Grouting effects in rectangular pipe jacking: centrifuge modelling and field data

Extensive field monitoring and a series of centrifuge model tests of grouting for rectangular pipe jacking were carried out to investigate the mechanism of grouting and its effects. An innovative jacking grouting device was developed to model the entire grouting process in a centrifuge test. Validation work was carried out by comparing the ground settlement between the centrifuge model test results and the field results, and reasonable agreement was obtained. The experimental results show that grouting slurry with low fluid loss and high viscosity is more conducive to controlling ground settlement during tunnelling; the ground settlement is strongly influenced by the grouting pressure. Within a certain range, increasing grouting pressure is conducive to controlling settlement; however, excessive grouting pressure will lift the ground surface.