Evaluation of side resistance for drilled shafts in rock sections

This study evaluated the side resistance of drilled shafts socketed into rock sections. Commonly used analysis methods for side resistance of piles in rocks are examined by utilizing a large number of load test data. The analysis of the unit side resistance of pile foundations embedded into rock sections is based on an empirical coefficient (a) and the uniaxial compressive strength (q(u)) or its root (root q(u)). The Davisson criterion was used to interpret the resistance capacity from the load test results to acquire the computed relationships. The alpha-root q(u) relationship is proven to be reliable in the prediction of friction resistance. This study further analyzed the relationship by including the effect of rock quality designation (RQD) on the results. Analysis results showed that the analysis model of alpha-root q(u)-RQD provided better prediction and reliability considering the RQD classification. Based on these analyses, the side resistance of drilled shafts socked into rocks is provided with statistical data to support the analysis.