# Eriksson Wall — method & structure spec, and the gap to our code

What Eriksson Wall actually computes, reverse-engineered from **six** real
output packages, so that `tools/panelanalysis.py` + the `panelanalysis/1` deck
schema can replace it. Part A is the spec; Part B is the concrete punch-list of
what our code must add to reach parity, ordered by importance for a wall panel.

**Scrub note.** The packages carry a client, a developer, an engineering
office, its address, job numbers, designer initials and per-run model
(`.ewf`) filenames. **None of those appear here.** The samples are named only
by their piece-mark / sheet labels, which are generic precast nomenclature:

| label | what it is (type, not identity) |
| --- | --- |
| **WPA1.0** | 12" solid wall, non-prestressed, in-place only |
| **WPA2.0** | 16" horizontal wall, prestressed, handling + in-place |
| **WPA3.0** | 8" horizontal wall, non-prestressed, in-place only |
| **WPA4.0** | 8" vertical (spanning) wall, prestressed, one unified handling + in-place run |
| **SWA1.0** | 12" shear wall, non-prestressed |
| **MWH1.0** | 8" prestressed wall, one file carrying several analysis units |

Page cites are **PDF page numbers** written `WPA4.0 p.10`. Software on every
run is **Eriksson Wall v4.3.2**, spec **ACI 318-14**, losses **PCI Design
Handbook 8th Ed.** (The richer insulated-sandwich package studied earlier —
call it **WPB (v4.13.2)** — is `knowledge/library/notes/E1-wpb10-eriksson-package.md`;
this note reconciles against it and does not repeat its arithmetic proofs.)

Read: 2026-09-02, text layer via PyMuPDF, all six extract cleanly. Numbers
below are transcribed as printed; anything image-only is flagged in §A.8, not
guessed.

---

# Part A — the Eriksson method & structure

## A.1 The invariant section order, and the two-model split

Every Eriksson Wall run prints the same input blocks in the same order, then a
results half whose sections depend on which stages were enabled. Confirmed
identical across all six samples and WPB:

```
Project Information   materials (f'ci/f'c, Eci/Ec, unit wt, type; rebar fy/Es,
                      strand fpu/Ep), prestress-loss method + humidity + release/
                      erection times, exterior/interior soil, LOAD COMBINATIONS
Settings              deflection limit, 2nd-order + βd, R-value, stress options,
                      in-place stress limits, handling stress limits, flexure
                      options, resistance factors, development multipliers,
                      shear options, axial options   ← this page IS the method
Concrete Extents      panel geometry (top/bottom elevation, height, section
                      type, "top in form", miters, width, thickness), openings/
                      reveals/solid zones, then SECTION PROPERTIES (Area, Cx, Cy,
                      Izz, Iyy, Izy, Sb, St)
Structural Model      restraints (foundation + floor ties, each an elevation +
                      type + gravity/thermal restraint + stiffness), releases,
                      concentrated loads, load options, WIND loads, SEISMIC
                      loads, TEMPERATURE loads, SOIL loads, additional self
                      weight, structural sections
[handling runs] Handling  panel weight + CG, face lifters, edge lifters, then
                      per-stage Stripping / Transportation / Erection blocks
Reinforcement         strands / rebar / mesh / interrupts tables, plus a Strand
                      summary box (Aps, cgx, cgy, ex, ey) and a Mild box (As...)
------ results ------
[handling] Stripping (and Transportation/Erection if run):
                      Reactions (+ Tilt Potential) → Stresses table → Flexure
                      table → Shear table
[in-place] In-Place Strength Summary:
                      Reaction Forces → Flexure table → Shear table → Axial table
           In-Place Service Summary:
                      Tension table → Total Compression table → Deflection graph
```

Every page carries the header (`Eriksson Wall v4.3.2` / `Licensee:` / timestamp)
and footer (`<file>.ewf` / copyright / `pg. n / N`).

**Handling and In-Place are two separate models of the same panel, and the two
are NOT always in the same run.** WPB ran them as separate `.ewf` files (one
mild-only, one strand-only, each deliberately blind to the other's steel).
WPA4.0 instead runs **both in one file** (§A.3/A.4) — strand credited in both.
Which pattern you get is a per-job modelling choice, not an Eriksson rule. What
IS invariant: the block order above, and that a handling result section only
appears when that stage is enabled.

