Permeability of lined tunnel

[sango]

Dear all,

Any information on the permeability of segmental concrete lining that without gasket in the connections.

Thanks.

 

[LHA]

It seems like without gaskets, the joints would be more permeable than the concrete cross section?

Remember: The Chinese ideogram for “crisis” is comprised of the characters for “danger” and “opportunity.”
-Steve

 

[Dirtguy4587]

It also depends on what type of joint is used (butt, knuckle, etc...). I have not had experience with an ungasketed tunnel lining that didn't have some sort of liner installed post-construction.

 

[sango]

Dear lha,

You are right. The permeability of joint without gasket is much higher than the concretre section. Having such arrangement is to allow the liner behaving in "semi-drained" condition, in which water can be drained throught the joints.

In my case, dewatering is not a concern and the "rock" tunnel itself is stable even without lining, but the client would like to have lining. "Semi-drained" lining allows a more economic design than a "water-tighted" lining.

Any idea on estimating the permeability of the joints? so that water pressure on the semi-drained lining can be estimated.

Thanks!