Skip to main content
Infradigital Logo
Back to Dashboard
Offline processing active

Vertical Alignment Formatter

Clean, restructure, and validate Civil 3D profile vertical intersection point (PVI) data. Automatically check slope limits and K-values against AASHTO speed specifications, customize column ordering, and download fully formatted Times New Roman Excel reports.

Import Profile Export

Design parameters

Station Equations

No Vertical Data Imported

Upload your profile export (Excel Worksheet or CSV) from Autodesk Civil 3D. We will parse it and check all values client-side.

Engineering Reference Manual

Vertical Alignment Formatter Documentation

Technical specifications, mathematical formulas, and civil guidelines

1. Functional Purpose

When vertical profile geometries are exported from Autodesk Civil 3D, the resulting files contain redundant elevation lines, inconsistent slopes, and gaps in PVI (Point of Vertical Intersection) coordinates. The **Vertical Alignment Formatter** cleans up these exports by isolating PVIs, validating grade transitions, verifying K-values for crest and sag parabolic curves, and ensuring that no blank lines disrupt file parsing.

This tool helps engineers quickly check whether the designed vertical grades and curve lengths comply with site design guidelines. It formats raw profiles into neat tables listing PVI station, elevation, grade in, grade out, curve length, and K-values.

2. Practical Workflow Instructions

To process your vertical alignment files:

  1. Export Profile from Civil 3D: Generate a vertical profile report (under Reports Manager > Profile). Save the PVI table to a CSV file.
  2. Upload & Select Profile: Upload your PVI CSV file. Enforce column mapping for PVI Station, Elevation, and Curve Length.
  3. Enter Threshold Speeds: Input the design speed of the highway stretch (e.g., 60 km/h, 100 km/h) and standard grade thresholds.
  4. Analyze & Download: The tool will highlights crest and sag parabolic curve segments and check their K-values. Export the structured spreadsheet containing all compiled calculations and validations.

3. Mathematical & Civil Engineering Basis

Vertical curves are modeled as symmetric parabolas. Key mathematical relationships include:

  • Grade Change (A): Absolute difference between incoming and outgoing slopes (G1 and G2):
    A = |G2 - G1|
  • K-Value (K): Represents the horizontal distance required to achieve a 1% change in grade:
    K = L / A
    Where L is the vertical curve length in meters.

The tool checks these K-values against minimum stopping sight distance (SSD) and comfort criteria from **AASHTO** and **ERA 2013 manuals**:

Crest Curves:

K_min = S^2 / (200 * (sqrt(h1) + sqrt(h2))^2)

h1 (driver eye height) = 1.08m, h2 (object height) = 0.60m

Sag Curves (Headlight Control):

K_min = S^2 / (200 * (h3 + S * tan(theta)))

h3 (headlight height) = 0.60m, theta (upward divergence) = 1 degree

Any curve violating these safety envelopes is highlighted to prevent accidents from restricted sight distances.

AASHTO / ERA Standard Compliance•100% Client-Side Processing•Verification Mandated