Experimental Study On Damping Coefficient Of Soli Effect On Quality Detection Of Pile

Pile foundation has been widely applied in many engineering fields, such as high-speed railway,bridges, tall buildings, port wharfs and so on. The paper does systematic research on transient response of integrate pile embedded in homogeneous Huang-he River sand, transient response of integrate pile embedded partially in homogeneous self-weight collapse loess or salty soils, transient response of defective pile embedded partially in homogeneous Huang-he River sand, the pile-soil interaction damping coefficient of soil,and the discrimination of defect type and defect position of defective pile embedded partially in homogeneous Huang-he River sand with reverberation-ray matrix method and indoor model tests. The major contents of this research include:Firstly, based on the pile-soil interaction model, the transient response of defect pile embedded partially in homogeneous soil under semi-sine exciting force is determined with reverberation-ray matrix method. The results show that the related parameter is setted in different indoor model test in order to meet the needs of parameter in different test.Secondly, the influence of damping of pile on velocity wave of pile head by indoor pile model test of the naked pile is analyzed.Based on the pile-soil interaction model, the transient response of the integrate pile embedded in homogeneous Huang-he River sand under semi-sine exciting force is determined, which is adopted to do research on attenuation law of the integrate pile embedded in homogeneous Huang-he River sand with theoretical analysis and indoor pile model test; the damping coefficient of soil and variable law of the damping coefficient are obtained by fitting time curve of the velocity wave of pile head;finally, the dependency relation among amplitude ratios, time, and damping coefficient of soil is established, which is in order to obtain damping coefficient distribution. The experiment results show that damping of pile can be ignored, fitted damping coefficient of soil mainly is damping coefficient of surrounding soil and bottom soil;damping coefficient and stiffness coefficient of Huang-he sand are obtained in different relative compaction by indoor model test.Thirdly, based on the pile-soil interaction model,the transient response of integrate pile embedded partially in homogeneous surrounding self-weight collapse loess under semi-sine exciting force is determined.By indoor model test, the attenuation law of velocity wave of pile embedded partially in different compaction soil and different depth of burial of pile is analyzed.Damping coefficient of homogeneous surrounding soil of pile and variable law of damping coefficient are obtained by fitting time curve of the pile head;finally dependency relation between amplitude ratios, time, and damping coefficient of soil and damping coefficient distribution are obtained.Damping coefficient distribution is adopted to support reliable parameter of quantized analysis of defect position and defect type of the defect pile embedded partially in homogeneous surrounding self-weight collapse loess. The experiment results show that the velocity wave energy dissipation increases along with the depth of burial of pile increases; damping coefficient and stiffness coefficient of surrounding self-weight collapse loess are obtained in different depth of burial of pile and compaction.Fourthly, based on the pile-soil interaction model,the bottom soil of pile is homogeneous self-weight collapse loess or salty soils, the transient response of integrate pile under semi-sine exciting force is determined. By indoor model test, the attenuation law of velocity wave of pile in different soil and different compaction are analyzed.Damping coefficient of self-weight collapse loess or salty soils of bottom pile and variable law of damping coefficient are obtained by fitting time curve of the pile head;finally dependency relation between amplitude ratios, time, and damping coefficient of soil and damping coefficient distribution are obtained.Damping coefficient distribution is adopted to support reliable parameter of quantized analysis of defect position and defect type of the defect pile embedded partially in homogeneous soil.The experiment results show damping coefficient and stiffness coefficient of bottom self-weight collapse loess or salty soils of pile are obtained in different compaction.Fifthly, based on the pile-soil interaction model,the transient response of defect pile embedded partially in homogeneous Huang-he River sand under semi-sine exciting force is determined. The attenuation law of velocity wave of integrate pile embedded in homogeneous soil and integrate pile embedded partially in soil,damping coefficient distribution of surrounding soil and bottom soil, and indoor model test of defect pile such as change in cross-section or segregation are adopted to distinguish defect position and defect type of defect pile embedded partially in homogeneous soil with reverberation-ray matrix method.Finally, main conclusions are drawn and further research and suggestions are proposed.