Three dimensional analysis was performed by regarding vibration isolation performance cast-in-place concrete thin-wall pipe pile (PCC) and using the finite element analysis software ANSYS. The ground vertical amplitud...Three dimensional analysis was performed by regarding vibration isolation performance cast-in-place concrete thin-wall pipe pile (PCC) and using the finite element analysis software ANSYS. The ground vertical amplitude was analyzed behind the single row cast-in-place concrete thin-wall pipe pile after the source vibration, and the influencing factors were also studied. The results indicate that in the one time of wavelength before the barrier, the oscillation amplitude is weakened; meanwhile the range which covers 4 times wavelength behind the barrier has a good vibration isolation effect, when the distance is larger than the barrier latter 4 times wavelength vibration isolation expiration.展开更多
Topography effects on the vertical vibration responses of pile group are revealed though numerical analysis and model tests.First,a series of model tests with different topography of ground and bedrock are conducted.T...Topography effects on the vertical vibration responses of pile group are revealed though numerical analysis and model tests.First,a series of model tests with different topography of ground and bedrock are conducted.The results indicate that displacement amplitude of the pile head in sloping ground topography is larger than in horizontal ground.Differential displacement at various positions of the pile cap is observed in non-horizontal topography.Afterwards,a numerical algorithm is employed to further explore the essential response characteristics in group piles of different topography configurations,which has been verified by the test results.The lengths of the exposed and frictional segment,together with the thickness of the subsoil layer,are the dominant factors which cause non-axisymmetric vibration at the pile cap.展开更多
A theoretical study on the ground vibration isolation efficiency by a row of piles as passive barrier in a three-dimensional context was presented. The analysis was accomplished with the aid of integral equations gove...A theoretical study on the ground vibration isolation efficiency by a row of piles as passive barrier in a three-dimensional context was presented. The analysis was accomplished with the aid of integral equations governing Rayleigh wave scattering, used to predict the complicated Rayleigh wave field generated by a number of irregular scatters embedded in an elastic half-space. Then, the passive isolation effectiveness of a row of piles for screening Rayleigh wave was studied in detail. The effects of relevant parameters on the screening effectiveness were investigated and analyzed from the perspective of equivalence with in-filled trench. The results show that using a row of rigid piles as wave barrier is more effective than that of flexible ones, and an optimum reduction of vibration can be achieved either by increasing the size of piles or by decreasing the net spacing between the piles. Finally, based on the derived integral equation for Rayleigh wave scattering, the principle of equivalent modeling of the barrier of piles by an in-filled trench is put forward, which simplifies the analysis of vibration isolation by a row of piles.展开更多
基金Project(50679017) supported by the National Natural Science Foundation of China
文摘Three dimensional analysis was performed by regarding vibration isolation performance cast-in-place concrete thin-wall pipe pile (PCC) and using the finite element analysis software ANSYS. The ground vertical amplitude was analyzed behind the single row cast-in-place concrete thin-wall pipe pile after the source vibration, and the influencing factors were also studied. The results indicate that in the one time of wavelength before the barrier, the oscillation amplitude is weakened; meanwhile the range which covers 4 times wavelength behind the barrier has a good vibration isolation effect, when the distance is larger than the barrier latter 4 times wavelength vibration isolation expiration.
基金National Science Foundation of China under Grant Nos.51622803 and 51778092Innovation Group Science Foundation of the Natural Science Foundation of Chongqing,China under Grant No.cstc2020jcyjcxttX0003China Scholarship Council(File No:201806050121)for financial support to visit Purdue University。
文摘Topography effects on the vertical vibration responses of pile group are revealed though numerical analysis and model tests.First,a series of model tests with different topography of ground and bedrock are conducted.The results indicate that displacement amplitude of the pile head in sloping ground topography is larger than in horizontal ground.Differential displacement at various positions of the pile cap is observed in non-horizontal topography.Afterwards,a numerical algorithm is employed to further explore the essential response characteristics in group piles of different topography configurations,which has been verified by the test results.The lengths of the exposed and frictional segment,together with the thickness of the subsoil layer,are the dominant factors which cause non-axisymmetric vibration at the pile cap.
基金Project(51178342)supported by the National Natural Science Foundation of ChinaProject(20130072110016)supported by Specialized Research Fund for the Doctoral Program of Higher Education,China
文摘A theoretical study on the ground vibration isolation efficiency by a row of piles as passive barrier in a three-dimensional context was presented. The analysis was accomplished with the aid of integral equations governing Rayleigh wave scattering, used to predict the complicated Rayleigh wave field generated by a number of irregular scatters embedded in an elastic half-space. Then, the passive isolation effectiveness of a row of piles for screening Rayleigh wave was studied in detail. The effects of relevant parameters on the screening effectiveness were investigated and analyzed from the perspective of equivalence with in-filled trench. The results show that using a row of rigid piles as wave barrier is more effective than that of flexible ones, and an optimum reduction of vibration can be achieved either by increasing the size of piles or by decreasing the net spacing between the piles. Finally, based on the derived integral equation for Rayleigh wave scattering, the principle of equivalent modeling of the barrier of piles by an in-filled trench is put forward, which simplifies the analysis of vibration isolation by a row of piles.
