Geotechnical Exploration Manual 2

[geodad]

I am a long time thread-stalker and member with a new username. I have a new job working with the State and I am currently developing a Geotechnical Exploration Manual for the Department of Transportation. I am looking to poll the great minds of this community and ask; what topics do you believe are a "must have" in a document like this from a state transportation organization? Do you think the manual should include direction as to how tests should be performed? I am sure more questions will come to mind.

Thank you in advance, I look forward to your responses!

 

[fel3]

This is not my area of expertise. However, I see that the California Department of Transportation (Caltrans) has a manual like you describe. Here is the link:

http://www.dot.ca.gov/hq/esc/geotech/geo_manual/manual.html

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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[PEinc]

https://www.amazon.com/Roy-E.-Hunt/e/B001JS140M&ref_=fsclp_pl_s_10

http://www.PeirceEngineering.com

 

[MTNClimber]

I would look through other state's documentation on subsurface investigations and add these to your reading list:
Link
Link

 

[geodad]

Thank you, I have a number of examples, namely other state manuals and published standards. I am looking to get some ideas from the professional community who has to do business with a state DOT, as to what they feel is needed and/or topics they feel are lacking.

 

[oldestguy]

Much depends on who does the field work. For instance State crews probably do not need inspection. Also they may not have the budget restrictions that contract "drilling" should have. Also, what sort of training should State inspectors have, in house vs hired? Engineers as inspectors? Who decided on number of bore holes, tests? Consultants? State employees?

 

[geodad]

Thank you oldestguy, those are good questions, the manual will include minimum qualifications for drillers and inspectors.
It actually seems easier to qualify an inspector, just list minimum years of experience, education and locally approved certification course. Can still list years of experience for driller, but education is not as relevant and there does not appear to be many certification courses specifically for geotechnical drillers.

The intent of this manual is to be utilized by any customer performing an exploration for the state, and will be a reference to both state and public employees. I believe the book should provide narratives about the goals and minimum requirements for explorations, and stay away from providing specific directions for performance. I've seen some manuals that appear to limit the scope by specifying too much, I would like to leave room for new innovation and technology to be utilized.

 

[PEinc]

Nice references, MTNClimber.

http://www.PeirceEngineering.com

 

[MTNClimber]

Thanks PEinc.

geodad - Can you explain a little more of how the typical geotechnical investigations are awarded in your state? Do they go through the main engineering consultant, contractors, or directly through the state? What are the normal geotechnical issues across your state? What are the issues that the State is encountering with geotechnical engineers? Are there geotechnical engineers that are getting away with providing sub-standard reports that skimped on testing or number of borings to win the job? Is the state having an issue with geotechs not meeting some idea of the minimum requirements? Instead of having a manual, have you thought of having a generic site investigation specification (which could be tailored for each project) and/or guidelines for site investigations?

It's very difficult to address this manual idea. Most of us probably don't work regularly, or at all, in your state. I would suggest polling the engineering firms that do. Is there a geotechnical society in your state that could help out with your poll?

 

[GeoEnvGuy]

FYI ASTM just reinstated D420 geotechnical exploration. For a state geotechnical exploration manual as a consultant I would want to see the following.

Lists for acceptable
Field procedures
Lab procedures
Drilling methods

These are all ASTM or equivalent I do not see value in the state explaining field Vanes and atterberg limits.

Tell me the state wants ASTM or aashto or other procedures followed. My opinion reference latest version of ASTM as they update every few years.

A table of minimum exploration holes or spacing for different dot projects. This will make it easier for bidding purposes.

Table of seismic investigation and analysis requirements. This will make it clearer on what level of effort is required for bidding.

Report requirements and what it needs to state for each type of job. This will standardize the reports and allow for a basic check to see the report is providing what the rfp is asking for.

I see some manuals state how to do SPT tests and how the organization wants to correct for n160. To me this is not wise as the manual may not be updated and be out of date. If anything the state should list only relevant research journal articles completed in the state and provide high level maps for geology, seismic, frost depth etc. If you want the maps used in analysis it should be made digital to determine what the value is at which coordinate.

 

[fattdad]

Here's the manual I prepared when I came to work at VDOT. I also refer you to the FHWA, GEC 5, which was just recently updated.

There are certain aspects of our Manual of Instructions that are unique to our program. For example, VDOT separates soil-structure interaction matters to our structure and bridge division. So, I don't discuss P-Y relations or pile capacity in the manual. That's mostly covered in LRFD; however.

http://www.virginiadot.org/business/resources/Materials/bu-mat-MOI-III.pdf

f-d

p.s., just to add that our Manual of Instructions is referenced in all our professional service agreements and all design-build contracts. So, internally, we have the latitude to make adjustments to what we do. Externally (i.e., to our consultants and d-b contractors), it's contractual.

ípapß gordo ainÆt no madre flaca!

 

[geodad]

Thank you all so much, all info is appreciated.

MTNClimber - Currently the state has multiple award term contracts for drilling support and engineering consultants, however we also operate with a handful of drilling crews internally. We have subsurface investigation specifications for the term contracts, and SOP's for our state crews. Everything goes through the state and is inspected by the state, so no issues with investigations or reports. There is a desire from the state to create/update state documentation to stay current with the new NCHRP Manual. There is also a desire by the state to find more ways to employ the public, and creation of a manual could potentially allow more work to be performed through the contracts in the future.

 

[Okiryu]

I just saw this ASCE publication:

https://ascelibrary.org/doi/book/10...1-GI Alert&utm_medium=email&utm_source=Eloqua

MTN, those reference are good !

 

[Okiryu]

Another one here:

https://www.nap.edu/catalog/25379/manual-on-subsurface-investigations