Soil Mechanics


Hi there,

My name is Paul Joseph and I am the author of this blog. I did my Masters in Civil Engineering (Soil Mechanics) at MIT  in the mid 80s.  In 2010, I finished a Masters in Applied Mathematics at the University of Massachusetts (Lowell), and in 2013 Fall, obtained my Ph.D.

The insight I am most thankful for is this paper–it attempts to shed scientific light on a 2,500 year old mystery.

Since 2008 my interests have expanded to the mathematical modeling of various problems in cognitive neuroscience/computer science. My first publication on this topic suggests that structures in our brain that handle emotions can work as a decision system that is independent of our analytical decision system.   You can find this paper here.  As best I know, the human animal is the only surviving animal (the Neanderthal may have been similar in this regard)  that has two decision systems of roughly equal power built into its brain.  The implications of this dual decision system are, I think, momentous–nothing short of empirical evidence for the basis of an internal Hegelian dialectic within us all.

Steady states are ubiquitous in nature and a mathematical framework (loosely called “dynamical systems theory”) exists to describe systems with a steady state.  The Great Red Spot on Jupiter is an example of a steady state generated by a dynamical system;  mathematicians have extensively studied such dynamical systems.

In 1971, Steve Poulos at Harvard first described the steady-state condition in soils.  Based on this I was able to show that soil shear can be described as a “dynamical system.”  You can find this publication here .  If you don’t have a subscription to the ASCE, you can find the pre-publication version here .

I also have a publication in Géotechnique, that provides additional evidence for a dynamical systems based approach to soil shear.  This publication is available  here.

The ASCE International Journal of Geomechanics (IJOG) recently published my paper describing the physical basis of this earlier finding that soil shear is a dynamical system. You can find this paper here and the pre-publication version here.  This IJOG paper shows that the underlying basis of the soil shear dynamical system is  nothing but Poisson process based simple friction.

Together these basic findings (steady-state, dynamical systems, Poisson process based simple friction) mark the advent of a new paradigm for describing soil deformation that is at once both simple and powerful.  I call this new paradigm Dynamical Systems Soil Mechanics (DSSM for short).  It is the only theory that predicts the linear semi-log relationship between the void-ratio and the vertical effective stress in one-dimensional compression, and not, as does other theory, simply take it as a given.

Looking back on my journey in soil mechanics, it seems nothing but the same old story–The Three Metamorphoses of the Spirit–that Nietzsche powerfully described in his classic Thus Spake Zarathustra. Thus during my undergraduate with Prof. Ramaswamy, at the University of Madras, Guindy, India, and then in graduate school at Purdue and MIT, I was like a camel, loading myself with knowledge.  After MIT I wandered in the desert until at GEI, thanks to the nurturing kindness of Gonzalo Castro and Steve Poulos, I turned into a lion.  For the next ten years I fought with the great dragon: “‘Thou-shalt,’ is the great dragon called. But the spirit of the lion saith, ‘I will’.”  And then, in the course of this struggle, I became like a child in soil mechanics: “Innocence is the child, and forgetfulness, a new beginning, a game, a self-rolling wheel, a first movement, a holy Yea.

I wonder how many of you will understand how exactly Nietzsche described this, my long (three decades)  journey in soil mechanics—I myself understood this only recently, several years after it was all done.

I have created a short, free, online course on DSSM.  Should you do this course (it should take you a week or so), you will have a complete understanding of DSSM.  The course’s introduction provides guidelines on how to get the most out of it with relatively little effort–just 20% of the course (three chapters) will provide you 80% of the knowledge of DSSM, including the KEY concepts–the balance 80% that covers the finer details is intended for researchers.  I hope you do this course and ask me any questions you may have–I promise you that unless I am physically or otherwise incapacitated, that I will reply to any email question.

I greatly enjoy the questions and comments I get so please continue to send these to me using the box below.  


Paul G. Joseph Ph.D., P.E., M. ASCE


2 Responses

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  1. andreea said, on January 25, 2009 at 5:33 pm i’m in the third year at the technical university of construction in bucharest,romania and i was wondering if you could send my your lecture notes from soil mechanics(i’ve found some lecture notes on the mit website..but i needed something more complex-i don’t quite understand from my incomplete and insufficient courses)..i’m very interested in this subject as my examination is approaching..
    i would be most grateful if you could help me in any way.thank you

  2. Paul Joseph said, on January 26, 2009 at 12:51 am

    Dear Andreea,

    Thank you for your e-mail. From it I gather that you are an under-graduate student. The reason I point this out, is because for undergraduates, the best approach is to focus “narrowly” on the exam. This means studying the notes that your teacher may have given during the class. Going to a new text book suddenly will be confusing at this stage–later on, once you have a good understanding of the fundamentals, you can look at the other authors to see what they say.

    IF like me, you did NOT take notes during class ;-), then I suggest that you purchase the textbook recommended for your course. If no text book was recommended, then I’d suggest the cheapest undergraduate textbook (preferably a used one to save money) which appears to cover the material you will be tested on. After your exam, should you find that you are still interested in soil mechanics, then you can get more books, new ones too if you wish!

    I wish you the very best on your exam–take it easy–life is more than exams and grades are never a measure of your future creativity, which in the end, is far more important than rote knowledge.

    Paul Joseph

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