Bearing capacity of rigidly capped pile group in purely cohesive soils using finite element limit analysis
Abstract
The failure envelopes have been increasingly employed to evaluate the bearing capacity of foundation systems under both static and dynamic loads. Particularly, the aim of this study is to compute the ultimate bearing capacity of a rigid vertical pile group foundation systems subjected to a planar loading horizontal (H) and bending moment (M) in homogeneous purely cohesive soil. Accurate upper and lower bounds to the limit loads are calculated using finite element methods in combination with limit analyses theory via a novel numerical limit analysis code (OptumG3). The effects of key parameters such as pile length-to-diameter ratio (L/D), group spacing (S/D) and the group size as well. The resulting failure envelopes are presented in normalized form with an error ranging from ±1% to ±5%. The numerical results are compared and validated against several experimental results for rigid pile groups in cohesive soil. Finally, an empirical equation is proposed for the safe load domain and fitted to the numerical results. © 2019 Associazione Geotecnica Italiana, Rome, Italy.
Keywords
Bearing capacity
Bearings (machine parts)
Dynamic loads
Earthquakes
Finite element method
Geotechnical engineering
Numerical methods
Soils
Empirical equations
Failure envelope
Finite element limit analysis
Foundation systems
Numerical results
Static and dynamic loads
Ultimate bearing capacity
Upper and lower bounds
Piles