Geotechnical 101 reference 2

[AlexWong122]

Hi all,

I am a structural engineer and am very fresh new in geotechnical field. Now my work requires me to go to site to identify the soil strata in the cut slope and identify the foundation soil type and estimate the capacity. Previously it is mostly done by geotechcnial engineer therefore I don't need to worry about these items but now I have to do it on my own. Is there any good geotechncial introduction reference book or website that is recommended?

Many thanks,

Alex

 

[Ron]

Lambe and Whitman is a good start. There are many others. The Asphalt Institute has a good basic soil classification manual as does the US Department of Agriculture Soil Conservation Service.

 

[oldestguy]

One of the pitfalls of many texts is their use of equations, etc. giving support capability based on soil shear strength. Whereas, most situations I have dealt with the shear strength bearing value is far above the pressure that results in excessive settlement. Thus, I'd use references that relate settlement potential to bearing pressure. One reference that brings that out is an ASCE paper by B.K. Hough "Compressibility as the basis for soil baring value", ASCE Journal of Soil Mechanics and Foundations Division, August 1959 SM4, #2135 At the time that paper received more discussion submitting than any before for that division. One of them gave examples as to where his work was used to reasonably well predict settlements on many jobs. However, one situation was found to under estimate settlements. That was with granular soil fully saturated with high ground water.

Hough wrote a text called "Basic Soil Engineering", Ronald Press 1957. It is available on Line in used books I think. In there he has useful charts also tied to split spoon blow count when sampling tied to settlement as the controlling criteria. Get the second edition.

 

[BigH]

Above any other advice I or others can and will give: I DO STRONGLY SUGGEST THAT YOU FIND YOURSELF AN EXPERIENCED GEOTECHNICAL ENGINEER AS A MENTOR . . .

I would suggest, though, that Terzaghi and Peck (1967) would be a good book to look at first (the 1995 edition with Mesri is much more complex) - the 1967 version will give you the way forward into thinking like a geotechnical engineer. The NAVFAC series (DM-1, DM-2 which can be obtained from VulcanHammer's site) is another good basic and understandable document. Yes, these books are old but it seems to me that you should be gaining a basic understanding before being pushed into the much more complex and numerical side of the field. Poulos' paper at the Istanbul ISSMFE conference is another good one to find and read. He goes through what was and is and if was is still applicable. Other books that I find useful would be Tomlinson's Design and Construction of Foundations - I prefer the older versions. These are chock full or real problems, not idealized problems that the newer text books seem to put forth.

 

[Ron]

BigH...excellent suggestions!

 

[oldestguy]

A little more info from you please. What sort of structures will sit on your sites? Depending on the various loads and tolerances to settlement there may or may not be the need for you to pass the individual job on to someone more experienced. Of course Big H is right, but if you don't have that help,you can make mistakes. For instance when should test borings and maybe some lab tests be done ahead of any site visit, etc. Remember if there is a problem down the road, your reputation, livelihood, etc might be on the line and that isn't nice. Let's reverse the story. Suppose a junior geotech engineer is asked to OK the structural drawings from your shop and stamp them. Courses as undergrad in structures don't say much about details like bolt types, shop drawings, etc.