Construction of Niuzhaishan Tunnel, the first tunnel on Pingtan Island, began recently. [Photo provided to China Daily]

Construction of Niuzhaishan Tunnel, the first tunnel on Pingtan Island, began recently. The double arc-tube tunnel will span four lanes in each direction when completed.

The tunnel will run 1,697 meters and have a cross sectional area of 260 square meters. Located on soft surrounding rocks, the tunnel's construction is expected to face significant difficulties and risks.

In spite of the tunnel's unique design and construction, construction safety and quality will be ensured through strict monitoring, management and risk assessment.

The soft surrounding rocks are fractured, suffer from serious weathering and have high water permeability. The project will adopt a double-sidewalls heading excavation method to address its special geographic conditions.

The double-tube design will have a beautiful and natural appearance, complementing its environment organically. The construction site currently has monitoring equipment and escape tubes to ensure safety.

Edited by Chen Zhilin and Michael Thai