It is expected that during spanning in mixed ground, due to the difference in the modulus of subgrade reaction TBM is easily to deviate from the designed alignment. Also, the seepage paths existed in permeable soft ground may provide a channel for groundwater to flow into completed tunnel and/or subway station. This will further cause voids and/or fissures and disturbances resulting from shield tunnelling could lead to collapse of voids, leading to ground surface settlement. This surface settlement significantly endangers the adjacent buildings and/or structures.