The bulb of influence - Explaining the SmartJack System
The bulb of influence is what sets the SmartJack system apart from other repair options. It’s based around sound engineering. The SmartJack pre-cast concrete base and cast aluminum base are 12 inches wide. How sound engineering works is that at a depth of twice the bearing width, bearing stresses dissipate to approximately ten percent of those at the bearing surface. So the 12 inches is the bearing width, and two times 12 inches is 24 inches. Therefore, at the bottom of the two-foot hole , the pressure that was being exerted at the structural footing base is reduced down to only 10 percent of what it was.
Even if the soil at the bottom of the excavated hole isn’t all that strong, you can be assured that the ‘Bulb of significant Stress Influence’ has already been distributed within the compacted crushed stone or recycled concrete fill.
The bottom line: The SmartJack system, as it name implies, is smart. It reduces stress on the original soil by 90%, making it a long term effective solution for your home.