Experimental study on the vibration damping of two parallel shield tunnels connected by an assembled transverse passage

Transverse passages are ubiquitous in urban subways, and they pose serious mutual threats to the two adjacent tunnels they connect. In this paper, the frequency sweep loads were applied in model tests and the influence mechanism of integral transverse passage (ITP) was studied by using the one-third octave of the frequency response function (FRF). Subsequently, a new assembled transverse passage (ATP) was proposed and its vibration attenuation effect was studied. The results showed that, when the frequency sweep load is applied to one tunnel, the adjacent tunnel is more susceptible to a load that has a central frequency of 12.5–80 Hz due to the existence of ITP. The closer the loading frequency is to 31.5 Hz, the greater the impact on the adjacent tunnel becomes. When an ATP is used, the vertical acceleration level (VAL) of the tunnel to which the load is applied will increase by 1.3 dB, while that of the adjacent tunnel will decrease by 7.2 dB, and the transverse passage will decrease by 8.7 dB. Compared to the ITP, when the lining structure of an adjacent tunnel is closer to the ATP, the reduction in the vibration response of the structure is more pronounced, and the vibration response is reduced over a larger central frequency range.