Tag Archives: Geotechnical Engineering

NCHRP Report 697 – Design Guidelines for Increasing Lateral Resistance of Bridge Pile Foundations

nchrp_rpt_697_coverWe have added a link to the NCHRP Report No. 697 Design Guidelines for Increasing Lateral Resistance of Bridge Pile Foundations.  This report was published in 2011 and authored by Kyle Rollins, Pd.D., P.E. of Brigham Young University and our own Dan Brown.  Dr. Rollins is a Professor in Geotechnical Engineering specializing in earthquake engineering and soil improvement.

 

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 Additional resources and design guidelines will be helpful to designers responsible for bridge foundations likely to be exposed to significant lateral loads.

Be sure to browse all of the nifty reports and projects in geotechnical and foundation engineering at TRB here.

Also check out our Publications page regularly for new postings.

Websites That ROCK!

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, although most of the childs these days just like to play LOL.

Happy Karl Terzaghi’s Birthday 2013!

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Happy Karl Terzaghi’s Birthday, my friends!  Yes, it is time to raise our coffee, espresso, tea, wine, beer or other beverage to toast the Father of Modern Soil Mechanics as has been our custom here at the DBA blog.

As I pondered what to write this year, I perused a couple of books and ended up looking through my copy of Richard Goodman’s  “Karl Terzaghi – The Engineer as Artist”.  Among the many stories and accounts, I found this passage recounting an incident in the late 1950s (Ch. 17, pp245):

At this critical time, the world was reminded of the terrible consequences of dam failure when Board member Andre Coyne’s Malpassat Dam failed in France, causing more than 400 deaths (in Frejus, very near Ruth’s 1939 refuge on the French Riviera).  It failed on the initial filling of the reservoir due to geological weakness in one of the rock abutments of the very thin concrete arch.Later Karl would express sever criticism of the decision to bold such a structure on a geologically inadequate site.  But now he comforted his distraught colleague, writing that “failures of this kind are, unfortunately, essential and inevitable links in the chain of progress in the realm of engineering, because there are no other means for detecting the limits to the validity of our concepts and procedures…. The torments which you experienced should at least be tempered by the knowledge that the sympathies of your colleagues in the engineering profession will be coupled with their gratitude for the benefits which they have derived from your bold pioneering.”

Throughout the book, Goodman does an excellent job of showing the different facets of Terzaghi, and this is no exception.  He had a reputation of being a tough, direct, and straight-forward engineer that did not pull punches.  Here we see a somewhat softer side as he comforts a colleague, who was an expert in his own right.

If you have not read Goodman’s book, I highly recommend it for all Terzaghi fans!  It is published by ASCE and can be found through the ASCE Bookstore, or at other book retailers.  (Disclosure:  Neither DBA or any of its employees receive any commissions, compensation, or other considerations for promoting this book.)

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

Call for Abstracts – 2015 International Foundations Congress and Equipment Exposition (IFCEE 2015)

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Although 2015 seems like a long way away, when you are planning the largest foundation engineering and construction conference in the U.S., you need to get started early!  The organizing committee for the  the 2015 International Foundations Congress and Equipment Exposition (IFCEE 2015) has released the Call for Abstracts here at the conference website.

This conference will be at the JW Marriott in San Antonio, Texas, March 17-21, 2015 and is hosted by a joint effort of ADSC: The International Association of Foundation Drilling (ADSC), Deep Foundations Institute (DFI), Geo-Institute of the ASCE (G-I), and Pile Driving Contractors Association (PDCA).  The program will include technical paper sessions (as poster or podium presentations), panel discussions and debates, indoor exhibits, an outdoor equipment exposition, educational short courses, technical committee meetings, and networking events.

