geotechguy1
Civil/Environmental
- Oct 23, 2009
- 663
Curious what people think about these documents on engineering geological modelling linked below. I increasingly struggle with engineering geologists who reference these documents essentially as a way to take almost the entire profession away from geotechnical engineers. The main concerns I have are:
1. The statements in the document that call mechanical / engineering properties of soil (shear strength, cohesion, stiffness, permeability etc) as 'engineering geological' or 'geological properties'. Generally what I encounter is geologists and engineering geologists using something like the Burt Look book to copy paste a bunch of parameters they don't understand. It seems like the engineering geology education is very light on understanding of soil behaviour or engineering properties - most cannot explain basic concepts like effective stress or explain why friction angle often decreases with increasing confining stress etc.
2. The propensity to turn the entire process - including geotechnical modelling - into something controlled by engineering geology. Frequently the models derived by engineering geologists make little sense for engineering purposes or are derived with a mis-understanding of the available data (eg. this sand is loose (because they used non-corrected N-values), this soil is not organic (because they don't know how to interpret the CPT data)
Often what I find is models derived by engineering geologists are mostly useless for geotechnical engineering or require substantial modifications (eg. ignoring obvious features like a strength or stiffness increase with depth or subdividing the model in a way that is not useful for analysis or design).
To me the whole thing seems like a make-work document for engineering geologists.
Granted I agree in general that traditional geotechnical engineers are light on geology education (usually supplemented by in-house specialists in geology, hydrogeology etc) but it seems like there is a move to replacing one problem with another (now there is a whole generation of engineering geology practioners in NZ / Australia / UK that understand very little to anything about conventional geotechnical engineering and modelling).
1. The statements in the document that call mechanical / engineering properties of soil (shear strength, cohesion, stiffness, permeability etc) as 'engineering geological' or 'geological properties'. Generally what I encounter is geologists and engineering geologists using something like the Burt Look book to copy paste a bunch of parameters they don't understand. It seems like the engineering geology education is very light on understanding of soil behaviour or engineering properties - most cannot explain basic concepts like effective stress or explain why friction angle often decreases with increasing confining stress etc.
2. The propensity to turn the entire process - including geotechnical modelling - into something controlled by engineering geology. Frequently the models derived by engineering geologists make little sense for engineering purposes or are derived with a mis-understanding of the available data (eg. this sand is loose (because they used non-corrected N-values), this soil is not organic (because they don't know how to interpret the CPT data)
Often what I find is models derived by engineering geologists are mostly useless for geotechnical engineering or require substantial modifications (eg. ignoring obvious features like a strength or stiffness increase with depth or subdividing the model in a way that is not useful for analysis or design).
To me the whole thing seems like a make-work document for engineering geologists.
Granted I agree in general that traditional geotechnical engineers are light on geology education (usually supplemented by in-house specialists in geology, hydrogeology etc) but it seems like there is a move to replacing one problem with another (now there is a whole generation of engineering geology practioners in NZ / Australia / UK that understand very little to anything about conventional geotechnical engineering and modelling).
