关键词: 盾构施工, 环境振动, 现场试验, 衰减规律

Abstract: Ground vibration induced by shield construction has become a major environmental vibration problem in urban areas. Based on a sandy pebble formation of a shield construction in Lanzhou, by synchronizing the test tunnel and three-direction vibration acceleration on the surface of the earth, this paper studies the shield construction-induced vibration in the time domain, and frequency domain propagation law within the surface of the 50 m×50 m area. The findings of this study are as follows: 1) the spread of the surface free field acceleration with the distance firstly increases and then sharply attenuates. In X direction, the amplification phenomenon repeatedly appears; 2) the transverse maximum peak of 0.33 m/s2 is harmful to sensitive ancient buildings; 3) within the scope of 50 meters, the surface frequency mainly ranges from 4 to 80 Hz, the vibration spectrum magnitude does not monotonously decrease with the increase of the vibration source distance, but has rebounding phenomenon, which is associated with excellent frequency field soil; 4) the influence of three directions of vibration should be considered in the evaluation of shield induced environmental vibration.

Key words: shield construction, environmental vibration, field-test, attenuation law