Surcharge

Definition

A surcharge is an increase in the lateral earth pressure of a retaining wall, caused by a vertical load behind the wall. It can also refer to a load placed over an area to compact it or change its characteristics.

Purpose

The purpose of a surcharge is to simulate additional load conditions or to pre-compress the soil, improving the stability and performance of retaining walls or preparing the ground for construction.

Examples of Use

• Retaining walls experience surcharge loads from nearby structures, vehicles, or stockpiled materials.
• Construction sites use surcharges to pre-load soil and reduce settlement for future building foundations.
• Highway embankments are often surcharged to ensure stability and prevent future settling.

Related Terms

• Retaining Wall: A structure that holds back soil or rock from a building, structure, or area.
• Soil Compaction: The process of increasing the density of soil by mechanical means.
• Earth Pressure: The force exerted by soil on a retaining structure.

Notes

Understanding and managing surcharges is crucial in geotechnical engineering to ensure the safety and stability of retaining structures and prepared ground surfaces.