SPT Values from Soil Description

[BridgeBuilder]

Afternoon all,

Does anyone know where I might find appropriate (approximate) values of SPT to use based on soil descriptions taken from window samples?

Cheers

BridgeBuilder

 

[pdavis1]

That is a bit of a stretch, going in reverse, as the descriptions evolve from spt. However, to give you a 'general' sense:

Sand/gravel

SPT Relative Density
0-4 very loose
5-10 loose
11-30 medium dense
31-50 dense
50< very dense



Fine-

<2 very soft
2-4 soft
5-8 firm
9-15 stiff
16-30 very stiff
30< hard

 

[Ron]

BridgeBuilder...pdavis1 has given you the ranges of SPT for general classification. As he indicated, it is a significant stretch to use these in reverse. As an example, your foundation and sitework recommendations can vary tremendously for a clean fine sand that has SPT values of less than 10 as compared to the same material with SPT values over 20.

This is a multi-parametric evaluation that should be approached from the &quot;other&quot; direction.