Model Testing of Rock-Socketed Piles under Combined Vertical–Lateral Loading

This paper presents the findings from a model experimental setup designed and fabricated for conducting single gravity (1-g) model experiments on model aluminum instrumented piles embedded in synthetic rock subjected to both independent vertical–compressive and lateral loading and combined vertical–compressive and lateral loading. Synthetic rock was prepared based on a mix design that can simulate the strength and modulus of soft rocks. Model tests were carried out on single piles of different socketing lengths (L/D ratios: 6, 9, and 12). Combined loading tests were done such that the resultant of the vertical–compressive and lateral loads was at constant inclinations (30° and 60°). Piles with smooth and rough surfaces were simulated for examining the effect of the pile–rock roughness profile. The vertical load–settlement and the lateral load–deflection response were measured from the tests. The bending behavior of piles under both independent and combined loading was also measured. The deflection profile of the rock-socketed pile was obtained by tracing the tested/failed piles after extracting them. The axial and lateral resistance of the rock-socketed piles are interpreted and discussed. It is observed that the rock-socketed piles behave in a distinctly different manner under combined loading compared with independent loading.