**A per-file run can also contain several analysis units.** MWH1.0 prints
`2.1 In-Place Strength Summary` and `4.1 In-Place Strength Summary`
(MWH1.0 p.1763, p.3260) — one document, multiple numbered runs. Our schema must
tolerate a package that is a *list* of runs, not assume one.

Reconciliation with WPB's per-run order: **identical.** WPB additionally had
`Sandwich Panel Properties`, `Design Parameters` (composite/non-composite
section interpolation) and `Horizontal Shear Analysis` — those appear **only for
insulated sandwich panels**. None of the six solid walls here print them (§A.7).

## A.2 The checks Eriksson runs, with the method as printed

| check | where | method / criterion as printed |
| --- | --- | --- |
| **Flexure** | handling + in-place | `Util = |Mu|/|ΦMn|`. ΦMn from **Whitney stress block** (Settings: `Flexure Method: Whitney Stress Block`) on a P-M interaction surface at the actual `Pu` (in-place). Columns carry `c`, `θ`, `As`, `A's`, `Aps`, `Loss`, `d`. **Φ is not constant** — it ramps 0.75→0.90 down the table (§A.2.1). |
| **Shear** | handling + in-place | ACI 318 **detailed method**: both `Vci` and `Vcw` printed side by side, `Vc = min(Vci, Vcw)`, `ϕVn = 0.75·Vc` (verified: WPA4.0 p.11 Loc 5.51 → 154.5/206.1 = 0.75). `bwd` printed as one product (in²). `∞` printed for `Vci` at a zero-moment station. Settings: `Shear Options: Treat as column, Use ACI 22.5.8.2`. |
| **Axial** | in-place only | Columns `Pu`, `ΦPn (C)`, `ΦPn (T)`, `ΦPcrit`, `Ag`. `ΦPcrit` is the **critical buckling** load (`∞` where slenderness does not bind). Settings: `Axial Options: Ignore tensile strength failures, Ignore buckling failures` (both defeat-able switches, both ON here). |
| **P-M interaction** | in-place | ΦMn is read off the interaction diagram at the station's `Pu`. The one-page summary prints an **Interaction Diagram (Controlling Section @ 0.95L)** (WPA4.0 p.9). |
| **Service tension / cracking** | in-place | extreme-fibre tension vs a **Cracking** limit = `7.5√f'c` (= 580.9 psi at 6000, WPA4.0 p.15). Prestressed: **Class U** `7.5√f'c` / **Class T** transition `12√f'c` (WPA4.0 p.15 section view). Non-prestressed: a single **Modulus of Rupture** `7.5√f'c` (SWA1.0 p.10). |
| **Service compression** | in-place | total compression vs **Limit = 0.6 f'c** (= 3600 psi at 6000, WPA4.0 p.16 / SWA1.0 p.17). |
| **Handling stresses** | handling | extreme-fibre tension vs **`5√f'ci` or `7.5√f'ci`** (per job, §A.6) and compression vs **`0.6 f'ci`** (= 2100 at 3500), with an `fci req` column = the f'ci the station would need. This is the check that usually **governs stripping** (§A.3). |
| **Deflection** | in-place | vs `L / 150` (or `L/120`, `L/240` per job, §A.6). Graph only, no table. |
| **Torsion** | — | **Eriksson Wall does not run torsion for a wall.** No torsion table in any of the six. (WPB's torsion table came from Eriksson *Beam*, a different program, for a lintel.) Not needed for wall parity. |

### A.2.1 The Φ ramp (flexure) — development, not strain

`Φ` in every flexure table runs `0.75 → 0.90` with distance from the piece end
(WPA4.0 p.10: 0.75 at 1.84 ft, 0.90 by mid-panel). It is **ACI 318-19 §21.2.3**:
Φ = 0.75 from the end through the **transfer** length, linear 0.75→0.90 to the
end of the **development** length, then 0.90 — not the c/dₜ strain transition.
The transfer/development lengths are scaled by the **Development Multipliers**
setting. WPB proved the mechanism (its own §4.1); these six confirm the ramp and
pin the multiplier at **1.0** for all v4.3.2 runs (§A.6), where WPB used **1.3**.

