Several factors can affect vibration levels during transmission from a tunnel to the ground surface. The object of this study is to investigate the effect of a tunnel cavity in bedrock with force excitationat the tunnel floor. This tunnel shielding effect is here investigated in terms of sensor position and direction, and directivity of wave propagation up to 1 kHz using the finite element method. An underground tunnel is modelled in 2D and 3D for a bedrock ground typical for Swedish conditions. The results show that the velocity levels at the tunnel floor are higher than at the tunnel wall. It is also shown that the tunnel shielding effect causes decreased vibration levels at mid frequencies above the tunnel and significant level fluctuations especially at higher frequencies. The results from the 3D modeling corroborate the 2D results.