To study the influence of original defects on the dynamic stability of the columns under periodic transient loadings,the approximate solution method and the Fourier method of the stable periodic solution are adopted w...To study the influence of original defects on the dynamic stability of the columns under periodic transient loadings,the approximate solution method and the Fourier method of the stable periodic solution are adopted while considering the influence of original defects on columns.The dynamic stability of the columns under periodic transient loadings is analyzed theoretically.Through the study of different deflections,the dynamic instability of the columns is obtained by Maple software.The results of theoretical analysis show that the larger the original defects,the greater the unstable area,the stable solution amplitude of columns and the risk of instability caused by parametric resonance will be.The damping of columns is a vital factor in reducing dynamic instability at the same original defects.On the basis of the Mathieu-Hill equation,the relationship between the original defects and deflection is deduced,and the dynamic instability region of the columns under different original defects is obtained.Therefore,reducing the original defects of columns can further enhance the dynamic stability of the compressed columns in practical engineering.展开更多
The pressure grouting pile of driven tube can improve the load bearing capacity of the single pile from the mechanism of pressure grouting pile of driven tube.On the basis of analyzing the mechanism,the authors design...The pressure grouting pile of driven tube can improve the load bearing capacity of the single pile from the mechanism of pressure grouting pile of driven tube.On the basis of analyzing the mechanism,the authors designed the machines and tools of pressure grouting,determined the operating manufacture and technology parameter on the pressure grouting secondly.The result shows that the pressure grouting pile of driven tube not only changes the pile type but also reduce the length of the pile and its engineering cost,it enhances the load bearing capacity of single pile an the same time.展开更多
基金The National Natural Science Foundation of Chin(No.51078354)
文摘To study the influence of original defects on the dynamic stability of the columns under periodic transient loadings,the approximate solution method and the Fourier method of the stable periodic solution are adopted while considering the influence of original defects on columns.The dynamic stability of the columns under periodic transient loadings is analyzed theoretically.Through the study of different deflections,the dynamic instability of the columns is obtained by Maple software.The results of theoretical analysis show that the larger the original defects,the greater the unstable area,the stable solution amplitude of columns and the risk of instability caused by parametric resonance will be.The damping of columns is a vital factor in reducing dynamic instability at the same original defects.On the basis of the Mathieu-Hill equation,the relationship between the original defects and deflection is deduced,and the dynamic instability region of the columns under different original defects is obtained.Therefore,reducing the original defects of columns can further enhance the dynamic stability of the compressed columns in practical engineering.
文摘The pressure grouting pile of driven tube can improve the load bearing capacity of the single pile from the mechanism of pressure grouting pile of driven tube.On the basis of analyzing the mechanism,the authors designed the machines and tools of pressure grouting,determined the operating manufacture and technology parameter on the pressure grouting secondly.The result shows that the pressure grouting pile of driven tube not only changes the pile type but also reduce the length of the pile and its engineering cost,it enhances the load bearing capacity of single pile an the same time.