## A.3 Handling stages

Two stages are ever enabled on these walls; a third exists and is off:

| | Stripping | Transportation | Erection (Primary/Secondary) |
| --- | --- | --- | --- |
| **Load Multiplier** | **1.4** | **1.5** (WPB) | — (never run in any of the six) |
| Concrete strength | **Initial** (f'ci) | In-Place (f'c) | — |
| Stress limits | **Handling** (§A.6) | In-Place | — |
| Lift Type | Static Lift | Static Lift | — |
| Sling Angle | 60° | — | — |

Confirmed WPA4.0 p.7 (Stripping, mult 1.4, Initial, Handling limits, Static,
60°; Transportation/Erection "not being performed") and WPA2.0 p.853 (Stripping,
mult 1.4). The multiplier is the equipment/dynamic factor; **no strength-design
load factor stacks on top of it** (WPB §6: handling `Mu` = self-weight × the
stage multiplier, nothing else).

**PCI basis & rigging idealisation.** The panel is idealised as a **beam whose
supports are the lifter lines**, not dunnage. Lifters are entered as **Face
Lifters** and **Top-Edge Lifters**, each a number of columns and lateral
locations given as a **fraction of panel width** (WPA4.0 p.7: 2 columns at
0.207 from each side). The run prints:
- `Panel weighs X kips and its center of gravity is …` (WPA4.0 p.7),
- **Reactions** as `Location | Vertical | Horizontal (k)` per lifter line, with
  a **Tilt Potential (deg)** value (WPA4.0 p.10),
- reactions are printed **unfactored per lifter** while the Stresses/Flexure
  moments are **factored** — the run says which is which.

The Stripping **Stresses** table (WPA4.0 p.10) is the governing handling check:
`Loc | Tension | Limit | Comp. | Limit | fci req | Mg | Aps | Losses | Pi | Mzi | Myi`.
`Pi` is the prestress force (negative = compression), `Mzi/Myi` the prestress
moments about the two axes, `Mg` the stage moment.

## A.4 The In-Place model

The panel is analysed as a member spanning between its **restraints** (a
foundation connection + floor ties — WPA4.0 p.6 lists 5 restrained elevations)
under lateral + gravity + axial demand.

**Load cases applied** (Structural Model, WPA4.0 p.6 / SWA1.0 p.12):
| case | how applied |
| --- | --- |
| Dead + Self weight | self weight distributed; self-weight eccentricity from panel CG |
| Live, Roof | as part of concentrated loads / tributary |
| **Wind** | out-of-plane **distributed**, a `W1…W4` table of **Pressure** and **Suction** magnitudes (psf), varying start→end over height (WPA4.0 p.6: 68/82 psf then 212/212 psf zones) |
| **Seismic** | zone(s) over `x/L`, `Cs` as % of dead, applied to Deadload + Self weight |
| **Earth / soil** | interior & exterior soil, elevation + surcharge; lateral pressure coefficient set in Project Information |
| Temperature | exterior/interior °F + thermal-elasticity multiplier (out-of-plane thermal bow) |
| **Concentrated axial** | `P1/P2 …` at an elevation with an eccentricity, split Dead/Live/Roof/Pres/Suct/Seis (SWA1.0 p.12: 139.6k D + 44.6k L each) |

**Load combinations** (Project Information): the ACI 318-14 set with columns
`D L R W E T H`, printed as **Strength** (8 combinations: 1.4D; 1.2D+1.6L+0.5R;
… 0.9D+1.0W; 0.9D+1.0E — each with `T` at 1.0 and soil `H` at 1.6, Include=1)
and **Service** (5–10 combinations, WPA4.0 p.4 shows 10; SWA1.0 p.10 shows 5).
The result tables are headed `All Combinations` and each controlling section
names its governing LC (e.g. WPA4.0 p.9 `Flexure LC: LC 7 - 0.9D + 1.0W + 1.0T + 1.6H`).

