Application And Numerical Analysis Of Pre-stressed Concrete Tube Pile In Deep Soft Soil Foundation With Interlayer

Pre-stressed pipe pile has high bearing capacity of single pile,pile with high strength,durable,pile quality stability,short construction period and other advantages,in recent years,especially in the soft soil area of engineering has been extensively studied and applied in reinforcing soft soil foundation in coastal areas,the application of pre-stressed pipe pile with deep soft soil foundation a thin layer of hard layer reinforcement,the inter-layer as bearing layer of pile tip,which can ensure the reinforcement effect,and can save cost.However,due to the existence of soft soil below the inter-layer,the factors affecting the bearing capacity of the pile foundation are more,and the bearing mechanism and the failure mode of the pile foundation are more complicated.The application of pre-stressed pipe pile in deep soft soil inter-layer in the pile foundation,bearing capacity and load transfer mechanism of influence factors analysis is still not perfect,so in the actual project,the system analysis of bearing characteristics of pile response,to ensure the safety and reliability engineering.For the analysis of vertical pre-stressed pipe pile in deep soft soil interlayer in bearing characteristics,this paper is based on the example of a project in Fuzhou City,a three-dimensional numerical model for single pile vertical pre-stressed pile static load test using the FLAC3 D program,through the numerical calculation results and static load test results were analyzed to verify the rationality of numerical model based on these,interlayer thickness,pile end into the effect of interlayer depth,sandwich type on the bearing capacity of single pile vertical ultimate pre-stressed pile.The results show that the basis of other conditions unchanged,the sandwich(bearing layer)the large thickness of single pile vertical ultimate bearing capacity of pre-stressed concrete pipe pile is bigger;when the thickness is less than 5.0m,it will be as a sandwich of pre-stressed concrete pipe pile bearing layer;interlayer thickness is 5.6m,the depth of the pile into the interlayer should be between 2.0m~3.0m;when the pile into the bearing layer depth is less than 3.0m,with the pile into the bearing layer depth increases,the bearing capacity of pre-stressed concrete pipe pile increases when the pile into the bearing layer depth is more than 3.0m,to reduce the bearing capacity of pile,and the increase of the load,the greater the extent of reduction of the other;under the same conditions,with the physical and mechanical indexes of interlayer increases,especially the high modulus,increases the ultimate bearing capacity of single pile,therefore in design and construction,should try to make pre-stressed pile end Into the hard soil where the modulus is large.The results of this analysis can provide reference for the design of similar projects and field construction.