ABSTRACT
Tail grouting is regarded as an efficient method for reducing ground loss during shield tunnelling. The grout will inevitably be compressed under earth pressure, resulting in ground loss and surface settlement that have not been accurately estimated. In this paper, the compressed deformation of tail grouts subjected to earth pressure in different types of soils was investigated using a lab device. The lab test results reveal that compressed deformation rises with increased pressure and soil permeability. As the pressure increases, the increase rate of ultimate compressed deformation becomes smaller. Based on test results, analysis was conducted to determine how ground loss and surface settlement were affected by various parameters, including tail gap, tunnel radius, pressure, burial depth and soil permeability. The study could provide accurate predictions of ground loss and surface settlement considering grouting material properties.
