An Experimental Study of Compensation Grouting in Silt

Wilson Au, Cambridge University
Geotechnical Engineering Group


Compensation grouting is one of the most commonly used geotechnical techniques to control excessive settlement induced by tunneling excavation. Previous compensation grouting research projects involved mostly sand and clays. Therefore, the behavior of grout-soil interaction in silty soils is not well understood. This research presents the results of a laboratory experimental investigation at the Schofield Centre at the University of Cambridge, U.K. to examine the behavior of compensation grouting in silty soil. The effects of water cement ratio, injection rate, and confining pressure to fracture pressure and final compensation effectiveness ratio is investigated. The water cement ratio shows a negative relationship with fracture pressure and final compensation effectiveness ratio. On the other hand, the injection rate and confining pressure resulted in a positive relationship with the fracture pressure. The opposite trend is observed with the final compensation effectiveness ratio and injection rate and confining pressure. The core explanation of the corresponding soil behavior is presented.