API Reference

Inputs

The driving record, the pile and hammer that produced it, and the ground it was driven through.

DriveLog: A pile-driving record, one entry per logged foot.
Pile: Pile geometry and stiffness.
Hammer: Driving hammer.
SoilProfile: Ground conditions at a pile location.
bpm_to_stroke(): Hammer stroke from the blow rate of a free-falling ram.
stroke_to_bpm(): Blow rate of a free-falling ram from its stroke; inverse of bpm_to_stroke.

Options

Model parameters and Monte Carlo settings, with the published values as defaults.

ModelOptions: Parameters of the drive model.
MonteCarloOptions: Monte Carlo settings.

Pipeline

One function per stage of the method, and one call that runs them all.

analyze(): Characterize the soil from a driving log and estimate long-term capacity.
prepare_target(): Build the capacity target from a driving log.
sweep_top_phi(): Sweep a constant top-segment friction angle and find the admissible band.
run_drive(): Characterize every foot sequentially from the capacity target, top down.
long_term_capacity(): Long-term shaft and toe resistance of a DriveResult.
monte_carlo(): Realizations of the long-term capacity under the five uncertainty sources.

Results

Dataclasses of plain NumPy arrays.

Analysis: Everything analyze produces.
Target: Per-foot capacity target and static soil state on the analysis grid.
TopPhiBand: Admissible friction angles for the unlogged top segment.
DriveResult: Soil characterization and capacities from one drive-model run.
MonteCarloResult: Monte Carlo realizations of the long-term capacity.

DriveResult Methods

Methods for the DriveResult class

DriveResult.n_logged: Number of logged feet.
DriveResult.logged: Boolean mask of the logged feet.
DriveResult.reason_counts(): Count of each outcome code over the logged feet.
DriveResult.fraction_liquefied(): Fraction of logged feet that liquefied during the drive.
DriveResult.plot_profile(): Plot friction angle, blow count and pore-pressure ratio versus elevation.
DriveResult.plot_fit(): Plot the capacity target and the modeled capacity versus elevation.

Equation-level functions

The equations of the method, importable from the submodules for teaching and testing.

formulas.elastic_set(): Elastic compression term of the Danish formula.
formulas.danish_capacity(): Capacity at the time of driving from the recalibrated Danish formula.
preprocess.smooth_capacity(): Savitzky-Golay smoothing of a capacity sequence.
preprocess.sigma_v0_profile(): Static vertical effective stress at each elevation.
preprocess.extend_to_mudline(): Prepend the unlogged feet between the mudline and the first logged foot.
preprocess.residual_scale(): Robust standard deviation of the raw-minus-smoothed capacity residuals.
bearing.nq_vesic(): Vesic bearing capacity factor on vertical effective stress.
bearing.rigidity_index(): Rigidity index from a stress-dependent shear modulus.
bearing.toe_bearing(): Unit toe resistance q_p = N_q*(phi, I_r) sigma'_v, ksf.
bearing.phi_from_toe_bearing(): Friction angle whose toe bearing on sigma_v equals q_needed.
bearing.phi_from_toe_bearing_grid(): Friction angle from toe bearing by interpolation on a fixed grid.
spt.phi_from_n160(): Friction angle from the corrected SPT blow count.
spt.n160_from_phi(): Corrected blow count whose correlated friction angle equals phi.
shaft.coyle_castello_k(): Coyle and Castello earth pressure coefficient at the ground surface.
shaft.nordlund_k_delta(): Nordlund lateral coefficient for a non-tapered displacement pile.
shaft.fs_coyle_castello(): Unit shaft resistance of a driven pile in sand.
shaft.interface_alpha(): Interface factor on the residual strength of liquefied soil.
shaft.fs_partially_liquefied(): Unit shaft resistance through soil at pore-pressure ratio ru.
liquefaction.delta_n_fines(): Fines-content adjustment to the clean-sand equivalent blow count.
liquefaction.n160_clean_sand(): Clean-sand equivalent blow count N1,60cs = N1,60 + dN(FC).
liquefaction.crr_m75(): Cyclic resistance ratio at the magnitude 7.5 reference and 1 atm.
liquefaction.k_sigma(): Overburden correction factor on the cyclic resistance ratio.
liquefaction.crr_15(): In-situ cyclic resistance ratio at the 15-cycle reference.
liquefaction.csr_driving(): Cyclic stress ratio applied by a hammer blow that fails the soil.
liquefaction.cycles_to_liquefaction(): Uniform cycles at csr needed to trigger liquefaction.
liquefaction.ru_linear(): Pore-pressure ratio growing linearly with the cycle ratio.
liquefaction.residual_strength(): Residual strength of liquefied soil.
capacity.shaft_long_term(): Long-term shaft resistance, kips.
capacity.toe_end_of_drive(): Toe resistance at the end of the drive, kips.
characterization.triggering_state(): Blow count, cyclic stress and resistance, and cycles to liquefaction.
characterization.characterize_foot(): Characterize the soil at the toe from the required toe resistance.