Abstract:

In recent years,over-track buildings have been planned and constructed at the upper space above metrodepots in many Chinese cities.In order to analyze and evaluate the influence of train-induced environment vibra-tions at metro depots,the field measurements of vibrations of ground and buildings adjacent to the test-line at Xia-jiao Metro Depot of Guangzhou Metro Line 3 were carried out,and the propagation characteristics of the vibrationswere analyzed in the domains of time and frequency.Then,the results were compared with the national vibrationstandards for the environmental impact assessment of vibration.It is found that (1) when the train at the metrodepot runs normally on the test-line,the vertical vibration of adjacent ground is significantly larger than the horizon-tal vibration with a measured maximum vertical vibration acceleration level of 66.4 ～91.2dB and a vertical vibra-tion frequency range of 10 ～ 120 Hz; furthermore,the vertical vibration peak values appear within the frequencyrange of 25 ～40Hz; (2) the maximum vertical vibration acceleration level of adjacent buildings is 48.9 ～76.2dB,and when the vibrations propagate upward along the structures,the vibration frequencies are mainly 5 ～60Hz andthe maximum vibration acceleration levels of floor appear within 20 ～25Hz; and (3) the ground and building vi-bration levels within the range of 0 ～ 30 m from the track center both exceed the relevant national vibration stan-dards.Therefore,it is very necessary to adopt measures to reduce the influence of environmental vibrations in thearea adjacent to the test-line when over-track buildings are going to be constructed above metro depots.

Key words: subways, depot, test-line, vibration, building, in-situ measurement