op3.anchors.UndrainedClayProfile

class op3.anchors.UndrainedClayProfile(su_mudline_kPa: float, su_gradient_kPa_per_m: float, gamma_eff_kN_per_m3: float = 6.0, sensitivity: float = 3.0, plasticity_index: float = 30.0)[source]

Bases: object

Linearly increasing undrained shear strength profile.

This is the standard design profile for deep-water normally or lightly over-consolidated clay at anchor sites. For more complex profiles, split into layers and integrate numerically.

Parameters:

su_mudline_kPa (float) – s_u(z=0). Typical range 2-10 kPa for NC clay, higher for over-consolidated crusts.
su_gradient_kPa_per_m (float) – k = ds_u/dz. Typical range 1-3 kPa/m.
gamma_eff_kN_per_m3 (float, default 6.0) – Effective unit weight of the clay (saturated minus seawater). 6 kN/m^3 is typical for Gulf-of-Mexico soft clay per API RP 2GEO Table 8.5.
sensitivity (float, default 3.0) – S_t = s_u / s_u_remoulded. Drives self-weight penetration resistance. Typical 2-5.
plasticity_index (float, default 30.0) – PI [%]. Drives cyclic strength per Andersen 2015 contour diagrams.

References

Randolph & Gourvenec 2011, Ch. 3. API RP 2GEO (2011) Table 8.5.

__init__(su_mudline_kPa: float, su_gradient_kPa_per_m: float, gamma_eff_kN_per_m3: float = 6.0, sensitivity: float = 3.0, plasticity_index: float = 30.0) → None

Methods

`__init__`(su_mudline_kPa, su_gradient_kPa_per_m)
`su_at_depth`(z_m)	Intact undrained shear strength at depth z below mudline.
`su_average_to_depth`(z_m)	Depth-averaged intact s_u from mudline to z.
`su_remoulded_at_depth`(z_m)	Remoulded undrained shear strength, `s_u / S_t`.

Attributes

`gamma_eff_kN_per_m3`
`plasticity_index`
`sensitivity`
`su_mudline_kPa`
`su_gradient_kPa_per_m`

gamma_eff_kN_per_m3: float = 6.0

plasticity_index: float = 30.0

sensitivity: float = 3.0

su_at_depth(z_m: float | ndarray) → float | ndarray[source]: Intact undrained shear strength at depth z below mudline.

su_average_to_depth(z_m: float) → float[source]

Depth-averaged intact s_u from mudline to z.

For a linear profile this is s_u_mudline + k * z / 2.

su_gradient_kPa_per_m: float

su_mudline_kPa: float

su_remoulded_at_depth(z_m: float | ndarray) → float | ndarray[source]: Remoulded undrained shear strength, s_u / S_t.