**Second-order / slenderness.** Settings `2nd Order Effects: P-Delta`,
`Analysis βd: Non-Sway` (all six). The restraints define the unbraced spans; the
axial table's `ΦPcrit` is the buckling capacity; the summary prints a controlling
P-M interaction section at `0.95L`. (WPB additionally printed a `Second Order
Effects` block with `kL/r`, 1st-order vs 2nd-order moment, `% Increase`.)

## A.5 Service checks

- **Tension**: `Location | Tension (psi) | Cracking (psi) | M (k-ft) | P (k)`
  (+ prestress `Aps/Losses/Pi/Mzi/Myi`). Cracking = **7.5√f'c**. Prestressed
  runs classify each section **Class U** (≤7.5√f'c) / **Class T** (≤12√f'c)
  (WPA4.0 p.15). Non-prestressed use a single Modulus-of-Rupture 7.5√f'c.
- **Total Compression**: `Location | Comp. (psi) | Limit (psi) | M | P`.
  Limit = **0.6 f'c** = 3600 (WPA4.0 p.16, SWA1.0 p.17).
- **Deflection**: graph vs allowable = the deflection limit (§A.6). A `Δlim`
  and `Δmax` also print in the one-page summary.
- The controlling section for each prints a **Section View** block (section
  properties Ag/Cx/Cy/Izz/Iyy, θ, strand Aps/%Loss/ex/ey, the stress vs limit).

## A.6 Settings / parameters Eriksson exposes (and the per-job variation)

The Settings page is the method statement. Verbatim-equivalent across the six,
with the per-job values called out:

```
Deflection Limit        L/150 (WPA3, WPA4) | L/120 (WPA1) | L/240 (WPA2, SWA, MWH)
2nd Order Effects       P-Delta | Analysis βd: Non-Sway
Stress Options          Failure if cracked | Ignore Lateral Strand Eccentricity
                        | Use Principal Axis
In-Place Stress Limits  Tension 7.5 √fc (Uncracked / Class U) / 12 √fc (Transition
                        / Class T) | Compression 0.6 fc | Allowable Δfps 36 ksi
                        (non-prestressed prints one "Modulus of Rupture 7.5 √fc")
Handling Stress Limits  Tension 5 √fc (WPA1, MWH, WPB) OR 7.5 √fc (WPA2, WPA3,
                        WPA4) | Compression 0.6 fc          ← PER-JOB, both occur
Flexure Options         Method: Whitney Stress Block | Cracking Check: None
Resistance Factors      Developed:  Tension 0.90, Compression 0.65, Shear 0.75
                        Transferring: Tension 0.75
                        (values verified against the shear tables; the printed
                        grid's column order is ambiguous — see §A.8)
Development Multipliers  Strand Normal 1.0 | Debonded 2.0 | Cut 1.0 | Mild 1.0
                        (ALL v4.3.2 runs here; WPB v4.13.2 used 1.3 — PER-JOB)
Shear Options           Treat as column | Use ACI 22.5.8.2
Axial Options           Ignore tensile strength failures | Ignore buckling failures
Prestress Losses        PCI Design Handbook | Humidity 70 | Release ~8 hrs |
                        Erection 30 days
Materials               f'ci 2.5–3.5 ksi, f'c 6.0 ksi, 150 pcf normalweight;
                        strand fpu 270, Ep 28500; mild fy 60, Es 29000
```

