Abstract: Construction monitoring plan for the ribbed double arch tunnel excavation was established based on its structural and stress-strain characteristics. The major risk in the tunnel excavation, which is the cracking at the crest of the tunnel, was evaluated based on the construction monitoring data. The lining structure, ribbed strengthening, and the midwall were evaluated based on the monitoring results and mitigation measures were implemented accordingly to ensure the safe excavation and operation of the tunnel.

Key words: Ribbed Double Arch Tunnel, Ribbed Beams, Ground Subsidence, Monitoring and Measurement, Back Analysis