LABORATORY INVESTIGATION OF SHAFT RESISTANCE OF ROCK-SOCKETED PIERS USING THE CONSTANT NORMAL STIFFNESS DIRECT SHEAR TEST

This paper presents the results of a laboratory investigation of shaft resistance of rock-socketed piers using constant normal stiffness (CN S) direct shear tests. In this context, an experimental program is con ducted in which small-scale piers are loaded in compression, and speci mens having the same pier-surrounding medium interface geometry and co mponents as those found in the small-scale models are subjected to dir ect shearing. Pseudorock materials were used for the construction of t he model piers and shear specimens. These materials were chosen to sim ulate rocks of very weak to medium strength to investigate the influen ce of relative stiffness of pier and surrounding medium construction m aterials on the shear resistance. Furthermore, predicted values of sid e shear resistance using empirical relationships are compared with exp erimental results to examine the validity of these relationships.