冻胀对越冬深基坑支护结构受力与变形的影响OA

This paper is focused on a study in response to the influence of frost heave on the stress and deformation of the supporting structure of wintering deep foundation pit.Combined with a deep foun-dation pit project in Harbin City,the study involves establishing a model of surface temperature field and the soil initial temperature field in Harbin area based on thermal coupling theory,and analyzing the effect of frost heave on stress and deformation of the supporting structure of the wintering deep foundation pit with FLAC3D.The results show that the level frost heave behind the walls presents a curve distribution pattern of smaller upper,larger middle and lower parts along the depth direction of the foundation pit.The supreme level frost force is located near 7 m to the top of wall and the level frost heave force adds the the ground pressure value behind the wall by about 1.0 times.The frost heave effect has a significant im-pact on the internal support axial force,by showing the increase of the axial force of the three internal supports by 50%,146.26%and 145.08%respectively after 120 days of freezing,compared with the freezing before.The level shift of the wall and the eminence of the pit bottom are both greatly affected by the frost heave,by showing the increase of the level shift of the wall and the eminence shift of the pit bot-tom by139.72%and 149.13%respectively after 90 days of freezing,compared with freezing before.Therefore,in Harbin area,effective measures must be taken to reduce the impact of frost heave on the stress and deformation of the supporting construction of the wintering deep foundation pit.