Numerical Simulation And Model Test Study Of High-frequency Hydraulic Vibration Sinking Of Steel Pipe Pile

Due to the advantages of good pile quality,high shear strength of the pile,simple construction operation and recyclability,the steel pipe pile is widely used in the high-level and super high-rise's foundation pit support engineering of lacustrine sedimentary soil layers,Because the vibration sinking technology has the outstanding advantages of high pile sinking efficiency and good environmental protection,and has been widely used in the field of steel pipe pile construction.However,at present,the research on vibration and sinking technology in China is still not mature.The research on pile-forming mechanism and fine construction control technology of steel pipe piles still lags behind actual engineering.Therefore,this dissertation relies on the example of vibration-sinking piles of deep foundation pit steel pipe retaining piles in No.4 block of Kunming Dianchi International Exhibition Center,Based on Midas GTS NX finite element software establish the corresponding three-dimensional dynamic sinking pile model,and combined with self-built small structure vibration sinking model test study the mechanism of vibration sinking.The specific research contents of this dissertation are as follows:(1)From the theoretical research,numerical simulation,experimental research and engineering application summarized and concluded the research of the predecessors in detail,and then brief introduce the vibration piler system,the mechanical properties between piles and soils,etc.(2)Review the engineering geological and hydrogeological data of the project,and obtain the basic physical and mechanical properties cof the soil layer through indoor and outdoor geotechnical tests,and provide reliable parameters for the subsequent establishment of the corresponding three-dimensional dynamic sinking pile model.(3)Based on Midas GTS NX finite element software,the corresponding three-dimensional dynamic sinking pile model is established to study the displacement field,velocity field,acceleration field and stress field of steel pipe pile and its surrounding soil under the action of 10s excitation force.(4)In view of the various process parameters involved in the vibration sinking process,starting from the three aspects of excitation frequency,eccentricity and soil,the penetration of vibrating piles,the environment of surrounding structures and the environmental impact of the surrounding residents is parameter analysised.(5)By studying the sinking principle of the vibrating pile driver system,a small structure vibration sinking pile model test system was established.With the aid of this system,the vibro-sinking test of dry sand,wet sand and peat soil samples with different physical properties is carried out to study the sandfs relative compactness,sand's saturation,peat soil's water eontent 3excitation frequency and exciting force relationship with the driveability of the steel pipe pile.