Study On The Vertical Bearing Capacity Of Slurry Dado Large-Diameter Bored Cast-In-Situ Pile

The mechanism of the slurry job and the factors influencing on the production of mud are analyzed in this thesis.besides, the measuring data about the slurry dado large-diameter bored cast-in-situ test pile of a brige, is collated,analyzed and studyed in this thesis.the results of the research indicate that, load-transfor functions of the gravel,mudstone and mud-graystone accord with the hyperbolic model,while load-transfor function of the fine sand accords with double broken line model.They are fitted by one mathematical method, while their correlation coefficients are all about0.99,and the load transfor founctions in the different rock-soil layer about the test pile are defined. Relative displacement for reaching ultimate lateral friction is different to different rock-soil layer.For semblable characteristic gravel layer, with the depth increases the ultimate lateral friction increases and corresponding to the relative displacement also increases.under the slurry,the mud is formed between the piles and soil or rock around the piles and the ultimate lateral friction of the pile is weakened in varying degrees by mud.Accoding to the load transfor founctions in different rock-soil layer and using a particular load transfor method,the displacement-coordinating method,analyzes the vertical allowable load capacity of test pile.the results indicate, the mud greatly weakens the bearing capacity of test pile and the code doesn’t consider the effect of the mud.Using the ANSYS finite element software analyze the vertical allowable load capacity of the slurry dado large-diameter bored cast-in-situ test pile in different mud in different soil.combined with the test result,the results indicate the bearing capacity of the test pile with mud only account to60%-80%of the bearing capacity of the test pile without mud.when calculating piles as the code,the bearing capacity can be reduced by60%-80%.