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Quick start (5 minutes)

In five minutes you go from opening the app to reading a complete verification. Open nx.geostru.ai/rpd and follow the steps.

1. General data

In the Parameters tab, General data section, set:

  • a project description (optional);
  • the road type (defines the traffic spectrum);
  • the design life in years;
  • the reliability R (%) and the initial and final service indices (PSI) — required by the AASHTO method.

2. Geometry and 2D/3D preview

Open Geometry and sections and enter the number of lanes, widths, shoulders and slopes. On the right, the cross-section preview updates in real time.

With the 2D / 3D toggle at the top of the panel you switch from the dimensioned drawing to the three-dimensional model of the embankment.

See while you design

The preview stays visible at all times: every value you change is reflected in the drawing immediately, without pressing any button.

3. Pavement layering

In Layering you define the thicknesses (cm) and the coefficients of the layers — wearing course, binder, base, subbase — and, if needed, add a bituminous geogrid reinforcement. Each layer can be enabled or disabled with the switch next to its name.

4. Subgrade and traffic

  • In Subgrade properties choose the parameter (CBR or Resilient modulus) and its value.
  • In Design traffic enter the AADT (annual average daily traffic), the growth rate and the percentages of commercial and lane vehicles.

5. Calculation method

In the Calculation method card choose between:

  • Empirical — AASHTO 1993
  • Rational — Ivanov (deflection)
  • Rational — Westergaard (rigid pavements)

6. Results

Open the Results tab: the calculation runs automatically. You will see the safety factor (FS), the Structural Number, the allowable axles and the full table of quantities, with the outcome Verified or Not verified.

Understanding each value

Hover over a results row and click the ✨ Explain icon: the AI assistant explains that parameter using the values of your project.

7. If it fails: recover with one click

When FS is below 1, the How to pass the check card appears with concrete proposals:

  • increase the thickness of one layer (each chip is clickable: it applies and recomputes);
  • or insert a geogrid with a given TBR.

After applying a solution, the Undo and choose another solution bar lets you go back and compare the alternatives.

Optimization

If instead the package is over-designed, RPD NX proposes to reduce a layer while keeping the check satisfied — less material, same safety.

8. Report and export

From the Report menu you generate the calculation document in Word or PDF; from the Export menu you save the project (.rpdnx) or the cross-section as SVG. See File formats and export.

Found an error on this page? Let us know or open a Pull Request.