Experimental study on excavation behaviour using model EPB shield with a diameter of 1.8m

Earth pressure balanced(EPB) shield is one of the most important methods in tunneling.However,EPB shield has been adopted to different soils.In order to study the adoption of EPB shield with different ratios of opening on cutterdisc and different working parameters,on a large scale test platform built recently,using a model EPB shield with a diameter of 1.8 m,an excavation test was carried out in clay,sand and gravel.The working parameters of the model EPB shield were collected during the process of test.The correlation between earth pressures inside and outside the chamber,variation of torque of cutterdisc and their influencing factors had been studied.The influence of ratio of opening and total shield thrust,as well as torque of cutterdisc were also studied.The obtained results could be a useful reference for the design of an EPB shield and its tunnelling.