Analyse Of Ground Surface Deformation In Underground Freezing Project Affected By Frost-heaving And Thawing-settlement

Frost-heaving and thawing-settlement can lead to ground surface lift up or subside in the underground freezing engineering usually, and thus it will create disadvantageous influences to the ground's surface environment and shallow pipelines . It's important to set up a model to predict ground deformation exactly . So this practical problem is regarded as main study object of the paper . Firstly , the mechanism and influence factors of frost heaving and thawing-settlement is analyzed . Under the influence of factors such as temperture , water content , load ,the experiments of frost-heaving and thawing-settlement's character of shanghai stratum soil are carried on , and experience formulas are erected . Secondly ,The practical temperature field has been simplified . the simple model of amount of frost-heaving and thawing-settlement of certain local section is set up . Using stochastic medium theory , the corresponding forthcoming ground deformation of the section is predicted .The forecast formulas of ground surface heave , subsidence , horizontal motion is given . And using this model , a certain practical engineering is predicted . Finally, the practical monitoring datum of Shanghai tunnels are analysed using statistical regressive method .The regressive result of the monitoring datum of ground and tunnel's deformation shows that the vertical and horizontal deformation of ground surface and tunnel take on distributed character of the Gauss curve. The contrastive analysis of the example and monitoring datum show this simple model is feasible.