Review of Bearing Capacity Enhancement Performance of Post-Grouting Piles in Railway Bridge

Abstract

This review comprehensively examines post-grouting technology for enhancing bearing capacity of railway bridge pile foundations. It elucidates three core mechanisms: grout diffusion/penetration in soil matrices (influenced by soil tortuosity and grout viscosity), soil property improvement through void filling and crack sealing, and altered pile-soil interaction via grout bulb formation. Key influencing factors include soil grain size/permeability, pile geometry/installation methods, and grouting parameters (pressure/volume/material properties). Experimental analyses reveal that optimized grout control can increase pile-soil interface cohesion (5.8-18.8) and shear strength (1.16-2.91), with field tests showing 133% bearing capacity improvement using geopolymer grouts. Numerical modeling confirms up to 51% lateral load enhancement. The review emphasizes the need for site-specific parameter optimization considering geological conditions (e.g., karst formations) and groundwater dynamics, providing practical guidance for infrastructure rehabilitation projects.