Tag Archives: Deep Foundation Construction

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)

Bubble Curtain for Driving Piles at Tappan Zee

TZ curtain_lohud

Image source: lohud.com

The design-build team Tappan Zee Constructors that is building the Tappan Zee Bridge is installing the over 200-ft long steel pipe piles using a relatively simple concept to mitigate vibration impacts on fish – a bubble curtain.  Such curtains have become more common as an approach to mitigate potential impacts (pardon the pun) on aquatic life when large piles are driven over water.  The vibrations from the hammer impact on the pile during driving are reduced or dampened by a curtain of bubbles generated around the pile by compressed air.  An item in the December 26th ASCE Smart Brief linked an article in The Journal News (White Plains, NY) highlighting the use of the curtain on the Tappan Zee project.

 

A rubber-looking sleeve covered the hammer where it met the pile, dampening some of the noise in the air. Underwater, however, it was a curtain of bubbles serving as the aquatic equivalent of earplugs for fish and other creatures in the Hudson River.

Aluminum rings are slid over the pilings like the rings on a shower curtain rod before any banging starts. Air pumped into the rings produces a sheath of bubbles in the water around the pile. The froth generated in the water is called a bubble curtain.

“Bubble curtains are designed to protect the fish in the area from the noise generated by the hammer impact below the water level,” said Walter Reichert, project manager for Tappan Zee Constructors. “This divides the water into basically two sections. It greatly reduces the sound waves.”

Check out the article for some neat pictures and a cool video about the process (with hammer sounds!).  Here is a small picture gallery from lohud.com.

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