Numerical Analysis of Precast Pile Cap for Accelerated Construction.

Precast pile caps have been widely used in the accelerated construction of cross-sea bridges in recent years. Precast caps are connected to steel pipe composite piles through shear connection keys and reserved postpouring concrete, and the load-bearing system is transformed by pouring the postpouring concrete in hole-by-hole or layer-by-layer fashion. The process of system transformation is complicated, and it must bear the combined effects of flowing water pressure and wave force, which have a significant impact on the safety of system transformation. In this study, the finite-element method was used to analyze the influence of the hole-by-hole pouring scheme and layer-by-layer pouring scheme on the mechanical properties of shear keys and piles. It was determined that both pouring schemes are feasible, but the stress distributions of the shear keys and piles differ significantly. For the hole-by-hole pouring scheme, the stress on each pile and its shear keys varies significantly, and the maximum shear key von Mises stresses at the corresponding positions of different piles are 6.1 times the minimum von Mises stresses. In contrast to the hole-by-hole pouring scheme, the stresses of each pile and the corresponding shear keys are similar in the layer-by-layer pouring scheme, and the maximum shear key von Mises stress is only 21.7% of that in the hole-by-hole pouring scheme. Therefore, the layer-by-layer pouring scheme is more desirable. [ABSTRACT FROM AUTHOR]