DBA Engineers Coauthor Cover Story of Latest DFI Magazine

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Cover Image of the Hastings Mississippi River Arch Bridge

The featured article in the July/August 2013 issue of Deep Foundations, the magazine of the Deep Foundations Institute, is coauthored by Dan, Paul, and Rich Lamb, P.E., of the Minnesota Department of Transportation (MnDOT).  The article summarizes how load testing has been used successfully as part of the foundation design process by DBA and MnDOT on five major bridge projects along the Mississippi and St. Croix Rivers during the last 10 years and the lessons learned from these successive projects.   The featured bridge projects include two major design-build projects, the emergency replacement of the I-35W St. Anthony Falls Bridge (2007) and the Hastings Mississippi River Arch Bridge (2011).  The other traditional design-bid-build projects include the I-494 Wakota Mississippi River Bridge, the U.S. Hwy 52 Lafayette Mississippi River Bridge, and the St Croix River Bridge.  As is often the case, each of these projects presented unique geological and hydrogeological challenges to foundation design – despite the projects all being within 30 miles of each other – including thick layers of highly organic compressible soils overlying bedrock, layers of cobbles and boulders, artesian groundwater conditions, and bedrock ranging from weak weathered sandstone to very hard dolostone.  These varying conditions resulted in the use and testing of a variety of foundations.  Load testing “with a purpose” has proven to be an integral part of the design and construction process on these projects, as the load tests were not simply for verification of a design but provided valuable information used to optimize the designs and provide quality assurance of the construction practices.

Please read the full article here or in a copy of Deep Foundations, a bi-monthly magazine published by the Deep Foundations Institute.   DFI is an international technical association of firms and individuals involved in the deep foundations and related industry.  More information about DFI and how to become a member can be found at www.dfi.org.

Also see our Projects Page for more about some of these projects and our other major projects.

NCHRP Synthesis 429 – Geotechnical Information Practices in Design-Build Projects

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Early this year, NCHRP released a synthesis report on geotechnical practices related to design-build projects.  I have had writing a blog post on this on my “to do” list for a few months and finally got down the list!

NCHRP Synthesis 429 – Geotechnical Information Practices in Design-Build Projects is a report on the current practices of allocating and managing geotechnical risk through the use (or lack of!) geotechnical information in transportation project bid documents.  Even though design-build as a delivery process for projects has been around for a while now, the allocation of risk due to subsurface conditions is an issue still treated with a variety of approaches. 

Those of us who have been in this industry for a while know that a thorough geotechnical investigation reduces both cost risk and construction/schedule risk.  Design-build is an effective method for accelerating project construction and delivery; however, the acceleration of the schedule puts more pressure on the geotechnical design since “geotechnical investigation and design is usually the first design package that must be completed and geotechnical uncertainty is usually high at the time of DB contract award.”

Because geotechnical investigation and design is usually the first design package that must be completed and geotechnical uncertainty is usually high at the time of DB contract award, the design-builder’s geotechnical designers are under pressure to complete their work and enable foundation and other subsurface construction to commence. Successfully managing the geotechnical risk in a DB project is imperative to achieving the requisite level of quality in the finished product. The purpose of this synthesis is to benchmark the state of the practice regarding the use of geotechnical information in DB solicitation documents and contracts. The high level federal encouragement through EDC for state DOTs to accelerate project delivery by using DB elevates the need to manage geotechnical risk while expediting geotechnical design to a critical project success factor, and makes the results of this synthesis both timely and valuable.

As is the case with NCHRP synthesis reports, the authors conducted a literature review, conducted a survey of state DOTs and other agencies, and developed some conclusions that include effective practices for managing geotechnical risk.

The synthesis was based on a comprehensive literature review; a survey of U.S. DOTs, which received responses from 42 states (response rate = 84%); a content analysis of DB solicitation documents from 26 states; a content analysis of DB policy documents/guidelines from 12 state DOTs and 5 federal agencies; and interviews of 11 DB contractors whose markets encompass more than 30 states. The synthesis also furnishes three legal case studies (Colorado, Illinois, and Virginia) on cogent geotechnical issues and four geotechnical engineering case studies (Hawaii, Minnesota, Missouri, and Montana) that illustrate the methods transportation agencies use to deal with geotechnical issues on DB projects. Conclusions were drawn from the intersection of independent sources of information from the survey, case studies, and literature.

Some of the effective practices highlighted include the use of confidential Alternative Technical Concepts (ATC) during pre-bid, explicit differing site conditions (DSC) clauses that clearly quantify the design-build team’s risk and the threshold above which the DOT assumes the risk, the use of qualified personnel, and timely review schedules for geotechnical design items early in the project.

