EPSFEMWall

Compare existing and proposed conditions

1. Define the wall, retained-side domain and mesh. Check that the domain boundaries are far enough from the wall for the comparison being made.
2. Enter horizontal soil layers and material stiffness, unit weight and K₀ parameters. Add the retained-side water table where relevant.
3. Build the existing-condition case with its EPS zones and surface strips, then define the proposed case with the altered EPS arrangement.
4. Run both cases and compare the wall reaction-derived pressure profiles, total thrust, wall-base moment and diagnostic plots.
5. Refine the mesh and domain as a sensitivity check, then save the model or export the A4 report.

What is included

• A two-dimensional, drained, small-strain, linear-elastic plane-strain continuum with conforming constant-strain triangular soil and EPS elements.
• K₀ initial effective stresses, self-weight, EPS weight replacement and uniform surface strips are applied through the continuum model.
• The wall is smooth and rigid, with compression-only contact; the reported q3 profile is smoothed from solved wall reactions and preserves total thrust and base moment.
• Multiple horizontal layers and axis-aligned rectangular EPS zones can be represented in each condition.

Limitations and verification

The model does not include Mohr–Coulomb yielding, wall flexibility, interface slip, nonlinear EPS compression or creep, direct hydrostatic pressure on the wall, seismic loading or global stability. Check water-pressure treatment, mesh and boundary sensitivity, and independently verify results before engineering use.

In-app help

Implemented model

A two-dimensional, small-strain, drained, linear-elastic plane-strain model of the retained ground behind a smooth rigid wall. Soil layers and rectangular EPS zones use conforming constant-strain triangular elements. The wall, far boundary and base are displacement boundaries; wall pressure is recovered from the solved horizontal wall reactions.

Initial effective stresses: σv0'(z) = ∫ γ' dz; σh0'(z) = K0 σv0'(z)

No Rankine or Coulomb pressure is applied to the wall. Surface strips, EPS weight and stress redistribution are assembled through the continuum model. The reported q3 is a smoothed, nonnegative action-equivalent profile recovered from the wall reactions; it preserves their total thrust and moment about the bottom of the retained wall.

Current scope

Horizontal soil layers and any number of axis-aligned rectangular EPS zones within the retained-side domain.

Equivalent-linear soil and EPS stiffness, self-weight, K0 geostatic stress and uniform surface strips.

Smooth rigid wall; perfect bond between soil and EPS; static loading; small strain.

The water table changes effective unit weight below its level. Hydrostatic pressure acting directly on the wall is not included.

Not yet modelled

Mohr-Coulomb yielding, non-associated plastic flow, tension cracking or a true active-state wall movement.

Compression-only opening/sliding at soil-wall and soil-EPS interfaces.

EPS nonlinear compression, creep, temperature effects, damage or buoyancy.

Construction history beyond the phase-one equivalent stress redistribution, three-dimensional effects, global slip-circle stability or seismic loading.

This is an elastic/K0 sensitivity and comparison model. Check mesh and boundary sensitivity and independently verify results before engineering use. It is not a substitute for a validated nonlinear geotechnical FEM package or project-specific design assessment.

Areas in the app

Use these sections to locate the inputs, checks and results shown in the app:

• Project
• Wall, domain and mesh
• Soil materialsAdd
• EPS materialsAdd
• Horizontal soil layersAdd
• Case 1: Existing condition
• EPS zonesAdd zone
• Surface stripsAdd strip
• Case 2: Proposed EPS condition
• Implemented model
• Current scope
• Not yet modelled
• Use

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