## A.7 Result presentation

- **Per-check tables**, each preceded by a `Legend`, a `Max/Min` header block, a
  `Summary Graph` (x-axis in **inches**, 11 ticks 0→L) and a `Summary Table`.
- **`Loc.` always first, in feet, two decimals.** Signs: sagging +, hogging −;
  a separate `θ (deg)` column carries the sense (0 sagging / 180 hogging). `c`
  prints an inch mark inside the cell.
- **Zero rows at the piece ends are printed, not suppressed** (Φ, ΦMn, Aps all
  0.00 there). `∞` where a quantity is genuinely unbounded. **No colour, no
  FAIL flag** — the verdict lives in the `Max Utilization:` header and the
  engineer's margin.
- Station spacing ≈ **L/20** plus a straddling pair at every geometric
  discontinuity; **Section Properties at L/10** (11 rows).
- **A one-page summary** (WPA4.0 p.9) collects, per stage: utilizations
  (shear/flexure/axial), controlling LC, `Max Comp/Tension vs limit`, and the
  P-M interaction diagram. This is the at-a-glance sheet an engineer reads first.
- Column sets, exactly:
  - **Handling Stresses**: `Loc | Tension | Limit | Comp | Limit | fci req | Mg | Aps | Losses | Pi | Mzi | Myi`
  - **Flexure (handling)**: `Loc | Util | Mu | Φ | ΦMn | c | θ | As | A's | Aps | Loss | d`
  - **Flexure (in-place)** adds `Mcr | Pu | ΦPn` (15 cols)
  - **Shear**: `Loc | Util | Vu | ϕVn | Vc | Vs Req | bwd | Av Min | Vci | Vcw` (Vci/Vcw handling only; in-place drops them)
  - **Axial**: `Loc | Util | Pu | ΦPn(C) | ΦPn(T) | ΦPcrit | As | Aps | Loss | Ag`
  - **Service Tension**: `Loc | Tension | Cracking | M | P | (Aps | Loss | Pi | Mzi | Myi)`
  - **Service Compression**: `Loc | Comp | Limit | M | P | …`

## A.8 What Eriksson Wall does NOT do here (and what is image-only)

**Not done for a solid wall — do not build to mimic:**
- **No torsion** (§A.2). **No horizontal-shear / percent-composite / C-GRID**
  interpolation — those are sandwich-panel sections (WPB only), absent from all
  six solid walls.
- **No in-plane shear-wall / diaphragm design.** SWA1.0's in-plane shear
  (`Vc1/Vc2`, ACI 11.5.4/11.6, `Vcmax = 10√f'c·h·d`), overturning/uplift
  story-by-story spreadsheet, horizontal-joint shear-friction and corbel
  (PCI 5.3.1) are all **hand Mathcad/spreadsheet** sheets by the engineer
  (SWA1.0 p.4–8, p.18). Eriksson Wall itself only did SWA's **out-of-plane**
  bending + axial + service. Our tool replaces the Eriksson part, not these.
- **No minimum-reinforcement / Mcr floor** (`Cracking Check: None`); `Mcr` is an
  informational column.

**Image-only — flagged, NOT transcribed, needs image verification before any
number is trusted:**
1. **Resistance-factor grid** (WPA4.0 p.4): the Developed/Transferring × Tension/
   Compression/Shear cell placement extracts jumbled (`0.9 / 0.75 / 0.65`). The
   *values* 0.90/0.65/0.75 are verified against the shear tables and WPB p.71,
   but confirm the exact cell layout from the rendered page.
2. **Interaction (P-M) diagrams** (WPA4.0 p.9, and each service Section View):
   plotted curves, axis values partially OCR'd — read from image if a numeric
   PM point is ever needed.
3. **Summary Graphs** on every results section: the curve is an image; only the
   Summary Table beneath it is text. We rely on the table.
4. **Cover-sheet strand/reinforcing patterns and stripping-pick geometry**
   (each p.1): dimensioned drawings — pick fractions (`.104L / .291L`) read as
   text but the layout is an image.

---

# Part B — GAP analysis vs our current code

Scope of what exists today (`tools/panelanalysis.py`, `panelanalysis_schema.py`,
schema `panelanalysis/1`, engine `panellift`): a **self-weight handling beam**
solved on `structural_model.supports` (continuous beam, rigid supports),
strand-only capacity (`ΦMn`, `Mcr` informational, `ΦVn`, `f_se`) at L/20
stations, section properties at L/10, a demand-vs-capacity table with
`M/ΦMn` and `V/ΦVn` ratios, and every In-Place section rendered as an explicit
NOT-BUILT placeholder. Legend of status: **(a) covered · (b) partial/different ·
(c) missing.**

Ordered by importance for a wall panel: **flexure / shear / handling → in-place
wind → service → the rest.**

