LATERAL LOAD CARRYING CAPACITY OF A PILE IN ROCK MASS

Abstract

Drilled shafts socketed into rock are widely used as foundations for bridges and other important stnictures. Rock-socketed drilled shafts are also used to stabilize a landslide. The main loads applied on the drilled shafts are axial compressive or uplift loads as well as lateral loads with accompanying moments. Although there exists several analysis and design methods especially for rock-socketed drilled shafts under lateral loading, these methods were developed with assumptions without actual validations with field load test results. Some of the methods have been found to provide unsafe designs when compared to recently available field test data. Therefore, there is a need to develop a more rational design approach for laterally loaded drilled shafts socketed in rock. A parametric study has been conducted to investigate the effects of joint orientation and embedment length of pile on the lateral load carrying capacity of pile in the rock mass. Two joint sets with three joint orientations: 45/45, 0/90 and 30/60 have been considered for the current study. Joint spacing has been kept constant to 25 mm. The model pile of 35mm x75mm rectangular cross-section, steel with concrete at the core has been castcd. The embedment lengths which have been considered are: 4d, 6d, 8d and lOd (where d=35 mm). Joint orientation has been found to be an important parameter which affects the lateral load carrying capacity of pile in rock mass. However a detailed study is required to he carried out on different rock type, joint orientations, infill materials etc.