SlipSurface Pile

Foundations

Pile capacity, groups and settlement

Shaft friction by the α, β and λ methods, Meyerhof/Vesić/Janbu base resistance, group efficiency and block failure, compression and uplift under seismic loading, required length, single and group settlement; rock sockets by twelve correlations.

$ pip install slipsurface-pile

Run

slipsurface-pile

Default port

8783

Python

3.10+

Version

0.2.0

Licence

AGPL-3.0

See the examples →ReferenceSource ↗

Axial capacity, group action and settlement of piles in layered ground, and the length of a rock socket. A circular or square pile — bored, or driven with a small or a large displacement — alone or in a rectangular group under a cap, is checked by every method an engineer is likely to be asked for, side by side.

What it computes

1. Shaft friction — in clay by the α methods of API RP 2A, Kulhawy & Phoon and Sladen, the β method (Burland) and the λ method (Vijayvergiya & Focht); in sand by K·σ′_v·tan δ with Meyerhof's critical depth; and Meyerhof's SPT rule.
2. Base resistance — Meyerhof, Vesić (rigidity index) and Janbu; 9·c_u, Vesić's and Janbu's N_c* in clay; Meyerhof's SPT rule.
3. The pile's weight — buoyant below the water table — taken off the ultimate capacity: Q_ult,net = Q_s + Q_b − W, Q_all = Q_ult,net / FS.
4. Group action — the efficiency of Converse–Labarre, Los Angeles Group, Seiler–Keeney and Feld, and block failure; the group capacity is the smaller.
5. Required length — the shortest pile that passes the single-pile, the group and the seismic checks, with the capacity drawn against the length.
6. Seismic load case — the rigid cap shares the seismic V, M_B and M_L among the piles; the most loaded pile is checked in compression, the piles in tension against their shaft friction in tension (reduced for sand and for cyclic loading) plus their weight, and the group against being lifted as one block. New in 0.2.0.
7. Settlement — a single pile by Vesić; the group by the equivalent raft at 2/3·L, by Vesić's √(B_g/D) rule and by Meyerhof's SPT rule.
8. Rock-socketed piles — the unit side shear of twelve published correlations, the base resistance of six more, the socket length each of them needs, a design length from their mean, median or bounds, and the elastic settlement by Randolph & Wroth and by Vesić.

On top of it, a parametric or reliability study reports the probability that the pile, the group or the settlement fails, with a confidence interval and β.

Screenshots

Pile group — summary

Rock socket — summary

Stresses and shaft friction — dark theme, Turkish

Capacity against length

Group plan and efficiency

Socket length by correlation

Section with the critical depth and the equivalent raft

Stresses under the raft and settlement by method

Quick start

pip install slipsurface-pile
slipsurface-pile                                    # interface: http://127.0.0.1:8783/

slipsurface-pile example -o project.pile
slipsurface-pile run project.pile -o report.pdf            # the pile and its group
slipsurface-pile run project.pile --socket -o report.pdf   # … with the rock socket as well
slipsurface-pile socket project.pile -o socket.pdf         # the rock socket alone
slipsurface-pile study project.pile -o samples.csv

Figures

Section through the group with the critical depth and the equivalent raft · σ′_v, u₀, the unit shaft friction of every method and the load down the shaft · shaft and base resistance by method · capacity against length with the required length · plan of the group and the efficiency of every method · the stresses under the raft and the settlement by method · the pile loads under the seismic case. Rock socket: section · side shear by correlation · socket length by correlation · head settlement against socket length.

Next steps

• Examples — a bored pile group, a length sweep, group efficiency, a rock socket, a seismic load case.
• Reference — expressions, inputs, modules.