A surcharge is a weight load which is placed on the surface of soil to cause lateral pressure. It is used to improve the weak compressible earth and provide a more sturdy, stable ground for construction. Some examples of a surcharge load include embankments, construction equipment, adjacent structures, and material stockpiles and railroads.
During the surcharge process, monitor plates are used to examine the rate of settlement and compute the time required for a surcharge load to cause the necessary level of settlement.
The basic soil pressure needed can be calculated using the equation below:
Here, S h is horizontal soil pressure caused by surcharge, K is the lateral soil pressure coefficient caused by surcharge, and Q is the uniform surcharge applied to the backfill of the surface wall.
Stahl used an embankment surcharge load at the new 135,000-square-foot Army National Guard Readiness Center site in Arden Hills, MN to improve the soil conditions.