Online tools

The homework toolbox

Every tool here exists because a homework needs it β€” most of them to compute something, one of them to draw the figure the write-up asks for. They run entirely in your browser β€” nothing to install, nothing to license β€” and the calculators are built to let you check hand calculations, not skip them.

2 of 20 are open. The rest unlock alongside the homework that needs them, so the toolbox grows with the course rather than arriving all at once.

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Unlocks later
Resilient Modulus Fitter
HW2

Fit k₁, kβ‚‚, k₃ of the generalized Mr model to triaxial data β€” live LINEST-style regression with RΒ², a parity plot, and paste-from-Excel input.

MEPDG k₁–k₂–k₃ Β· Huang Ch. 7 Coming soon
CBR Reduction
HW2

Reduce a piston penetration test to a CBR, with the tangent construction that corrects a concave-up curve β€” and a toggle to see how much that correction is worth.

AASHTO T 193 Β· ASTM D1883 Coming soon
Layered Elastic Analysis
HW3HW4

The real N-layer elastic solution in your browser: stresses, strains and deflections at any depth, dual and tandem wheels superposed β€” a check on WinJULEA, not a substitute for understanding it.

Huang App. B Β· Hankel transform Coming soon
Stress Explorer
HW3HW4

One-layer (Boussinesq) response under a circular load: stress, strain, and deflection profiles, a draggable depth probe, and the classic Οƒz/p pressure bulb.

Boussinesq Β· Huang Eqs. 2.1–2.6 Coming soon
ESAL Calculator
HW5HW7

Exact AASHTO load equivalency factors, a mixed axle spectrum with presets, and the full design-lane projection β€” D, L, growth β€” shown factor by factor.

AASHTO 1993 Β· App. D Coming soon
ESWL Comparator
HW5

Four published criteria for converting duals to one wheel, which give four different answers β€” 5630 to 7410 lb on the same example in Huang. The question is which failure mode you are designing against.

Huang Β§6.2 Β· Eqs. 6.1-6.14 Coming soon
Drainage Designer
HW6

Surface infiltration by Ridgeway and Cedergren, groundwater and meltwater inflow, drainage-layer capacity and time to drain, Manning pipe sizing, and filter criteria.

Huang Ch. 8 Β· Eqs. 8.18–8.34 Coming soon
AASHTO Design Studio
HW7HW9

The 1993 design equations solved in any direction β€” SN, slab thickness, reliability, roadbed support β€” with the layered thickness solution and the seasonal effective k.

AASHTO 1993 Β· Huang Eqs. 11.34, 12.21, 12.29–12.30 Coming soon
Transfer-Function Damage
HW8

Feed WinJULEA strains through the HW8 transfer functions: rutting per layer, Miner’s damage, and bottom-up cracking growing with every repetition.

AASHTOWare transfer functions Coming soon
PCA Rigid Thickness
HW9

Fatigue and erosion damage summed over an axle load distribution. You read four values off the PCA tables; the tool runs both criteria and tells you which one governs.

PCA 1984 Β· Huang Eqs. 12.7–12.9 Coming soon
Joints & Load Transfer
HW9

Dowel group action, bearing stress, tie bars, joint opening and faulting β€” under the three different conventions Huang uses in three different places, one of which may fail your design.

Huang Eqs. 4.35-4.45 Β· 12.3 Coming soon
Westergaard Slab Stress
HW9

Every published case in Huang Ch. 4 β€” interior, edge under both circular and semicircular contact, and corner by both the original and Ioannides formulas, which disagree. Plus Bradbury curling and the dual-tyre equivalent circle.

Westergaard Β· Huang Eqs. 4.9–4.31 Coming soon
Dynamic Modulus & Master Curve
HW2HW8

Asphalt has no single modulus. Predict |E*| by two published routes that disagree by 65%, then shift the isotherms onto one master curve β€” and read whether time-temperature superposition actually held.

Huang Eqs. 7.24-7.28 Β· 2.44-2.46 Coming soon
FWD Backcalculation Studio
Ch. 9Ch. 13

The forward problem run backwards: a measured deflection basin becomes layer moduli, by layered-elastic inversion and by the AASHTO closed form β€” plus the sensitivity that says which of those moduli the data actually determines.

Huang Β§9.4.3 Β· Eqs. 13.22-13.26 Coming soon
Reliability & Variability
Ch. 10

Give every design input a coefficient of variation and watch the reliability fall out. Ranks which input owns the uncertainty, and runs Taylor, Rosenblueth, and Monte Carlo side by side.

Huang Ch. 10 Β· Eqs. 10.38-10.46 Coming soon
Serviceability & Skid Resistance
HW1HW10

Fit the PSI equation yourself to a rating panel and watch the rut coefficient come out 27x the published value with an R-squared above 0.98. Plus skid number against speed.

Huang Eqs. 9.14-9.15 Β· 9.31-9.34 Coming soon
ACR/PCR Compatibility
HW10

Parse runway rating codes and decide where an aircraft may operate β€” strength, subgrade category, tyre pressure, and the occasional-overload allowance.

ICAO Annex 14 Β· ACR/PCR Coming soon
Pavement LCA Worksheet
HW10

Life-cycle GHG for one lane-mile across all six stages, with the IRI sawtooth driving the rehab schedule and every inventory factor editable.

FHWA LCA framework Coming soon