Field Investigations On Performance Of Short Drilled Shafts Under Inclined Loading

Abstract

In the Kaufman County area within the Texas Department of Transportation's Dallas District, several short drilled shaft foundations supporting three-cable median barrier systems wereobserved to be distressed during severe winter storm conditions in late 2006 through early 2007. A research study was initiated at UT Arlington to determine and understand the mechanisms causing these shaft failures. The ends of the three-cable median barrier systems are fastened to a single drilled shaft foundation. In general, these shafts are short in depth and of the same dimensions, diameter, and depth. They are typically used in all soil conditions. This paper presents the tasks of this study which includes the estimations of loads on the shafts and the design of reaction test piles for the application of inclined loads on test shafts of varyingdiameters and depths simulating the field construction of cable barrier systems. The application of inclined loading is a unique type of testing for which very little work has been published. Inclined load analyses results were utilized in the design of reaction shaft dimensions and spacings between reaction and test shafts. Salient details of analytical approaches used for load calculations are also included.