def test_positive_friction(self):
chamfered_qc = bearing.chamfer_positive_friction(
self.gef.df.qc.values, self.gef.df.depth.values)
# pile tip level
ptl = nap_to_depth(self.gef.zid, -13.5)
tipping_point = nap_to_depth(self.gef.zid, -2.1)
idx_ptl = np.argmin(np.abs(self.gef.df.depth.values - ptl))
idx_tp = np.argmin(np.abs(self.gef.df.depth.values - tipping_point))
s = slice(idx_tp, idx_ptl)
f = bearing.positive_friction(self.gef.df.depth.values[s],
chamfered_qc[s], 0.25 * 4, 0.01)
# d-foundation result is 1375, we have 1371. Small difference due to chamfering method. We chamfer better ;)
deviation = abs(1 - 1375 / (f.sum() * 1000))
self.assertTrue(deviation < 1e-2)
self.assertEqual(f.sum(), 1.3710468170000003)
if SHOW_PLOTS:
# show chamfer line
fig = self.gef.plot(show=False)
fig.axes[0].plot(chamfered_qc[s],
self.gef.df.depth[s],
color="red")
fig.axes[0].hlines(ptl, 0, chamfered_qc.max())
fig.axes[0].hlines(tipping_point, 0, chamfered_qc.max())
plt.show()
def positive_friction(
self, positive_friction_range=None, agg=True, conservative=False
):
"""
Determine shaft friction Rs.
Parameters
----------
positive_friction_range : np.array[float]
Length == 2.
Start and end depth of positive friction.
agg : bool
Influences return type.
True: aggregates the friction values in total friction.
False: Return friction values per cpt layer.
conservative : bool
Returns
-------
out : Union[float, np.array[float]]
unit [MPa]
See agg parameter
"""
if positive_friction_range:
self.positive_friction_slice = det_slice(
positive_friction_range, self.merged_soil_properties.depth.values
)
self.chamfered_qc = bearing.chamfer_positive_friction(
self.merged_soil_properties.qc.values, self.cpt.df.depth.values
)[self.positive_friction_slice]
positive_friction = bearing.positive_friction(
depth=self.merged_soil_properties.depth.values[
self.positive_friction_slice
],
chamfered_qc=self.chamfered_qc,
circum=self.circum,
alpha_s=self.alpha_s,
)
self.rs = positive_friction.sum()
if agg:
return self.rs
return positive_friction
negative_friction = (bearing.negative_friction(
depth=df.depth.values[negative_friction_slice],
grain_pressure=df.grain_pressure.values[negative_friction_slice],
circum=circum,
phi=df.phi[negative_friction_slice],
gamma_m=1,
)).sum() * 1000
positive_friction_slice = slice(idx_tp, idx_ptl)
chamfered_qc = bearing.chamfer_positive_friction(
df.qc.values, gef.df.depth.values)[positive_friction_slice]
rs = (bearing.positive_friction(
depth=df.depth.values[positive_friction_slice],
chamfered_qc=chamfered_qc,
circum=circum,
alpha_s=0.01,
)).sum() * 1000
rb = (bearing.compute_pile_tip_resistance(
ptl=ptl,
qc=df.qc.values,
depth=df.depth.values,
d_eq=1.13 * pile_width,
alpha=0.7,
beta=1,
s=1,
area=pile_width**2,
)) * 1000
print(rb, rs, negative_friction)