The comprehensive effect of partial acidlity of working medium , flowing status of fluid , nocuous material in atmosphere , together with the overlong usage , largely increased the corrosion rate and caused the leakage
2.
In the process of construction , some special geological hazards will be met because of the great depth and long distance , such as high external waterpressure , watergushing , high geostress , rockburst , high geotemperature and nocuous gas and so on . these geological hazards become the main restricted factors of tunnel construction
मोबाइल