# ModelOptions

Parameters of the drive model.

Usage

[Source](https://github.com/lornearnold/driven-pile/blob/main/src/driven_pile/options.py#L8-L84)

``` python
ModelOptions(
    c1=0.45,
    c2=0.0,
    phi_lo=25.0,
    phi_hi=45.0,
    g_ratio=0.05,
    k2_lo=30.0,
    k2_hi=75.0,
    irr_bounds=(10.0, 500.0),
    cc_delta_ratio=0.8,
    sr_psi_nc=0.22,
    zone_factor=1.5,
    b_exponent=0.34,
    ru_cap_toe=0.9,
    dphi=0.0,
    crr_multiplier=1.0,
    smoothing_window=13,
    smoothing_order=2,
    tip_anchor=True,
    top_sweep_step=1.0,
    top_sweep_tol_frac=0.05,
    top_sweep_tol_kips=1.0,
    max_iter=60,
    ru_tol=0.0001,
)
```

## Attributes

`c1, c2: float`  
Multiplicative and additive (kips) recalibration coefficients of the Danish formula (Reddy and Stuedlein, 2013).

`phi_lo, phi_hi: float`  
Bounds on the friction angle, deg (WSDOT GDM correlation range).

`g_ratio: float`  
Ratio of the operative shear modulus to the small-strain modulus in the rigidity index.

`k2_lo, k2_hi: float`  
Seed and Idriss (1970) modulus coefficient K2,max at `phi_lo` and `phi_hi`; interpolated linearly in friction angle.

`irr_bounds: tuple of float`  
Clamp on the rigidity index.

`cc_delta_ratio: float`  
Interface friction angle divided by the soil friction angle in the Coyle and Castello (1981) shaft resistance.

`sr_psi_nc: float`  
Normally consolidated strength ratio in the Randolph and Murphy (1985) interface factor applied to the residual strength.

`zone_factor: float`  
A foot starts accumulating blows when the toe is within `zone_factor * width` above it.

`b_exponent: float`  
Exponent of the cyclic strength curve.

`ru_cap_toe: float`  
Largest pore-pressure ratio applied to the toe stress.

`dphi: float`  
Shift of the friction angle correlation line, deg.

`crr_multiplier: float`  
Multiplier on the cyclic resistance ratio.

`smoothing_window, smoothing_order: int`  
Savitzky-Golay window (feet) and polynomial order for the capacity target.

`tip_anchor: bool`  
Replace the smoothed capacity at the final foot with the unsmoothed value.

`top_sweep_step: float`  
Step of the top-segment friction angle sweep, deg.

`top_sweep_tol_frac, top_sweep_tol_kips: float`  
A swept value is admissible when its log-fit RMS is within `max(top_sweep_tol_frac * rms_min, top_sweep_tol_kips)` of the minimum.

`max_iter: int`  
Iteration limit of the per-foot solves.

`ru_tol: float`  
Tolerance of the pore-pressure ratio fixed point.