napkin.

Type part of a title or topic, such as “beam”, “pulley” or “units”.

Menu

CALCULATORS / CIVIL, GEOTECHNICAL AND WATER SCREENING

Buried-pipe load screening calculator

Prismatic soil overburden on pipe projected width; arching and traffic omitted.

civil-pipe-cover-load.napkin / editable
✓ checks pass

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

ScenariopressurekPalineLoadN/m
17.6583531.6
14.12642825.28

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

line load budget3531.60 N/m✓ passes

BASELINE INPUTS

CALCULATED

pressure17.658 kPa
lineLoad3531.6 N/m

Edits change the baseline source.

Calculated from your source · not saved
Baseline · Baseline
line load budget3531.60 N/m ✓ passes
alternative · alternative
line load budget2825.28 N/m ✓ passes

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

pressure
pressure = density*gravity*cover [kPa]
line load
lineLoad = pressure*diameter [N/m]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

density
1800 kg/m^3
cover
1 m
diameter
0.2 m
gravity
9.81 m/s^2

Calculated

pressure
17.658 kPa
line load
3531.6 N/m

Assumptions and limits

Prismatic soil overburden on pipe projected width; arching and traffic omitted.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Buried-pipe load screening. Inputs: cover depth; soil/unit loads; trench model. Outputs: external load; model limitations. Model scope: Preliminary geometry and loads; site/code inputs supplied externally. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

  • Inputs: cover depth, soil/unit loads, trench model
  • Outputs: external load, model limitations
  • Modes: calculate, compare, sweep
  • Drawing: Load and site section diagram

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS

More in civil, geotechnical and water screening