Abstract:

On the coast land portion of Xiang’an subsea tunnel in Xiamen, China, there exist 800～1000m long fullyweathered soil ground and fullyheavily weathered rock/soil alternative ground. The cover depth of the coast land portion of Xian’an subsea tunnel ranges from 6m to 30m, however, the cover depth of more than 80% of the coast land portion of the tunnel ranges from 6m to 17m. Therefore, the coast land portion of Xiang’an subsea tunnel belongs to shallow/supershallow covered tunnel. The coast land portion of the tunnel is completely located below the ground water table. Furthermore, due to the heavy rainfall in Xiamen area, the ground contains abundant ground water. The soil ground of the tunnel will collapse as soon as water is encountered. The tunnel is constructed by means of CRD method. On basis of the construction of the tunnel, the author expounds on the construction sequences, primary reinforcement parameters, construction step lengths and equipment matching of CRD construction method adopted for the mentioned ground and draws some conclusions related to the construction parameters in similar grounds.

Key words:  , subsea tunnelshallow coverfullyheavily weathered groundlong distanceCRD methodconstruction parameter