MEASUREMENT AND SIMULATION OF GROUND VIBRATION NEAR LONGYANG STATION OF SHANGHAI METRO LINE TWO

To study the train induced ground vibrations near Longyang Station of Shanghai Metro line 2,field test was conducted in this area, and the test data was analyzed in detail. The attenuation laws of waves with different frequency bands were evaluated; and the factors which resulted in the distribution fluctuation were determined. In the meantime, three two-dimensional numerical tunnel-soil interaction models were established, based on ANSYS finite element software. The dynamic metro load determined from field test was exerted to the established models to simulate the ground vibrations induced by metro operation. The wave attenuation law was specifically analyzed, and its variation with different tunnel embedded depth was investigated. The research results show that, site topography and soil conditions affected test results significantly. With the distance increasing, the vertical peak displacement decreases continuously, while the horizontal vibration amplitude increases firstly and then decreases. The amplitude attenuation of vertical vibration is relatively slower than that of horizontal vibration. In addition, tunnel embedded depth do have a positive effect on ground vibration mitigation; the ground vibration decreases with deeper embedded depth.