GeoStructPy
Changelog Main Menu
Disclaimer: This tool is intended for use by the APEC Consultancy team for preliminary geotechnical calculations only. The developers assume no liability for design decisions made based on the output of this application. All results must be verified by a qualified geotechnical or structural engineer before use in any project.

Cantilever Sheet Pile in Sand — PYWALL Example 4 (LRFD)

Closed-form limit-equilibrium analysis of a cantilever sheet-pile wall in a two-layer sand profile, matching the static Strength I case of PYWALL 2019 Examples Manual §4.1 — Example 4 (LRFD Analysis of Sheet-Pile Wall for Static and Seismic Conditions, Ensoft, Reese et al. 2021). Defaults are the metric conversion of Example 4 Tables 4.1 and 4.3. The four output plots (pressure, shear, bending moment, deflection) reproduce the limit-equilibrium comparison shown in PYWALL Figure 4.3.

Scope of this build: two-layer homogeneous sand profile with the layer boundary exactly at the dredge line, no water table, uniform surcharge, cantilever (unanchored). Rankine active & passive coefficients (δ = 0). The more refined p-y / subgrade-reaction solution (PYWALL Fig. 4.5) uses the discrete-element beam-column method of Matlock & Halliburton (1965) — that is beyond the closed-form scope of this module. References for every input are in the tooltips.

Wall Geometry

AASHTO LRFD Factors (Strength I)

Soil Profile — Layer Table

Each row is one soil layer stacked from top to bottom. Right-click to insert or remove rows. The design layer for the below-dredge calculation is automatically the one covering z = L. Defaults match PYWALL 2019 Example 4 Tables 4.1 & 4.3.

References & Methodology

  1. Reese, L.C., Wang, S.T., Arrellaga, J.A. & Vasquez, L. (2021). PYWALL 2019 — A Program for the Analysis of Flexible Retaining Structures. Ensoft, Inc., Austin, TX. Examples Manual §4.1 — Example 4 LRFD Analysis of Sheet-Pile Wall for Static and Seismic Conditions (pp. 4-1 through 4-12, Tables 4.1–4.5, Figures 4.1–4.8). The metric defaults on this page are the SI conversion of Tables 4.1 and 4.3.
  2. PYWALL 2019 Technical Manual (Ensoft, 2021): §2.1–2.3 Earth-pressure theory (Rankine & Coulomb); §2.5 Lateral pressure from surcharges; §3.1 Modified subgrade-reaction method; §3.2 Differential equation of the beam on elastic foundation (Eq. 3.7 M = EI·y″, Eq. 3.8 EI·y‴′ = w + p, Eq. 3.10 with axial load per Hetenyi 1956); §3.3 Discrete-element beam-column model (Matlock & Halliburton 1965); §3.4 Solutions with nonlinear Winkler-soil springs.
  3. Das, B.M. & Sivakugan, N. (2019). Principles of Foundation Engineering, 9th Edition, SI. Cengage Learning. Ch. 18 §18.4 Cantilever Sheet Piling Penetrating Sandy Soil (pp. 758–764, Eq. 18.7–18.22) — the closed-form quartic used to solve for the embedment depth in this module.
  4. Matlock, H. & Halliburton, T.A. (1965). A Finite-Element Method of Solution for Linearly Elastic Beam-Columns. Research Report No. 56-1, Center for Highway Research, University of Texas at Austin. The discrete-element mechanical model used by PYWALL for the full p-y solution.
  5. Hetenyi, M. (1946). Beams on Elastic Foundation. University of Michigan Press. Derivation of the beam-column equation with axial loading (PYWALL Tech Manual Eq. 3.10).
  6. Terzaghi, K. (1954). Anchored bulkheads. Transactions ASCE, 119. Earth pressure vs. wall movement relationship, referenced in PYWALL Tech Manual §3.5.
  7. AASHTO (2020). LRFD Bridge Design Specifications. Load and resistance factor method applied to Example 4 Strength I and Extreme I load cases.
  8. Rankine, W.J.M. (1857). On the stability of loose earth. Phil. Trans. Royal Society of London, 147. Source of the Ka / Kp coefficients used in this module.