SECOND-ORDER DIRECT ANALYSIS FOR STEEL H-PILES ACCOUNTING FOR POST-DRIVING RESIDUAL STRESSES

"Driven steel H-piles are extensively adopted in engineering practice due to their convenience and efficiency in both economic and construction. The post-driving residual stress, a compressive axial stress distributed along the pile induced by the pile installation, might significantly deteriorate the pile bearing capacity. Thus, a large enough factor of safety is adopted in the traditional analysis to cover the influence caused by the post-driving residual stress. However, it sometimes leads to a large waste in costs and materials. Thus, the present study adopted the second-order analysis, a modern simulationbased design method, for the design of the driven steel H-pile. A robust and efficient finite element formula is necessary to conduct the second-order design method in practice. Hence, a new Line-Finite Element (LFE) formula is proposed in this paper. The developed LFE directly captures all the crucial factors in the analysis of the driven steel H pile, including the nonlinear Soil-Structure Interaction (SSI) and the post-driving residual stress. A validation example is presented at the end of this paper, which illustrates the accuracy and the computational efficiency of the proposed LFE formula."