.E., D.GE of DBA, Dr. Erik Loehr, P.E. of the University of Missouri and DBA, and Mr. Ray Castelli, P.E. of WSP.

This version is an update of the 2010 publication.  A complete list of changes made since 2010 is in the opening chapter.  Some of the revisions include:

  • streamlining materials covered in other GEC publications (for example, site investigation and lateral loading) to focus on aspects particular or unique to drilled shafts;
  • updates to reflect the evolution of construction procedures, tooling, materials, drilling fluids, and concrete placement;
  • updated design equations for axial loading, particularly for earthquake loading;
  • updated group design to reflect recent changes to AASHTO design guidelines;
  • updates on integrity testing (including use of Thermal Integrity Profiling, or TIP); and,
  • an outline for a process for assessment and acceptance of drilled shafts based on inspection records and integrity tests.

You can download the new PDF here.  The PDF posted is “preliminary” with some minor formatting and other items to be cleaned up by the fall.

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)

Ground Breaking of New TH 53 Bridge in Minnesota

TH 53 Bridge

TH 53 Bridge, artistic rendering courtesy of MnDOT

The official groundbreaking for the Trunk Highway (TH) 53 Bridge and Relocation Project occurred last week at the project site in Virginia, Minnesota.  The bridge, which is the main element of the project, will span the Rouchleau Iron Ore Mine Pit.  The project is scheduled to be completed in a brisk two years in order to allow for mining where a section of TH 53 is currently located.  Upon completion the 1,100-foot long bridge will be Minnesota’s highest, with the roadway sitting approximately 330 feet above the bottom of the floor of the Rouchleau Pit.  Kiewit was selected as the general contractor for the project with Veit Specialty Contracting as the foundation contractor.

Foundation construction will start in late November or early December with the installation of 30-inch diameter micropile foundations for the western pier of the three span, steel plate girder bridge.  Although the foundation work is just about to get started, DBA has been hard at work on the project for over a year.  DBA first got involved as a consultant to MnDOT for the design-phase load test program conducted last fall.  Since then, DBA was contracted as the geotechnical engineer of record for the project.  Working with bridge designer Parsons, DBA designed the bridge foundations, an anchored abutment, and rockfall hazard mitigation systems for this geologically challenging site.  DBA has also analyzed several soil and rock slopes to verify stability of the bridge and roadway.

Most recently, some of us were on site to inspect some of the rockfall protection elements on the east side of the mine pit. Last week we spent two days climbing and repelling a on a portion of the eastern highwall, which is currently covered in rockfall protection drapery. The drapery was installed for the protection of workers excavating rock for the eastern bridge pier.   The drapery was installed by Pacific Blasting in association with Hoover Construction.  Some pictures from our drapery inspection visit are below.

For more information about the project, click here, and for our previous blog posts on this project, click here.

John and Paul provide some scale to this picture as they work their way down the drapery.

 John concentrating as he inspects the drapery seam as he decends.

Deep Foundations Events Update–October 2013

As involved as we are in the deep foundations industry (and just returning from the DFI annual conference), it seemed appropriate to take time to highlight several upcoming events in the industry.  All of these are great opportunities to get PDH credits, do some networking, and build relationships in the deep foundations industry.  Most are cooperative efforts of one or more of the G-I, DFI, PDCA, and ADSC.  All of them have a line-up of great speakers that are leaders in the industry.  Click on the links below to learn more about each one. 

 

14th Annual Design and Installation of Cost-Efficient Piles Conference
Wednesday, October 23, 2013
Sheraton North Houston, Houston, TX

The DICEP conference will present modern approaches to maximize Efficiency, Effectiveness and Economy (E3) of driven piles through a series of presentations including driven pile design, testing, evaluation and case studies.  Steel sheet pile design and corrosion protection are also addressed.

 

 

Drilled Shaft Foundations Seminar – Reliability in Drilled Shaft Foundations
Thursday, November 7, 2013
Hilton Midtown, New York, NY

The program will feature presentations by leading industry design engineers and civil engineering contractors on some problems encountered with drilled shaft foundations and how those problems were solved.

 

 

Driven Pile – A Foundation for the 21st Century
Wednesday, November 13, 2013
Loews Vanderbilt Hotel, Nashville, TN

  • A one-day specialty seminar on driven piles
  • Featuring 11 presentations by key industry professionals
  • Provides 6 PDH credits for all participants, including 1 PDH on Ethics  

 

 

Here are few open Calls for Abstracts (by order of due date):

IFCEE 2015 – March 17-21, 2015 – San Antoniio, TX – Due October 28, 2013

DFI 39th Annual Conference on Deep Foundations – October 21-24, 2014 – Atlanta, GA – Due January 10, 2014

DFI Superpile 2014 – June 19-20, 2014 – Cambridge, MA – Due February 3, 2014