Finite Element Modelling of Tunnel Shielding in Vibration Measurements of Ground-Borne Noise
Paper i proceeding, 2024

Several factors can affect vibration levels during transmission from a tunnel to the ground surface. This study investigates the effect of a tunnel cavity in bedrock with force excitation at the tunnel floor. The tunnel geometry affects the wave propagation around the tunnel and the directivity pattern of waves propagating to the ground surface. For instance, there is no direct propagation path of ground waves from the excitation in the tunnel floor to positions on the tunnel walls. The waves reaching the walls have been diffracted at the tunnel corners. This tunnel shielding effect is here investigated regarding 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 support the 2D results.

Tunnel shielding effect

Ground-borne noise

Finite element method

Wave propagation

Railway tunnel

Författare

Fatemeh Dashti

Chalmers, Arkitektur och samhällsbyggnadsteknik, Teknisk akustik

Patrik Höstmad

Chalmers, Arkitektur och samhällsbyggnadsteknik, Teknisk akustik

Jens Forssén

Chalmers, Arkitektur och samhällsbyggnadsteknik, Teknisk akustik

Lecture Notes in Mechanical Engineering

2195-4356 (ISSN) 2195-4364 (eISSN)

Vol. 14th International Work-shop on Railway Noise, IWRN 2022 723-730
9789819978519 (ISBN)

14th International Work-shop on Railway Noise, IWRN 2022
Shanghai, China,

Ämneskategorier

Strömningsmekanik och akustik

DOI

10.1007/978-981-99-7852-6_69

Mer information

Senast uppdaterat

2024-07-30