Soil spring stiffness
Soil spring stiffness
(OP)
Hi,
I have read thread256-285800: Spring Stifness and got stuck here:
"If you look at Bowles Table 9-1, modulus subgrade, kv (kN/m3)
approx equal to 240 Cu (kPa).
Allowable bearing pressure, qa (kPa) = Nc Cu / SF = (5.14 /3) Cu..."
Bowles Table 9-1 shows ks (not kv), and there is no Cu there...
Also, where is the 5.14 value coming from?
Thanks.
I have read thread256-285800: Spring Stifness and got stuck here:
"If you look at Bowles Table 9-1, modulus subgrade, kv (kN/m3)
approx equal to 240 Cu (kPa).
Allowable bearing pressure, qa (kPa) = Nc Cu / SF = (5.14 /3) Cu..."
Bowles Table 9-1 shows ks (not kv), and there is no Cu there...
Also, where is the 5.14 value coming from?
Thanks.
RE: Soil spring stiffness
RE: Soil spring stiffness
So for phi=0 (cohesive soils) use Nc=5.14, but what if c=0 or for c-phi soil types?
RE: Soil spring stiffness
c is typically taken as 0 in c-phi soils as it is conservative (generally).
When c = 0 the first part of the bearing capacity equation is ignored. The second and third parts, which includes Ngamma and Nq are used to calculate bearing capacity.