Load-Displacement Appraisal of Spread Footings

Shallow foundations represent a common and economically viable solution for many construction projects. Their design, however, demands careful consideration of soil properties and the anticipated structural loads. A key aspect of shallow foundation design is understanding the load-displacement behavior, embracing bearing capacity, settlement and structural design interactively. Performance-based design approaches, which directly consider allowable displacements under service loads, are increasingly important. These methodologies ensure both the safety and serviceability of the structure while optimizing material usage and construction costs. Accordingly, a database of load-displacement records was compiled, including thirty-six full-scale load tests on spread footings installed in different soil types worldwide. The effect of foundation breadth, embedment depth, and soil deposit type on foundation load-displacement behavior was investigated. To enhance comparability, pressure and displacement were normalized to eliminate soil-dependent variability and consistent behavioral patterns were revealed. Additionally, the pressure-displacement curves were fitted with a hyperbolic model to extract the modulus of subgrade reaction and asymptotic pressure, enabling further interpretation of foundation performance. The results contribute to a better understanding of the behavior of shallow foundations under vertical loading and provide insights applicable to design optimization, performance-based assessment, and the development of predictive geotechnical models.

Keywords:

Spread Footings , Load-Displacement , Database , Stress-Strain , Performance-Based Design