"This report presents the following three recent projects on load testing of geosynthetic-reinforced soil (GRS) bridge abutments and piers: a full-scale bridge pier load test conducted by the Turner-Fairbank Highway Research Center, Federal Highway Administration, in 1996 (referred to as the Turner-Fairbank pier), a full-scale, long-term load test of a bridge abutment and a bridge pier conducted by the Colorado Department of Transportation and the University of Colorado at Denver in 1996-I 997 (referred to as the Havana Yard piers and abutment); and a production bridge abutment load test conducted by Yenter Companies in Black Hawk, Colorado, in 1997 (referred to as the Black Hawk Abutment). All the bridge supporting structures were instrumented to measure their performance during the load test. The effect of pre-loading. was also investigated in the Turner-Fairbank pier and the Black Hawk abutment. The report describes each of the projects in detail, presents the measured test results and discussion of the results, and offers recommendations on the applications of the GRS bridge abutments and piers"--Tech. report doc. page.

Introduction and research approach -- Findings -- Interpretation, appraisal, and applications -- Conclusions and suggested research -- Appendixes.

Summary of current research studies.

This report explains the use of the Erodibility Index Method (also known as Annandale's Method) to calculate bridge pier scour. The method can be used to predict scour in any earth material, including rock and cohesive and noncohesive soils. Earth material properties are represented by a geo-mechanical index that integrates the role of material mass strength, block/particle size, internal shear strength and orientation in quantifying the relative ability of earth material to resist scour. A relationship between the geo-mechanical index and the erosive power of water defines the scour threshold that is used in the scour calculations. By comparing the erosive power that is required to scour an earth material (obtained from the threshold relationship) with the erosive power that is available at the base of a bridge pier, it is possible to calculate scour depth. The report outlines the methods that are used to quantify the geo-mechanical index and those that are used to estimate the erosive power of water flowing around bridge piers, and explains how to calculate scour depth. Application of the method is illustrated with an example.