In soft ground tunneling,the deformation of each cross-section differs very much,which causes great difficulties to the determination of the preset deformation.

After a detailed analysis on the structure of an automotive bumper,a die was developed in which the CAE technology,some measures such as prearrangement of deformation amount,feasible sprue gate and two-way core-pulling mechanism were adopted to meet the requirements for the appearance and fit precision of the plastic component.

With the technical development of the railway,the high stability of line and subgrade are required to support high running speed,hence accurately controlling and estimating the preformed settlement of the embankment are very important.