Development and Use of High-Quality Databases of Deep Foundation Load Tests

Abstract

Foundation load test databases are needed by researchers in reliability calibration to develop accurate and economical foundation geotechnical design methods (for implementation of load and resistance factor design) and by designers to evaluate and improve the geotechnical design for production foundations in their projects. These databases should include a complete and adequate number of high-quality records of data at load test sites. FHWA developed the Deep Foundation Load Test Database (DFLTD), which was used by researchers and state departments of transportation (DOTs) to develop their databases. Only a few reliability-based resistance factors for foundations have been developed by AASHTO and state DOTs because of a lack of high-quality databases of foundation load tests. Therefore, transportation agencies (e.g., state DOTs) and universities should work together to develop local, regional, and national databases of foundation load tests that cover all common foundation design and construction conditions encountered in the United States. The goal of this paper is to help transportation engineering agencies develop and use consistent and high-quality deep foundation load test databases. Initially, the paper describes the contents and applications of foundation load test databases and then the contents, limitations, and distribution of the DFLTD. Contents and use of other deep foundation load test databases are also described. Finally, recommendations for the development and sharing of high-quality databases of foundation load tests are presented, followed by a roadmap to implement the recommendations.