Bearing capacity of static drill rooted pile subjected to traffic loads and a design method

As urban railway networks expand globally, demands for sustainable pile foundations with high bearing capacity and environmental compatibility have intensified. Traditional pile methods generate significant waste and quality control issues, while static drill rooted (SDR) piles, combining precast elements with cement-soil mixtures, offer environmental advantages over traditional pile foundations. However, their performance under railway traffic loads remains insufficiently investigated. Through field testing and numerical modeling, this study analyzes SDR pile’s performance under traffic loading and develops modified design methods. Results reveal that dynamic effects become critical when load ratio λ exceeds 0.61, requiring capacity reduction factors up to 4.3%. Modified load-settlement curves and design equations are developed specifically for railway applications. This quantitative framework provides practical engineering guidance for implementing this environmentally friendly pile foundation technology in urban railway infrastructure worldwide.