| As a kind of special vibration mitigation products, ladder track has been used in domestic bridges and obtained very good effect. However, ladder track has not been used in the domestic underground metro lines, it is necessary to study its properties in tunnels before the practical application. By using prototype vibration test and numerical simulation method, the dynamic characteristics and mitigation effectiveness of the ladder track are studied in this paper.Firstly, the prototype test of the SSFST is carried out in the UTEL (Underground Track Engineering Laboratory) . The measurement data are used to study the regulation of vibration propagation in tunnel and on the ground surface within 100m from the vibration source. And the transfer function in the soil is also obtaind. By compared with the common rail and the steel spring floating track, the mitigation effectiveness of the ladder track is evaluated. The conclusion indicates that the VL_Z on the rail supports is smaller than that on the rail, and the difference is about 20dB in the range of 5 and 11Hz, 30dB in the range of 11 and 29Hz. The mitigation effectiveness of ladder track is better than the common rail in the range between 5 and 25Hz, and better than SSFST in the range of 5 and 10Hz.As the limitation of excitation equipment that the output frequency ranges of 5 and 30Hz, the paper calculated the dynamic response of the ladder track-tunnel-soil system under impact load using numerical simulation method, and further studied the regulation of surface vibration attenuation between 0 and 100Hz, The calculation results suggested that the nature frequency of the entire system ranges of 0 and 6Hz in the region near the source.Finally, the generalized recursive neural network (GRNN) is used to predict the regulation of subway vibration propagation in the soil with the experimental data, and the feasibility and applicability of GRNN in the prediction is proved.
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