Risk analysis and control of large-section rectangular river-crossing pipe jacking floating
Under complex geological conditions,floating Problems are often encountered during river crossing and pipe jacking construction.This paper analyzes the floating risk of rectangular pipe jacking from the perspective of design.Firstly,the reasons for the floating of segments in the construction of pipe jacking are discussed:the factors of soil covering,buoyancy and segment structure.The anti floating risk is controlled from five aspects:increasing the buried depth of soil covering,improving the properties of soil covering,reducing the grouting pressure,controlling the slurry concentration and increasing the additional load of pipe jacking,The anti floating design control index of rectangular pipe jacking crossing the river considering the factors of mud jacket pressure and concentration is put forward.According to the design experience of large section river crossing rectangular pipe jacking project in Longgang Road,it is obtained that:After the soil covering of the pipeline is increased by 3 m,the overlying load of the pipe jacking is increased by 40.5％,the sum of the pipe jacking self weight and overlying load is increased by 29.4％,and the buoyancy action value are increased by 21.9％;It is difficult to meet the anti floating deformation conditions of large cross-section rectangular pipe jacking,and the anti floating deformation of pipe jacking needs to be strictly considered in the design.
large sectionrectangular pipe jackinganti floating risk controlmud casing pressure
万方数据
维普