Our (DBA) experience in design-build has seen the range from effective practices to poor practices.  This report provides a great summary of many of the effective practices we have found to be beneficial and that help reduce conflicts and delays.  We can’t completely eliminate geotechnical risk, but it can be effectively and equitably managed.

Click on the link below to get a copy from NCHRP.

NCHRP Synthesis 429 – Geotechnical Information Practices in Design-Build Projects

ENR’s Best of the Best 2012–Audubon Bridge

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The John James Audubon Bridge was recently selected as the Editor’s Choice/Transportation for ENR’s Best of the Best Projects for 2012.  The annual competition culminated in honoring ENR’s selection of the most outstanding construction projects in the U.s. And Puerto Rico complete between July 2011 and June 2012.

Nearly 1,000 project teams submitted their best work to ENR’s regional "Best Projects" competitions. For each of the nine regions, our editors assembled an independent panel of industry judges to home in on the winners in 19 categories. The winners of the regional contests moved on to the national competition. A different set of industry judges examined the projects to distinguish the "Best of the Best" in teamwork, success in overcoming challenges, innovation and quality. This year, a new award honors the safest project, judged by industry safety experts in both the regional and national competitions. Also, ENR’s editorial staff chose one special project as the "Editors’ Choice" to represent the pinnacle of design and construction excellence.

The Audubon Bridge won the Editor’s Choice – the editorial staff’s selection of the “pinnacle of design and construction excellence”.  Congratulations to everyone at Audubon Bridge Constructors (Flatiron, Granite and Parsons), Louisiana DOTD, and all who worked on the project!

Regular readers of our blog will be very familiar with the JJA as we often called it.   You can catch all of the geotechnical and foundation highlights on our project page, or check out previous posts.

Images from: ENR.com

“Geotechnical Monument” in St. Louis

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It may not have been intended as such, but we will “claim” this large rock core on the Mississippi River as a “geotechnical monument”.  At the site of the new I-70 crossing over the Mississippi River in St. Louis, one of the 11-foot diameter limestone rock cores retrieved from one of the rock sockets drilled for the bridge foundations has been placed on the river bank along with a sign. Our own David Graham stopped by and had some pictures taken when on a personal trip their last year.  So, the next time you are in St. Louis, look for the big hunk of rock on the west bank (St. Louis side) near the new bridge north of the Arch.

Check out our previous posts on this project here.

 

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Happy Karl Terzaghi’s Birthday 2012 (Updated)

Ah, October….here in the U.S. the leaves are beginning to turn as fall begins (or, in some places, fall off due to summer heat and lack of rain).  The beginning of fall marks a lot of things, such as the Major League Baseball playoffs (insert favorite team name here!), but more importantly the anniversary of the birthday of Karl Terzaghi!

I know that the past few years I have written an extended post highlighting something from Professor Terzaghi’s life or contributions to soil mechanics.  Alas, this fall I let the date creep up on me and my schedule this week left me little time to spend on a more detailed post.  I hope to resume that tradition next year.

Nonetheless, after a busy day of conference calls, design reviews, and calculations of pile resistance (or capacity for all of the folks still living in the ASD world), there will be time for a toast today, or maybe even a slice of birthday cake, in honor of our hero, Karl Terzaghi!

 

UPDATE 2!

Randy Post at Geoprac.net has set up 12 Terzghi Tweets for today.

UPDATE!

My friend (and former professor) Dr. Dave Elton, P.E., currently on sabbatical from Auburn University (War Eagle!), sent this ode today:

A timely ode to our Profession.

The beauty of soil’s

What we consider today,

In which cause we toil,

Be it silt, be it clay.

Foundations are mighty!

The piles we drive!

Geosynthetics are awesome!

We feel so alive!

Tho’ our pride sometimes suffers:

The hillside displaces.

And foundations still settle,

Leaving dirt on our faces.

Still our cause it is just!

From gravel to marl,

Our technology awesome!

Started by Karl!

So onward we press,

With our powers, expert.

As to-day we honor,

The Father of Dirt.

Happy Terzaghi’s Birthday.

Karl Terzaghi (1883 – 1963)

(Celebrate: Go trigger a landslide. You have my permission.)

 

D. Elton, P.E.

Auburn University October 02, 2012

Not copyrighted. Forward at will.