def calc_horz_strip_via_gazetas_1991(sl,
fd,
ip_axis='width',
a0=0.0,
f_contact=1.0,
h_rigid=None):
"""
Assumes out-of-plane is infinite, stiffness is returned as a per metre length
Parameters
----------
sl: Soil Object
fd: Foundation object
ip_axis: str
The axis that is in the plane of deformation
axis: str
The axis which it should be computed around (if not None, then ip_axis is ignored)
a0: float
dynamic factor
f_contact: float
Effective sidewall contact scaling factor
Returns
-------
"""
l_ip = getattr(fd, ip_axis)
b = l_ip / 2
k_strip = 2.0 * sl.g_mod / (2 - sl.poissons_ratio)
if h_rigid:
n_rigid = 1 + 2 * b / h_rigid
else:
n_rigid = 1
if a0:
f_dyn = tdc.get_ky_gazetas(a0, 1000)
else:
f_dyn = 1.0
if fd.depth is not None and fd.depth != 0.0:
if fd.depth < 0.0:
raise ValueError(
f'foundation depth must be zero or greater, not {fd.depth}')
if f_contact == 0.0:
dw = 0.0
else:
dw = min(fd.height, fd.depth) * f_contact
n_emb = 1 + 1.26 * (dw / b)
else:
n_emb = 1.
if h_rigid:
n_rigid = 1 + 2.0 * b / h_rigid
else:
n_rigid = 1
return k_strip * n_emb * f_dyn * n_rigid
def calc_horz_via_gazetas_1991(sl,
fd,
ip_axis='width',
axis=None,
a0=0.0,
f_contact=1.0):
"""
Calculate the shear stiffness for translation along an axis.
Parameters
----------
sl: Soil Object
fd: Foundation object
ip_axis: str
The axis that is in the plane of deformation
axis: str
The axis which it should be computed around (if not None, then ip_axis is ignored)
a0: float
dynamic factor
f_contact: float
Effective sidewall contact scaling factor
Returns
-------
"""
if axis is not None:
ip_axis = axis
n_emb = 1.0
if fd.length >= fd.width:
len_dominant = True
l = fd.length * 0.5
b = fd.width * 0.5
else:
len_dominant = False
l = fd.width * 0.5
b = fd.length * 0.5
if (ip_axis == 'length' and len_dominant) or (ip_axis == 'width'
and not len_dominant):
y_axis = True # Direction of l
else:
y_axis = False # Direction of b
v = sl.poissons_ratio
k_y = 2 * sl.g_mod * l / (2 - v) * (2.0 + 2.5 * (b / l)**0.85)
if y_axis is False: # x_axis
k_shear = (k_y - (0.2 * sl.g_mod * l) / (0.75 - v) * (1.0 - b / l))
f_dyn = 1.0
if fd.depth:
z_w = (fd.depth + (fd.depth - fd.height)) / 2
h = min([fd.height, fd.depth])
a_w = 2 * h * (fd.width + fd.length) * f_contact
n_emb = (1 + 0.15 * (fd.depth / l)**0.5) * (1 + 0.52 *
(z_w * a_w /
(l * b**2))**0.4)
else:
if a0:
f_dyn = tdc.get_ky_gazetas(a0, l / b)
else:
f_dyn = 1.0
if fd.depth:
z_w = (fd.depth + (fd.depth - fd.height)) / 2
h = min([fd.height, fd.depth])
a_w = 2 * h * (fd.width + fd.length) * f_contact
n_emb = (1 + 0.15 * (fd.depth / b)**0.5) * (1 + 0.52 *
(z_w * a_w /
(b * l**2))**0.4)
k_shear = k_y
return k_shear * n_emb * f_dyn