### Tier 1 — handling & the capacity primitives (build first)

1. **(c) Handling STRESS check — the governing stripping check is not computed.**
   Eriksson's Stripping *Stresses* table (extreme-fibre tension vs `5`/`7.5√f'ci`,
   compression vs `0.6 f'ci`, and `fci req`) is what governs stripping — and we
   compute `ΦMn` strength but never the service stress that actually controls.
   The settings block already carries `tension_limit_sqrt_fc` /
   `compression_limit_ratio`; **nothing reads them.** Add: extreme-fibre stress
   from `(Pi/A ± Pi·e·y/I ± Mg·y/I)` at each station, compared to the two limits,
   plus the `fci req` back-solve. **Highest handling priority.**

2. **(b) Handling is one self-weight stage; Eriksson runs staged multipliers.**
   We have a single stage at `loading.self_weight.load_factor`. Eriksson runs
   **Stripping ×1.4 @ f'ci with Handling limits** and **Transportation ×1.5 @
   f'c with In-Place limits** (and an Erection stage, off here). Add a
   `handling.stages[]` list, each with `{multiplier, concrete: initial|in_place,
   stress_limits: handling|in_place}`, and solve/report each. The engine already
   takes a per-stage `fc_psi` and `multiplier`.

3. **(b) Handling idealisation is dunnage, not lifters.** Eriksson idealises
   stripping as a **beam on lifter lines** (Face + Top-Edge lifters at width
   fractions, sling angle, **Tilt Potential**, per-lifter Vertical/Horizontal
   reactions). We solve a beam on generic `supports`. `panellift` already models
   lifters/rigging — wire `structural_model` to carry lifter columns + lateral
   fractions and let the handling solve use the lift path, reporting reactions
   per lifter (unfactored) with moments factored, matching Eriksson's split.

4. **(c) Φ development ramp + development multiplier.** Our Φ is a constant 0.90;
   Eriksson ramps **0.75→0.90 across the transfer→development length** (ACI
   21.2.3), scaled by the Development Multiplier (1.0 here, 1.3 on WPB). Our
   `pci.development_length_in` applies no multiplier. Add the ramp to Φ and to
   the effective `Aps(x)`; expose `development_length_multiplier` in settings
   (already a field, currently unused). Materially changes near-end capacity.

5. **(c) Non-prestressed / mild-steel capacity path.** `panellift.capacity` is
   **strand-only** — so WPA1.0, WPA3.0 and SWA1.0 (mild-reinforced walls) cannot
   be analysed at all today; the tool renders a "no prestress → not computed"
   box. Eriksson runs full flexure/shear/axial on mild `As` (with `A's`). Add a
   mild-steel flexural/axial capacity path. **Unlocks whole panel classes.**

6. **(b) Shear method.** Confirm our `ΦVn` uses the Eriksson **detailed
   Vci/Vcw** method (`Vc = min(Vci, Vcw)`, `ΦVn = 0.75·Vc`, `bwd` as a product,
   `∞` at zero-moment) and reports both columns for handling. WPB §4.6 found our
   `d` and √f'c-coefficient handling differed from Eriksson's — re-check against
   these tables and align, or document the deviation.

### Tier 2 — the In-Place engine (the large missing piece, Stage 3)

7. **(c) Load-case engine.** None of it exists. Build the cases of §A.4:
   self/dead, live, roof, **wind (out-of-plane distributed Pressure + Suction,
   varying over height)**, **seismic (Cs % of dead over x/L zones)**, **soil
   (interior/exterior surcharge + lateral coefficient)**, temperature (thermal
   bow), and **concentrated axial loads** at an elevation + eccentricity. The
   `loading.wind` / `loading.combinations` fields are already `unread`
   placeholders waiting for this. The owner has named a `wallanalysis` Project
   Config module (wind speed, Kzt, ASCE edition, parameter table) as the input
   source — not built.

8. **(c) ACI 318-14 load combinations.** The `D L R W E T H` **8 strength /
   N service** matrix, envelopes per station, and the "controlling LC" naming.
   Prerequisite for everything in-place.

9. **(c) In-place flexure with axial (P-M interaction).** In-place `ΦMn` is
   evaluated at the actual `Pu` on the interaction surface, with `Mcr`, `Pu`,
   `ΦPn` columns. Our flexure is pure bending, no axial. Add the P-M surface and
   evaluate demand `(Mu, Pu)` against it.

