Research On The Frost Heaving Protection Measure Of Retaining Structure On Foundation Pit In Season Frozen Area

With the gradual expansion of the foundation pit project,the problem of overwintering foundation pit retaining structure in seasonal frozen area has received people's extensive attention.As a result of the frost heaving of soil,the retaining structure appears wreck,such as forward displacement,crack and overturning,the stability of the foundation pit and the safety of the project and builders are seriously threatened.Based on this,the frost heave protection measures commonly used in engineering are selected in this paper,research on the frost heaving protection measure of retaining structure on foundation pit in season frozen area using ABAQUS the main results are as follows:First,the influence of frost heave on the retaining structure and the research status of frost heave prevention measures are described in detail.Second,combined with the engineering accidents of the retaining structure,analyzed the main factors that influence the frost heaving of the retaining structure of foundation pit and the failure characteristics of the retaining structure.Third,discussed the basic principle of the application of ABAQUS in the simulation of frost heaving of foundation pit,the selection of the constitutive model and the contact principle,the setting of the load and boundary conditions.Forth,analyzed the types and protective effect of frost heave protection measures for foundation pit retaining structure in seasonal frozen area by numerical simulation method.According to the research,insulation,replacemet,excavation unloading hole,back pressure loading frost heave prevention measures have certaineffects on reducing horizontal displacement and stress of retaining structures,With insulation layer thickening and coverage increase,the insulation protective measures obvious effectly.To increase the depth of filling and the use of small impact on the expansion of the material,will be better the effect of replacement of the protection.In the excavation and unloading hole protection measures,with the increase of unloading hole diameter,depth,and the reduce of excavation pit edge,the distance between the unloading hole spacing,the diaphragm wall's displacement and stress decrease.When the soil slope definited,with the increase of stack width,the displacement and stress value of the retaining structure decrease gradually.