Effects of pile extraction and refilling with cement slurry on ground settlements

Abstract

Secant pile walls reinforced with steel I-beams are widely used worldwide. Although ground surface settlement caused by the installation of secant pile walls has been investigated, there is minimal data available on ground surface settlement due to extraction of steel I-beams from secant pile walls. This note aims to investigate the effectiveness of cement slurry refilling on reducing ground settlements during extraction of steel I-beams. Measured ground surface settlements during the extraction of steel I-beams from secant pile walls with and without cement slurry refilling are reported, discussed, and explained. Two different influence zones due to steel I-beam extraction can be identified. Ground settlement due to steel I-beam extraction can be minimized with the refilling of cement slurry. By using such a refilling technique, measured maximum surface settlement was reduced by 70%. The average measured settlement rate was reduced by 61%.