Posted in Pile Driving Equipment

The Pile Buck Ads 1: Vulcan 3100 Assembled

This site has never had an “advertising budget” but in the last decade the publisher Pile Buck gave it the opportunity to advertise itself in its books Sheet Pile Design by Pile Buck and Pile Driving by Pile Buck.  There were five in the series, and this is the first, using the assembly of the first 3100 hammer as a backdrop.

The ads were placed before the inception of the one site not mentioned on the ad:, so the “Wave Equation for Piling” was still on this site.  More about the Vulcan 3100 is here.

Posted in Civil Engineering

Jean-Louis Briaud Elected President of ASCE

Congratulations are in order to Jean-Louis Briaud, Ph.D., P.E., D.GE, Dist.M.ASCE, and Spencer Buchanan Distinguished Professor of Civil Engineering at Texas A&M University, for his election as President of the American Society of Civil Engineers for 2019-20.

Jean-Louis is an old friend and a great person.  Our association goes back to the 1980’s when I was principal at Vulcan Iron Works and active in the Deep Foundations Institute.  He has been an encouragement to me through the years, especially with this effort.

On this site he was featured for his “pet peeve” regarding consolidation a few months ago.  He posed an interesting problem that needs some discussion.  I believe he will challenge us to tackle other interesting and important problems during his term as President.

Posted in Soil Mechanics

Terzaghi “Low Walls” Curve Correlations

Practitioners who design gravity retaining walls are familiar with the existence of Terzaghi’s “low walls” curves to estimate the equivalent fluid pressure on the wall, horizontal and vertical.  The basic chart comes in several versions but the one (for straight backfill) from NAVFAC DM 7.02 is above.  The explanation for it (important when one is using it) is below.


In the “slide rule” days, reading charts like this was routine.  A better way now, with spreadsheets abounding, is to have a formula available.  Some least squares curve fitting correlations are shown below.  The variable \beta is the slope angle as shown in the figure.  As is the case with the chart, the formulas return K_v and K_h in units of \frac {psf}{ft} of wall length.

  • K_v (top chart)
    • Soil 1 K_v = 0.0127 \beta^{2.21}
    • Soil 2 K_v = 0.043 \beta^{1.92}
    • Soil 3 K_v = 0.109 \beta^{1.71}
  • K_h (bottom chart)
    • Soil 1 K_h = 30 + \frac{exp^{0.139 \beta}}{4}
    • Soil 2 K_h = 37 + \frac{exp^{0.138 \beta}}{4}
    • Soil 3 K_h = 48 + \frac{exp^{0.148 \beta}}{5}

The Esplanade Bridge is a 261-metre-long (850 ft.) road bridge that spans across the mouth of the Singapore River in Singapore with the Esplanade – Theatres on the Bay on its northern abutment and the Merlion on the southern. The 70 metre-wide (230 ft.) low-level concrete arched bridge has seven spans and supports two four-lane carriageways and walkways along both sides. The bridge was built to provide faster vehicular access between Marina Centre and the […]

via Esplanade Bridge over Marina Bay, Singapore — Construction and architecture

Esplanade Bridge over Marina Bay, Singapore — Construction and architecture