Parameters

Every parameter of the method is a field of ModelOptions or MonteCarloOptions. Pass a modified copy to any pipeline function:

from dataclasses import replace
opts = replace(dp.ModelOptions(), smoothing_window=9)
out = dp.analyze(log, soil, options=opts)

Both option classes are frozen dataclasses, so a modified copy is the only way to change a value.

ModelOptions

Field	Default	Role	Source
`c1`	0.45	multiplicative recalibration coefficient of the Danish formula	Reddy and Stuedlein (2013), Puget Sound
`c2`	0.0 kips	additive recalibration term	Reddy and Stuedlein (2013)
`phi_lo`	25 deg	lower bound on the friction angle; floor of the inversion and start of the top-segment sweep	range of the WSDOT (2022) correlation
`phi_hi`	45 deg	upper bound; ceiling of the inversion, cap of the friction angle correlation and end of the sweep	WSDOT (2022)
`g_ratio`	0.05	operative over small-strain shear modulus in the rigidity index	method default
`k2_lo`, `k2_hi`	30, 75	modulus coefficient K_{2,max} at `phi_lo` and `phi_hi`, interpolated linearly	Seed and Idriss (1970)
`irr_bounds`	(10, 500)	clamp on the rigidity index	method default
`cc_delta_ratio`	0.8	interface friction angle over soil friction angle in the shaft resistance	Coyle and Castello (1981); see note below
`sr_psi_nc`	0.22	normally consolidated undrained strength ratio in the interface factor on the residual strength	Randolph and Murphy (1985)
`zone_factor`	1.5	a foot feels blows once the toe is within `zone_factor` times the pile width above it	method default
`b_exponent`	0.34	exponent of the cyclic strength curve	Idriss and Boulanger (2008)
`ru_cap_toe`	0.9	largest pore-pressure ratio applied to the stress the toe bears on	method default
`dphi`	0 deg	shift of the friction angle line; the Monte Carlo draws it	perturbation hook
`crr_multiplier`	1.0	multiplier on the cyclic resistance ratio; the Monte Carlo draws it	perturbation hook
`smoothing_window`	13 ft	Savitzky-Golay window on the per-foot capacity	method default
`smoothing_order`	2	Savitzky-Golay polynomial order	method default
`tip_anchor`	True	keep the unsmoothed capacity at the final foot so the end-of-drive total matches the log	method default
`top_sweep_step`	1 deg	step of the top-segment sweep	method default
`top_sweep_tol_frac`	0.05	a swept angle is admissible when its misfit is within this fraction of the minimum …	method default
`top_sweep_tol_kips`	1 kip	… or within this many kips of it, whichever is larger	method default
`max_iter`	60	iteration limit of the per-foot solves	numerics
`ru_tol`	1e-4	tolerance of the toe pore-pressure fixed point	numerics

Interface friction angle

The default interface friction angle is 0.8 times the soil friction angle, the ratio Coyle and Castello (1981) used with their earth pressure coefficients. Set cc_delta_ratio=1.0 to take the interface friction angle equal to the soil friction angle.

MonteCarloOptions

Field	Default	Role	Source
`bias_cov`	0.35	coefficient of variation of the lognormal bias on the formula capacity, mean 1	Reddy and Stuedlein (2013)
`crr_sigma_ln`	0.20	log standard deviation of the lognormal multiplier on the cyclic resistance ratio, median 1	method default
`dphi_bound`	2.5 deg	half-width of the uniform shift of the friction angle line	method default
`target_noise`	True	add normal noise to each foot’s target with the robust standard deviation of the raw-minus-smoothed residuals	method default
`ci_target`	0.02	stop when the 95 percent confidence half-width of the mean capacity is below this fraction of the mean	method default
`chunk`	100	realizations between convergence checks	numerics
`max_realizations`	1200	upper limit on realizations	numerics
`seed`	None	seed of the random number generator; set it for a reproducible run	numerics

Site and pile inputs

Input	Default	Role
`SoilProfile.mudline`	required	elevation of the soil surface, ft; sets the unlogged top segment
`SoilProfile.fines`	required	percent passing the No. 200 sieve, one value or a table against `elevation`
`SoilProfile.water_elevation`	0 ft	water table for the effective stress profile
`SoilProfile.gamma_total`	0.122 ksf/ft	total unit weight of the soil
`Pile.modulus`	864,000 ksf	elastic modulus of the pile material (the default is prestressed concrete)
`Hammer.ram_weight`	required	ram weight in kips, W in the Danish formula

Physical constants, in driven_pile.constants: unit weight of water 0.0624 ksf/ft, atmospheric pressure 2.116 ksf, gravitational acceleration 32.2 ft/s², and the one-foot analysis increment.