Maximum Impact Load & Penetration Depth

The focal point of this application is to assess strain due to a falling object such as a piece of construction equipment, material or vehicle falls over an operating pipeline.
Some of the limitations of this calculation are as follows: drop height, maximum load at the soil surface, type of soil, etc. to determine the penetration depth.

Maximum Impact Load

Where:
𝐿_𝑚𝑎𝑥 − Maximum Load at Soil Surface(lbs)
𝑊 − Weight of Falling Object(lbs)
𝐻_𝑓 − Drop Height(in)
𝑟_𝑜 − Least Horizontal Radius of Falling Object(in)
𝐺 − Soil Shear Modulus(psi)
𝑣 − Poisson′s Ratio for Soil(dimensionless)
For large strains, near the region of impact, the shear modulus is one-tenth the low amplitude shear modulus.

Where:
𝑉_𝑠 − Shear Wave Velocity of Near Surface Soils(in/sec)
𝜌 − Mass Density of Near Surface Soil(Unit Weight of Soil/Acceleration due to Gravity)(lb.sec2/in⁴)

Penetration Depth

Where:
𝑥_𝑝 − Penetration Depth(ft)
𝑃_𝑎 −Weight per Unit Impact Area(lb/ft2)
𝑉 − Impact Velocity—

𝑘 − Empirical Coefficient of Penetration
(𝑘=0.0367 for Sandy Soil, k=0.0482 for Soil with Vegetation, k=0.0732 for Soft Soil)

Input Parameters

1. Select the Maximum Impact Load & Penetration Depth application from the Steel Pipe – Design and Stress Analysis module
2. To create a new case, click the “+” button
3. Enter Case Name, Location, Date and any necessary notes
4. Fill out all required fields
5. Make sure the values you are inputting are in the correct units
6. Click the CALCULATE button

• Weight of Falling Object(lbs.)
• Drop Height(ft), Impact Area Diameter(ft)
• Unit Weight of Soil(lbs./ft³)
• Poisson’s Ratio for Soil
  Shear Wave Velocity of Near Surface Soil(in/sec)
• Empirical Coefficient of Penetration

Outputs/Reports

1. View the results
2. If an input parameter needs to be edited be sure to hit the CALCULATE button after the change
3. To SAVE, fill out all required case details then click the SAVE button
4. To rename an existing file, click the SAVE As button. Provide all case info then click SAVE
5. To generate a REPORT, click the REPORT button
6. The user may export the Case/Report by clicking the Export to Excel/PowerPoint icon
7. To delete a case, click the DELETE icon near the top of the widget

• Soil Shear Modulus(psi)
• Maximum Load at the Soil Surface(lbs.)
• Impact Velocity(ft/sec)
• Impact Pressure(psi)
• Weight per Unit of Impact Area(psi)
• Penetration Depth(ft)

Related Links

Pipeline Design & Stress Analysis
Pipeline HUB — User Resources