Shield Construction Process Induced Vibration Source Characteristics

Cutter and soil structure interaction, muck and segment transport vehicle, shield equipment were the primary cause of shield construction vibration based on field investigation and preliminary test in Beijing metro line shield tunnels. According to the researches of field investigation and numerical simulation, the following conclusions could be drawn: 1) vibration frequency band caused by cutter is wide, and dominant frequency is concentrated in the range of 20 ~ 90 Hz; 2) vibration amplitude value caused by supporting vehicles is smaller than other factors, and frequency band of vibration amplitude is concentrated in the range of 0 ~ 20 Hz; 3) there is no attenuation in medium high frequency result from the interaction between track and structure. The frequency correspond to vibration amplitude is concentrated in 70 ~ 90 Hz. The frequency will drop below 20 Hz when vibration propagates to the earth surface. Vibration incidence is concentrated in the scope of 15 m from tunnel center line. The researches have reference for the vibration induced by shield construction in sand and gravel stratum in Beijing, Chengdu, Shenyang and so on.