MTR Tseung Kwan O Extension - Pak Shing Kok Tunnels

Forming part of the project of MTR Tseung Kwan O Extension, the tunnel would connect Tseung Kwan O Station to the depot at Siu Chik Sha.

Environmental Concern

Tunnel excavation was carried out continuously during night-time under the tight schedule of the construction work. Heavy duty equipment such as rock drill, excavator mounted breaker, concrete pump, concrete lorry mixers and ventilation fans were used inside the tunnels. The tunnel entrance was at Chiu Shun Road opposite to the La Cite' Noble and Yuk Ming Court. About 700 dwellings were directly facing the portal and noise affected.

Measures Adopted

Enclosure - A purpose-built acoustic enclosure was constructed which covered the tunnel portal entirely.

Administration - Heavy duty equipment were restricted for use at least 500 m from the portal opening after 7 p.m.

Quieter Method - Ventilation fans were fitted with silencers to minimise the noise. To further reduce the noise nuisance of the ventilation fans, they were operated at low speed after 7 p.m.

Monitoring - Proactive checks were conducted to ensure effectiveness of the mitigation measures.

Acoustic enclosure at the tunnel portal

Observations & Achievements

The dominant noise sources of this project were the ventilation fans as they were mounted at the tunnel portal to provide adequate ventilation for the construction work inside the tunnels. After the fan speed was reduced, no noise nuisance was identified.