We have situation where a Soakaway 2m diameter, 10m deep has been constructed on top of Tunnel Portal which is at least 70m below the bottom of the Soakaway. The underlying soil is chalk. At present the Soakaway is working perfectly well and there is no detrimental effect on the Tunnel. However...
I have a situation where there is a 10m deep, 2m diameter soakaway on the top of a Tunnel Portal with a water proof membrane capable of taking only 2 bar pressure. The Tunnel is approximately 70m below the Soakaway. The soil is made of Chalk. The question is will the membrane sustain the water...
