Time-Frequency Characteristics of Online Dynamic Monitoring of Operating Metro Tunnel
The modal characteristics of the shield tunnel under the construction disturbance of the upper soil-layers are being studied,utilizing a shield tunnel of Shanghai Metro Line 12 as the engineering reference,in-site vibration tests of the shield tunnel are conducted to analyze the characteristic variation laws of the tunnel struc-ture in the time and frequency domain under the influence of train vibration loads based on the auto regressive moving average(ARMA)method.The results show that the shield tunnel structure displays distinct medium and low frequency characteristics,primarily within the 0～200 Hz frequency range,while the high-frequency components of train vibration source dissipate rapidly.Following soil layer construction disturbances,the overall amplitudes and data fluctuations of tunnel wall vibration are observed to decrease.The modal frequencies of the shield tunnel demonstrate a downward trend,with the maximum frequency variation noted at-2.935 Hz.This research offers a foundation and support for the modal identification of shield tunnel structure,as well as health monitoring and evaluation of operational performance under complex conditions.
metro tunneldynamic monitoringtime-frequency characteristicssoil disturbancemodal fre-quency
NETL
NSTL
万方数据
维普
