Spread Footings for Highway Bridges

摘要

A long-term study of the settlement performance of 21 bridge foundations supported on cohesionless soil--sand or silt--was completed to provide a reliable data base for engineering evaluation. The observations documented the successful performance of the foundations where total average settlement of 0.75 in was recorded while an average of only 0.25 in of settlement was noted after construction of the bridge decks. Geotechnical engineering methods for prediction of settlement of foundations on sand were evaluated with five methods compared in detail to observed data. Recommendations for design are provided. Geotechnical instrumentation monitoring systems for observation of settlement and tilt and related parameters are described along with preparation of a computerized data base for data storage and retrieval. Design recommendations for foundations on rock as well as risk-based design concepts are presented.