Bearing behavior of six-pile thick pile caps under different reinforcement configurationsOA

To investigate the bearing behavior and failure modes of six-pile thick pile caps under different reinforcement configurations and explore the optimal reinforcement scheme,this study examined four scaled specimens(S1-S4)with distinct reinforcement designs.The bearing capacity of each pile cap was first calculated using various methods,and laboratory tests were then conducted to determine cracking and ultimate loads.Reinforcement stresses and key strain measurements in the pile caps were monitored,and the crack propagation process was documented in detail.The results demonstrate that the spatial truss model yielded calculations closest to experimental values.Specimen S3 with mesh reinforcement exhibited the highest bearing capacity but required greater steel consumption.The truss-reinforced S4 showed enhanced ductility at failure but posed constructability challenges.Uniformly reinforced S1 delivered the lowest bearing capacity and developed more uneven cracks.Furthermore,a comprehensive analysis of reinforcement stress distribution,internal force flow transfer,and the validity of the plane-section assumption at the pile-cap sides revealed that the mechanical behavior of the six-pile thick pile cap is more closely aligned with the spatial truss model.The concentrated reinforcement scheme at the pile head,as suggested by this model,proves to be an efficient and practical design solution.