Research On The Thawing Subsidence Rule And Grouting Method For Subway Connecting Aisle

The ground freezing method has been applied widely for the subway connecting aisle because of its good waterproofing, high intensity, outstanding compatibility, but the thawing subsidence of the frozen soil that has an unfavorable effect on environment restricts the development of ground freezing method. Regarding thawing subsidence of the frozen soil as research object, Melted rule of frozen soil, the ground subsidence rule and the corresponding grouting method were researched in detail by theoretical analysis, numerical simulation, and in-site survey .Firstly, Researching on the thawing temperature field by in-site survey and numerical simulation of the subway connecting aisle between the Shanghai university station and Nanchen Road station of Shanghai metro line 7, the logarithmic distribution rule between the temperature increasing of frozen soil and thawing time was concluded. Moreover, ground subsidence was produced by thawing of frozen soil. Based on stochastic medium theory, regarding both thawing subsidence and grouting uplifting as stochastic medium events, the stochastic medium predicating model for ground deformation affected by interaction between the thawing subsidence and the grouting for the subway connecting aisle was achieved and used by an engineering example. And also the new grouting construction method of thawing subsidence for the subway connecting aisle was put forward according to the thawing rule. During the grouting practice, The rule of the ground subsidence that likes "the shape of saddle" was drawn by the ground deformation timely monitoring. Meanwhile, comparing the in-site monitoring results of ground subsidence with theoretical computing results with random predicting model, both the reliability of theoretical predicting model and the feasibility of the new grouting methods for thawing subsidence based on the thawing rule of the subway connecting aisle were confirmed.