Analysis And Prediction Of Deep Foundation Pit Deformation In Complicated Geological Conditions

With the economic and social developing,construction land is more and more tense in urban,the land that is not suitable for the construction have to be used.At the same time,with the progress of technology,buildings are higher and higher,foundation pit also more and more deep.The environment surrounding foundation pit is becoming more and more complex.Accidents that is caused by excavation major workplace occur frequently.Enormous economic is lost.so the deep foundation pit shoud be monitored,informatization construction and management should be achieved.In the background of a deep foundation in karst and empty double bad geological condition of tangshan.The influence of different support forms of deep foundation pit deformation is analysised.In the stages of deep foundation pit excavation and excavation complete to backfill,the relationship between the deformation is analysised.The grey model is used to forecast the deformation of foundation pit,the following conclusions:(1)In the excavation stage,two different supporting form of foundation pit slope top horizontal displacement difference is bigger,the bolt support top horizontal displacement of pile is greater than pile + bolt support top horizontal displacement and vertical displacement of foundation pit slope difference is very small.(2)In the excavation stage,horizontal displacement accounted for about 68% ~ 78% of the total deformation,vertical displacement of the top accounts for about 61% ~ 61% of total deformation.(3)In the horizontal displacement of the slope prediction of the excavation stage,the optimal dimensiom is 5 d,the optimal time interval is 5 days.(4)In the horizontal displacement prediction of the excavation stage to backfill,the dimension and the time interval is no influence on accuracy of predicted results.