Design groundwater of rock tunnel 1

[sango]

Dear all,

I am preparing a rock tunnel lining design. The tunnel is proposed to be drilled through hilly region which is far above the sea level. I think the groundwater in rock is mainly come from rainfall.

As it is a preliminary design, no groundwater monitoring is carried out. I assume a design groundwater table of 10m above the lining in this assignment. Is there any reference to assign the design groundwater table in rock tunnel?

Thanks

 

[GeoPaveTraffic]

You need field measurements at the project site. There is no "universal" groundwater level to design for.

 

[ctmtwilliams]

What about using the elevation of the closest stream or lake? Using the assumption that the stream or lake is basically groundwater exposed at the surface.

 

[sango]

It is a deep rock tunnel underground of about 200m. Desk studies find out there is no major water source above the tunnel. Packer tests have been carried out to determine the permeablity of the rock mass.

(1) What is the next step to predict the inflow in rock during tunneling? I know there is a IMS system to predict the water inflow. Another common methods or key parameters required to predict the water inflow?

(2) Any reference/ suggestion on permenant drainage system for a lined deep rock tunnel by TBM?

Thanks