Republished 8 August 2026
Scaled Depth of Burial (SDOB) is one of the most important metrics in blast design. It is a critical engineering parameter used in blasting to measure the confinement of an explosive charge. It’s calculated as the ratio of stemming height to explosive column length, scaled to a reference of 10 hole diameters. This ratio helps engineers assess how well the explosive energy is contained within the blast hole—directly influencing safety, fragmentation, and overall blast performance.
When SDOB is properly controlled, it enhances rock breakage, reduces environmental impact, and improves compliance with safety protocols.
🔍 Why Scaled Depth of Burial (SDOB) Matters
1. Energy Containment
A higher Scaled Depth of Burial value means greater confinement. This ensures more of the explosive energy is directed into breaking the rock, rather than escaping as flyrock, air blast, or excessive vibration.
A foundational paper on this is Chiappetta, R.F., & Treleaven, D.E. (1997) – “Flyrock Prediction with Characterization of SDOB”. This is the pioneering technical paper establishing the relationship between SDOB, stemming length, and predictive flyrock exclusion zones.
2. Safety and Efficiency
Scaled Depth of Burial helps mitigate risks like flyrock and ground vibration. It’s a key factor in meeting regulatory standards and maintaining safe working conditions on site.
3. Design and Planning
Engineers use Scaled Depth of Burial during blast design to determine the optimal stemming height and explosive placement. Products like Varistem plugs are specifically designed to improve stemming effectiveness and confinement—making them ideal tools for managing SDOB in the field.
4. Blast Outcome Analysis
Post-blast, Scaled Depth of Burial can be used to evaluate performance—helping correlate the design intent with actual results. This feedback loop supports continuous improvement in blast practices.
🧠 Final Thought
Whether you’re designing a new blast pattern or reviewing site performance, Scaled Depth of Burial offers a measurable, scalable way to optimize outcomes. It’s not just a number—it’s a tool for safer, smarter blasting.
