The prediction of ground residual subsidence is the basis of anti-deformation structure design for newly-built construction over abandoned golfs.

Based on analyzing the mechanism of filtration, some parameters which affect the filtration efficiency, pressure drop or residual pressure drop, such as structure of the mesh, cycle index, filtration velocity, fluid concentration and temperature, compressibility of filter cake, maximum permission pressure drop and backflowing pressure, are discus.

The test results show that in the initial period of the filtration cycle,the residual pressure drop of the filter increases rapidly,and then increases slowly.

To avoid the confusion that residual settlement is regarded as settlement after construction,two equations between the residual settlement and settlement after construction are given based on the analysis of their difference.

There are many methods that can be employed to calculate final settlement by field settlement curve,but no formula can be straightly employed to forecast residual settlement and unloading time under bounded unloading settlement velocity in soft soil treatment project.

The settlement-velocity and post construction settlement including residual settlement and secondary consolidation settlement are very important unloading standard in foundation soil treatment project.