10. **(c) Axial check.** `ΦPn(C)`, `ΦPn(T)`, and `ΦPcrit` (buckling) with
    utilization — entirely absent. Include the two "ignore tensile/buckling
    failure" switches from Axial Options.

11. **(c) Second-order / slenderness.** P-Delta with non-sway βd, `kL/r` per
    restrained span, moment magnification, 1st vs 2nd-order `% increase`.
    Depends on the restraint model (next).

12. **(c) Restraint / span model.** `structural_model.restraints` is an `unread`
    placeholder. In-place needs the foundation + floor-tie restraints (elevation,
    type, gravity/thermal, stiffness) to set spans for both bending and
    slenderness.

### Tier 3 — service, then presentation & settings

13. **(c) Service checks.** Tension vs cracking (`7.5√f'c`; Class U/T `12√f'c`
    for prestressed; Modulus of Rupture for mild), total compression vs `0.6 f'c`,
    and deflection vs the per-job limit (`L/150` etc.). None built. Reuse the
    extreme-fibre stress primitive from item 1 with in-place loads/limits.

14. **(b) Settings coverage.** Expose the full Settings page: in-place stress
    limits (`7.5/12√f'c`, `Δfps 36 ksi`), the resistance-factor matrix
    (developed 0.90/0.65/0.75 + transferring 0.75), stress options (Failure if
    cracked, Ignore Lateral Strand Eccentricity, Use Principal Axis), shear/axial
    options, cracking method. Our `settings` block is thin. **Per-job values
    (handling limit 5 vs 7.5√f'ci; dev multiplier 1 vs 1.3; deflection limit)
    must be inputs, not constants** — both values occur across the six.

15. **(b) Result presentation parity.** Move from our single combined
    demand-vs-capacity table toward Eriksson's **separate Stresses / Flexure /
    Shear / Axial** tables with the exact column sets in §A.7 (`θ`, `c`, `Loss`,
    `d`, `As`, `A's`, `Aps` …), plus the **one-page summary** (per-stage
    utilizations, controlling LC, P-M diagram). Lower priority — arithmetic
    first, layout second.

16. **(c) Multi-run / multi-section packages.** A deck must be able to carry
    **several analysis runs** (MWH1.0's `2.1`/`4.1`) and Eriksson's optional
    `Structural Sections` (analysing sub-strips of the cross-section). Our schema
    assumes one panel/one run.

### Explicitly NOT on the punch-list (scope guards)

- **Torsion** — Eriksson Wall does not run it for a wall (§A.2). Do not add.
- **Horizontal shear / percent-composite / C-GRID** — sandwich-panel only (WPB),
  absent from every solid wall here. Needed only when insulated panels enter
  scope; our code already marks it N/A for a solid section, which is correct.
- **In-plane shear-wall / diaphragm / corbel design** — the engineer does this
  by hand (SWA1.0), Eriksson Wall does not, so neither must the replacement.
- **1.2 Mcr floor / minimum-steel check** — Eriksson has `Cracking Check: None`;
  keep `Mcr` informational (matches our current behaviour — do not "fix").

---

## Reconciliation summary (this note vs WPB note)

| item | WPB (v4.13.2, sandwich) | these six (v4.3.2, solid walls) |
| --- | --- | --- |
| section/page order | as §A.1 | **identical** |
| handling/in-place split | separate `.ewf`, mild-only vs strand-only | either separate OR one unified run (WPA4.0); MWH multi-run |
| handling tension limit | 5√f'ci | 5√f'ci (WPA1,MWH) or 7.5√f'ci (WPA2/3/4) — per job |
| development multiplier | 1.3 | 1.0 (all v4.3.2) — per job, confirms WPB open-Q #4 |
| torsion | from Eriksson *Beam* (lintel) | none |
| horizontal shear / % composite | yes (C-GRID sandwich) | none (solid) |
| Φ ramp, Whitney block, Vci/Vcw, P-M, service limits, combos | as §A.2–A.6 | **same method** |