Thursday, August 21, 2014

Geotechnical vs Structural

The dividing line between structural and geotechnical becomes blurred some of the time.

The structural engineers have come up with a closed form solution, that if they had a suitable "soil" value, slab on grade design would be totally numeric. This value they would like is termed a "modulus of subgrade reaction", and it was derived theoretically by creating a term for everything the structural engineers do not know about slab on grades. It is a abstract term, which is also a system dependent number.

Now it seems that they have done the same for screw piles, but even worse. They have used a typical test value result as a system parameter in cohesive soils. This will not be given by any geotechnical engineer in a report, for it is potentially dangerous if miss-used, and lowers geotechnical to technician work. In cohesionless soils, they are using typically assumed parameters for design, not measured values. They are going from measured values to classification, and estimating from those the closed form solution values. When this get into court, the screw pile guys should be held responsible.

It is time to hang my shingle in the garage, and retire. Put my sliderule on blocks. what would be the correct euphemism? Not put out to pasture, for that was what was done to old unwanted horses. They we not put in the pasture, where they would need to be feed all winter. They were put out by the cruel bastards, to starve, eat the neighbors hat, or become coyote food. Most of those who use the expression do not understand what it means.     

No comments:

Post a Comment